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 "qobject/qdict.h" 37 #include "qobject/qlist.h" 38 #include "qobject/qstring.h" 39 #include "qapi/qobject-input-visitor.h" 40 #include "system/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_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); 1108