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