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 "qapi/qmp/qbool.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             ret = -EINVAL;
 248             goto fail;
 249         }
 250     }
 251
 252     qemu_config_parse_qdict(options, config_groups, &local_err);
 253     if (local_err) {
 254         error_propagate(errp, local_err);
 255         ret = -EINVAL;
 256         goto fail;
 257     }
 258
 259     d.s = s;
 260     d.action = ACTION_INJECT_ERROR;
 261     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 262     if (local_err) {
 263         error_propagate(errp, local_err);
 264         ret = -EINVAL;
 265         goto fail;
 266     }
 267
 268     d.action = ACTION_SET_STATE;
 269     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 270     if (local_err) {
 271         error_propagate(errp, local_err);
 272         ret = -EINVAL;
 273         goto fail;
 274     }
 275
 276     ret = 0;
 277 fail:
 278     qemu_opts_reset(&inject_error_opts);
 279     qemu_opts_reset(&set_state_opts);
 280     if (f) {
 281         fclose(f);
 282     }
 283     return ret;
 284 }
 285
 286 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 287 static void blkdebug_parse_filename(const char *filename, QDict *options,
 288                                     Error **errp)
 289 {
 290     const char *c;
 291
 292     /* Parse the blkdebug: prefix */
 293     if (!strstart(filename, "blkdebug:", &filename)) {
 294         /* There was no prefix; therefore, all options have to be already
 295            present in the QDict (except for the filename) */
 296         qdict_put_str(options, "x-image", filename);
 297         return;
 298     }
 299
 300     /* Parse config file path */
 301     c = strchr(filename, ':');
 302     if (c == NULL) {
 303         error_setg(errp, "blkdebug requires both config file and image path");
 304         return;
 305     }
 306
 307     if (c != filename) {
 308         QString *config_path;
 309         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 310         qdict_put(options, "config", config_path);
 311     }
 312
 313     /* TODO Allow multi-level nesting and set file.filename here */
 314     filename = c + 1;
 315     qdict_put_str(options, "x-image", filename);
 316 }
 317
 318 static QemuOptsList runtime_opts = {
 319     .name = "blkdebug",
 320     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 321     .desc = {
 322         {
 323             .name = "config",
 324             .type = QEMU_OPT_STRING,
 325             .help = "Path to the configuration file",
 326         },
 327         {
 328             .name = "x-image",
 329             .type = QEMU_OPT_STRING,
 330             .help = "[internal use only, will be removed]",
 331         },
 332         {
 333             .name = "align",
 334             .type = QEMU_OPT_SIZE,
 335             .help = "Required alignment in bytes",
 336         },
 337         {
 338             .name = "max-transfer",
 339             .type = QEMU_OPT_SIZE,
 340             .help = "Maximum transfer size in bytes",
 341         },
 342         {
 343             .name = "opt-write-zero",
 344             .type = QEMU_OPT_SIZE,
 345             .help = "Optimum write zero alignment in bytes",
 346         },
 347         {
 348             .name = "max-write-zero",
 349             .type = QEMU_OPT_SIZE,
 350             .help = "Maximum write zero size in bytes",
 351         },
 352         {
 353             .name = "opt-discard",
 354             .type = QEMU_OPT_SIZE,
 355             .help = "Optimum discard alignment in bytes",
 356         },
 357         {
 358             .name = "max-discard",
 359             .type = QEMU_OPT_SIZE,
 360             .help = "Maximum discard size in bytes",
 361         },
 362         { /* end of list */ }
 363     },
 364 };
 365
 366 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 367                          Error **errp)
 368 {
 369     BDRVBlkdebugState *s = bs->opaque;
 370     QemuOpts *opts;
 371     Error *local_err = NULL;
 372     int ret;
 373     uint64_t align;
 374
 375     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 376     qemu_opts_absorb_qdict(opts, options, &local_err);
 377     if (local_err) {
 378         error_propagate(errp, local_err);
 379         ret = -EINVAL;
 380         goto out;
 381     }
 382
 383     /* Read rules from config file or command line options */
 384     s->config_file = g_strdup(qemu_opt_get(opts, "config"));
 385     ret = read_config(s, s->config_file, options, errp);
 386     if (ret) {
 387         goto out;
 388     }
 389
 390     /* Set initial state */
 391     s->state = 1;
 392
 393     /* Open the image file */
 394     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
 395                                bs, &child_file, false, &local_err);
 396     if (local_err) {
 397         ret = -EINVAL;
 398         error_propagate(errp, local_err);
 399         goto out;
 400     }
 401
 402     bs->supported_write_flags = BDRV_REQ_FUA &
 403         bs->file->bs->supported_write_flags;
 404     bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
 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->bs, offset, bytes);
 629 }
 630
 631 static void blkdebug_close(BlockDriverState *bs)
 632 {
 633     BDRVBlkdebugState *s = bs->opaque;
 634     BlkdebugRule *rule, *next;
 635     int i;
 636
 637     for (i = 0; i < BLKDBG__MAX; i++) {
 638         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 639             remove_rule(rule);
 640         }
 641     }
 642
 643     g_free(s->config_file);
 644 }
 645
 646 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 647 {
 648     BDRVBlkdebugState *s = bs->opaque;
 649     BlkdebugSuspendedReq r;
 650
 651     r = (BlkdebugSuspendedReq) {
 652         .co         = qemu_coroutine_self(),
 653         .tag        = g_strdup(rule->options.suspend.tag),
 654     };
 655
 656     remove_rule(rule);
 657     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 658
 659     if (!qtest_enabled()) {
 660         printf("blkdebug: Suspended request '%s'\n", r.tag);
 661     }
 662     qemu_coroutine_yield();
 663     if (!qtest_enabled()) {
 664         printf("blkdebug: Resuming request '%s'\n", r.tag);
 665     }
 666
 667     QLIST_REMOVE(&r, next);
 668     g_free(r.tag);
 669 }
 670
 671 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 672     bool injected)
 673 {
 674     BDRVBlkdebugState *s = bs->opaque;
 675
 676     /* Only process rules for the current state */
 677     if (rule->state && rule->state != s->state) {
 678         return injected;
 679     }
 680
 681     /* Take the action */
 682     switch (rule->action) {
 683     case ACTION_INJECT_ERROR:
 684         if (!injected) {
 685             QSIMPLEQ_INIT(&s->active_rules);
 686             injected = true;
 687         }
 688         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 689         break;
 690
 691     case ACTION_SET_STATE:
 692         s->new_state = rule->options.set_state.new_state;
 693         break;
 694
 695     case ACTION_SUSPEND:
 696         suspend_request(bs, rule);
 697         break;
 698     }
 699     return injected;
 700 }
 701
 702 static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 703 {
 704     BDRVBlkdebugState *s = bs->opaque;
 705     struct BlkdebugRule *rule, *next;
 706     bool injected;
 707
 708     assert((int)event >= 0 && event < BLKDBG__MAX);
 709
 710     injected = false;
 711     s->new_state = s->state;
 712     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 713         injected = process_rule(bs, rule, injected);
 714     }
 715     s->state = s->new_state;
 716 }
 717
 718 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 719                                      const char *tag)
 720 {
 721     BDRVBlkdebugState *s = bs->opaque;
 722     struct BlkdebugRule *rule;
 723     int blkdebug_event;
 724
 725     blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
 726     if (blkdebug_event < 0) {
 727         return -ENOENT;
 728     }
 729
 730     rule = g_malloc(sizeof(*rule));
 731     *rule = (struct BlkdebugRule) {
 732         .event  = blkdebug_event,
 733         .action = ACTION_SUSPEND,
 734         .state  = 0,
 735         .options.suspend.tag = g_strdup(tag),
 736     };
 737
 738     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 739
 740     return 0;
 741 }
 742
 743 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 744 {
 745     BDRVBlkdebugState *s = bs->opaque;
 746     BlkdebugSuspendedReq *r, *next;
 747
 748     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 749         if (!strcmp(r->tag, tag)) {
 750             qemu_coroutine_enter(r->co);
 751             return 0;
 752         }
 753     }
 754     return -ENOENT;
 755 }
 756
 757 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 758                                             const char *tag)
 759 {
 760     BDRVBlkdebugState *s = bs->opaque;
 761     BlkdebugSuspendedReq *r, *r_next;
 762     BlkdebugRule *rule, *next;
 763     int i, ret = -ENOENT;
 764
 765     for (i = 0; i < BLKDBG__MAX; i++) {
 766         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 767             if (rule->action == ACTION_SUSPEND &&
 768                 !strcmp(rule->options.suspend.tag, tag)) {
 769                 remove_rule(rule);
 770                 ret = 0;
 771             }
 772         }
 773     }
 774     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 775         if (!strcmp(r->tag, tag)) {
 776             qemu_coroutine_enter(r->co);
 777             ret = 0;
 778         }
 779     }
 780     return ret;
 781 }
 782
 783 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 784 {
 785     BDRVBlkdebugState *s = bs->opaque;
 786     BlkdebugSuspendedReq *r;
 787
 788     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 789         if (!strcmp(r->tag, tag)) {
 790             return true;
 791         }
 792     }
 793     return false;
 794 }
 795
 796 static int64_t blkdebug_getlength(BlockDriverState *bs)
 797 {
 798     return bdrv_getlength(bs->file->bs);
 799 }
 800
 801 static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
 802 {
 803     BDRVBlkdebugState *s = bs->opaque;
 804     QDict *opts;
 805     const QDictEntry *e;
 806     bool force_json = false;
 807
 808     for (e = qdict_first(options); e; e = qdict_next(options, e)) {
 809         if (strcmp(qdict_entry_key(e), "config") &&
 810             strcmp(qdict_entry_key(e), "x-image"))
 811         {
 812             force_json = true;
 813             break;
 814         }
 815     }
 816
 817     if (force_json && !bs->file->bs->full_open_options) {
 818         /* The config file cannot be recreated, so creating a plain filename
 819          * is impossible */
 820         return;
 821     }
 822
 823     if (!force_json && bs->file->bs->exact_filename[0]) {
 824         int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 825                            "blkdebug:%s:%s", s->config_file ?: "",
 826                            bs->file->bs->exact_filename);
 827         if (ret >= sizeof(bs->exact_filename)) {
 828             /* An overflow makes the filename unusable, so do not report any */
 829             bs->exact_filename[0] = 0;
 830         }
 831     }
 832
 833     opts = qdict_new();
 834     qdict_put_str(opts, "driver", "blkdebug");
 835
 836     QINCREF(bs->file->bs->full_open_options);
 837     qdict_put(opts, "image", bs->file->bs->full_open_options);
 838
 839     for (e = qdict_first(options); e; e = qdict_next(options, e)) {
 840         if (strcmp(qdict_entry_key(e), "x-image")) {
 841             qobject_incref(qdict_entry_value(e));
 842             qdict_put_obj(opts, qdict_entry_key(e), qdict_entry_value(e));
 843         }
 844     }
 845
 846     bs->full_open_options = opts;
 847 }
 848
 849 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
 850 {
 851     BDRVBlkdebugState *s = bs->opaque;
 852
 853     if (s->align) {
 854         bs->bl.request_alignment = s->align;
 855     }
 856     if (s->max_transfer) {
 857         bs->bl.max_transfer = s->max_transfer;
 858     }
 859     if (s->opt_write_zero) {
 860         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
 861     }
 862     if (s->max_write_zero) {
 863         bs->bl.max_pwrite_zeroes = s->max_write_zero;
 864     }
 865     if (s->opt_discard) {
 866         bs->bl.pdiscard_alignment = s->opt_discard;
 867     }
 868     if (s->max_discard) {
 869         bs->bl.max_pdiscard = s->max_discard;
 870     }
 871 }
 872
 873 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
 874                                    BlockReopenQueue *queue, Error **errp)
 875 {
 876     return 0;
 877 }
 878
 879 static BlockDriver bdrv_blkdebug = {
 880     .format_name            = "blkdebug",
 881     .protocol_name          = "blkdebug",
 882     .instance_size          = sizeof(BDRVBlkdebugState),
 883     .is_filter              = true,
 884
 885     .bdrv_parse_filename    = blkdebug_parse_filename,
 886     .bdrv_file_open         = blkdebug_open,
 887     .bdrv_close             = blkdebug_close,
 888     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
 889     .bdrv_child_perm        = bdrv_filter_default_perms,
 890
 891     .bdrv_getlength         = blkdebug_getlength,
 892     .bdrv_refresh_filename  = blkdebug_refresh_filename,
 893     .bdrv_refresh_limits    = blkdebug_refresh_limits,
 894
 895     .bdrv_co_preadv         = blkdebug_co_preadv,
 896     .bdrv_co_pwritev        = blkdebug_co_pwritev,
 897     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
 898     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
 899     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
 900     .bdrv_co_get_block_status = bdrv_co_get_block_status_from_file,
 901
 902     .bdrv_debug_event           = blkdebug_debug_event,
 903     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 904     .bdrv_debug_remove_breakpoint
 905                                 = blkdebug_debug_remove_breakpoint,
 906     .bdrv_debug_resume          = blkdebug_debug_resume,
 907     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 908 };
 909
 910 static void bdrv_blkdebug_init(void)
 911 {
 912     bdrv_register(&bdrv_blkdebug);
 913 }
 914
 915 block_init(bdrv_blkdebug_init);