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