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 "block/qdict.h"
  32 #include "qemu/module.h"
  33 #include "qemu/option.h"
  34 #include "qapi/qapi-visit-block-core.h"
  35 #include "qapi/qmp/qdict.h"
  36 #include "qapi/qmp/qlist.h"
  37 #include "qapi/qmp/qstring.h"
  38 #include "qapi/qobject-input-visitor.h"
  39 #include "sysemu/qtest.h"
  40
  41 typedef struct BDRVBlkdebugState {
  42     int state;
  43     int new_state;
  44     uint64_t align;
  45     uint64_t max_transfer;
  46     uint64_t opt_write_zero;
  47     uint64_t max_write_zero;
  48     uint64_t opt_discard;
  49     uint64_t max_discard;
  50
  51     uint64_t take_child_perms;
  52     uint64_t unshare_child_perms;
  53
  54     /* For blkdebug_refresh_filename() */
  55     char *config_file;
  56
  57     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
  58     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  59     QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
  60 } BDRVBlkdebugState;
  61
  62 typedef struct BlkdebugAIOCB {
  63     BlockAIOCB common;
  64     int ret;
  65 } BlkdebugAIOCB;
  66
  67 typedef struct BlkdebugSuspendedReq {
  68     Coroutine *co;
  69     char *tag;
  70     QLIST_ENTRY(BlkdebugSuspendedReq) next;
  71 } BlkdebugSuspendedReq;
  72
  73 enum {
  74     ACTION_INJECT_ERROR,
  75     ACTION_SET_STATE,
  76     ACTION_SUSPEND,
  77 };
  78
  79 typedef struct BlkdebugRule {
  80     BlkdebugEvent event;
  81     int action;
  82     int state;
  83     union {
  84         struct {
  85             uint64_t iotype_mask;
  86             int error;
  87             int immediately;
  88             int once;
  89             int64_t offset;
  90         } inject;
  91         struct {
  92             int new_state;
  93         } set_state;
  94         struct {
  95             char *tag;
  96         } suspend;
  97     } options;
  98     QLIST_ENTRY(BlkdebugRule) next;
  99     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
 100 } BlkdebugRule;
 101
 102 QEMU_BUILD_BUG_MSG(BLKDEBUG_IO_TYPE__MAX > 64,
 103                    "BlkdebugIOType mask does not fit into an uint64_t");
 104
 105 static QemuOptsList inject_error_opts = {
 106     .name = "inject-error",
 107     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
 108     .desc = {
 109         {
 110             .name = "event",
 111             .type = QEMU_OPT_STRING,
 112         },
 113         {
 114             .name = "state",
 115             .type = QEMU_OPT_NUMBER,
 116         },
 117         {
 118             .name = "iotype",
 119             .type = QEMU_OPT_STRING,
 120         },
 121         {
 122             .name = "errno",
 123             .type = QEMU_OPT_NUMBER,
 124         },
 125         {
 126             .name = "sector",
 127             .type = QEMU_OPT_NUMBER,
 128         },
 129         {
 130             .name = "once",
 131             .type = QEMU_OPT_BOOL,
 132         },
 133         {
 134             .name = "immediately",
 135             .type = QEMU_OPT_BOOL,
 136         },
 137         { /* end of list */ }
 138     },
 139 };
 140
 141 static QemuOptsList set_state_opts = {
 142     .name = "set-state",
 143     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 144     .desc = {
 145         {
 146             .name = "event",
 147             .type = QEMU_OPT_STRING,
 148         },
 149         {
 150             .name = "state",
 151             .type = QEMU_OPT_NUMBER,
 152         },
 153         {
 154             .name = "new_state",
 155             .type = QEMU_OPT_NUMBER,
 156         },
 157         { /* end of list */ }
 158     },
 159 };
 160
 161 static QemuOptsList *config_groups[] = {
 162     &inject_error_opts,
 163     &set_state_opts,
 164     NULL
 165 };
 166
 167 struct add_rule_data {
 168     BDRVBlkdebugState *s;
 169     int action;
 170 };
 171
 172 static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
 173 {
 174     struct add_rule_data *d = opaque;
 175     BDRVBlkdebugState *s = d->s;
 176     const char* event_name;
 177     int event;
 178     struct BlkdebugRule *rule;
 179     int64_t sector;
 180     BlkdebugIOType iotype;
 181     Error *local_error = NULL;
 182
 183     /* Find the right event for the rule */
 184     event_name = qemu_opt_get(opts, "event");
 185     if (!event_name) {
 186         error_setg(errp, "Missing event name for rule");
 187         return -1;
 188     }
 189     event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
 190     if (event < 0) {
 191         return -1;
 192     }
 193
 194     /* Set attributes common for all actions */
 195     rule = g_malloc0(sizeof(*rule));
 196     *rule = (struct BlkdebugRule) {
 197         .event  = event,
 198         .action = d->action,
 199         .state  = qemu_opt_get_number(opts, "state", 0),
 200     };
 201
 202     /* Parse action-specific options */
 203     switch (d->action) {
 204     case ACTION_INJECT_ERROR:
 205         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 206         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 207         rule->options.inject.immediately =
 208             qemu_opt_get_bool(opts, "immediately", 0);
 209         sector = qemu_opt_get_number(opts, "sector", -1);
 210         rule->options.inject.offset =
 211             sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
 212
 213         iotype = qapi_enum_parse(&BlkdebugIOType_lookup,
 214                                  qemu_opt_get(opts, "iotype"),
 215                                  BLKDEBUG_IO_TYPE__MAX, &local_error);
 216         if (local_error) {
 217             error_propagate(errp, local_error);
 218             return -1;
 219         }
 220         if (iotype != BLKDEBUG_IO_TYPE__MAX) {
 221             rule->options.inject.iotype_mask = (1ull << iotype);
 222         } else {
 223             /* Apply the default */
 224             rule->options.inject.iotype_mask =
 225                 (1ull << BLKDEBUG_IO_TYPE_READ)
 226                 | (1ull << BLKDEBUG_IO_TYPE_WRITE)
 227                 | (1ull << BLKDEBUG_IO_TYPE_WRITE_ZEROES)
 228                 | (1ull << BLKDEBUG_IO_TYPE_DISCARD)
 229                 | (1ull << BLKDEBUG_IO_TYPE_FLUSH);
 230         }
 231
 232         break;
 233
 234     case ACTION_SET_STATE:
 235         rule->options.set_state.new_state =
 236             qemu_opt_get_number(opts, "new_state", 0);
 237         break;
 238
 239     case ACTION_SUSPEND:
 240         rule->options.suspend.tag =
 241             g_strdup(qemu_opt_get(opts, "tag"));
 242         break;
 243     };
 244
 245     /* Add the rule */
 246     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 247
 248     return 0;
 249 }
 250
 251 static void remove_rule(BlkdebugRule *rule)
 252 {
 253     switch (rule->action) {
 254     case ACTION_INJECT_ERROR:
 255     case ACTION_SET_STATE:
 256         break;
 257     case ACTION_SUSPEND:
 258         g_free(rule->options.suspend.tag);
 259         break;
 260     }
 261
 262     QLIST_REMOVE(rule, next);
 263     g_free(rule);
 264 }
 265
 266 static int read_config(BDRVBlkdebugState *s, const char *filename,
 267                        QDict *options, Error **errp)
 268 {
 269     FILE *f = NULL;
 270     int ret;
 271     struct add_rule_data d;
 272     Error *local_err = NULL;
 273
 274     if (filename) {
 275         f = fopen(filename, "r");
 276         if (f == NULL) {
 277             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 278             return -errno;
 279         }
 280
 281         ret = qemu_config_parse(f, config_groups, filename);
 282         if (ret < 0) {
 283             error_setg(errp, "Could not parse blkdebug config file");
 284             goto fail;
 285         }
 286     }
 287
 288     qemu_config_parse_qdict(options, config_groups, &local_err);
 289     if (local_err) {
 290         error_propagate(errp, local_err);
 291         ret = -EINVAL;
 292         goto fail;
 293     }
 294
 295     d.s = s;
 296     d.action = ACTION_INJECT_ERROR;
 297     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 298     if (local_err) {
 299         error_propagate(errp, local_err);
 300         ret = -EINVAL;
 301         goto fail;
 302     }
 303
 304     d.action = ACTION_SET_STATE;
 305     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 306     if (local_err) {
 307         error_propagate(errp, local_err);
 308         ret = -EINVAL;
 309         goto fail;
 310     }
 311
 312     ret = 0;
 313 fail:
 314     qemu_opts_reset(&inject_error_opts);
 315     qemu_opts_reset(&set_state_opts);
 316     if (f) {
 317         fclose(f);
 318     }
 319     return ret;
 320 }
 321
 322 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 323 static void blkdebug_parse_filename(const char *filename, QDict *options,
 324                                     Error **errp)
 325 {
 326     const char *c;
 327
 328     /* Parse the blkdebug: prefix */
 329     if (!strstart(filename, "blkdebug:", &filename)) {
 330         /* There was no prefix; therefore, all options have to be already
 331            present in the QDict (except for the filename) */
 332         qdict_put_str(options, "x-image", filename);
 333         return;
 334     }
 335
 336     /* Parse config file path */
 337     c = strchr(filename, ':');
 338     if (c == NULL) {
 339         error_setg(errp, "blkdebug requires both config file and image path");
 340         return;
 341     }
 342
 343     if (c != filename) {
 344         QString *config_path;
 345         config_path = qstring_from_substr(filename, 0, c - filename);
 346         qdict_put(options, "config", config_path);
 347     }
 348
 349     /* TODO Allow multi-level nesting and set file.filename here */
 350     filename = c + 1;
 351     qdict_put_str(options, "x-image", filename);
 352 }
 353
 354 static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
 355                                     const char *prefix, Error **errp)
 356 {
 357     int ret = 0;
 358     QDict *subqdict = NULL;
 359     QObject *crumpled_subqdict = NULL;
 360     Visitor *v = NULL;
 361     BlockPermissionList *perm_list = NULL, *element;
 362     Error *local_err = NULL;
 363
 364     *dest = 0;
 365
 366     qdict_extract_subqdict(options, &subqdict, prefix);
 367     if (!qdict_size(subqdict)) {
 368         goto out;
 369     }
 370
 371     crumpled_subqdict = qdict_crumple(subqdict, errp);
 372     if (!crumpled_subqdict) {
 373         ret = -EINVAL;
 374         goto out;
 375     }
 376
 377     v = qobject_input_visitor_new(crumpled_subqdict);
 378     visit_type_BlockPermissionList(v, NULL, &perm_list, &local_err);
 379     if (local_err) {
 380         error_propagate(errp, local_err);
 381         ret = -EINVAL;
 382         goto out;
 383     }
 384
 385     for (element = perm_list; element; element = element->next) {
 386         *dest |= bdrv_qapi_perm_to_blk_perm(element->value);
 387     }
 388
 389 out:
 390     qapi_free_BlockPermissionList(perm_list);
 391     visit_free(v);
 392     qobject_unref(subqdict);
 393     qobject_unref(crumpled_subqdict);
 394     return ret;
 395 }
 396
 397 static int blkdebug_parse_perms(BDRVBlkdebugState *s, QDict *options,
 398                                 Error **errp)
 399 {
 400     int ret;
 401
 402     ret = blkdebug_parse_perm_list(&s->take_child_perms, options,
 403                                    "take-child-perms.", errp);
 404     if (ret < 0) {
 405         return ret;
 406     }
 407
 408     ret = blkdebug_parse_perm_list(&s->unshare_child_perms, options,
 409                                    "unshare-child-perms.", errp);
 410     if (ret < 0) {
 411         return ret;
 412     }
 413
 414     return 0;
 415 }
 416
 417 static QemuOptsList runtime_opts = {
 418     .name = "blkdebug",
 419     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 420     .desc = {
 421         {
 422             .name = "config",
 423             .type = QEMU_OPT_STRING,
 424             .help = "Path to the configuration file",
 425         },
 426         {
 427             .name = "x-image",
 428             .type = QEMU_OPT_STRING,
 429             .help = "[internal use only, will be removed]",
 430         },
 431         {
 432             .name = "align",
 433             .type = QEMU_OPT_SIZE,
 434             .help = "Required alignment in bytes",
 435         },
 436         {
 437             .name = "max-transfer",
 438             .type = QEMU_OPT_SIZE,
 439             .help = "Maximum transfer size in bytes",
 440         },
 441         {
 442             .name = "opt-write-zero",
 443             .type = QEMU_OPT_SIZE,
 444             .help = "Optimum write zero alignment in bytes",
 445         },
 446         {
 447             .name = "max-write-zero",
 448             .type = QEMU_OPT_SIZE,
 449             .help = "Maximum write zero size in bytes",
 450         },
 451         {
 452             .name = "opt-discard",
 453             .type = QEMU_OPT_SIZE,
 454             .help = "Optimum discard alignment in bytes",
 455         },
 456         {
 457             .name = "max-discard",
 458             .type = QEMU_OPT_SIZE,
 459             .help = "Maximum discard size in bytes",
 460         },
 461         { /* end of list */ }
 462     },
 463 };
 464
 465 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 466                          Error **errp)
 467 {
 468     BDRVBlkdebugState *s = bs->opaque;
 469     QemuOpts *opts;
 470     Error *local_err = NULL;
 471     int ret;
 472     uint64_t align;
 473
 474     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 475     qemu_opts_absorb_qdict(opts, options, &local_err);
 476     if (local_err) {
 477         error_propagate(errp, local_err);
 478         ret = -EINVAL;
 479         goto out;
 480     }
 481
 482     /* Read rules from config file or command line options */
 483     s->config_file = g_strdup(qemu_opt_get(opts, "config"));
 484     ret = read_config(s, s->config_file, options, errp);
 485     if (ret) {
 486         goto out;
 487     }
 488
 489     /* Set initial state */
 490     s->state = 1;
 491
 492     /* Parse permissions modifiers before opening the image file */
 493     ret = blkdebug_parse_perms(s, options, errp);
 494     if (ret < 0) {
 495         goto out;
 496     }
 497
 498     /* Open the image file */
 499     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
 500                                bs, &child_of_bds,
 501                                BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
 502                                false, &local_err);
 503     if (local_err) {
 504         ret = -EINVAL;
 505         error_propagate(errp, local_err);
 506         goto out;
 507     }
 508
 509     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
 510         (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
 511     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
 512         ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
 513             bs->file->bs->supported_zero_flags);
 514     ret = -EINVAL;
 515
 516     /* Set alignment overrides */
 517     s->align = qemu_opt_get_size(opts, "align", 0);
 518     if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
 519         error_setg(errp, "Cannot meet constraints with align %" PRIu64,
 520                    s->align);
 521         goto out;
 522     }
 523     align = MAX(s->align, bs->file->bs->bl.request_alignment);
 524
 525     s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
 526     if (s->max_transfer &&
 527         (s->max_transfer >= INT_MAX ||
 528          !QEMU_IS_ALIGNED(s->max_transfer, align))) {
 529         error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
 530                    s->max_transfer);
 531         goto out;
 532     }
 533
 534     s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
 535     if (s->opt_write_zero &&
 536         (s->opt_write_zero >= INT_MAX ||
 537          !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
 538         error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
 539                    s->opt_write_zero);
 540         goto out;
 541     }
 542
 543     s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
 544     if (s->max_write_zero &&
 545         (s->max_write_zero >= INT_MAX ||
 546          !QEMU_IS_ALIGNED(s->max_write_zero,
 547                           MAX(s->opt_write_zero, align)))) {
 548         error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
 549                    s->max_write_zero);
 550         goto out;
 551     }
 552
 553     s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
 554     if (s->opt_discard &&
 555         (s->opt_discard >= INT_MAX ||
 556          !QEMU_IS_ALIGNED(s->opt_discard, align))) {
 557         error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
 558                    s->opt_discard);
 559         goto out;
 560     }
 561
 562     s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
 563     if (s->max_discard &&
 564         (s->max_discard >= INT_MAX ||
 565          !QEMU_IS_ALIGNED(s->max_discard,
 566                           MAX(s->opt_discard, align)))) {
 567         error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
 568                    s->max_discard);
 569         goto out;
 570     }
 571
 572     bdrv_debug_event(bs, BLKDBG_NONE);
 573
 574     ret = 0;
 575 out:
 576     if (ret < 0) {
 577         g_free(s->config_file);
 578     }
 579     qemu_opts_del(opts);
 580     return ret;
 581 }
 582
 583 static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 584                       BlkdebugIOType iotype)
 585 {
 586     BDRVBlkdebugState *s = bs->opaque;
 587     BlkdebugRule *rule = NULL;
 588     int error;
 589     bool immediately;
 590
 591     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 592         uint64_t inject_offset = rule->options.inject.offset;
 593
 594         if ((inject_offset == -1 ||
 595              (bytes && inject_offset >= offset &&
 596               inject_offset < offset + bytes)) &&
 597             (rule->options.inject.iotype_mask & (1ull << iotype)))
 598         {
 599             break;
 600         }
 601     }
 602
 603     if (!rule || !rule->options.inject.error) {
 604         return 0;
 605     }
 606
 607     immediately = rule->options.inject.immediately;
 608     error = rule->options.inject.error;
 609
 610     if (rule->options.inject.once) {
 611         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 612         remove_rule(rule);
 613     }
 614
 615     if (!immediately) {
 616         aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
 617         qemu_coroutine_yield();
 618     }
 619
 620     return -error;
 621 }
 622
 623 static int coroutine_fn
 624 blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 625                    QEMUIOVector *qiov, int flags)
 626 {
 627     int err;
 628
 629     /* Sanity check block layer guarantees */
 630     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 631     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 632     if (bs->bl.max_transfer) {
 633         assert(bytes <= bs->bl.max_transfer);
 634     }
 635
 636     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_READ);
 637     if (err) {
 638         return err;
 639     }
 640
 641     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 642 }
 643
 644 static int coroutine_fn
 645 blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 646                     QEMUIOVector *qiov, int flags)
 647 {
 648     int err;
 649
 650     /* Sanity check block layer guarantees */
 651     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 652     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 653     if (bs->bl.max_transfer) {
 654         assert(bytes <= bs->bl.max_transfer);
 655     }
 656
 657     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE);
 658     if (err) {
 659         return err;
 660     }
 661
 662     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 663 }
 664
 665 static int blkdebug_co_flush(BlockDriverState *bs)
 666 {
 667     int err = rule_check(bs, 0, 0, BLKDEBUG_IO_TYPE_FLUSH);
 668
 669     if (err) {
 670         return err;
 671     }
 672
 673     return bdrv_co_flush(bs->file->bs);
 674 }
 675
 676 static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
 677                                                   int64_t offset, int bytes,
 678                                                   BdrvRequestFlags flags)
 679 {
 680     uint32_t align = MAX(bs->bl.request_alignment,
 681                          bs->bl.pwrite_zeroes_alignment);
 682     int err;
 683
 684     /* Only pass through requests that are larger than requested
 685      * preferred alignment (so that we test the fallback to writes on
 686      * unaligned portions), and check that the block layer never hands
 687      * us anything unaligned that crosses an alignment boundary.  */
 688     if (bytes < align) {
 689         assert(QEMU_IS_ALIGNED(offset, align) ||
 690                QEMU_IS_ALIGNED(offset + bytes, align) ||
 691                DIV_ROUND_UP(offset, align) ==
 692                DIV_ROUND_UP(offset + bytes, align));
 693         return -ENOTSUP;
 694     }
 695     assert(QEMU_IS_ALIGNED(offset, align));
 696     assert(QEMU_IS_ALIGNED(bytes, align));
 697     if (bs->bl.max_pwrite_zeroes) {
 698         assert(bytes <= bs->bl.max_pwrite_zeroes);
 699     }
 700
 701     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE_ZEROES);
 702     if (err) {
 703         return err;
 704     }
 705
 706     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 707 }
 708
 709 static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
 710                                              int64_t offset, int bytes)
 711 {
 712     uint32_t align = bs->bl.pdiscard_alignment;
 713     int err;
 714
 715     /* Only pass through requests that are larger than requested
 716      * minimum alignment, and ensure that unaligned requests do not
 717      * cross optimum discard boundaries. */
 718     if (bytes < bs->bl.request_alignment) {
 719         assert(QEMU_IS_ALIGNED(offset, align) ||
 720                QEMU_IS_ALIGNED(offset + bytes, align) ||
 721                DIV_ROUND_UP(offset, align) ==
 722                DIV_ROUND_UP(offset + bytes, align));
 723         return -ENOTSUP;
 724     }
 725     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 726     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 727     if (align && bytes >= align) {
 728         assert(QEMU_IS_ALIGNED(offset, align));
 729         assert(QEMU_IS_ALIGNED(bytes, align));
 730     }
 731     if (bs->bl.max_pdiscard) {
 732         assert(bytes <= bs->bl.max_pdiscard);
 733     }
 734
 735     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_DISCARD);
 736     if (err) {
 737         return err;
 738     }
 739
 740     return bdrv_co_pdiscard(bs->file, offset, bytes);
 741 }
 742
 743 static int coroutine_fn blkdebug_co_block_status(BlockDriverState *bs,
 744                                                  bool want_zero,
 745                                                  int64_t offset,
 746                                                  int64_t bytes,
 747                                                  int64_t *pnum,
 748                                                  int64_t *map,
 749                                                  BlockDriverState **file)
 750 {
 751     int err;
 752
 753     assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
 754
 755     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_BLOCK_STATUS);
 756     if (err) {
 757         return err;
 758     }
 759
 760     return bdrv_co_block_status_from_file(bs, want_zero, offset, bytes,
 761                                           pnum, map, file);
 762 }
 763
 764 static void blkdebug_close(BlockDriverState *bs)
 765 {
 766     BDRVBlkdebugState *s = bs->opaque;
 767     BlkdebugRule *rule, *next;
 768     int i;
 769
 770     for (i = 0; i < BLKDBG__MAX; i++) {
 771         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 772             remove_rule(rule);
 773         }
 774     }
 775
 776     g_free(s->config_file);
 777 }
 778
 779 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 780 {
 781     BDRVBlkdebugState *s = bs->opaque;
 782     BlkdebugSuspendedReq r;
 783
 784     r = (BlkdebugSuspendedReq) {
 785         .co         = qemu_coroutine_self(),
 786         .tag        = g_strdup(rule->options.suspend.tag),
 787     };
 788
 789     remove_rule(rule);
 790     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 791
 792     if (!qtest_enabled()) {
 793         printf("blkdebug: Suspended request '%s'\n", r.tag);
 794     }
 795     qemu_coroutine_yield();
 796     if (!qtest_enabled()) {
 797         printf("blkdebug: Resuming request '%s'\n", r.tag);
 798     }
 799
 800     QLIST_REMOVE(&r, next);
 801     g_free(r.tag);
 802 }
 803
 804 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 805     bool injected)
 806 {
 807     BDRVBlkdebugState *s = bs->opaque;
 808
 809     /* Only process rules for the current state */
 810     if (rule->state && rule->state != s->state) {
 811         return injected;
 812     }
 813
 814     /* Take the action */
 815     switch (rule->action) {
 816     case ACTION_INJECT_ERROR:
 817         if (!injected) {
 818             QSIMPLEQ_INIT(&s->active_rules);
 819             injected = true;
 820         }
 821         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 822         break;
 823
 824     case ACTION_SET_STATE:
 825         s->new_state = rule->options.set_state.new_state;
 826         break;
 827
 828     case ACTION_SUSPEND:
 829         suspend_request(bs, rule);
 830         break;
 831     }
 832     return injected;
 833 }
 834
 835 static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 836 {
 837     BDRVBlkdebugState *s = bs->opaque;
 838     struct BlkdebugRule *rule, *next;
 839     bool injected;
 840
 841     assert((int)event >= 0 && event < BLKDBG__MAX);
 842
 843     injected = false;
 844     s->new_state = s->state;
 845     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 846         injected = process_rule(bs, rule, injected);
 847     }
 848     s->state = s->new_state;
 849 }
 850
 851 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 852                                      const char *tag)
 853 {
 854     BDRVBlkdebugState *s = bs->opaque;
 855     struct BlkdebugRule *rule;
 856     int blkdebug_event;
 857
 858     blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
 859     if (blkdebug_event < 0) {
 860         return -ENOENT;
 861     }
 862
 863     rule = g_malloc(sizeof(*rule));
 864     *rule = (struct BlkdebugRule) {
 865         .event  = blkdebug_event,
 866         .action = ACTION_SUSPEND,
 867         .state  = 0,
 868         .options.suspend.tag = g_strdup(tag),
 869     };
 870
 871     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 872
 873     return 0;
 874 }
 875
 876 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 877 {
 878     BDRVBlkdebugState *s = bs->opaque;
 879     BlkdebugSuspendedReq *r, *next;
 880
 881     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 882         if (!strcmp(r->tag, tag)) {
 883             qemu_coroutine_enter(r->co);
 884             return 0;
 885         }
 886     }
 887     return -ENOENT;
 888 }
 889
 890 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 891                                             const char *tag)
 892 {
 893     BDRVBlkdebugState *s = bs->opaque;
 894     BlkdebugSuspendedReq *r, *r_next;
 895     BlkdebugRule *rule, *next;
 896     int i, ret = -ENOENT;
 897
 898     for (i = 0; i < BLKDBG__MAX; i++) {
 899         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 900             if (rule->action == ACTION_SUSPEND &&
 901                 !strcmp(rule->options.suspend.tag, tag)) {
 902                 remove_rule(rule);
 903                 ret = 0;
 904             }
 905         }
 906     }
 907     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 908         if (!strcmp(r->tag, tag)) {
 909             qemu_coroutine_enter(r->co);
 910             ret = 0;
 911         }
 912     }
 913     return ret;
 914 }
 915
 916 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 917 {
 918     BDRVBlkdebugState *s = bs->opaque;
 919     BlkdebugSuspendedReq *r;
 920
 921     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 922         if (!strcmp(r->tag, tag)) {
 923             return true;
 924         }
 925     }
 926     return false;
 927 }
 928
 929 static int64_t blkdebug_getlength(BlockDriverState *bs)
 930 {
 931     return bdrv_getlength(bs->file->bs);
 932 }
 933
 934 static void blkdebug_refresh_filename(BlockDriverState *bs)
 935 {
 936     BDRVBlkdebugState *s = bs->opaque;
 937     const QDictEntry *e;
 938     int ret;
 939
 940     if (!bs->file->bs->exact_filename[0]) {
 941         return;
 942     }
 943
 944     for (e = qdict_first(bs->full_open_options); e;
 945          e = qdict_next(bs->full_open_options, e))
 946     {
 947         /* Real child options are under "image", but "x-image" may
 948          * contain a filename */
 949         if (strcmp(qdict_entry_key(e), "config") &&
 950             strcmp(qdict_entry_key(e), "image") &&
 951             strcmp(qdict_entry_key(e), "x-image") &&
 952             strcmp(qdict_entry_key(e), "driver"))
 953         {
 954             return;
 955         }
 956     }
 957
 958     ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 959                    "blkdebug:%s:%s",
 960                    s->config_file ?: "", bs->file->bs->exact_filename);
 961     if (ret >= sizeof(bs->exact_filename)) {
 962         /* An overflow makes the filename unusable, so do not report any */
 963         bs->exact_filename[0] = 0;
 964     }
 965 }
 966
 967 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
 968 {
 969     BDRVBlkdebugState *s = bs->opaque;
 970
 971     if (s->align) {
 972         bs->bl.request_alignment = s->align;
 973     }
 974     if (s->max_transfer) {
 975         bs->bl.max_transfer = s->max_transfer;
 976     }
 977     if (s->opt_write_zero) {
 978         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
 979     }
 980     if (s->max_write_zero) {
 981         bs->bl.max_pwrite_zeroes = s->max_write_zero;
 982     }
 983     if (s->opt_discard) {
 984         bs->bl.pdiscard_alignment = s->opt_discard;
 985     }
 986     if (s->max_discard) {
 987         bs->bl.max_pdiscard = s->max_discard;
 988     }
 989 }
 990
 991 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
 992                                    BlockReopenQueue *queue, Error **errp)
 993 {
 994     return 0;
 995 }
 996
 997 static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c,
 998                                 const BdrvChildClass *child_class,
 999                                 BdrvChildRole role,
1000                                 BlockReopenQueue *reopen_queue,
1001                                 uint64_t perm, uint64_t shared,
1002                                 uint64_t *nperm, uint64_t *nshared)
1003 {
1004     BDRVBlkdebugState *s = bs->opaque;
1005
1006     bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue,
1007                               perm, shared, nperm, nshared);
1008
1009     *nperm |= s->take_child_perms;
1010     *nshared &= ~s->unshare_child_perms;
1011 }
1012
1013 static const char *const blkdebug_strong_runtime_opts[] = {
1014     "config",
1015     "inject-error.",
1016     "set-state.",
1017     "align",
1018     "max-transfer",
1019     "opt-write-zero",
1020     "max-write-zero",
1021     "opt-discard",
1022     "max-discard",
1023
1024     NULL
1025 };
1026
1027 static BlockDriver bdrv_blkdebug = {
1028     .format_name            = "blkdebug",
1029     .protocol_name          = "blkdebug",
1030     .instance_size          = sizeof(BDRVBlkdebugState),
1031     .is_filter              = true,
1032
1033     .bdrv_parse_filename    = blkdebug_parse_filename,
1034     .bdrv_file_open         = blkdebug_open,
1035     .bdrv_close             = blkdebug_close,
1036     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
1037     .bdrv_child_perm        = blkdebug_child_perm,
1038
1039     .bdrv_getlength         = blkdebug_getlength,
1040     .bdrv_refresh_filename  = blkdebug_refresh_filename,
1041     .bdrv_refresh_limits    = blkdebug_refresh_limits,
1042
1043     .bdrv_co_preadv         = blkdebug_co_preadv,
1044     .bdrv_co_pwritev        = blkdebug_co_pwritev,
1045     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
1046     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
1047     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
1048     .bdrv_co_block_status   = blkdebug_co_block_status,
1049
1050     .bdrv_debug_event           = blkdebug_debug_event,
1051     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
1052     .bdrv_debug_remove_breakpoint
1053                                 = blkdebug_debug_remove_breakpoint,
1054     .bdrv_debug_resume          = blkdebug_debug_resume,
1055     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
1056
1057     .strong_runtime_opts        = blkdebug_strong_runtime_opts,
1058 };
1059
1060 static void bdrv_blkdebug_init(void)
1061 {
1062     bdrv_register(&bdrv_blkdebug);
1063 }
1064
1065 block_init(bdrv_blkdebug_init);