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 static int get_event_by_name(const char *name, BlkdebugEvent *event)
 153 {
 154     int i;
 155
 156     for (i = 0; i < BLKDBG__MAX; i++) {
 157         if (!strcmp(BlkdebugEvent_lookup[i], name)) {
 158             *event = i;
 159             return 0;
 160         }
 161     }
 162
 163     return -1;
 164 }
 165
 166 struct add_rule_data {
 167     BDRVBlkdebugState *s;
 168     int action;
 169 };
 170
 171 static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
 172 {
 173     struct add_rule_data *d = opaque;
 174     BDRVBlkdebugState *s = d->s;
 175     const char* event_name;
 176     BlkdebugEvent event;
 177     struct BlkdebugRule *rule;
 178     int64_t sector;
 179
 180     /* Find the right event for the rule */
 181     event_name = qemu_opt_get(opts, "event");
 182     if (!event_name) {
 183         error_setg(errp, "Missing event name for rule");
 184         return -1;
 185     } else if (get_event_by_name(event_name, &event) < 0) {
 186         error_setg(errp, "Invalid event name \"%s\"", event_name);
 187         return -1;
 188     }
 189
 190     /* Set attributes common for all actions */
 191     rule = g_malloc0(sizeof(*rule));
 192     *rule = (struct BlkdebugRule) {
 193         .event  = event,
 194         .action = d->action,
 195         .state  = qemu_opt_get_number(opts, "state", 0),
 196     };
 197
 198     /* Parse action-specific options */
 199     switch (d->action) {
 200     case ACTION_INJECT_ERROR:
 201         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 202         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 203         rule->options.inject.immediately =
 204             qemu_opt_get_bool(opts, "immediately", 0);
 205         sector = qemu_opt_get_number(opts, "sector", -1);
 206         rule->options.inject.offset =
 207             sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
 208         break;
 209
 210     case ACTION_SET_STATE:
 211         rule->options.set_state.new_state =
 212             qemu_opt_get_number(opts, "new_state", 0);
 213         break;
 214
 215     case ACTION_SUSPEND:
 216         rule->options.suspend.tag =
 217             g_strdup(qemu_opt_get(opts, "tag"));
 218         break;
 219     };
 220
 221     /* Add the rule */
 222     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 223
 224     return 0;
 225 }
 226
 227 static void remove_rule(BlkdebugRule *rule)
 228 {
 229     switch (rule->action) {
 230     case ACTION_INJECT_ERROR:
 231     case ACTION_SET_STATE:
 232         break;
 233     case ACTION_SUSPEND:
 234         g_free(rule->options.suspend.tag);
 235         break;
 236     }
 237
 238     QLIST_REMOVE(rule, next);
 239     g_free(rule);
 240 }
 241
 242 static int read_config(BDRVBlkdebugState *s, const char *filename,
 243                        QDict *options, Error **errp)
 244 {
 245     FILE *f = NULL;
 246     int ret;
 247     struct add_rule_data d;
 248     Error *local_err = NULL;
 249
 250     if (filename) {
 251         f = fopen(filename, "r");
 252         if (f == NULL) {
 253             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 254             return -errno;
 255         }
 256
 257         ret = qemu_config_parse(f, config_groups, filename);
 258         if (ret < 0) {
 259             error_setg(errp, "Could not parse blkdebug config file");
 260             ret = -EINVAL;
 261             goto fail;
 262         }
 263     }
 264
 265     qemu_config_parse_qdict(options, config_groups, &local_err);
 266     if (local_err) {
 267         error_propagate(errp, local_err);
 268         ret = -EINVAL;
 269         goto fail;
 270     }
 271
 272     d.s = s;
 273     d.action = ACTION_INJECT_ERROR;
 274     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 275     if (local_err) {
 276         error_propagate(errp, local_err);
 277         ret = -EINVAL;
 278         goto fail;
 279     }
 280
 281     d.action = ACTION_SET_STATE;
 282     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 283     if (local_err) {
 284         error_propagate(errp, local_err);
 285         ret = -EINVAL;
 286         goto fail;
 287     }
 288
 289     ret = 0;
 290 fail:
 291     qemu_opts_reset(&inject_error_opts);
 292     qemu_opts_reset(&set_state_opts);
 293     if (f) {
 294         fclose(f);
 295     }
 296     return ret;
 297 }
 298
 299 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 300 static void blkdebug_parse_filename(const char *filename, QDict *options,
 301                                     Error **errp)
 302 {
 303     const char *c;
 304
 305     /* Parse the blkdebug: prefix */
 306     if (!strstart(filename, "blkdebug:", &filename)) {
 307         /* There was no prefix; therefore, all options have to be already
 308            present in the QDict (except for the filename) */
 309         qdict_put_str(options, "x-image", filename);
 310         return;
 311     }
 312
 313     /* Parse config file path */
 314     c = strchr(filename, ':');
 315     if (c == NULL) {
 316         error_setg(errp, "blkdebug requires both config file and image path");
 317         return;
 318     }
 319
 320     if (c != filename) {
 321         QString *config_path;
 322         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 323         qdict_put(options, "config", config_path);
 324     }
 325
 326     /* TODO Allow multi-level nesting and set file.filename here */
 327     filename = c + 1;
 328     qdict_put_str(options, "x-image", filename);
 329 }
 330
 331 static QemuOptsList runtime_opts = {
 332     .name = "blkdebug",
 333     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 334     .desc = {
 335         {
 336             .name = "config",
 337             .type = QEMU_OPT_STRING,
 338             .help = "Path to the configuration file",
 339         },
 340         {
 341             .name = "x-image",
 342             .type = QEMU_OPT_STRING,
 343             .help = "[internal use only, will be removed]",
 344         },
 345         {
 346             .name = "align",
 347             .type = QEMU_OPT_SIZE,
 348             .help = "Required alignment in bytes",
 349         },
 350         {
 351             .name = "max-transfer",
 352             .type = QEMU_OPT_SIZE,
 353             .help = "Maximum transfer size in bytes",
 354         },
 355         {
 356             .name = "opt-write-zero",
 357             .type = QEMU_OPT_SIZE,
 358             .help = "Optimum write zero alignment in bytes",
 359         },
 360         {
 361             .name = "max-write-zero",
 362             .type = QEMU_OPT_SIZE,
 363             .help = "Maximum write zero size in bytes",
 364         },
 365         {
 366             .name = "opt-discard",
 367             .type = QEMU_OPT_SIZE,
 368             .help = "Optimum discard alignment in bytes",
 369         },
 370         {
 371             .name = "max-discard",
 372             .type = QEMU_OPT_SIZE,
 373             .help = "Maximum discard size in bytes",
 374         },
 375         { /* end of list */ }
 376     },
 377 };
 378
 379 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 380                          Error **errp)
 381 {
 382     BDRVBlkdebugState *s = bs->opaque;
 383     QemuOpts *opts;
 384     Error *local_err = NULL;
 385     int ret;
 386     uint64_t align;
 387
 388     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 389     qemu_opts_absorb_qdict(opts, options, &local_err);
 390     if (local_err) {
 391         error_propagate(errp, local_err);
 392         ret = -EINVAL;
 393         goto out;
 394     }
 395
 396     /* Read rules from config file or command line options */
 397     s->config_file = g_strdup(qemu_opt_get(opts, "config"));
 398     ret = read_config(s, s->config_file, options, errp);
 399     if (ret) {
 400         goto out;
 401     }
 402
 403     /* Set initial state */
 404     s->state = 1;
 405
 406     /* Open the image file */
 407     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
 408                                bs, &child_file, false, &local_err);
 409     if (local_err) {
 410         ret = -EINVAL;
 411         error_propagate(errp, local_err);
 412         goto out;
 413     }
 414
 415     bs->supported_write_flags = BDRV_REQ_FUA &
 416         bs->file->bs->supported_write_flags;
 417     bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
 418         bs->file->bs->supported_zero_flags;
 419     ret = -EINVAL;
 420
 421     /* Set alignment overrides */
 422     s->align = qemu_opt_get_size(opts, "align", 0);
 423     if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
 424         error_setg(errp, "Cannot meet constraints with align %" PRIu64,
 425                    s->align);
 426         goto out;
 427     }
 428     align = MAX(s->align, bs->file->bs->bl.request_alignment);
 429
 430     s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
 431     if (s->max_transfer &&
 432         (s->max_transfer >= INT_MAX ||
 433          !QEMU_IS_ALIGNED(s->max_transfer, align))) {
 434         error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
 435                    s->max_transfer);
 436         goto out;
 437     }
 438
 439     s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
 440     if (s->opt_write_zero &&
 441         (s->opt_write_zero >= INT_MAX ||
 442          !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
 443         error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
 444                    s->opt_write_zero);
 445         goto out;
 446     }
 447
 448     s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
 449     if (s->max_write_zero &&
 450         (s->max_write_zero >= INT_MAX ||
 451          !QEMU_IS_ALIGNED(s->max_write_zero,
 452                           MAX(s->opt_write_zero, align)))) {
 453         error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
 454                    s->max_write_zero);
 455         goto out;
 456     }
 457
 458     s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
 459     if (s->opt_discard &&
 460         (s->opt_discard >= INT_MAX ||
 461          !QEMU_IS_ALIGNED(s->opt_discard, align))) {
 462         error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
 463                    s->opt_discard);
 464         goto out;
 465     }
 466
 467     s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
 468     if (s->max_discard &&
 469         (s->max_discard >= INT_MAX ||
 470          !QEMU_IS_ALIGNED(s->max_discard,
 471                           MAX(s->opt_discard, align)))) {
 472         error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
 473                    s->max_discard);
 474         goto out;
 475     }
 476
 477     ret = 0;
 478 out:
 479     if (ret < 0) {
 480         g_free(s->config_file);
 481     }
 482     qemu_opts_del(opts);
 483     return ret;
 484 }
 485
 486 static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes)
 487 {
 488     BDRVBlkdebugState *s = bs->opaque;
 489     BlkdebugRule *rule = NULL;
 490     int error;
 491     bool immediately;
 492
 493     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 494         uint64_t inject_offset = rule->options.inject.offset;
 495
 496         if (inject_offset == -1 ||
 497             (bytes && inject_offset >= offset &&
 498              inject_offset < offset + bytes))
 499         {
 500             break;
 501         }
 502     }
 503
 504     if (!rule || !rule->options.inject.error) {
 505         return 0;
 506     }
 507
 508     immediately = rule->options.inject.immediately;
 509     error = rule->options.inject.error;
 510
 511     if (rule->options.inject.once) {
 512         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 513         remove_rule(rule);
 514     }
 515
 516     if (!immediately) {
 517         aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
 518         qemu_coroutine_yield();
 519     }
 520
 521     return -error;
 522 }
 523
 524 static int coroutine_fn
 525 blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 526                    QEMUIOVector *qiov, int flags)
 527 {
 528     int err;
 529
 530     /* Sanity check block layer guarantees */
 531     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 532     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 533     if (bs->bl.max_transfer) {
 534         assert(bytes <= bs->bl.max_transfer);
 535     }
 536
 537     err = rule_check(bs, offset, bytes);
 538     if (err) {
 539         return err;
 540     }
 541
 542     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 543 }
 544
 545 static int coroutine_fn
 546 blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 547                     QEMUIOVector *qiov, int flags)
 548 {
 549     int err;
 550
 551     /* Sanity check block layer guarantees */
 552     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 553     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 554     if (bs->bl.max_transfer) {
 555         assert(bytes <= bs->bl.max_transfer);
 556     }
 557
 558     err = rule_check(bs, offset, bytes);
 559     if (err) {
 560         return err;
 561     }
 562
 563     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 564 }
 565
 566 static int blkdebug_co_flush(BlockDriverState *bs)
 567 {
 568     int err = rule_check(bs, 0, 0);
 569
 570     if (err) {
 571         return err;
 572     }
 573
 574     return bdrv_co_flush(bs->file->bs);
 575 }
 576
 577 static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
 578                                                   int64_t offset, int bytes,
 579                                                   BdrvRequestFlags flags)
 580 {
 581     uint32_t align = MAX(bs->bl.request_alignment,
 582                          bs->bl.pwrite_zeroes_alignment);
 583     int err;
 584
 585     /* Only pass through requests that are larger than requested
 586      * preferred alignment (so that we test the fallback to writes on
 587      * unaligned portions), and check that the block layer never hands
 588      * us anything unaligned that crosses an alignment boundary.  */
 589     if (bytes < align) {
 590         assert(QEMU_IS_ALIGNED(offset, align) ||
 591                QEMU_IS_ALIGNED(offset + bytes, align) ||
 592                DIV_ROUND_UP(offset, align) ==
 593                DIV_ROUND_UP(offset + bytes, align));
 594         return -ENOTSUP;
 595     }
 596     assert(QEMU_IS_ALIGNED(offset, align));
 597     assert(QEMU_IS_ALIGNED(bytes, align));
 598     if (bs->bl.max_pwrite_zeroes) {
 599         assert(bytes <= bs->bl.max_pwrite_zeroes);
 600     }
 601
 602     err = rule_check(bs, offset, bytes);
 603     if (err) {
 604         return err;
 605     }
 606
 607     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 608 }
 609
 610 static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
 611                                              int64_t offset, int bytes)
 612 {
 613     uint32_t align = bs->bl.pdiscard_alignment;
 614     int err;
 615
 616     /* Only pass through requests that are larger than requested
 617      * minimum alignment, and ensure that unaligned requests do not
 618      * cross optimum discard boundaries. */
 619     if (bytes < bs->bl.request_alignment) {
 620         assert(QEMU_IS_ALIGNED(offset, align) ||
 621                QEMU_IS_ALIGNED(offset + bytes, align) ||
 622                DIV_ROUND_UP(offset, align) ==
 623                DIV_ROUND_UP(offset + bytes, align));
 624         return -ENOTSUP;
 625     }
 626     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 627     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 628     if (align && bytes >= align) {
 629         assert(QEMU_IS_ALIGNED(offset, align));
 630         assert(QEMU_IS_ALIGNED(bytes, align));
 631     }
 632     if (bs->bl.max_pdiscard) {
 633         assert(bytes <= bs->bl.max_pdiscard);
 634     }
 635
 636     err = rule_check(bs, offset, bytes);
 637     if (err) {
 638         return err;
 639     }
 640
 641     return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
 642 }
 643
 644 static int64_t coroutine_fn blkdebug_co_get_block_status(
 645     BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
 646     BlockDriverState **file)
 647 {
 648     *pnum = nb_sectors;
 649     *file = bs->file->bs;
 650     return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
 651         (sector_num << BDRV_SECTOR_BITS);
 652 }
 653
 654 static void blkdebug_close(BlockDriverState *bs)
 655 {
 656     BDRVBlkdebugState *s = bs->opaque;
 657     BlkdebugRule *rule, *next;
 658     int i;
 659
 660     for (i = 0; i < BLKDBG__MAX; i++) {
 661         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 662             remove_rule(rule);
 663         }
 664     }
 665
 666     g_free(s->config_file);
 667 }
 668
 669 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 670 {
 671     BDRVBlkdebugState *s = bs->opaque;
 672     BlkdebugSuspendedReq r;
 673
 674     r = (BlkdebugSuspendedReq) {
 675         .co         = qemu_coroutine_self(),
 676         .tag        = g_strdup(rule->options.suspend.tag),
 677     };
 678
 679     remove_rule(rule);
 680     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 681
 682     if (!qtest_enabled()) {
 683         printf("blkdebug: Suspended request '%s'\n", r.tag);
 684     }
 685     qemu_coroutine_yield();
 686     if (!qtest_enabled()) {
 687         printf("blkdebug: Resuming request '%s'\n", r.tag);
 688     }
 689
 690     QLIST_REMOVE(&r, next);
 691     g_free(r.tag);
 692 }
 693
 694 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 695     bool injected)
 696 {
 697     BDRVBlkdebugState *s = bs->opaque;
 698
 699     /* Only process rules for the current state */
 700     if (rule->state && rule->state != s->state) {
 701         return injected;
 702     }
 703
 704     /* Take the action */
 705     switch (rule->action) {
 706     case ACTION_INJECT_ERROR:
 707         if (!injected) {
 708             QSIMPLEQ_INIT(&s->active_rules);
 709             injected = true;
 710         }
 711         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 712         break;
 713
 714     case ACTION_SET_STATE:
 715         s->new_state = rule->options.set_state.new_state;
 716         break;
 717
 718     case ACTION_SUSPEND:
 719         suspend_request(bs, rule);
 720         break;
 721     }
 722     return injected;
 723 }
 724
 725 static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 726 {
 727     BDRVBlkdebugState *s = bs->opaque;
 728     struct BlkdebugRule *rule, *next;
 729     bool injected;
 730
 731     assert((int)event >= 0 && event < BLKDBG__MAX);
 732
 733     injected = false;
 734     s->new_state = s->state;
 735     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 736         injected = process_rule(bs, rule, injected);
 737     }
 738     s->state = s->new_state;
 739 }
 740
 741 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 742                                      const char *tag)
 743 {
 744     BDRVBlkdebugState *s = bs->opaque;
 745     struct BlkdebugRule *rule;
 746     BlkdebugEvent blkdebug_event;
 747
 748     if (get_event_by_name(event, &blkdebug_event) < 0) {
 749         return -ENOENT;
 750     }
 751
 752
 753     rule = g_malloc(sizeof(*rule));
 754     *rule = (struct BlkdebugRule) {
 755         .event  = blkdebug_event,
 756         .action = ACTION_SUSPEND,
 757         .state  = 0,
 758         .options.suspend.tag = g_strdup(tag),
 759     };
 760
 761     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 762
 763     return 0;
 764 }
 765
 766 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 767 {
 768     BDRVBlkdebugState *s = bs->opaque;
 769     BlkdebugSuspendedReq *r, *next;
 770
 771     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 772         if (!strcmp(r->tag, tag)) {
 773             qemu_coroutine_enter(r->co);
 774             return 0;
 775         }
 776     }
 777     return -ENOENT;
 778 }
 779
 780 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 781                                             const char *tag)
 782 {
 783     BDRVBlkdebugState *s = bs->opaque;
 784     BlkdebugSuspendedReq *r, *r_next;
 785     BlkdebugRule *rule, *next;
 786     int i, ret = -ENOENT;
 787
 788     for (i = 0; i < BLKDBG__MAX; i++) {
 789         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 790             if (rule->action == ACTION_SUSPEND &&
 791                 !strcmp(rule->options.suspend.tag, tag)) {
 792                 remove_rule(rule);
 793                 ret = 0;
 794             }
 795         }
 796     }
 797     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 798         if (!strcmp(r->tag, tag)) {
 799             qemu_coroutine_enter(r->co);
 800             ret = 0;
 801         }
 802     }
 803     return ret;
 804 }
 805
 806 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 807 {
 808     BDRVBlkdebugState *s = bs->opaque;
 809     BlkdebugSuspendedReq *r;
 810
 811     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 812         if (!strcmp(r->tag, tag)) {
 813             return true;
 814         }
 815     }
 816     return false;
 817 }
 818
 819 static int64_t blkdebug_getlength(BlockDriverState *bs)
 820 {
 821     return bdrv_getlength(bs->file->bs);
 822 }
 823
 824 static int blkdebug_truncate(BlockDriverState *bs, int64_t offset,
 825                              PreallocMode prealloc, Error **errp)
 826 {
 827     return bdrv_truncate(bs->file, offset, prealloc, errp);
 828 }
 829
 830 static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
 831 {
 832     BDRVBlkdebugState *s = bs->opaque;
 833     QDict *opts;
 834     const QDictEntry *e;
 835     bool force_json = false;
 836
 837     for (e = qdict_first(options); e; e = qdict_next(options, e)) {
 838         if (strcmp(qdict_entry_key(e), "config") &&
 839             strcmp(qdict_entry_key(e), "x-image"))
 840         {
 841             force_json = true;
 842             break;
 843         }
 844     }
 845
 846     if (force_json && !bs->file->bs->full_open_options) {
 847         /* The config file cannot be recreated, so creating a plain filename
 848          * is impossible */
 849         return;
 850     }
 851
 852     if (!force_json && bs->file->bs->exact_filename[0]) {
 853         int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 854                            "blkdebug:%s:%s", s->config_file ?: "",
 855                            bs->file->bs->exact_filename);
 856         if (ret >= sizeof(bs->exact_filename)) {
 857             /* An overflow makes the filename unusable, so do not report any */
 858             bs->exact_filename[0] = 0;
 859         }
 860     }
 861
 862     opts = qdict_new();
 863     qdict_put_str(opts, "driver", "blkdebug");
 864
 865     QINCREF(bs->file->bs->full_open_options);
 866     qdict_put(opts, "image", bs->file->bs->full_open_options);
 867
 868     for (e = qdict_first(options); e; e = qdict_next(options, e)) {
 869         if (strcmp(qdict_entry_key(e), "x-image")) {
 870             qobject_incref(qdict_entry_value(e));
 871             qdict_put_obj(opts, qdict_entry_key(e), qdict_entry_value(e));
 872         }
 873     }
 874
 875     bs->full_open_options = opts;
 876 }
 877
 878 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
 879 {
 880     BDRVBlkdebugState *s = bs->opaque;
 881
 882     if (s->align) {
 883         bs->bl.request_alignment = s->align;
 884     }
 885     if (s->max_transfer) {
 886         bs->bl.max_transfer = s->max_transfer;
 887     }
 888     if (s->opt_write_zero) {
 889         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
 890     }
 891     if (s->max_write_zero) {
 892         bs->bl.max_pwrite_zeroes = s->max_write_zero;
 893     }
 894     if (s->opt_discard) {
 895         bs->bl.pdiscard_alignment = s->opt_discard;
 896     }
 897     if (s->max_discard) {
 898         bs->bl.max_pdiscard = s->max_discard;
 899     }
 900 }
 901
 902 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
 903                                    BlockReopenQueue *queue, Error **errp)
 904 {
 905     return 0;
 906 }
 907
 908 static BlockDriver bdrv_blkdebug = {
 909     .format_name            = "blkdebug",
 910     .protocol_name          = "blkdebug",
 911     .instance_size          = sizeof(BDRVBlkdebugState),
 912
 913     .bdrv_parse_filename    = blkdebug_parse_filename,
 914     .bdrv_file_open         = blkdebug_open,
 915     .bdrv_close             = blkdebug_close,
 916     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
 917     .bdrv_child_perm        = bdrv_filter_default_perms,
 918
 919     .bdrv_getlength         = blkdebug_getlength,
 920     .bdrv_truncate          = blkdebug_truncate,
 921     .bdrv_refresh_filename  = blkdebug_refresh_filename,
 922     .bdrv_refresh_limits    = blkdebug_refresh_limits,
 923
 924     .bdrv_co_preadv         = blkdebug_co_preadv,
 925     .bdrv_co_pwritev        = blkdebug_co_pwritev,
 926     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
 927     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
 928     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
 929     .bdrv_co_get_block_status = blkdebug_co_get_block_status,
 930
 931     .bdrv_debug_event           = blkdebug_debug_event,
 932     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 933     .bdrv_debug_remove_breakpoint
 934                                 = blkdebug_debug_remove_breakpoint,
 935     .bdrv_debug_resume          = blkdebug_debug_resume,
 936     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 937 };
 938
 939 static void bdrv_blkdebug_init(void)
 940 {
 941     bdrv_register(&bdrv_blkdebug);
 942 }
 943
 944 block_init(bdrv_blkdebug_init);