block/blkdebug.c

   1 /*
   2  * Block protocol for I/O error injection
   3  *
   4  * Copyright (C) 2016-2017 Red Hat, Inc.
   5  * Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include "qemu/osdep.h"
  27 #include "qapi/error.h"
  28 #include "qemu/cutils.h"
  29 #include "qemu/config-file.h"
  30 #include "block/block_int.h"
  31 #include "qemu/module.h"
  32 #include "qemu/option.h"
  33 #include "qapi/qmp/qdict.h"
  34 #include "qapi/qmp/qstring.h"
  35 #include "sysemu/qtest.h"
  36
  37 typedef struct BDRVBlkdebugState {
  38     int state;
  39     int new_state;
  40     uint64_t align;
  41     uint64_t max_transfer;
  42     uint64_t opt_write_zero;
  43     uint64_t max_write_zero;
  44     uint64_t opt_discard;
  45     uint64_t max_discard;
  46
  47     /* For blkdebug_refresh_filename() */
  48     char *config_file;
  49
  50     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
  51     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  52     QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
  53 } BDRVBlkdebugState;
  54
  55 typedef struct BlkdebugAIOCB {
  56     BlockAIOCB common;
  57     int ret;
  58 } BlkdebugAIOCB;
  59
  60 typedef struct BlkdebugSuspendedReq {
  61     Coroutine *co;
  62     char *tag;
  63     QLIST_ENTRY(BlkdebugSuspendedReq) next;
  64 } BlkdebugSuspendedReq;
  65
  66 enum {
  67     ACTION_INJECT_ERROR,
  68     ACTION_SET_STATE,
  69     ACTION_SUSPEND,
  70 };
  71
  72 typedef struct BlkdebugRule {
  73     BlkdebugEvent event;
  74     int action;
  75     int state;
  76     union {
  77         struct {
  78             int error;
  79             int immediately;
  80             int once;
  81             int64_t offset;
  82         } inject;
  83         struct {
  84             int new_state;
  85         } set_state;
  86         struct {
  87             char *tag;
  88         } suspend;
  89     } options;
  90     QLIST_ENTRY(BlkdebugRule) next;
  91     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
  92 } BlkdebugRule;
  93
  94 static QemuOptsList inject_error_opts = {
  95     .name = "inject-error",
  96     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
  97     .desc = {
  98         {
  99             .name = "event",
 100             .type = QEMU_OPT_STRING,
 101         },
 102         {
 103             .name = "state",
 104             .type = QEMU_OPT_NUMBER,
 105         },
 106         {
 107             .name = "errno",
 108             .type = QEMU_OPT_NUMBER,
 109         },
 110         {
 111             .name = "sector",
 112             .type = QEMU_OPT_NUMBER,
 113         },
 114         {
 115             .name = "once",
 116             .type = QEMU_OPT_BOOL,
 117         },
 118         {
 119             .name = "immediately",
 120             .type = QEMU_OPT_BOOL,
 121         },
 122         { /* end of list */ }
 123     },
 124 };
 125
 126 static QemuOptsList set_state_opts = {
 127     .name = "set-state",
 128     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 129     .desc = {
 130         {
 131             .name = "event",
 132             .type = QEMU_OPT_STRING,
 133         },
 134         {
 135             .name = "state",
 136             .type = QEMU_OPT_NUMBER,
 137         },
 138         {
 139             .name = "new_state",
 140             .type = QEMU_OPT_NUMBER,
 141         },
 142         { /* end of list */ }
 143     },
 144 };
 145
 146 static QemuOptsList *config_groups[] = {
 147     &inject_error_opts,
 148     &set_state_opts,
 149     NULL
 150 };
 151
 152 struct add_rule_data {
 153     BDRVBlkdebugState *s;
 154     int action;
 155 };
 156
 157 static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
 158 {
 159     struct add_rule_data *d = opaque;
 160     BDRVBlkdebugState *s = d->s;
 161     const char* event_name;
 162     int event;
 163     struct BlkdebugRule *rule;
 164     int64_t sector;
 165
 166     /* Find the right event for the rule */
 167     event_name = qemu_opt_get(opts, "event");
 168     if (!event_name) {
 169         error_setg(errp, "Missing event name for rule");
 170         return -1;
 171     }
 172     event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
 173     if (event < 0) {
 174         return -1;
 175     }
 176
 177     /* Set attributes common for all actions */
 178     rule = g_malloc0(sizeof(*rule));
 179     *rule = (struct BlkdebugRule) {
 180         .event  = event,
 181         .action = d->action,
 182         .state  = qemu_opt_get_number(opts, "state", 0),
 183     };
 184
 185     /* Parse action-specific options */
 186     switch (d->action) {
 187     case ACTION_INJECT_ERROR:
 188         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 189         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 190         rule->options.inject.immediately =
 191             qemu_opt_get_bool(opts, "immediately", 0);
 192         sector = qemu_opt_get_number(opts, "sector", -1);
 193         rule->options.inject.offset =
 194             sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
 195         break;
 196
 197     case ACTION_SET_STATE:
 198         rule->options.set_state.new_state =
 199             qemu_opt_get_number(opts, "new_state", 0);
 200         break;
 201
 202     case ACTION_SUSPEND:
 203         rule->options.suspend.tag =
 204             g_strdup(qemu_opt_get(opts, "tag"));
 205         break;
 206     };
 207
 208     /* Add the rule */
 209     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 210
 211     return 0;
 212 }
 213
 214 static void remove_rule(BlkdebugRule *rule)
 215 {
 216     switch (rule->action) {
 217     case ACTION_INJECT_ERROR:
 218     case ACTION_SET_STATE:
 219         break;
 220     case ACTION_SUSPEND:
 221         g_free(rule->options.suspend.tag);
 222         break;
 223     }
 224
 225     QLIST_REMOVE(rule, next);
 226     g_free(rule);
 227 }
 228
 229 static int read_config(BDRVBlkdebugState *s, const char *filename,
 230                        QDict *options, Error **errp)
 231 {
 232     FILE *f = NULL;
 233     int ret;
 234     struct add_rule_data d;
 235     Error *local_err = NULL;
 236
 237     if (filename) {
 238         f = fopen(filename, "r");
 239         if (f == NULL) {
 240             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 241             return -errno;
 242         }
 243
 244         ret = qemu_config_parse(f, config_groups, filename);
 245         if (ret < 0) {
 246             error_setg(errp, "Could not parse blkdebug config file");
 247             goto fail;
 248         }
 249     }
 250
 251     qemu_config_parse_qdict(options, config_groups, &local_err);
 252     if (local_err) {
 253         error_propagate(errp, local_err);
 254         ret = -EINVAL;
 255         goto fail;
 256     }
 257
 258     d.s = s;
 259     d.action = ACTION_INJECT_ERROR;
 260     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 261     if (local_err) {
 262         error_propagate(errp, local_err);
 263         ret = -EINVAL;
 264         goto fail;
 265     }
 266
 267     d.action = ACTION_SET_STATE;
 268     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 269     if (local_err) {
 270         error_propagate(errp, local_err);
 271         ret = -EINVAL;
 272         goto fail;
 273     }
 274
 275     ret = 0;
 276 fail:
 277     qemu_opts_reset(&inject_error_opts);
 278     qemu_opts_reset(&set_state_opts);
 279     if (f) {
 280         fclose(f);
 281     }
 282     return ret;
 283 }
 284
 285 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 286 static void blkdebug_parse_filename(const char *filename, QDict *options,
 287                                     Error **errp)
 288 {
 289     const char *c;
 290
 291     /* Parse the blkdebug: prefix */
 292     if (!strstart(filename, "blkdebug:", &filename)) {
 293         /* There was no prefix; therefore, all options have to be already
 294            present in the QDict (except for the filename) */
 295         qdict_put_str(options, "x-image", filename);
 296         return;
 297     }
 298
 299     /* Parse config file path */
 300     c = strchr(filename, ':');
 301     if (c == NULL) {
 302         error_setg(errp, "blkdebug requires both config file and image path");
 303         return;
 304     }
 305
 306     if (c != filename) {
 307         QString *config_path;
 308         config_path = qstring_from_substr(filename, 0, c - filename);
 309         qdict_put(options, "config", config_path);
 310     }
 311
 312     /* TODO Allow multi-level nesting and set file.filename here */
 313     filename = c + 1;
 314     qdict_put_str(options, "x-image", filename);
 315 }
 316
 317 static QemuOptsList runtime_opts = {
 318     .name = "blkdebug",
 319     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 320     .desc = {
 321         {
 322             .name = "config",
 323             .type = QEMU_OPT_STRING,
 324             .help = "Path to the configuration file",
 325         },
 326         {
 327             .name = "x-image",
 328             .type = QEMU_OPT_STRING,
 329             .help = "[internal use only, will be removed]",
 330         },
 331         {
 332             .name = "align",
 333             .type = QEMU_OPT_SIZE,
 334             .help = "Required alignment in bytes",
 335         },
 336         {
 337             .name = "max-transfer",
 338             .type = QEMU_OPT_SIZE,
 339             .help = "Maximum transfer size in bytes",
 340         },
 341         {
 342             .name = "opt-write-zero",
 343             .type = QEMU_OPT_SIZE,
 344             .help = "Optimum write zero alignment in bytes",
 345         },
 346         {
 347             .name = "max-write-zero",
 348             .type = QEMU_OPT_SIZE,
 349             .help = "Maximum write zero size in bytes",
 350         },
 351         {
 352             .name = "opt-discard",
 353             .type = QEMU_OPT_SIZE,
 354             .help = "Optimum discard alignment in bytes",
 355         },
 356         {
 357             .name = "max-discard",
 358             .type = QEMU_OPT_SIZE,
 359             .help = "Maximum discard size in bytes",
 360         },
 361         { /* end of list */ }
 362     },
 363 };
 364
 365 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 366                          Error **errp)
 367 {
 368     BDRVBlkdebugState *s = bs->opaque;
 369     QemuOpts *opts;
 370     Error *local_err = NULL;
 371     int ret;
 372     uint64_t align;
 373
 374     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 375     qemu_opts_absorb_qdict(opts, options, &local_err);
 376     if (local_err) {
 377         error_propagate(errp, local_err);
 378         ret = -EINVAL;
 379         goto out;
 380     }
 381
 382     /* Read rules from config file or command line options */
 383     s->config_file = g_strdup(qemu_opt_get(opts, "config"));
 384     ret = read_config(s, s->config_file, options, errp);
 385     if (ret) {
 386         goto out;
 387     }
 388
 389     /* Set initial state */
 390     s->state = 1;
 391
 392     /* Open the image file */
 393     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
 394                                bs, &child_file, false, &local_err);
 395     if (local_err) {
 396         ret = -EINVAL;
 397         error_propagate(errp, local_err);
 398         goto out;
 399     }
 400
 401     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
 402         (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
 403     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
 404         ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
 405             bs->file->bs->supported_zero_flags);
 406     ret = -EINVAL;
 407
 408     /* Set alignment overrides */
 409     s->align = qemu_opt_get_size(opts, "align", 0);
 410     if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
 411         error_setg(errp, "Cannot meet constraints with align %" PRIu64,
 412                    s->align);
 413         goto out;
 414     }
 415     align = MAX(s->align, bs->file->bs->bl.request_alignment);
 416
 417     s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
 418     if (s->max_transfer &&
 419         (s->max_transfer >= INT_MAX ||
 420          !QEMU_IS_ALIGNED(s->max_transfer, align))) {
 421         error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
 422                    s->max_transfer);
 423         goto out;
 424     }
 425
 426     s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
 427     if (s->opt_write_zero &&
 428         (s->opt_write_zero >= INT_MAX ||
 429          !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
 430         error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
 431                    s->opt_write_zero);
 432         goto out;
 433     }
 434
 435     s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
 436     if (s->max_write_zero &&
 437         (s->max_write_zero >= INT_MAX ||
 438          !QEMU_IS_ALIGNED(s->max_write_zero,
 439                           MAX(s->opt_write_zero, align)))) {
 440         error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
 441                    s->max_write_zero);
 442         goto out;
 443     }
 444
 445     s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
 446     if (s->opt_discard &&
 447         (s->opt_discard >= INT_MAX ||
 448          !QEMU_IS_ALIGNED(s->opt_discard, align))) {
 449         error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
 450                    s->opt_discard);
 451         goto out;
 452     }
 453
 454     s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
 455     if (s->max_discard &&
 456         (s->max_discard >= INT_MAX ||
 457          !QEMU_IS_ALIGNED(s->max_discard,
 458                           MAX(s->opt_discard, align)))) {
 459         error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
 460                    s->max_discard);
 461         goto out;
 462     }
 463
 464     ret = 0;
 465 out:
 466     if (ret < 0) {
 467         g_free(s->config_file);
 468     }
 469     qemu_opts_del(opts);
 470     return ret;
 471 }
 472
 473 static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes)
 474 {
 475     BDRVBlkdebugState *s = bs->opaque;
 476     BlkdebugRule *rule = NULL;
 477     int error;
 478     bool immediately;
 479
 480     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 481         uint64_t inject_offset = rule->options.inject.offset;
 482
 483         if (inject_offset == -1 ||
 484             (bytes && inject_offset >= offset &&
 485              inject_offset < offset + bytes))
 486         {
 487             break;
 488         }
 489     }
 490
 491     if (!rule || !rule->options.inject.error) {
 492         return 0;
 493     }
 494
 495     immediately = rule->options.inject.immediately;
 496     error = rule->options.inject.error;
 497
 498     if (rule->options.inject.once) {
 499         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 500         remove_rule(rule);
 501     }
 502
 503     if (!immediately) {
 504         aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
 505         qemu_coroutine_yield();
 506     }
 507
 508     return -error;
 509 }
 510
 511 static int coroutine_fn
 512 blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 513                    QEMUIOVector *qiov, int flags)
 514 {
 515     int err;
 516
 517     /* Sanity check block layer guarantees */
 518     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 519     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 520     if (bs->bl.max_transfer) {
 521         assert(bytes <= bs->bl.max_transfer);
 522     }
 523
 524     err = rule_check(bs, offset, bytes);
 525     if (err) {
 526         return err;
 527     }
 528
 529     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 530 }
 531
 532 static int coroutine_fn
 533 blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 534                     QEMUIOVector *qiov, int flags)
 535 {
 536     int err;
 537
 538     /* Sanity check block layer guarantees */
 539     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 540     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 541     if (bs->bl.max_transfer) {
 542         assert(bytes <= bs->bl.max_transfer);
 543     }
 544
 545     err = rule_check(bs, offset, bytes);
 546     if (err) {
 547         return err;
 548     }
 549
 550     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 551 }
 552
 553 static int blkdebug_co_flush(BlockDriverState *bs)
 554 {
 555     int err = rule_check(bs, 0, 0);
 556
 557     if (err) {
 558         return err;
 559     }
 560
 561     return bdrv_co_flush(bs->file->bs);
 562 }
 563
 564 static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
 565                                                   int64_t offset, int bytes,
 566                                                   BdrvRequestFlags flags)
 567 {
 568     uint32_t align = MAX(bs->bl.request_alignment,
 569                          bs->bl.pwrite_zeroes_alignment);
 570     int err;
 571
 572     /* Only pass through requests that are larger than requested
 573      * preferred alignment (so that we test the fallback to writes on
 574      * unaligned portions), and check that the block layer never hands
 575      * us anything unaligned that crosses an alignment boundary.  */
 576     if (bytes < align) {
 577         assert(QEMU_IS_ALIGNED(offset, align) ||
 578                QEMU_IS_ALIGNED(offset + bytes, align) ||
 579                DIV_ROUND_UP(offset, align) ==
 580                DIV_ROUND_UP(offset + bytes, align));
 581         return -ENOTSUP;
 582     }
 583     assert(QEMU_IS_ALIGNED(offset, align));
 584     assert(QEMU_IS_ALIGNED(bytes, align));
 585     if (bs->bl.max_pwrite_zeroes) {
 586         assert(bytes <= bs->bl.max_pwrite_zeroes);
 587     }
 588
 589     err = rule_check(bs, offset, bytes);
 590     if (err) {
 591         return err;
 592     }
 593
 594     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 595 }
 596
 597 static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
 598                                              int64_t offset, int bytes)
 599 {
 600     uint32_t align = bs->bl.pdiscard_alignment;
 601     int err;
 602
 603     /* Only pass through requests that are larger than requested
 604      * minimum alignment, and ensure that unaligned requests do not
 605      * cross optimum discard boundaries. */
 606     if (bytes < bs->bl.request_alignment) {
 607         assert(QEMU_IS_ALIGNED(offset, align) ||
 608                QEMU_IS_ALIGNED(offset + bytes, align) ||
 609                DIV_ROUND_UP(offset, align) ==
 610                DIV_ROUND_UP(offset + bytes, align));
 611         return -ENOTSUP;
 612     }
 613     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 614     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 615     if (align && bytes >= align) {
 616         assert(QEMU_IS_ALIGNED(offset, align));
 617         assert(QEMU_IS_ALIGNED(bytes, align));
 618     }
 619     if (bs->bl.max_pdiscard) {
 620         assert(bytes <= bs->bl.max_pdiscard);
 621     }
 622
 623     err = rule_check(bs, offset, bytes);
 624     if (err) {
 625         return err;
 626     }
 627
 628     return bdrv_co_pdiscard(bs->file, offset, bytes);
 629 }
 630
 631 static int coroutine_fn blkdebug_co_block_status(BlockDriverState *bs,
 632                                                  bool want_zero,
 633                                                  int64_t offset,
 634                                                  int64_t bytes,
 635                                                  int64_t *pnum,
 636                                                  int64_t *map,
 637                                                  BlockDriverState **file)
 638 {
 639     assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
 640     return bdrv_co_block_status_from_file(bs, want_zero, offset, bytes,
 641                                           pnum, map, file);
 642 }
 643
 644 static void blkdebug_close(BlockDriverState *bs)
 645 {
 646     BDRVBlkdebugState *s = bs->opaque;
 647     BlkdebugRule *rule, *next;
 648     int i;
 649
 650     for (i = 0; i < BLKDBG__MAX; i++) {
 651         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 652             remove_rule(rule);
 653         }
 654     }
 655
 656     g_free(s->config_file);
 657 }
 658
 659 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 660 {
 661     BDRVBlkdebugState *s = bs->opaque;
 662     BlkdebugSuspendedReq r;
 663
 664     r = (BlkdebugSuspendedReq) {
 665         .co         = qemu_coroutine_self(),
 666         .tag        = g_strdup(rule->options.suspend.tag),
 667     };
 668
 669     remove_rule(rule);
 670     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 671
 672     if (!qtest_enabled()) {
 673         printf("blkdebug: Suspended request '%s'\n", r.tag);
 674     }
 675     qemu_coroutine_yield();
 676     if (!qtest_enabled()) {
 677         printf("blkdebug: Resuming request '%s'\n", r.tag);
 678     }
 679
 680     QLIST_REMOVE(&r, next);
 681     g_free(r.tag);
 682 }
 683
 684 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 685     bool injected)
 686 {
 687     BDRVBlkdebugState *s = bs->opaque;
 688
 689     /* Only process rules for the current state */
 690     if (rule->state && rule->state != s->state) {
 691         return injected;
 692     }
 693
 694     /* Take the action */
 695     switch (rule->action) {
 696     case ACTION_INJECT_ERROR:
 697         if (!injected) {
 698             QSIMPLEQ_INIT(&s->active_rules);
 699             injected = true;
 700         }
 701         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 702         break;
 703
 704     case ACTION_SET_STATE:
 705         s->new_state = rule->options.set_state.new_state;
 706         break;
 707
 708     case ACTION_SUSPEND:
 709         suspend_request(bs, rule);
 710         break;
 711     }
 712     return injected;
 713 }
 714
 715 static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 716 {
 717     BDRVBlkdebugState *s = bs->opaque;
 718     struct BlkdebugRule *rule, *next;
 719     bool injected;
 720
 721     assert((int)event >= 0 && event < BLKDBG__MAX);
 722
 723     injected = false;
 724     s->new_state = s->state;
 725     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 726         injected = process_rule(bs, rule, injected);
 727     }
 728     s->state = s->new_state;
 729 }
 730
 731 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 732                                      const char *tag)
 733 {
 734     BDRVBlkdebugState *s = bs->opaque;
 735     struct BlkdebugRule *rule;
 736     int blkdebug_event;
 737
 738     blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
 739     if (blkdebug_event < 0) {
 740         return -ENOENT;
 741     }
 742
 743     rule = g_malloc(sizeof(*rule));
 744     *rule = (struct BlkdebugRule) {
 745         .event  = blkdebug_event,
 746         .action = ACTION_SUSPEND,
 747         .state  = 0,
 748         .options.suspend.tag = g_strdup(tag),
 749     };
 750
 751     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 752
 753     return 0;
 754 }
 755
 756 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 757 {
 758     BDRVBlkdebugState *s = bs->opaque;
 759     BlkdebugSuspendedReq *r, *next;
 760
 761     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 762         if (!strcmp(r->tag, tag)) {
 763             qemu_coroutine_enter(r->co);
 764             return 0;
 765         }
 766     }
 767     return -ENOENT;
 768 }
 769
 770 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 771                                             const char *tag)
 772 {
 773     BDRVBlkdebugState *s = bs->opaque;
 774     BlkdebugSuspendedReq *r, *r_next;
 775     BlkdebugRule *rule, *next;
 776     int i, ret = -ENOENT;
 777
 778     for (i = 0; i < BLKDBG__MAX; i++) {
 779         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 780             if (rule->action == ACTION_SUSPEND &&
 781                 !strcmp(rule->options.suspend.tag, tag)) {
 782                 remove_rule(rule);
 783                 ret = 0;
 784             }
 785         }
 786     }
 787     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 788         if (!strcmp(r->tag, tag)) {
 789             qemu_coroutine_enter(r->co);
 790             ret = 0;
 791         }
 792     }
 793     return ret;
 794 }
 795
 796 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 797 {
 798     BDRVBlkdebugState *s = bs->opaque;
 799     BlkdebugSuspendedReq *r;
 800
 801     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 802         if (!strcmp(r->tag, tag)) {
 803             return true;
 804         }
 805     }
 806     return false;
 807 }
 808
 809 static int64_t blkdebug_getlength(BlockDriverState *bs)
 810 {
 811     return bdrv_getlength(bs->file->bs);
 812 }
 813
 814 static void blkdebug_refresh_filename(BlockDriverState *bs)
 815 {
 816     BDRVBlkdebugState *s = bs->opaque;
 817     const QDictEntry *e;
 818     int ret;
 819
 820     if (!bs->file->bs->exact_filename[0]) {
 821         return;
 822     }
 823
 824     for (e = qdict_first(bs->full_open_options); e;
 825          e = qdict_next(bs->full_open_options, e))
 826     {
 827         /* Real child options are under "image", but "x-image" may
 828          * contain a filename */
 829         if (strcmp(qdict_entry_key(e), "config") &&
 830             strcmp(qdict_entry_key(e), "image") &&
 831             strcmp(qdict_entry_key(e), "x-image") &&
 832             strcmp(qdict_entry_key(e), "driver"))
 833         {
 834             return;
 835         }
 836     }
 837
 838     ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 839                    "blkdebug:%s:%s",
 840                    s->config_file ?: "", bs->file->bs->exact_filename);
 841     if (ret >= sizeof(bs->exact_filename)) {
 842         /* An overflow makes the filename unusable, so do not report any */
 843         bs->exact_filename[0] = 0;
 844     }
 845 }
 846
 847 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
 848 {
 849     BDRVBlkdebugState *s = bs->opaque;
 850
 851     if (s->align) {
 852         bs->bl.request_alignment = s->align;
 853     }
 854     if (s->max_transfer) {
 855         bs->bl.max_transfer = s->max_transfer;
 856     }
 857     if (s->opt_write_zero) {
 858         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
 859     }
 860     if (s->max_write_zero) {
 861         bs->bl.max_pwrite_zeroes = s->max_write_zero;
 862     }
 863     if (s->opt_discard) {
 864         bs->bl.pdiscard_alignment = s->opt_discard;
 865     }
 866     if (s->max_discard) {
 867         bs->bl.max_pdiscard = s->max_discard;
 868     }
 869 }
 870
 871 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
 872                                    BlockReopenQueue *queue, Error **errp)
 873 {
 874     return 0;
 875 }
 876
 877 static const char *const blkdebug_strong_runtime_opts[] = {
 878     "config",
 879     "inject-error.",
 880     "set-state.",
 881     "align",
 882     "max-transfer",
 883     "opt-write-zero",
 884     "max-write-zero",
 885     "opt-discard",
 886     "max-discard",
 887
 888     NULL
 889 };
 890
 891 static BlockDriver bdrv_blkdebug = {
 892     .format_name            = "blkdebug",
 893     .protocol_name          = "blkdebug",
 894     .instance_size          = sizeof(BDRVBlkdebugState),
 895     .is_filter              = true,
 896
 897     .bdrv_parse_filename    = blkdebug_parse_filename,
 898     .bdrv_file_open         = blkdebug_open,
 899     .bdrv_close             = blkdebug_close,
 900     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
 901     .bdrv_child_perm        = bdrv_filter_default_perms,
 902
 903     .bdrv_getlength         = blkdebug_getlength,
 904     .bdrv_refresh_filename  = blkdebug_refresh_filename,
 905     .bdrv_refresh_limits    = blkdebug_refresh_limits,
 906
 907     .bdrv_co_preadv         = blkdebug_co_preadv,
 908     .bdrv_co_pwritev        = blkdebug_co_pwritev,
 909     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
 910     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
 911     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
 912     .bdrv_co_block_status   = blkdebug_co_block_status,
 913
 914     .bdrv_debug_event           = blkdebug_debug_event,
 915     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 916     .bdrv_debug_remove_breakpoint
 917                                 = blkdebug_debug_remove_breakpoint,
 918     .bdrv_debug_resume          = blkdebug_debug_resume,
 919     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 920
 921     .strong_runtime_opts        = blkdebug_strong_runtime_opts,
 922 };
 923
 924 static void bdrv_blkdebug_init(void)
 925 {
 926     bdrv_register(&bdrv_blkdebug);
 927 }
 928
 929 block_init(bdrv_blkdebug_init);