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-io.h"
  31 #include "block/block_int.h"
  32 #include "block/qdict.h"
  33 #include "qemu/module.h"
  34 #include "qemu/option.h"
  35 #include "qapi/qapi-visit-block-core.h"
  36 #include "qapi/qmp/qdict.h"
  37 #include "qapi/qmp/qlist.h"
  38 #include "qapi/qmp/qstring.h"
  39 #include "qapi/qobject-input-visitor.h"
  40 #include "sysemu/qtest.h"
  41
  42 /* All APIs are thread-safe */
  43
  44 typedef struct BDRVBlkdebugState {
  45     /* IN: initialized in blkdebug_open() and never changed */
  46     uint64_t align;
  47     uint64_t max_transfer;
  48     uint64_t opt_write_zero;
  49     uint64_t max_write_zero;
  50     uint64_t opt_discard;
  51     uint64_t max_discard;
  52     char *config_file; /* For blkdebug_refresh_filename() */
  53     /* initialized in blkdebug_parse_perms() */
  54     uint64_t take_child_perms;
  55     uint64_t unshare_child_perms;
  56
  57     /* State. Protected by lock */
  58     int state;
  59     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
  60     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  61     QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
  62     QemuMutex lock;
  63 } BDRVBlkdebugState;
  64
  65 typedef struct BlkdebugAIOCB {
  66     BlockAIOCB common;
  67     int ret;
  68 } BlkdebugAIOCB;
  69
  70 typedef struct BlkdebugSuspendedReq {
  71     /* IN: initialized in suspend_request() */
  72     Coroutine *co;
  73     char *tag;
  74
  75     /* List entry protected BDRVBlkdebugState's lock */
  76     QLIST_ENTRY(BlkdebugSuspendedReq) next;
  77 } BlkdebugSuspendedReq;
  78
  79 enum {
  80     ACTION_INJECT_ERROR,
  81     ACTION_SET_STATE,
  82     ACTION_SUSPEND,
  83     ACTION__MAX,
  84 };
  85
  86 typedef struct BlkdebugRule {
  87     /* IN: initialized in add_rule() or blkdebug_debug_breakpoint() */
  88     BlkdebugEvent event;
  89     int action;
  90     int state;
  91     union {
  92         struct {
  93             uint64_t iotype_mask;
  94             int error;
  95             int immediately;
  96             int once;
  97             int64_t offset;
  98         } inject;
  99         struct {
 100             int new_state;
 101         } set_state;
 102         struct {
 103             char *tag;
 104         } suspend;
 105     } options;
 106
 107     /* List entries protected BDRVBlkdebugState's lock */
 108     QLIST_ENTRY(BlkdebugRule) next;
 109     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
 110 } BlkdebugRule;
 111
 112 QEMU_BUILD_BUG_MSG(BLKDEBUG_IO_TYPE__MAX > 64,
 113                    "BlkdebugIOType mask does not fit into an uint64_t");
 114
 115 static QemuOptsList inject_error_opts = {
 116     .name = "inject-error",
 117     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
 118     .desc = {
 119         {
 120             .name = "event",
 121             .type = QEMU_OPT_STRING,
 122         },
 123         {
 124             .name = "state",
 125             .type = QEMU_OPT_NUMBER,
 126         },
 127         {
 128             .name = "iotype",
 129             .type = QEMU_OPT_STRING,
 130         },
 131         {
 132             .name = "errno",
 133             .type = QEMU_OPT_NUMBER,
 134         },
 135         {
 136             .name = "sector",
 137             .type = QEMU_OPT_NUMBER,
 138         },
 139         {
 140             .name = "once",
 141             .type = QEMU_OPT_BOOL,
 142         },
 143         {
 144             .name = "immediately",
 145             .type = QEMU_OPT_BOOL,
 146         },
 147         { /* end of list */ }
 148     },
 149 };
 150
 151 static QemuOptsList set_state_opts = {
 152     .name = "set-state",
 153     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 154     .desc = {
 155         {
 156             .name = "event",
 157             .type = QEMU_OPT_STRING,
 158         },
 159         {
 160             .name = "state",
 161             .type = QEMU_OPT_NUMBER,
 162         },
 163         {
 164             .name = "new_state",
 165             .type = QEMU_OPT_NUMBER,
 166         },
 167         { /* end of list */ }
 168     },
 169 };
 170
 171 static QemuOptsList *config_groups[] = {
 172     &inject_error_opts,
 173     &set_state_opts,
 174     NULL
 175 };
 176
 177 struct add_rule_data {
 178     BDRVBlkdebugState *s;
 179     int action;
 180 };
 181
 182 static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
 183 {
 184     struct add_rule_data *d = opaque;
 185     BDRVBlkdebugState *s = d->s;
 186     const char *event_name;
 187     int event;
 188     struct BlkdebugRule *rule;
 189     int64_t sector;
 190     BlkdebugIOType iotype;
 191     Error *local_error = NULL;
 192
 193     /* Find the right event for the rule */
 194     event_name = qemu_opt_get(opts, "event");
 195     if (!event_name) {
 196         error_setg(errp, "Missing event name for rule");
 197         return -1;
 198     }
 199     event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
 200     if (event < 0) {
 201         return -1;
 202     }
 203
 204     /* Set attributes common for all actions */
 205     rule = g_malloc0(sizeof(*rule));
 206     *rule = (struct BlkdebugRule) {
 207         .event  = event,
 208         .action = d->action,
 209         .state  = qemu_opt_get_number(opts, "state", 0),
 210     };
 211
 212     /* Parse action-specific options */
 213     switch (d->action) {
 214     case ACTION_INJECT_ERROR:
 215         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 216         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 217         rule->options.inject.immediately =
 218             qemu_opt_get_bool(opts, "immediately", 0);
 219         sector = qemu_opt_get_number(opts, "sector", -1);
 220         rule->options.inject.offset =
 221             sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
 222
 223         iotype = qapi_enum_parse(&BlkdebugIOType_lookup,
 224                                  qemu_opt_get(opts, "iotype"),
 225                                  BLKDEBUG_IO_TYPE__MAX, &local_error);
 226         if (local_error) {
 227             error_propagate(errp, local_error);
 228             g_free(rule);
 229             return -1;
 230         }
 231         if (iotype != BLKDEBUG_IO_TYPE__MAX) {
 232             rule->options.inject.iotype_mask = (1ull << iotype);
 233         } else {
 234             /* Apply the default */
 235             rule->options.inject.iotype_mask =
 236                 (1ull << BLKDEBUG_IO_TYPE_READ)
 237                 | (1ull << BLKDEBUG_IO_TYPE_WRITE)
 238                 | (1ull << BLKDEBUG_IO_TYPE_WRITE_ZEROES)
 239                 | (1ull << BLKDEBUG_IO_TYPE_DISCARD)
 240                 | (1ull << BLKDEBUG_IO_TYPE_FLUSH);
 241         }
 242
 243         break;
 244
 245     case ACTION_SET_STATE:
 246         rule->options.set_state.new_state =
 247             qemu_opt_get_number(opts, "new_state", 0);
 248         break;
 249
 250     case ACTION_SUSPEND:
 251         rule->options.suspend.tag =
 252             g_strdup(qemu_opt_get(opts, "tag"));
 253         break;
 254     };
 255
 256     /* Add the rule */
 257     qemu_mutex_lock(&s->lock);
 258     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 259     qemu_mutex_unlock(&s->lock);
 260
 261     return 0;
 262 }
 263
 264 /* Called with lock held or from .bdrv_close */
 265 static void remove_rule(BlkdebugRule *rule)
 266 {
 267     switch (rule->action) {
 268     case ACTION_INJECT_ERROR:
 269     case ACTION_SET_STATE:
 270         break;
 271     case ACTION_SUSPEND:
 272         g_free(rule->options.suspend.tag);
 273         break;
 274     }
 275
 276     QLIST_REMOVE(rule, next);
 277     g_free(rule);
 278 }
 279
 280 static int read_config(BDRVBlkdebugState *s, const char *filename,
 281                        QDict *options, Error **errp)
 282 {
 283     FILE *f = NULL;
 284     int ret;
 285     struct add_rule_data d;
 286     Error *local_err = NULL;
 287
 288     if (filename) {
 289         f = fopen(filename, "r");
 290         if (f == NULL) {
 291             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 292             return -errno;
 293         }
 294
 295         ret = qemu_config_parse(f, config_groups, filename, errp);
 296         if (ret < 0) {
 297             goto fail;
 298         }
 299     }
 300
 301     if (!qemu_config_parse_qdict(options, config_groups, errp)) {
 302         ret = -EINVAL;
 303         goto fail;
 304     }
 305
 306     d.s = s;
 307     d.action = ACTION_INJECT_ERROR;
 308     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 309     if (local_err) {
 310         error_propagate(errp, local_err);
 311         ret = -EINVAL;
 312         goto fail;
 313     }
 314
 315     d.action = ACTION_SET_STATE;
 316     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 317     if (local_err) {
 318         error_propagate(errp, local_err);
 319         ret = -EINVAL;
 320         goto fail;
 321     }
 322
 323     ret = 0;
 324 fail:
 325     qemu_opts_reset(&inject_error_opts);
 326     qemu_opts_reset(&set_state_opts);
 327     if (f) {
 328         fclose(f);
 329     }
 330     return ret;
 331 }
 332
 333 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 334 static void blkdebug_parse_filename(const char *filename, QDict *options,
 335                                     Error **errp)
 336 {
 337     const char *c;
 338
 339     /* Parse the blkdebug: prefix */
 340     if (!strstart(filename, "blkdebug:", &filename)) {
 341         /* There was no prefix; therefore, all options have to be already
 342            present in the QDict (except for the filename) */
 343         qdict_put_str(options, "x-image", filename);
 344         return;
 345     }
 346
 347     /* Parse config file path */
 348     c = strchr(filename, ':');
 349     if (c == NULL) {
 350         error_setg(errp, "blkdebug requires both config file and image path");
 351         return;
 352     }
 353
 354     if (c != filename) {
 355         QString *config_path;
 356         config_path = qstring_from_substr(filename, 0, c - filename);
 357         qdict_put(options, "config", config_path);
 358     }
 359
 360     /* TODO Allow multi-level nesting and set file.filename here */
 361     filename = c + 1;
 362     qdict_put_str(options, "x-image", filename);
 363 }
 364
 365 static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
 366                                     const char *prefix, Error **errp)
 367 {
 368     int ret = 0;
 369     QDict *subqdict = NULL;
 370     QObject *crumpled_subqdict = NULL;
 371     Visitor *v = NULL;
 372     BlockPermissionList *perm_list = NULL, *element;
 373
 374     *dest = 0;
 375
 376     qdict_extract_subqdict(options, &subqdict, prefix);
 377     if (!qdict_size(subqdict)) {
 378         goto out;
 379     }
 380
 381     crumpled_subqdict = qdict_crumple(subqdict, errp);
 382     if (!crumpled_subqdict) {
 383         ret = -EINVAL;
 384         goto out;
 385     }
 386
 387     v = qobject_input_visitor_new(crumpled_subqdict);
 388     if (!visit_type_BlockPermissionList(v, NULL, &perm_list, errp)) {
 389         ret = -EINVAL;
 390         goto out;
 391     }
 392
 393     for (element = perm_list; element; element = element->next) {
 394         *dest |= bdrv_qapi_perm_to_blk_perm(element->value);
 395     }
 396
 397 out:
 398     qapi_free_BlockPermissionList(perm_list);
 399     visit_free(v);
 400     qobject_unref(subqdict);
 401     qobject_unref(crumpled_subqdict);
 402     return ret;
 403 }
 404
 405 static int blkdebug_parse_perms(BDRVBlkdebugState *s, QDict *options,
 406                                 Error **errp)
 407 {
 408     int ret;
 409
 410     ret = blkdebug_parse_perm_list(&s->take_child_perms, options,
 411                                    "take-child-perms.", errp);
 412     if (ret < 0) {
 413         return ret;
 414     }
 415
 416     ret = blkdebug_parse_perm_list(&s->unshare_child_perms, options,
 417                                    "unshare-child-perms.", errp);
 418     if (ret < 0) {
 419         return ret;
 420     }
 421
 422     return 0;
 423 }
 424
 425 static QemuOptsList runtime_opts = {
 426     .name = "blkdebug",
 427     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 428     .desc = {
 429         {
 430             .name = "config",
 431             .type = QEMU_OPT_STRING,
 432             .help = "Path to the configuration file",
 433         },
 434         {
 435             .name = "x-image",
 436             .type = QEMU_OPT_STRING,
 437             .help = "[internal use only, will be removed]",
 438         },
 439         {
 440             .name = "align",
 441             .type = QEMU_OPT_SIZE,
 442             .help = "Required alignment in bytes",
 443         },
 444         {
 445             .name = "max-transfer",
 446             .type = QEMU_OPT_SIZE,
 447             .help = "Maximum transfer size in bytes",
 448         },
 449         {
 450             .name = "opt-write-zero",
 451             .type = QEMU_OPT_SIZE,
 452             .help = "Optimum write zero alignment in bytes",
 453         },
 454         {
 455             .name = "max-write-zero",
 456             .type = QEMU_OPT_SIZE,
 457             .help = "Maximum write zero size in bytes",
 458         },
 459         {
 460             .name = "opt-discard",
 461             .type = QEMU_OPT_SIZE,
 462             .help = "Optimum discard alignment in bytes",
 463         },
 464         {
 465             .name = "max-discard",
 466             .type = QEMU_OPT_SIZE,
 467             .help = "Maximum discard size in bytes",
 468         },
 469         { /* end of list */ }
 470     },
 471 };
 472
 473 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 474                          Error **errp)
 475 {
 476     BDRVBlkdebugState *s = bs->opaque;
 477     QemuOpts *opts;
 478     int ret;
 479     uint64_t align;
 480
 481     qemu_mutex_init(&s->lock);
 482     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 483     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 484         ret = -EINVAL;
 485         goto out;
 486     }
 487
 488     /* Read rules from config file or command line options */
 489     s->config_file = g_strdup(qemu_opt_get(opts, "config"));
 490     ret = read_config(s, s->config_file, options, errp);
 491     if (ret) {
 492         goto out;
 493     }
 494
 495     /* Set initial state */
 496     s->state = 1;
 497
 498     /* Parse permissions modifiers before opening the image file */
 499     ret = blkdebug_parse_perms(s, options, errp);
 500     if (ret < 0) {
 501         goto out;
 502     }
 503
 504     /* Open the image file */
 505     ret = bdrv_open_file_child(qemu_opt_get(opts, "x-image"), options, "image",
 506                                bs, errp);
 507     if (ret < 0) {
 508         goto out;
 509     }
 510
 511     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
 512         (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
 513     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
 514         ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
 515             bs->file->bs->supported_zero_flags);
 516     ret = -EINVAL;
 517
 518     /* Set alignment overrides */
 519     s->align = qemu_opt_get_size(opts, "align", 0);
 520     if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
 521         error_setg(errp, "Cannot meet constraints with align %" PRIu64,
 522                    s->align);
 523         goto out;
 524     }
 525     align = MAX(s->align, bs->file->bs->bl.request_alignment);
 526
 527     s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
 528     if (s->max_transfer &&
 529         (s->max_transfer >= INT_MAX ||
 530          !QEMU_IS_ALIGNED(s->max_transfer, align))) {
 531         error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
 532                    s->max_transfer);
 533         goto out;
 534     }
 535
 536     s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
 537     if (s->opt_write_zero &&
 538         (s->opt_write_zero >= INT_MAX ||
 539          !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
 540         error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
 541                    s->opt_write_zero);
 542         goto out;
 543     }
 544
 545     s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
 546     if (s->max_write_zero &&
 547         (s->max_write_zero >= INT_MAX ||
 548          !QEMU_IS_ALIGNED(s->max_write_zero,
 549                           MAX(s->opt_write_zero, align)))) {
 550         error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
 551                    s->max_write_zero);
 552         goto out;
 553     }
 554
 555     s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
 556     if (s->opt_discard &&
 557         (s->opt_discard >= INT_MAX ||
 558          !QEMU_IS_ALIGNED(s->opt_discard, align))) {
 559         error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
 560                    s->opt_discard);
 561         goto out;
 562     }
 563
 564     s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
 565     if (s->max_discard &&
 566         (s->max_discard >= INT_MAX ||
 567          !QEMU_IS_ALIGNED(s->max_discard,
 568                           MAX(s->opt_discard, align)))) {
 569         error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
 570                    s->max_discard);
 571         goto out;
 572     }
 573
 574     bdrv_debug_event(bs, BLKDBG_NONE);
 575
 576     ret = 0;
 577 out:
 578     if (ret < 0) {
 579         qemu_mutex_destroy(&s->lock);
 580         g_free(s->config_file);
 581     }
 582     qemu_opts_del(opts);
 583     return ret;
 584 }
 585
 586 static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 587                       BlkdebugIOType iotype)
 588 {
 589     BDRVBlkdebugState *s = bs->opaque;
 590     BlkdebugRule *rule = NULL;
 591     int error;
 592     bool immediately;
 593
 594     qemu_mutex_lock(&s->lock);
 595     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 596         uint64_t inject_offset = rule->options.inject.offset;
 597
 598         if ((inject_offset == -1 ||
 599              (bytes && inject_offset >= offset &&
 600               inject_offset < offset + bytes)) &&
 601             (rule->options.inject.iotype_mask & (1ull << iotype)))
 602         {
 603             break;
 604         }
 605     }
 606
 607     if (!rule || !rule->options.inject.error) {
 608         qemu_mutex_unlock(&s->lock);
 609         return 0;
 610     }
 611
 612     immediately = rule->options.inject.immediately;
 613     error = rule->options.inject.error;
 614
 615     if (rule->options.inject.once) {
 616         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 617         remove_rule(rule);
 618     }
 619
 620     qemu_mutex_unlock(&s->lock);
 621     if (!immediately) {
 622         aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
 623         qemu_coroutine_yield();
 624     }
 625
 626     return -error;
 627 }
 628
 629 static int coroutine_fn GRAPH_RDLOCK
 630 blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 631                    QEMUIOVector *qiov, BdrvRequestFlags flags)
 632 {
 633     int err;
 634
 635     /* Sanity check block layer guarantees */
 636     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 637     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 638     if (bs->bl.max_transfer) {
 639         assert(bytes <= bs->bl.max_transfer);
 640     }
 641
 642     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_READ);
 643     if (err) {
 644         return err;
 645     }
 646
 647     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 648 }
 649
 650 static int coroutine_fn GRAPH_RDLOCK
 651 blkdebug_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
 652                     QEMUIOVector *qiov, BdrvRequestFlags flags)
 653 {
 654     int err;
 655
 656     /* Sanity check block layer guarantees */
 657     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 658     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 659     if (bs->bl.max_transfer) {
 660         assert(bytes <= bs->bl.max_transfer);
 661     }
 662
 663     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE);
 664     if (err) {
 665         return err;
 666     }
 667
 668     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 669 }
 670
 671 static int GRAPH_RDLOCK coroutine_fn blkdebug_co_flush(BlockDriverState *bs)
 672 {
 673     int err = rule_check(bs, 0, 0, BLKDEBUG_IO_TYPE_FLUSH);
 674
 675     if (err) {
 676         return err;
 677     }
 678
 679     return bdrv_co_flush(bs->file->bs);
 680 }
 681
 682 static int coroutine_fn GRAPH_RDLOCK
 683 blkdebug_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
 684                           BdrvRequestFlags flags)
 685 {
 686     uint32_t align = MAX(bs->bl.request_alignment,
 687                          bs->bl.pwrite_zeroes_alignment);
 688     int err;
 689
 690     /* Only pass through requests that are larger than requested
 691      * preferred alignment (so that we test the fallback to writes on
 692      * unaligned portions), and check that the block layer never hands
 693      * us anything unaligned that crosses an alignment boundary.  */
 694     if (bytes < align) {
 695         assert(QEMU_IS_ALIGNED(offset, align) ||
 696                QEMU_IS_ALIGNED(offset + bytes, align) ||
 697                DIV_ROUND_UP(offset, align) ==
 698                DIV_ROUND_UP(offset + bytes, align));
 699         return -ENOTSUP;
 700     }
 701     assert(QEMU_IS_ALIGNED(offset, align));
 702     assert(QEMU_IS_ALIGNED(bytes, align));
 703     if (bs->bl.max_pwrite_zeroes) {
 704         assert(bytes <= bs->bl.max_pwrite_zeroes);
 705     }
 706
 707     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE_ZEROES);
 708     if (err) {
 709         return err;
 710     }
 711
 712     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 713 }
 714
 715 static int coroutine_fn GRAPH_RDLOCK
 716 blkdebug_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 717 {
 718     uint32_t align = bs->bl.pdiscard_alignment;
 719     int err;
 720
 721     /* Only pass through requests that are larger than requested
 722      * minimum alignment, and ensure that unaligned requests do not
 723      * cross optimum discard boundaries. */
 724     if (bytes < bs->bl.request_alignment) {
 725         assert(QEMU_IS_ALIGNED(offset, align) ||
 726                QEMU_IS_ALIGNED(offset + bytes, align) ||
 727                DIV_ROUND_UP(offset, align) ==
 728                DIV_ROUND_UP(offset + bytes, align));
 729         return -ENOTSUP;
 730     }
 731     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 732     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 733     if (align && bytes >= align) {
 734         assert(QEMU_IS_ALIGNED(offset, align));
 735         assert(QEMU_IS_ALIGNED(bytes, align));
 736     }
 737     if (bs->bl.max_pdiscard) {
 738         assert(bytes <= bs->bl.max_pdiscard);
 739     }
 740
 741     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_DISCARD);
 742     if (err) {
 743         return err;
 744     }
 745
 746     return bdrv_co_pdiscard(bs->file, offset, bytes);
 747 }
 748
 749 static int coroutine_fn blkdebug_co_block_status(BlockDriverState *bs,
 750                                                  bool want_zero,
 751                                                  int64_t offset,
 752                                                  int64_t bytes,
 753                                                  int64_t *pnum,
 754                                                  int64_t *map,
 755                                                  BlockDriverState **file)
 756 {
 757     int err;
 758
 759     assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
 760
 761     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_BLOCK_STATUS);
 762     if (err) {
 763         return err;
 764     }
 765
 766     assert(bs->file && bs->file->bs);
 767     *pnum = bytes;
 768     *map = offset;
 769     *file = bs->file->bs;
 770     return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
 771 }
 772
 773 static void blkdebug_close(BlockDriverState *bs)
 774 {
 775     BDRVBlkdebugState *s = bs->opaque;
 776     BlkdebugRule *rule, *next;
 777     int i;
 778
 779     for (i = 0; i < BLKDBG__MAX; i++) {
 780         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 781             remove_rule(rule);
 782         }
 783     }
 784
 785     g_free(s->config_file);
 786     qemu_mutex_destroy(&s->lock);
 787 }
 788
 789 /* Called with lock held.  */
 790 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 791 {
 792     BDRVBlkdebugState *s = bs->opaque;
 793     BlkdebugSuspendedReq *r;
 794
 795     r = g_new(BlkdebugSuspendedReq, 1);
 796
 797     r->co         = qemu_coroutine_self();
 798     r->tag        = g_strdup(rule->options.suspend.tag);
 799
 800     remove_rule(rule);
 801     QLIST_INSERT_HEAD(&s->suspended_reqs, r, next);
 802
 803     if (!qtest_enabled()) {
 804         printf("blkdebug: Suspended request '%s'\n", r->tag);
 805     }
 806 }
 807
 808 /* Called with lock held.  */
 809 static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 810                          int *action_count, int *new_state)
 811 {
 812     BDRVBlkdebugState *s = bs->opaque;
 813
 814     /* Only process rules for the current state */
 815     if (rule->state && rule->state != s->state) {
 816         return;
 817     }
 818
 819     /* Take the action */
 820     action_count[rule->action]++;
 821     switch (rule->action) {
 822     case ACTION_INJECT_ERROR:
 823         if (action_count[ACTION_INJECT_ERROR] == 1) {
 824             QSIMPLEQ_INIT(&s->active_rules);
 825         }
 826         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 827         break;
 828
 829     case ACTION_SET_STATE:
 830         *new_state = rule->options.set_state.new_state;
 831         break;
 832
 833     case ACTION_SUSPEND:
 834         suspend_request(bs, rule);
 835         break;
 836     }
 837 }
 838
 839 static void coroutine_fn
 840 blkdebug_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 841 {
 842     BDRVBlkdebugState *s = bs->opaque;
 843     struct BlkdebugRule *rule, *next;
 844     int new_state;
 845     int actions_count[ACTION__MAX] = { 0 };
 846
 847     assert((int)event >= 0 && event < BLKDBG__MAX);
 848
 849     WITH_QEMU_LOCK_GUARD(&s->lock) {
 850         new_state = s->state;
 851         QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 852             process_rule(bs, rule, actions_count, &new_state);
 853         }
 854         s->state = new_state;
 855     }
 856
 857     while (actions_count[ACTION_SUSPEND] > 0) {
 858         qemu_coroutine_yield();
 859         actions_count[ACTION_SUSPEND]--;
 860     }
 861 }
 862
 863 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 864                                      const char *tag)
 865 {
 866     BDRVBlkdebugState *s = bs->opaque;
 867     struct BlkdebugRule *rule;
 868     int blkdebug_event;
 869
 870     blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
 871     if (blkdebug_event < 0) {
 872         return -ENOENT;
 873     }
 874
 875     rule = g_malloc(sizeof(*rule));
 876     *rule = (struct BlkdebugRule) {
 877         .event  = blkdebug_event,
 878         .action = ACTION_SUSPEND,
 879         .state  = 0,
 880         .options.suspend.tag = g_strdup(tag),
 881     };
 882
 883     qemu_mutex_lock(&s->lock);
 884     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 885     qemu_mutex_unlock(&s->lock);
 886
 887     return 0;
 888 }
 889
 890 /* Called with lock held. May temporarily release lock. */
 891 static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool all)
 892 {
 893     BlkdebugSuspendedReq *r;
 894
 895 retry:
 896     /*
 897      * No need for _SAFE, since a different coroutine can remove another node
 898      * (not the current one) in this list, and when the current one is removed
 899      * the iteration starts back from beginning anyways.
 900      */
 901     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 902         if (!strcmp(r->tag, tag)) {
 903             Coroutine *co = r->co;
 904
 905             if (!qtest_enabled()) {
 906                 printf("blkdebug: Resuming request '%s'\n", r->tag);
 907             }
 908
 909             QLIST_REMOVE(r, next);
 910             g_free(r->tag);
 911             g_free(r);
 912
 913             qemu_mutex_unlock(&s->lock);
 914             qemu_coroutine_enter(co);
 915             qemu_mutex_lock(&s->lock);
 916
 917             if (all) {
 918                 goto retry;
 919             }
 920             return 0;
 921         }
 922     }
 923     return -ENOENT;
 924 }
 925
 926 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 927 {
 928     BDRVBlkdebugState *s = bs->opaque;
 929     QEMU_LOCK_GUARD(&s->lock);
 930     return resume_req_by_tag(s, tag, false);
 931 }
 932
 933 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 934                                             const char *tag)
 935 {
 936     BDRVBlkdebugState *s = bs->opaque;
 937     BlkdebugRule *rule, *next;
 938     int i, ret = -ENOENT;
 939
 940     QEMU_LOCK_GUARD(&s->lock);
 941     for (i = 0; i < BLKDBG__MAX; i++) {
 942         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 943             if (rule->action == ACTION_SUSPEND &&
 944                 !strcmp(rule->options.suspend.tag, tag)) {
 945                 remove_rule(rule);
 946                 ret = 0;
 947             }
 948         }
 949     }
 950     if (resume_req_by_tag(s, tag, true) == 0) {
 951         ret = 0;
 952     }
 953     return ret;
 954 }
 955
 956 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 957 {
 958     BDRVBlkdebugState *s = bs->opaque;
 959     BlkdebugSuspendedReq *r;
 960
 961     QEMU_LOCK_GUARD(&s->lock);
 962     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 963         if (!strcmp(r->tag, tag)) {
 964             return true;
 965         }
 966     }
 967     return false;
 968 }
 969
 970 static int64_t coroutine_fn GRAPH_RDLOCK
 971 blkdebug_co_getlength(BlockDriverState *bs)
 972 {
 973     return bdrv_co_getlength(bs->file->bs);
 974 }
 975
 976 static void blkdebug_refresh_filename(BlockDriverState *bs)
 977 {
 978     BDRVBlkdebugState *s = bs->opaque;
 979     const QDictEntry *e;
 980     int ret;
 981
 982     if (!bs->file->bs->exact_filename[0]) {
 983         return;
 984     }
 985
 986     for (e = qdict_first(bs->full_open_options); e;
 987          e = qdict_next(bs->full_open_options, e))
 988     {
 989         /* Real child options are under "image", but "x-image" may
 990          * contain a filename */
 991         if (strcmp(qdict_entry_key(e), "config") &&
 992             strcmp(qdict_entry_key(e), "image") &&
 993             strcmp(qdict_entry_key(e), "x-image") &&
 994             strcmp(qdict_entry_key(e), "driver"))
 995         {
 996             return;
 997         }
 998     }
 999
1000     ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
1001                    "blkdebug:%s:%s",
1002                    s->config_file ?: "", bs->file->bs->exact_filename);
1003     if (ret >= sizeof(bs->exact_filename)) {
1004         /* An overflow makes the filename unusable, so do not report any */
1005         bs->exact_filename[0] = 0;
1006     }
1007 }
1008
1009 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
1010 {
1011     BDRVBlkdebugState *s = bs->opaque;
1012
1013     if (s->align) {
1014         bs->bl.request_alignment = s->align;
1015     }
1016     if (s->max_transfer) {
1017         bs->bl.max_transfer = s->max_transfer;
1018     }
1019     if (s->opt_write_zero) {
1020         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
1021     }
1022     if (s->max_write_zero) {
1023         bs->bl.max_pwrite_zeroes = s->max_write_zero;
1024     }
1025     if (s->opt_discard) {
1026         bs->bl.pdiscard_alignment = s->opt_discard;
1027     }
1028     if (s->max_discard) {
1029         bs->bl.max_pdiscard = s->max_discard;
1030     }
1031 }
1032
1033 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
1034                                    BlockReopenQueue *queue, Error **errp)
1035 {
1036     return 0;
1037 }
1038
1039 static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c,
1040                                 BdrvChildRole role,
1041                                 BlockReopenQueue *reopen_queue,
1042                                 uint64_t perm, uint64_t shared,
1043                                 uint64_t *nperm, uint64_t *nshared)
1044 {
1045     BDRVBlkdebugState *s = bs->opaque;
1046
1047     bdrv_default_perms(bs, c, role, reopen_queue,
1048                        perm, shared, nperm, nshared);
1049
1050     *nperm |= s->take_child_perms;
1051     *nshared &= ~s->unshare_child_perms;
1052 }
1053
1054 static const char *const blkdebug_strong_runtime_opts[] = {
1055     "config",
1056     "inject-error.",
1057     "set-state.",
1058     "align",
1059     "max-transfer",
1060     "opt-write-zero",
1061     "max-write-zero",
1062     "opt-discard",
1063     "max-discard",
1064
1065     NULL
1066 };
1067
1068 static BlockDriver bdrv_blkdebug = {
1069     .format_name            = "blkdebug",
1070     .protocol_name          = "blkdebug",
1071     .instance_size          = sizeof(BDRVBlkdebugState),
1072     .is_filter              = true,
1073
1074     .bdrv_parse_filename    = blkdebug_parse_filename,
1075     .bdrv_file_open         = blkdebug_open,
1076     .bdrv_close             = blkdebug_close,
1077     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
1078     .bdrv_child_perm        = blkdebug_child_perm,
1079
1080     .bdrv_co_getlength      = blkdebug_co_getlength,
1081     .bdrv_refresh_filename  = blkdebug_refresh_filename,
1082     .bdrv_refresh_limits    = blkdebug_refresh_limits,
1083
1084     .bdrv_co_preadv         = blkdebug_co_preadv,
1085     .bdrv_co_pwritev        = blkdebug_co_pwritev,
1086     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
1087     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
1088     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
1089     .bdrv_co_block_status   = blkdebug_co_block_status,
1090
1091     .bdrv_co_debug_event        = blkdebug_co_debug_event,
1092     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
1093     .bdrv_debug_remove_breakpoint
1094                                 = blkdebug_debug_remove_breakpoint,
1095     .bdrv_debug_resume          = blkdebug_debug_resume,
1096     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
1097
1098     .strong_runtime_opts        = blkdebug_strong_runtime_opts,
1099 };
1100
1101 static void bdrv_blkdebug_init(void)
1102 {
1103     bdrv_register(&bdrv_blkdebug);
1104 }
1105
1106 block_init(bdrv_blkdebug_init);