1 /* 2 * QEMU System Emulator block driver 3 * 4 * Copyright (c) 2011 IBM Corp. 5 * Copyright (c) 2012 Red Hat, Inc. 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 "block/aio-wait.h" 28 #include "block/block.h" 29 #include "block/blockjob_int.h" 30 #include "block/block_int.h" 31 #include "block/trace.h" 32 #include "sysemu/block-backend.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-events-block-core.h" 35 #include "qapi/qmp/qerror.h" 36 #include "qemu/main-loop.h" 37 #include "qemu/timer.h" 38 39 static bool is_block_job(Job *job) 40 { 41 return job_type(job) == JOB_TYPE_BACKUP || 42 job_type(job) == JOB_TYPE_COMMIT || 43 job_type(job) == JOB_TYPE_MIRROR || 44 job_type(job) == JOB_TYPE_STREAM; 45 } 46 47 BlockJob *block_job_next_locked(BlockJob *bjob) 48 { 49 Job *job = bjob ? &bjob->job : NULL; 50 GLOBAL_STATE_CODE(); 51 52 do { 53 job = job_next_locked(job); 54 } while (job && !is_block_job(job)); 55 56 return job ? container_of(job, BlockJob, job) : NULL; 57 } 58 59 BlockJob *block_job_get_locked(const char *id) 60 { 61 Job *job = job_get_locked(id); 62 GLOBAL_STATE_CODE(); 63 64 if (job && is_block_job(job)) { 65 return container_of(job, BlockJob, job); 66 } else { 67 return NULL; 68 } 69 } 70 71 BlockJob *block_job_get(const char *id) 72 { 73 JOB_LOCK_GUARD(); 74 return block_job_get_locked(id); 75 } 76 77 void block_job_free(Job *job) 78 { 79 BlockJob *bjob = container_of(job, BlockJob, job); 80 GLOBAL_STATE_CODE(); 81 82 block_job_remove_all_bdrv(bjob); 83 ratelimit_destroy(&bjob->limit); 84 error_free(bjob->blocker); 85 } 86 87 static char *child_job_get_parent_desc(BdrvChild *c) 88 { 89 BlockJob *job = c->opaque; 90 return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id); 91 } 92 93 static void child_job_drained_begin(BdrvChild *c) 94 { 95 BlockJob *job = c->opaque; 96 job_pause(&job->job); 97 } 98 99 static bool child_job_drained_poll(BdrvChild *c) 100 { 101 BlockJob *bjob = c->opaque; 102 Job *job = &bjob->job; 103 const BlockJobDriver *drv = block_job_driver(bjob); 104 105 /* An inactive or completed job doesn't have any pending requests. Jobs 106 * with !job->busy are either already paused or have a pause point after 107 * being reentered, so no job driver code will run before they pause. */ 108 WITH_JOB_LOCK_GUARD() { 109 if (!job->busy || job_is_completed_locked(job)) { 110 return false; 111 } 112 } 113 114 /* Otherwise, assume that it isn't fully stopped yet, but allow the job to 115 * override this assumption. */ 116 if (drv->drained_poll) { 117 return drv->drained_poll(bjob); 118 } else { 119 return true; 120 } 121 } 122 123 static void child_job_drained_end(BdrvChild *c) 124 { 125 BlockJob *job = c->opaque; 126 job_resume(&job->job); 127 } 128 129 typedef struct BdrvStateChildJobContext { 130 AioContext *new_ctx; 131 BlockJob *job; 132 } BdrvStateChildJobContext; 133 134 static void child_job_set_aio_ctx_commit(void *opaque) 135 { 136 BdrvStateChildJobContext *s = opaque; 137 BlockJob *job = s->job; 138 139 job_set_aio_context(&job->job, s->new_ctx); 140 } 141 142 static TransactionActionDrv change_child_job_context = { 143 .commit = child_job_set_aio_ctx_commit, 144 .clean = g_free, 145 }; 146 147 static bool child_job_change_aio_ctx(BdrvChild *c, AioContext *ctx, 148 GHashTable *visited, Transaction *tran, 149 Error **errp) 150 { 151 BlockJob *job = c->opaque; 152 BdrvStateChildJobContext *s; 153 GSList *l; 154 155 for (l = job->nodes; l; l = l->next) { 156 BdrvChild *sibling = l->data; 157 if (!bdrv_child_change_aio_context(sibling, ctx, visited, 158 tran, errp)) { 159 return false; 160 } 161 } 162 163 s = g_new(BdrvStateChildJobContext, 1); 164 *s = (BdrvStateChildJobContext) { 165 .new_ctx = ctx, 166 .job = job, 167 }; 168 169 tran_add(tran, &change_child_job_context, s); 170 return true; 171 } 172 173 static AioContext *child_job_get_parent_aio_context(BdrvChild *c) 174 { 175 BlockJob *job = c->opaque; 176 IO_CODE(); 177 JOB_LOCK_GUARD(); 178 179 return job->job.aio_context; 180 } 181 182 static const BdrvChildClass child_job = { 183 .get_parent_desc = child_job_get_parent_desc, 184 .drained_begin = child_job_drained_begin, 185 .drained_poll = child_job_drained_poll, 186 .drained_end = child_job_drained_end, 187 .change_aio_ctx = child_job_change_aio_ctx, 188 .stay_at_node = true, 189 .get_parent_aio_context = child_job_get_parent_aio_context, 190 }; 191 192 void block_job_remove_all_bdrv(BlockJob *job) 193 { 194 GLOBAL_STATE_CODE(); 195 /* 196 * bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(), 197 * which will also traverse job->nodes, so consume the list one by 198 * one to make sure that such a concurrent access does not attempt 199 * to process an already freed BdrvChild. 200 */ 201 while (job->nodes) { 202 GSList *l = job->nodes; 203 BdrvChild *c = l->data; 204 205 job->nodes = l->next; 206 207 bdrv_op_unblock_all(c->bs, job->blocker); 208 bdrv_root_unref_child(c); 209 210 g_slist_free_1(l); 211 } 212 } 213 214 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs) 215 { 216 GSList *el; 217 GLOBAL_STATE_CODE(); 218 219 for (el = job->nodes; el; el = el->next) { 220 BdrvChild *c = el->data; 221 if (c->bs == bs) { 222 return true; 223 } 224 } 225 226 return false; 227 } 228 229 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, 230 uint64_t perm, uint64_t shared_perm, Error **errp) 231 { 232 BdrvChild *c; 233 bool need_context_ops; 234 GLOBAL_STATE_CODE(); 235 236 bdrv_ref(bs); 237 238 need_context_ops = bdrv_get_aio_context(bs) != job->job.aio_context; 239 240 if (need_context_ops && job->job.aio_context != qemu_get_aio_context()) { 241 aio_context_release(job->job.aio_context); 242 } 243 c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job, 244 errp); 245 if (need_context_ops && job->job.aio_context != qemu_get_aio_context()) { 246 aio_context_acquire(job->job.aio_context); 247 } 248 if (c == NULL) { 249 return -EPERM; 250 } 251 252 job->nodes = g_slist_prepend(job->nodes, c); 253 bdrv_op_block_all(bs, job->blocker); 254 255 return 0; 256 } 257 258 /* Called with job_mutex lock held. */ 259 static void block_job_on_idle_locked(Notifier *n, void *opaque) 260 { 261 aio_wait_kick(); 262 } 263 264 bool block_job_is_internal(BlockJob *job) 265 { 266 return (job->job.id == NULL); 267 } 268 269 const BlockJobDriver *block_job_driver(BlockJob *job) 270 { 271 return container_of(job->job.driver, BlockJobDriver, job_driver); 272 } 273 274 /* Assumes the job_mutex is held */ 275 static bool job_timer_pending(Job *job) 276 { 277 return timer_pending(&job->sleep_timer); 278 } 279 280 bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp) 281 { 282 const BlockJobDriver *drv = block_job_driver(job); 283 int64_t old_speed = job->speed; 284 285 GLOBAL_STATE_CODE(); 286 287 if (job_apply_verb_locked(&job->job, JOB_VERB_SET_SPEED, errp) < 0) { 288 return false; 289 } 290 if (speed < 0) { 291 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed", 292 "a non-negative value"); 293 return false; 294 } 295 296 ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME); 297 298 job->speed = speed; 299 300 if (drv->set_speed) { 301 job_unlock(); 302 drv->set_speed(job, speed); 303 job_lock(); 304 } 305 306 if (speed && speed <= old_speed) { 307 return true; 308 } 309 310 /* kick only if a timer is pending */ 311 job_enter_cond_locked(&job->job, job_timer_pending); 312 313 return true; 314 } 315 316 static bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) 317 { 318 JOB_LOCK_GUARD(); 319 return block_job_set_speed_locked(job, speed, errp); 320 } 321 322 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n) 323 { 324 IO_CODE(); 325 ratelimit_calculate_delay(&job->limit, n); 326 } 327 328 void block_job_ratelimit_sleep(BlockJob *job) 329 { 330 uint64_t delay_ns; 331 332 /* 333 * Sleep at least once. If the job is reentered early, keep waiting until 334 * we've waited for the full time that is necessary to keep the job at the 335 * right speed. 336 * 337 * Make sure to recalculate the delay after each (possibly interrupted) 338 * sleep because the speed can change while the job has yielded. 339 */ 340 do { 341 delay_ns = ratelimit_calculate_delay(&job->limit, 0); 342 job_sleep_ns(&job->job, delay_ns); 343 } while (delay_ns && !job_is_cancelled(&job->job)); 344 } 345 346 BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp) 347 { 348 BlockJobInfo *info; 349 uint64_t progress_current, progress_total; 350 351 GLOBAL_STATE_CODE(); 352 353 if (block_job_is_internal(job)) { 354 error_setg(errp, "Cannot query QEMU internal jobs"); 355 return NULL; 356 } 357 358 progress_get_snapshot(&job->job.progress, &progress_current, 359 &progress_total); 360 361 info = g_new0(BlockJobInfo, 1); 362 info->type = g_strdup(job_type_str(&job->job)); 363 info->device = g_strdup(job->job.id); 364 info->busy = job->job.busy; 365 info->paused = job->job.pause_count > 0; 366 info->offset = progress_current; 367 info->len = progress_total; 368 info->speed = job->speed; 369 info->io_status = job->iostatus; 370 info->ready = job_is_ready_locked(&job->job), 371 info->status = job->job.status; 372 info->auto_finalize = job->job.auto_finalize; 373 info->auto_dismiss = job->job.auto_dismiss; 374 if (job->job.ret) { 375 info->error = job->job.err ? 376 g_strdup(error_get_pretty(job->job.err)) : 377 g_strdup(strerror(-job->job.ret)); 378 } 379 return info; 380 } 381 382 /* Called with job lock held */ 383 static void block_job_iostatus_set_err_locked(BlockJob *job, int error) 384 { 385 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 386 job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : 387 BLOCK_DEVICE_IO_STATUS_FAILED; 388 } 389 } 390 391 /* Called with job_mutex lock held. */ 392 static void block_job_event_cancelled_locked(Notifier *n, void *opaque) 393 { 394 BlockJob *job = opaque; 395 uint64_t progress_current, progress_total; 396 397 if (block_job_is_internal(job)) { 398 return; 399 } 400 401 progress_get_snapshot(&job->job.progress, &progress_current, 402 &progress_total); 403 404 qapi_event_send_block_job_cancelled(job_type(&job->job), 405 job->job.id, 406 progress_total, 407 progress_current, 408 job->speed); 409 } 410 411 /* Called with job_mutex lock held. */ 412 static void block_job_event_completed_locked(Notifier *n, void *opaque) 413 { 414 BlockJob *job = opaque; 415 const char *msg = NULL; 416 uint64_t progress_current, progress_total; 417 418 if (block_job_is_internal(job)) { 419 return; 420 } 421 422 if (job->job.ret < 0) { 423 msg = error_get_pretty(job->job.err); 424 } 425 426 progress_get_snapshot(&job->job.progress, &progress_current, 427 &progress_total); 428 429 qapi_event_send_block_job_completed(job_type(&job->job), 430 job->job.id, 431 progress_total, 432 progress_current, 433 job->speed, 434 msg); 435 } 436 437 /* Called with job_mutex lock held. */ 438 static void block_job_event_pending_locked(Notifier *n, void *opaque) 439 { 440 BlockJob *job = opaque; 441 442 if (block_job_is_internal(job)) { 443 return; 444 } 445 446 qapi_event_send_block_job_pending(job_type(&job->job), 447 job->job.id); 448 } 449 450 /* Called with job_mutex lock held. */ 451 static void block_job_event_ready_locked(Notifier *n, void *opaque) 452 { 453 BlockJob *job = opaque; 454 uint64_t progress_current, progress_total; 455 456 if (block_job_is_internal(job)) { 457 return; 458 } 459 460 progress_get_snapshot(&job->job.progress, &progress_current, 461 &progress_total); 462 463 qapi_event_send_block_job_ready(job_type(&job->job), 464 job->job.id, 465 progress_total, 466 progress_current, 467 job->speed); 468 } 469 470 471 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 472 JobTxn *txn, BlockDriverState *bs, uint64_t perm, 473 uint64_t shared_perm, int64_t speed, int flags, 474 BlockCompletionFunc *cb, void *opaque, Error **errp) 475 { 476 BlockJob *job; 477 int ret; 478 GLOBAL_STATE_CODE(); 479 480 if (job_id == NULL && !(flags & JOB_INTERNAL)) { 481 job_id = bdrv_get_device_name(bs); 482 } 483 484 job = job_create(job_id, &driver->job_driver, txn, bdrv_get_aio_context(bs), 485 flags, cb, opaque, errp); 486 if (job == NULL) { 487 return NULL; 488 } 489 490 assert(is_block_job(&job->job)); 491 assert(job->job.driver->free == &block_job_free); 492 assert(job->job.driver->user_resume == &block_job_user_resume); 493 494 ratelimit_init(&job->limit); 495 496 job->finalize_cancelled_notifier.notify = block_job_event_cancelled_locked; 497 job->finalize_completed_notifier.notify = block_job_event_completed_locked; 498 job->pending_notifier.notify = block_job_event_pending_locked; 499 job->ready_notifier.notify = block_job_event_ready_locked; 500 job->idle_notifier.notify = block_job_on_idle_locked; 501 502 WITH_JOB_LOCK_GUARD() { 503 notifier_list_add(&job->job.on_finalize_cancelled, 504 &job->finalize_cancelled_notifier); 505 notifier_list_add(&job->job.on_finalize_completed, 506 &job->finalize_completed_notifier); 507 notifier_list_add(&job->job.on_pending, &job->pending_notifier); 508 notifier_list_add(&job->job.on_ready, &job->ready_notifier); 509 notifier_list_add(&job->job.on_idle, &job->idle_notifier); 510 } 511 512 error_setg(&job->blocker, "block device is in use by block job: %s", 513 job_type_str(&job->job)); 514 515 ret = block_job_add_bdrv(job, "main node", bs, perm, shared_perm, errp); 516 if (ret < 0) { 517 goto fail; 518 } 519 520 bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker); 521 522 if (!block_job_set_speed(job, speed, errp)) { 523 goto fail; 524 } 525 526 return job; 527 528 fail: 529 job_early_fail(&job->job); 530 return NULL; 531 } 532 533 void block_job_iostatus_reset_locked(BlockJob *job) 534 { 535 GLOBAL_STATE_CODE(); 536 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 537 return; 538 } 539 assert(job->job.user_paused && job->job.pause_count > 0); 540 job->iostatus = BLOCK_DEVICE_IO_STATUS_OK; 541 } 542 543 static void block_job_iostatus_reset(BlockJob *job) 544 { 545 JOB_LOCK_GUARD(); 546 block_job_iostatus_reset_locked(job); 547 } 548 549 void block_job_user_resume(Job *job) 550 { 551 BlockJob *bjob = container_of(job, BlockJob, job); 552 GLOBAL_STATE_CODE(); 553 block_job_iostatus_reset(bjob); 554 } 555 556 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 557 int is_read, int error) 558 { 559 BlockErrorAction action; 560 IO_CODE(); 561 562 switch (on_err) { 563 case BLOCKDEV_ON_ERROR_ENOSPC: 564 case BLOCKDEV_ON_ERROR_AUTO: 565 action = (error == ENOSPC) ? 566 BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; 567 break; 568 case BLOCKDEV_ON_ERROR_STOP: 569 action = BLOCK_ERROR_ACTION_STOP; 570 break; 571 case BLOCKDEV_ON_ERROR_REPORT: 572 action = BLOCK_ERROR_ACTION_REPORT; 573 break; 574 case BLOCKDEV_ON_ERROR_IGNORE: 575 action = BLOCK_ERROR_ACTION_IGNORE; 576 break; 577 default: 578 abort(); 579 } 580 if (!block_job_is_internal(job)) { 581 qapi_event_send_block_job_error(job->job.id, 582 is_read ? IO_OPERATION_TYPE_READ : 583 IO_OPERATION_TYPE_WRITE, 584 action); 585 } 586 if (action == BLOCK_ERROR_ACTION_STOP) { 587 WITH_JOB_LOCK_GUARD() { 588 if (!job->job.user_paused) { 589 job_pause_locked(&job->job); 590 /* 591 * make the pause user visible, which will be 592 * resumed from QMP. 593 */ 594 job->job.user_paused = true; 595 } 596 block_job_iostatus_set_err_locked(job, error); 597 } 598 } 599 return action; 600 } 601 602 AioContext *block_job_get_aio_context(BlockJob *job) 603 { 604 GLOBAL_STATE_CODE(); 605 return job->job.aio_context; 606 } 607