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     bdrv_graph_rdlock_main_loop();
 512
 513     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
 514         (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
 515     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
 516         ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
 517             bs->file->bs->supported_zero_flags);
 518     ret = -EINVAL;
 519
 520     /* Set alignment overrides */
 521     s->align = qemu_opt_get_size(opts, "align", 0);
 522     if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
 523         error_setg(errp, "Cannot meet constraints with align %" PRIu64,
 524                    s->align);
 525         goto out_rdlock;
 526     }
 527     align = MAX(s->align, bs->file->bs->bl.request_alignment);
 528
 529     s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
 530     if (s->max_transfer &&
 531         (s->max_transfer >= INT_MAX ||
 532          !QEMU_IS_ALIGNED(s->max_transfer, align))) {
 533         error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
 534                    s->max_transfer);
 535         goto out_rdlock;
 536     }
 537
 538     s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
 539     if (s->opt_write_zero &&
 540         (s->opt_write_zero >= INT_MAX ||
 541          !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
 542         error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
 543                    s->opt_write_zero);
 544         goto out_rdlock;
 545     }
 546
 547     s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
 548     if (s->max_write_zero &&
 549         (s->max_write_zero >= INT_MAX ||
 550          !QEMU_IS_ALIGNED(s->max_write_zero,
 551                           MAX(s->opt_write_zero, align)))) {
 552         error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
 553                    s->max_write_zero);
 554         goto out_rdlock;
 555     }
 556
 557     s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
 558     if (s->opt_discard &&
 559         (s->opt_discard >= INT_MAX ||
 560          !QEMU_IS_ALIGNED(s->opt_discard, align))) {
 561         error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
 562                    s->opt_discard);
 563         goto out_rdlock;
 564     }
 565
 566     s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
 567     if (s->max_discard &&
 568         (s->max_discard >= INT_MAX ||
 569          !QEMU_IS_ALIGNED(s->max_discard,
 570                           MAX(s->opt_discard, align)))) {
 571         error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
 572                    s->max_discard);
 573         goto out_rdlock;
 574     }
 575
 576     bdrv_debug_event(bs, BLKDBG_NONE);
 577
 578     ret = 0;
 579 out_rdlock:
 580     bdrv_graph_rdunlock_main_loop();
 581 out:
 582     if (ret < 0) {
 583         qemu_mutex_destroy(&s->lock);
 584         g_free(s->config_file);
 585     }
 586     qemu_opts_del(opts);
 587     return ret;
 588 }
 589
 590 static int coroutine_fn rule_check(BlockDriverState *bs, uint64_t offset,
 591                                    uint64_t bytes, BlkdebugIOType iotype)
 592 {
 593     BDRVBlkdebugState *s = bs->opaque;
 594     BlkdebugRule *rule = NULL;
 595     int error;
 596     bool immediately;
 597
 598     qemu_mutex_lock(&s->lock);
 599     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 600         uint64_t inject_offset = rule->options.inject.offset;
 601
 602         if ((inject_offset == -1 ||
 603              (bytes && inject_offset >= offset &&
 604               inject_offset < offset + bytes)) &&
 605             (rule->options.inject.iotype_mask & (1ull << iotype)))
 606         {
 607             break;
 608         }
 609     }
 610
 611     if (!rule || !rule->options.inject.error) {
 612         qemu_mutex_unlock(&s->lock);
 613         return 0;
 614     }
 615
 616     immediately = rule->options.inject.immediately;
 617     error = rule->options.inject.error;
 618
 619     if (rule->options.inject.once) {
 620         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 621         remove_rule(rule);
 622     }
 623
 624     qemu_mutex_unlock(&s->lock);
 625     if (!immediately) {
 626         aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
 627         qemu_coroutine_yield();
 628     }
 629
 630     return -error;
 631 }
 632
 633 static int coroutine_fn GRAPH_RDLOCK
 634 blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 635                    QEMUIOVector *qiov, BdrvRequestFlags flags)
 636 {
 637     int err;
 638
 639     /* Sanity check block layer guarantees */
 640     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 641     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 642     if (bs->bl.max_transfer) {
 643         assert(bytes <= bs->bl.max_transfer);
 644     }
 645
 646     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_READ);
 647     if (err) {
 648         return err;
 649     }
 650
 651     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 652 }
 653
 654 static int coroutine_fn GRAPH_RDLOCK
 655 blkdebug_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
 656                     QEMUIOVector *qiov, BdrvRequestFlags flags)
 657 {
 658     int err;
 659
 660     /* Sanity check block layer guarantees */
 661     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 662     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 663     if (bs->bl.max_transfer) {
 664         assert(bytes <= bs->bl.max_transfer);
 665     }
 666
 667     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE);
 668     if (err) {
 669         return err;
 670     }
 671
 672     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 673 }
 674
 675 static int GRAPH_RDLOCK coroutine_fn blkdebug_co_flush(BlockDriverState *bs)
 676 {
 677     int err = rule_check(bs, 0, 0, BLKDEBUG_IO_TYPE_FLUSH);
 678
 679     if (err) {
 680         return err;
 681     }
 682
 683     return bdrv_co_flush(bs->file->bs);
 684 }
 685
 686 static int coroutine_fn GRAPH_RDLOCK
 687 blkdebug_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
 688                           BdrvRequestFlags flags)
 689 {
 690     uint32_t align = MAX(bs->bl.request_alignment,
 691                          bs->bl.pwrite_zeroes_alignment);
 692     int err;
 693
 694     /* Only pass through requests that are larger than requested
 695      * preferred alignment (so that we test the fallback to writes on
 696      * unaligned portions), and check that the block layer never hands
 697      * us anything unaligned that crosses an alignment boundary.  */
 698     if (bytes < align) {
 699         assert(QEMU_IS_ALIGNED(offset, align) ||
 700                QEMU_IS_ALIGNED(offset + bytes, align) ||
 701                DIV_ROUND_UP(offset, align) ==
 702                DIV_ROUND_UP(offset + bytes, align));
 703         return -ENOTSUP;
 704     }
 705     assert(QEMU_IS_ALIGNED(offset, align));
 706     assert(QEMU_IS_ALIGNED(bytes, align));
 707     if (bs->bl.max_pwrite_zeroes) {
 708         assert(bytes <= bs->bl.max_pwrite_zeroes);
 709     }
 710
 711     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE_ZEROES);
 712     if (err) {
 713         return err;
 714     }
 715
 716     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 717 }
 718
 719 static int coroutine_fn GRAPH_RDLOCK
 720 blkdebug_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 721 {
 722     uint32_t align = bs->bl.pdiscard_alignment;
 723     int err;
 724
 725     /* Only pass through requests that are larger than requested
 726      * minimum alignment, and ensure that unaligned requests do not
 727      * cross optimum discard boundaries. */
 728     if (bytes < bs->bl.request_alignment) {
 729         assert(QEMU_IS_ALIGNED(offset, align) ||
 730                QEMU_IS_ALIGNED(offset + bytes, align) ||
 731                DIV_ROUND_UP(offset, align) ==
 732                DIV_ROUND_UP(offset + bytes, align));
 733         return -ENOTSUP;
 734     }
 735     assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
 736     assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
 737     if (align && bytes >= align) {
 738         assert(QEMU_IS_ALIGNED(offset, align));
 739         assert(QEMU_IS_ALIGNED(bytes, align));
 740     }
 741     if (bs->bl.max_pdiscard) {
 742         assert(bytes <= bs->bl.max_pdiscard);
 743     }
 744
 745     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_DISCARD);
 746     if (err) {
 747         return err;
 748     }
 749
 750     return bdrv_co_pdiscard(bs->file, offset, bytes);
 751 }
 752
 753 static int coroutine_fn GRAPH_RDLOCK
 754 blkdebug_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
 755                          int64_t bytes, int64_t *pnum, int64_t *map,
 756                          BlockDriverState **file)
 757 {
 758     int err;
 759
 760     assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
 761
 762     err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_BLOCK_STATUS);
 763     if (err) {
 764         return err;
 765     }
 766
 767     assert(bs->file && bs->file->bs);
 768     *pnum = bytes;
 769     *map = offset;
 770     *file = bs->file->bs;
 771     return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
 772 }
 773
 774 static void blkdebug_close(BlockDriverState *bs)
 775 {
 776     BDRVBlkdebugState *s = bs->opaque;
 777     BlkdebugRule *rule, *next;
 778     int i;
 779
 780     for (i = 0; i < BLKDBG__MAX; i++) {
 781         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 782             remove_rule(rule);
 783         }
 784     }
 785
 786     g_free(s->config_file);
 787     qemu_mutex_destroy(&s->lock);
 788 }
 789
 790 /* Called with lock held.  */
 791 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 792 {
 793     BDRVBlkdebugState *s = bs->opaque;
 794     BlkdebugSuspendedReq *r;
 795
 796     r = g_new(BlkdebugSuspendedReq, 1);
 797
 798     r->co         = qemu_coroutine_self();
 799     r->tag        = g_strdup(rule->options.suspend.tag);
 800
 801     remove_rule(rule);
 802     QLIST_INSERT_HEAD(&s->suspended_reqs, r, next);
 803
 804     if (!qtest_enabled()) {
 805         printf("blkdebug: Suspended request '%s'\n", r->tag);
 806     }
 807 }
 808
 809 /* Called with lock held.  */
 810 static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 811                          int *action_count, int *new_state)
 812 {
 813     BDRVBlkdebugState *s = bs->opaque;
 814
 815     /* Only process rules for the current state */
 816     if (rule->state && rule->state != s->state) {
 817         return;
 818     }
 819
 820     /* Take the action */
 821     action_count[rule->action]++;
 822     switch (rule->action) {
 823     case ACTION_INJECT_ERROR:
 824         if (action_count[ACTION_INJECT_ERROR] == 1) {
 825             QSIMPLEQ_INIT(&s->active_rules);
 826         }
 827         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 828         break;
 829
 830     case ACTION_SET_STATE:
 831         *new_state = rule->options.set_state.new_state;
 832         break;
 833
 834     case ACTION_SUSPEND:
 835         suspend_request(bs, rule);
 836         break;
 837     }
 838 }
 839
 840 static void coroutine_fn
 841 blkdebug_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 842 {
 843     BDRVBlkdebugState *s = bs->opaque;
 844     struct BlkdebugRule *rule, *next;
 845     int new_state;
 846     int actions_count[ACTION__MAX] = { 0 };
 847
 848     assert((int)event >= 0 && event < BLKDBG__MAX);
 849
 850     WITH_QEMU_LOCK_GUARD(&s->lock) {
 851         new_state = s->state;
 852         QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 853             process_rule(bs, rule, actions_count, &new_state);
 854         }
 855         s->state = new_state;
 856     }
 857
 858     while (actions_count[ACTION_SUSPEND] > 0) {
 859         qemu_coroutine_yield();
 860         actions_count[ACTION_SUSPEND]--;
 861     }
 862 }
 863
 864 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 865                                      const char *tag)
 866 {
 867     BDRVBlkdebugState *s = bs->opaque;
 868     struct BlkdebugRule *rule;
 869     int blkdebug_event;
 870
 871     blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
 872     if (blkdebug_event < 0) {
 873         return -ENOENT;
 874     }
 875
 876     rule = g_malloc(sizeof(*rule));
 877     *rule = (struct BlkdebugRule) {
 878         .event  = blkdebug_event,
 879         .action = ACTION_SUSPEND,
 880         .state  = 0,
 881         .options.suspend.tag = g_strdup(tag),
 882     };
 883
 884     qemu_mutex_lock(&s->lock);
 885     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 886     qemu_mutex_unlock(&s->lock);
 887
 888     return 0;
 889 }
 890
 891 /* Called with lock held. May temporarily release lock. */
 892 static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool all)
 893 {
 894     BlkdebugSuspendedReq *r;
 895
 896 retry:
 897     /*
 898      * No need for _SAFE, since a different coroutine can remove another node
 899      * (not the current one) in this list, and when the current one is removed
 900      * the iteration starts back from beginning anyways.
 901      */
 902     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 903         if (!strcmp(r->tag, tag)) {
 904             Coroutine *co = r->co;
 905
 906             if (!qtest_enabled()) {
 907                 printf("blkdebug: Resuming request '%s'\n", r->tag);
 908             }
 909
 910             QLIST_REMOVE(r, next);
 911             g_free(r->tag);
 912             g_free(r);
 913
 914             qemu_mutex_unlock(&s->lock);
 915             qemu_coroutine_enter(co);
 916             qemu_mutex_lock(&s->lock);
 917
 918             if (all) {
 919                 goto retry;
 920             }
 921             return 0;
 922         }
 923     }
 924     return -ENOENT;
 925 }
 926
 927 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 928 {
 929     BDRVBlkdebugState *s = bs->opaque;
 930     QEMU_LOCK_GUARD(&s->lock);
 931     return resume_req_by_tag(s, tag, false);
 932 }
 933
 934 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 935                                             const char *tag)
 936 {
 937     BDRVBlkdebugState *s = bs->opaque;
 938     BlkdebugRule *rule, *next;
 939     int i, ret = -ENOENT;
 940
 941     QEMU_LOCK_GUARD(&s->lock);
 942     for (i = 0; i < BLKDBG__MAX; i++) {
 943         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 944             if (rule->action == ACTION_SUSPEND &&
 945                 !strcmp(rule->options.suspend.tag, tag)) {
 946                 remove_rule(rule);
 947                 ret = 0;
 948             }
 949         }
 950     }
 951     if (resume_req_by_tag(s, tag, true) == 0) {
 952         ret = 0;
 953     }
 954     return ret;
 955 }
 956
 957 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 958 {
 959     BDRVBlkdebugState *s = bs->opaque;
 960     BlkdebugSuspendedReq *r;
 961
 962     QEMU_LOCK_GUARD(&s->lock);
 963     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 964         if (!strcmp(r->tag, tag)) {
 965             return true;
 966         }
 967     }
 968     return false;
 969 }
 970
 971 static int64_t coroutine_fn GRAPH_RDLOCK
 972 blkdebug_co_getlength(BlockDriverState *bs)
 973 {
 974     return bdrv_co_getlength(bs->file->bs);
 975 }
 976
 977 static void GRAPH_RDLOCK blkdebug_refresh_filename(BlockDriverState *bs)
 978 {
 979     BDRVBlkdebugState *s = bs->opaque;
 980     const QDictEntry *e;
 981     int ret;
 982
 983     if (!bs->file->bs->exact_filename[0]) {
 984         return;
 985     }
 986
 987     for (e = qdict_first(bs->full_open_options); e;
 988          e = qdict_next(bs->full_open_options, e))
 989     {
 990         /* Real child options are under "image", but "x-image" may
 991          * contain a filename */
 992         if (strcmp(qdict_entry_key(e), "config") &&
 993             strcmp(qdict_entry_key(e), "image") &&
 994             strcmp(qdict_entry_key(e), "x-image") &&
 995             strcmp(qdict_entry_key(e), "driver"))
 996         {
 997             return;
 998         }
 999     }
1000
1001     ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
1002                    "blkdebug:%s:%s",
1003                    s->config_file ?: "", bs->file->bs->exact_filename);
1004     if (ret >= sizeof(bs->exact_filename)) {
1005         /* An overflow makes the filename unusable, so do not report any */
1006         bs->exact_filename[0] = 0;
1007     }
1008 }
1009
1010 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
1011 {
1012     BDRVBlkdebugState *s = bs->opaque;
1013
1014     if (s->align) {
1015         bs->bl.request_alignment = s->align;
1016     }
1017     if (s->max_transfer) {
1018         bs->bl.max_transfer = s->max_transfer;
1019     }
1020     if (s->opt_write_zero) {
1021         bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
1022     }
1023     if (s->max_write_zero) {
1024         bs->bl.max_pwrite_zeroes = s->max_write_zero;
1025     }
1026     if (s->opt_discard) {
1027         bs->bl.pdiscard_alignment = s->opt_discard;
1028     }
1029     if (s->max_discard) {
1030         bs->bl.max_pdiscard = s->max_discard;
1031     }
1032 }
1033
1034 static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
1035                                    BlockReopenQueue *queue, Error **errp)
1036 {
1037     return 0;
1038 }
1039
1040 static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c,
1041                                 BdrvChildRole role,
1042                                 BlockReopenQueue *reopen_queue,
1043                                 uint64_t perm, uint64_t shared,
1044                                 uint64_t *nperm, uint64_t *nshared)
1045 {
1046     BDRVBlkdebugState *s = bs->opaque;
1047
1048     bdrv_default_perms(bs, c, role, reopen_queue,
1049                        perm, shared, nperm, nshared);
1050
1051     *nperm |= s->take_child_perms;
1052     *nshared &= ~s->unshare_child_perms;
1053 }
1054
1055 static const char *const blkdebug_strong_runtime_opts[] = {
1056     "config",
1057     "inject-error.",
1058     "set-state.",
1059     "align",
1060     "max-transfer",
1061     "opt-write-zero",
1062     "max-write-zero",
1063     "opt-discard",
1064     "max-discard",
1065
1066     NULL
1067 };
1068
1069 static BlockDriver bdrv_blkdebug = {
1070     .format_name            = "blkdebug",
1071     .protocol_name          = "blkdebug",
1072     .instance_size          = sizeof(BDRVBlkdebugState),
1073     .is_filter              = true,
1074
1075     .bdrv_parse_filename    = blkdebug_parse_filename,
1076     .bdrv_file_open         = blkdebug_open,
1077     .bdrv_close             = blkdebug_close,
1078     .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
1079     .bdrv_child_perm        = blkdebug_child_perm,
1080
1081     .bdrv_co_getlength      = blkdebug_co_getlength,
1082     .bdrv_refresh_filename  = blkdebug_refresh_filename,
1083     .bdrv_refresh_limits    = blkdebug_refresh_limits,
1084
1085     .bdrv_co_preadv         = blkdebug_co_preadv,
1086     .bdrv_co_pwritev        = blkdebug_co_pwritev,
1087     .bdrv_co_flush_to_disk  = blkdebug_co_flush,
1088     .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
1089     .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
1090     .bdrv_co_block_status   = blkdebug_co_block_status,
1091
1092     .bdrv_co_debug_event        = blkdebug_co_debug_event,
1093     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
1094     .bdrv_debug_remove_breakpoint
1095                                 = blkdebug_debug_remove_breakpoint,
1096     .bdrv_debug_resume          = blkdebug_debug_resume,
1097     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
1098
1099     .strong_runtime_opts        = blkdebug_strong_runtime_opts,
1100 };
1101
1102 static void bdrv_blkdebug_init(void)
1103 {
1104     bdrv_register(&bdrv_blkdebug);
1105 }
1106
1107 block_init(bdrv_blkdebug_init);