blockjob.c

   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     aio_context_release(job->job.aio_context);
 202     bdrv_graph_wrlock(NULL);
 203     aio_context_acquire(job->job.aio_context);
 204     while (job->nodes) {
 205         GSList *l = job->nodes;
 206         BdrvChild *c = l->data;
 207
 208         job->nodes = l->next;
 209
 210         bdrv_op_unblock_all(c->bs, job->blocker);
 211         bdrv_root_unref_child(c);
 212
 213         g_slist_free_1(l);
 214     }
 215     bdrv_graph_wrunlock();
 216 }
 217
 218 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
 219 {
 220     GSList *el;
 221     GLOBAL_STATE_CODE();
 222
 223     for (el = job->nodes; el; el = el->next) {
 224         BdrvChild *c = el->data;
 225         if (c->bs == bs) {
 226             return true;
 227         }
 228     }
 229
 230     return false;
 231 }
 232
 233 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 234                        uint64_t perm, uint64_t shared_perm, Error **errp)
 235 {
 236     BdrvChild *c;
 237     AioContext *ctx = bdrv_get_aio_context(bs);
 238     bool need_context_ops;
 239     GLOBAL_STATE_CODE();
 240
 241     bdrv_ref(bs);
 242
 243     need_context_ops = ctx != job->job.aio_context;
 244
 245     if (need_context_ops) {
 246         if (job->job.aio_context != qemu_get_aio_context()) {
 247             aio_context_release(job->job.aio_context);
 248         }
 249         aio_context_acquire(ctx);
 250     }
 251     c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job,
 252                                errp);
 253     if (need_context_ops) {
 254         aio_context_release(ctx);
 255         if (job->job.aio_context != qemu_get_aio_context()) {
 256             aio_context_acquire(job->job.aio_context);
 257         }
 258     }
 259     if (c == NULL) {
 260         return -EPERM;
 261     }
 262
 263     job->nodes = g_slist_prepend(job->nodes, c);
 264     bdrv_op_block_all(bs, job->blocker);
 265
 266     return 0;
 267 }
 268
 269 /* Called with job_mutex lock held. */
 270 static void block_job_on_idle_locked(Notifier *n, void *opaque)
 271 {
 272     aio_wait_kick();
 273 }
 274
 275 bool block_job_is_internal(BlockJob *job)
 276 {
 277     return (job->job.id == NULL);
 278 }
 279
 280 const BlockJobDriver *block_job_driver(BlockJob *job)
 281 {
 282     return container_of(job->job.driver, BlockJobDriver, job_driver);
 283 }
 284
 285 /* Assumes the job_mutex is held */
 286 static bool job_timer_pending(Job *job)
 287 {
 288     return timer_pending(&job->sleep_timer);
 289 }
 290
 291 bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp)
 292 {
 293     const BlockJobDriver *drv = block_job_driver(job);
 294     int64_t old_speed = job->speed;
 295
 296     GLOBAL_STATE_CODE();
 297
 298     if (job_apply_verb_locked(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
 299         return false;
 300     }
 301     if (speed < 0) {
 302         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed",
 303                    "a non-negative value");
 304         return false;
 305     }
 306
 307     ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);
 308
 309     job->speed = speed;
 310
 311     if (drv->set_speed) {
 312         job_unlock();
 313         drv->set_speed(job, speed);
 314         job_lock();
 315     }
 316
 317     if (speed && speed <= old_speed) {
 318         return true;
 319     }
 320
 321     /* kick only if a timer is pending */
 322     job_enter_cond_locked(&job->job, job_timer_pending);
 323
 324     return true;
 325 }
 326
 327 static bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 328 {
 329     JOB_LOCK_GUARD();
 330     return block_job_set_speed_locked(job, speed, errp);
 331 }
 332
 333 void block_job_change_locked(BlockJob *job, BlockJobChangeOptions *opts,
 334                              Error **errp)
 335 {
 336     const BlockJobDriver *drv = block_job_driver(job);
 337
 338     GLOBAL_STATE_CODE();
 339
 340     if (job_apply_verb_locked(&job->job, JOB_VERB_CHANGE, errp)) {
 341         return;
 342     }
 343
 344     if (drv->change) {
 345         job_unlock();
 346         drv->change(job, opts, errp);
 347         job_lock();
 348     } else {
 349         error_setg(errp, "Job type does not support change");
 350     }
 351 }
 352
 353 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n)
 354 {
 355     IO_CODE();
 356     ratelimit_calculate_delay(&job->limit, n);
 357 }
 358
 359 void block_job_ratelimit_sleep(BlockJob *job)
 360 {
 361     uint64_t delay_ns;
 362
 363     /*
 364      * Sleep at least once. If the job is reentered early, keep waiting until
 365      * we've waited for the full time that is necessary to keep the job at the
 366      * right speed.
 367      *
 368      * Make sure to recalculate the delay after each (possibly interrupted)
 369      * sleep because the speed can change while the job has yielded.
 370      */
 371     do {
 372         delay_ns = ratelimit_calculate_delay(&job->limit, 0);
 373         job_sleep_ns(&job->job, delay_ns);
 374     } while (delay_ns && !job_is_cancelled(&job->job));
 375 }
 376
 377 BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp)
 378 {
 379     BlockJobInfo *info;
 380     uint64_t progress_current, progress_total;
 381     const BlockJobDriver *drv = block_job_driver(job);
 382
 383     GLOBAL_STATE_CODE();
 384
 385     if (block_job_is_internal(job)) {
 386         error_setg(errp, "Cannot query QEMU internal jobs");
 387         return NULL;
 388     }
 389
 390     progress_get_snapshot(&job->job.progress, &progress_current,
 391                           &progress_total);
 392
 393     info = g_new0(BlockJobInfo, 1);
 394     info->type      = job_type(&job->job);
 395     info->device    = g_strdup(job->job.id);
 396     info->busy      = job->job.busy;
 397     info->paused    = job->job.pause_count > 0;
 398     info->offset    = progress_current;
 399     info->len       = progress_total;
 400     info->speed     = job->speed;
 401     info->io_status = job->iostatus;
 402     info->ready     = job_is_ready_locked(&job->job),
 403     info->status    = job->job.status;
 404     info->auto_finalize = job->job.auto_finalize;
 405     info->auto_dismiss  = job->job.auto_dismiss;
 406     if (job->job.ret) {
 407         info->error = job->job.err ?
 408                         g_strdup(error_get_pretty(job->job.err)) :
 409                         g_strdup(strerror(-job->job.ret));
 410     }
 411     if (drv->query) {
 412         job_unlock();
 413         drv->query(job, info);
 414         job_lock();
 415     }
 416     return info;
 417 }
 418
 419 /* Called with job lock held */
 420 static void block_job_iostatus_set_err_locked(BlockJob *job, int error)
 421 {
 422     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 423         job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
 424                                           BLOCK_DEVICE_IO_STATUS_FAILED;
 425     }
 426 }
 427
 428 /* Called with job_mutex lock held. */
 429 static void block_job_event_cancelled_locked(Notifier *n, void *opaque)
 430 {
 431     BlockJob *job = opaque;
 432     uint64_t progress_current, progress_total;
 433
 434     if (block_job_is_internal(job)) {
 435         return;
 436     }
 437
 438     progress_get_snapshot(&job->job.progress, &progress_current,
 439                           &progress_total);
 440
 441     qapi_event_send_block_job_cancelled(job_type(&job->job),
 442                                         job->job.id,
 443                                         progress_total,
 444                                         progress_current,
 445                                         job->speed);
 446 }
 447
 448 /* Called with job_mutex lock held. */
 449 static void block_job_event_completed_locked(Notifier *n, void *opaque)
 450 {
 451     BlockJob *job = opaque;
 452     const char *msg = NULL;
 453     uint64_t progress_current, progress_total;
 454
 455     if (block_job_is_internal(job)) {
 456         return;
 457     }
 458
 459     if (job->job.ret < 0) {
 460         msg = error_get_pretty(job->job.err);
 461     }
 462
 463     progress_get_snapshot(&job->job.progress, &progress_current,
 464                           &progress_total);
 465
 466     qapi_event_send_block_job_completed(job_type(&job->job),
 467                                         job->job.id,
 468                                         progress_total,
 469                                         progress_current,
 470                                         job->speed,
 471                                         msg);
 472 }
 473
 474 /* Called with job_mutex lock held. */
 475 static void block_job_event_pending_locked(Notifier *n, void *opaque)
 476 {
 477     BlockJob *job = opaque;
 478
 479     if (block_job_is_internal(job)) {
 480         return;
 481     }
 482
 483     qapi_event_send_block_job_pending(job_type(&job->job),
 484                                       job->job.id);
 485 }
 486
 487 /* Called with job_mutex lock held. */
 488 static void block_job_event_ready_locked(Notifier *n, void *opaque)
 489 {
 490     BlockJob *job = opaque;
 491     uint64_t progress_current, progress_total;
 492
 493     if (block_job_is_internal(job)) {
 494         return;
 495     }
 496
 497     progress_get_snapshot(&job->job.progress, &progress_current,
 498                           &progress_total);
 499
 500     qapi_event_send_block_job_ready(job_type(&job->job),
 501                                     job->job.id,
 502                                     progress_total,
 503                                     progress_current,
 504                                     job->speed);
 505 }
 506
 507
 508 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
 509                        JobTxn *txn, BlockDriverState *bs, uint64_t perm,
 510                        uint64_t shared_perm, int64_t speed, int flags,
 511                        BlockCompletionFunc *cb, void *opaque, Error **errp)
 512 {
 513     BlockJob *job;
 514     int ret;
 515     GLOBAL_STATE_CODE();
 516     GRAPH_RDLOCK_GUARD_MAINLOOP();
 517
 518     if (job_id == NULL && !(flags & JOB_INTERNAL)) {
 519         job_id = bdrv_get_device_name(bs);
 520     }
 521
 522     job = job_create(job_id, &driver->job_driver, txn, bdrv_get_aio_context(bs),
 523                      flags, cb, opaque, errp);
 524     if (job == NULL) {
 525         return NULL;
 526     }
 527
 528     assert(is_block_job(&job->job));
 529     assert(job->job.driver->free == &block_job_free);
 530     assert(job->job.driver->user_resume == &block_job_user_resume);
 531
 532     ratelimit_init(&job->limit);
 533
 534     job->finalize_cancelled_notifier.notify = block_job_event_cancelled_locked;
 535     job->finalize_completed_notifier.notify = block_job_event_completed_locked;
 536     job->pending_notifier.notify = block_job_event_pending_locked;
 537     job->ready_notifier.notify = block_job_event_ready_locked;
 538     job->idle_notifier.notify = block_job_on_idle_locked;
 539
 540     WITH_JOB_LOCK_GUARD() {
 541         notifier_list_add(&job->job.on_finalize_cancelled,
 542                           &job->finalize_cancelled_notifier);
 543         notifier_list_add(&job->job.on_finalize_completed,
 544                           &job->finalize_completed_notifier);
 545         notifier_list_add(&job->job.on_pending, &job->pending_notifier);
 546         notifier_list_add(&job->job.on_ready, &job->ready_notifier);
 547         notifier_list_add(&job->job.on_idle, &job->idle_notifier);
 548     }
 549
 550     error_setg(&job->blocker, "block device is in use by block job: %s",
 551                job_type_str(&job->job));
 552
 553     ret = block_job_add_bdrv(job, "main node", bs, perm, shared_perm, errp);
 554     if (ret < 0) {
 555         goto fail;
 556     }
 557
 558     bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
 559
 560     if (!block_job_set_speed(job, speed, errp)) {
 561         goto fail;
 562     }
 563
 564     return job;
 565
 566 fail:
 567     job_early_fail(&job->job);
 568     return NULL;
 569 }
 570
 571 void block_job_iostatus_reset_locked(BlockJob *job)
 572 {
 573     GLOBAL_STATE_CODE();
 574     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 575         return;
 576     }
 577     assert(job->job.user_paused && job->job.pause_count > 0);
 578     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 579 }
 580
 581 static void block_job_iostatus_reset(BlockJob *job)
 582 {
 583     JOB_LOCK_GUARD();
 584     block_job_iostatus_reset_locked(job);
 585 }
 586
 587 void block_job_user_resume(Job *job)
 588 {
 589     BlockJob *bjob = container_of(job, BlockJob, job);
 590     GLOBAL_STATE_CODE();
 591     block_job_iostatus_reset(bjob);
 592 }
 593
 594 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
 595                                         int is_read, int error)
 596 {
 597     BlockErrorAction action;
 598     IO_CODE();
 599
 600     switch (on_err) {
 601     case BLOCKDEV_ON_ERROR_ENOSPC:
 602     case BLOCKDEV_ON_ERROR_AUTO:
 603         action = (error == ENOSPC) ?
 604                  BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
 605         break;
 606     case BLOCKDEV_ON_ERROR_STOP:
 607         action = BLOCK_ERROR_ACTION_STOP;
 608         break;
 609     case BLOCKDEV_ON_ERROR_REPORT:
 610         action = BLOCK_ERROR_ACTION_REPORT;
 611         break;
 612     case BLOCKDEV_ON_ERROR_IGNORE:
 613         action = BLOCK_ERROR_ACTION_IGNORE;
 614         break;
 615     default:
 616         abort();
 617     }
 618     if (!block_job_is_internal(job)) {
 619         qapi_event_send_block_job_error(job->job.id,
 620                                         is_read ? IO_OPERATION_TYPE_READ :
 621                                         IO_OPERATION_TYPE_WRITE,
 622                                         action);
 623     }
 624     if (action == BLOCK_ERROR_ACTION_STOP) {
 625         WITH_JOB_LOCK_GUARD() {
 626             if (!job->job.user_paused) {
 627                 job_pause_locked(&job->job);
 628                 /*
 629                  * make the pause user visible, which will be
 630                  * resumed from QMP.
 631                  */
 632                 job->job.user_paused = true;
 633             }
 634             block_job_iostatus_set_err_locked(job, error);
 635         }
 636     }
 637     return action;
 638 }
 639
 640 AioContext *block_job_get_aio_context(BlockJob *job)
 641 {
 642     GLOBAL_STATE_CODE();
 643     return job->job.aio_context;
 644 }