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/block.h"
  28 #include "block/blockjob_int.h"
  29 #include "block/block_int.h"
  30 #include "block/trace.h"
  31 #include "sysemu/block-backend.h"
  32 #include "qapi/error.h"
  33 #include "qapi/qapi-events-block-core.h"
  34 #include "qapi/qmp/qerror.h"
  35 #include "qemu/coroutine.h"
  36 #include "qemu/main-loop.h"
  37 #include "qemu/timer.h"
  38
  39 /*
  40  * The block job API is composed of two categories of functions.
  41  *
  42  * The first includes functions used by the monitor.  The monitor is
  43  * peculiar in that it accesses the block job list with block_job_get, and
  44  * therefore needs consistency across block_job_get and the actual operation
  45  * (e.g. block_job_set_speed).  The consistency is achieved with
  46  * aio_context_acquire/release.  These functions are declared in blockjob.h.
  47  *
  48  * The second includes functions used by the block job drivers and sometimes
  49  * by the core block layer.  These do not care about locking, because the
  50  * whole coroutine runs under the AioContext lock, and are declared in
  51  * blockjob_int.h.
  52  */
  53
  54 static bool is_block_job(Job *job)
  55 {
  56     return job_type(job) == JOB_TYPE_BACKUP ||
  57            job_type(job) == JOB_TYPE_COMMIT ||
  58            job_type(job) == JOB_TYPE_MIRROR ||
  59            job_type(job) == JOB_TYPE_STREAM;
  60 }
  61
  62 BlockJob *block_job_next(BlockJob *bjob)
  63 {
  64     Job *job = bjob ? &bjob->job : NULL;
  65
  66     do {
  67         job = job_next(job);
  68     } while (job && !is_block_job(job));
  69
  70     return job ? container_of(job, BlockJob, job) : NULL;
  71 }
  72
  73 BlockJob *block_job_get(const char *id)
  74 {
  75     Job *job = job_get(id);
  76
  77     if (job && is_block_job(job)) {
  78         return container_of(job, BlockJob, job);
  79     } else {
  80         return NULL;
  81     }
  82 }
  83
  84 void block_job_free(Job *job)
  85 {
  86     BlockJob *bjob = container_of(job, BlockJob, job);
  87
  88     block_job_remove_all_bdrv(bjob);
  89     blk_unref(bjob->blk);
  90     error_free(bjob->blocker);
  91 }
  92
  93 void block_job_drain(Job *job)
  94 {
  95     BlockJob *bjob = container_of(job, BlockJob, job);
  96     const JobDriver *drv = job->driver;
  97     BlockJobDriver *bjdrv = container_of(drv, BlockJobDriver, job_driver);
  98
  99     blk_drain(bjob->blk);
 100     if (bjdrv->drain) {
 101         bjdrv->drain(bjob);
 102     }
 103 }
 104
 105 static char *child_job_get_parent_desc(BdrvChild *c)
 106 {
 107     BlockJob *job = c->opaque;
 108     return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id);
 109 }
 110
 111 static void child_job_drained_begin(BdrvChild *c)
 112 {
 113     BlockJob *job = c->opaque;
 114     job_pause(&job->job);
 115 }
 116
 117 static bool child_job_drained_poll(BdrvChild *c)
 118 {
 119     BlockJob *bjob = c->opaque;
 120     Job *job = &bjob->job;
 121     const BlockJobDriver *drv = block_job_driver(bjob);
 122
 123     /* An inactive or completed job doesn't have any pending requests. Jobs
 124      * with !job->busy are either already paused or have a pause point after
 125      * being reentered, so no job driver code will run before they pause. */
 126     if (!job->busy || job_is_completed(job)) {
 127         return false;
 128     }
 129
 130     /* Otherwise, assume that it isn't fully stopped yet, but allow the job to
 131      * override this assumption. */
 132     if (drv->drained_poll) {
 133         return drv->drained_poll(bjob);
 134     } else {
 135         return true;
 136     }
 137 }
 138
 139 static void child_job_drained_end(BdrvChild *c, int *drained_end_counter)
 140 {
 141     BlockJob *job = c->opaque;
 142     job_resume(&job->job);
 143 }
 144
 145 static bool child_job_can_set_aio_ctx(BdrvChild *c, AioContext *ctx,
 146                                       GSList **ignore, Error **errp)
 147 {
 148     BlockJob *job = c->opaque;
 149     GSList *l;
 150
 151     for (l = job->nodes; l; l = l->next) {
 152         BdrvChild *sibling = l->data;
 153         if (!bdrv_child_can_set_aio_context(sibling, ctx, ignore, errp)) {
 154             return false;
 155         }
 156     }
 157     return true;
 158 }
 159
 160 static void child_job_set_aio_ctx(BdrvChild *c, AioContext *ctx,
 161                                   GSList **ignore)
 162 {
 163     BlockJob *job = c->opaque;
 164     GSList *l;
 165
 166     for (l = job->nodes; l; l = l->next) {
 167         BdrvChild *sibling = l->data;
 168         if (g_slist_find(*ignore, sibling)) {
 169             continue;
 170         }
 171         *ignore = g_slist_prepend(*ignore, sibling);
 172         bdrv_set_aio_context_ignore(sibling->bs, ctx, ignore);
 173     }
 174
 175     job->job.aio_context = ctx;
 176 }
 177
 178 static const BdrvChildRole child_job = {
 179     .get_parent_desc    = child_job_get_parent_desc,
 180     .drained_begin      = child_job_drained_begin,
 181     .drained_poll       = child_job_drained_poll,
 182     .drained_end        = child_job_drained_end,
 183     .can_set_aio_ctx    = child_job_can_set_aio_ctx,
 184     .set_aio_ctx        = child_job_set_aio_ctx,
 185     .stay_at_node       = true,
 186 };
 187
 188 void block_job_remove_all_bdrv(BlockJob *job)
 189 {
 190     GSList *l;
 191     for (l = job->nodes; l; l = l->next) {
 192         BdrvChild *c = l->data;
 193         bdrv_op_unblock_all(c->bs, job->blocker);
 194         bdrv_root_unref_child(c);
 195     }
 196     g_slist_free(job->nodes);
 197     job->nodes = NULL;
 198 }
 199
 200 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
 201 {
 202     GSList *el;
 203
 204     for (el = job->nodes; el; el = el->next) {
 205         BdrvChild *c = el->data;
 206         if (c->bs == bs) {
 207             return true;
 208         }
 209     }
 210
 211     return false;
 212 }
 213
 214 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 215                        uint64_t perm, uint64_t shared_perm, Error **errp)
 216 {
 217     BdrvChild *c;
 218
 219     bdrv_ref(bs);
 220     if (job->job.aio_context != qemu_get_aio_context()) {
 221         aio_context_release(job->job.aio_context);
 222     }
 223     c = bdrv_root_attach_child(bs, name, &child_job, job->job.aio_context,
 224                                perm, shared_perm, job, errp);
 225     if (job->job.aio_context != qemu_get_aio_context()) {
 226         aio_context_acquire(job->job.aio_context);
 227     }
 228     if (c == NULL) {
 229         return -EPERM;
 230     }
 231
 232     job->nodes = g_slist_prepend(job->nodes, c);
 233     bdrv_op_block_all(bs, job->blocker);
 234
 235     return 0;
 236 }
 237
 238 static void block_job_on_idle(Notifier *n, void *opaque)
 239 {
 240     aio_wait_kick();
 241 }
 242
 243 bool block_job_is_internal(BlockJob *job)
 244 {
 245     return (job->job.id == NULL);
 246 }
 247
 248 const BlockJobDriver *block_job_driver(BlockJob *job)
 249 {
 250     return container_of(job->job.driver, BlockJobDriver, job_driver);
 251 }
 252
 253 /* Assumes the job_mutex is held */
 254 static bool job_timer_pending(Job *job)
 255 {
 256     return timer_pending(&job->sleep_timer);
 257 }
 258
 259 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 260 {
 261     int64_t old_speed = job->speed;
 262
 263     if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp)) {
 264         return;
 265     }
 266     if (speed < 0) {
 267         error_setg(errp, QERR_INVALID_PARAMETER, "speed");
 268         return;
 269     }
 270
 271     ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);
 272
 273     job->speed = speed;
 274     if (speed && speed <= old_speed) {
 275         return;
 276     }
 277
 278     /* kick only if a timer is pending */
 279     job_enter_cond(&job->job, job_timer_pending);
 280 }
 281
 282 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
 283 {
 284     if (!job->speed) {
 285         return 0;
 286     }
 287
 288     return ratelimit_calculate_delay(&job->limit, n);
 289 }
 290
 291 BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
 292 {
 293     BlockJobInfo *info;
 294
 295     if (block_job_is_internal(job)) {
 296         error_setg(errp, "Cannot query QEMU internal jobs");
 297         return NULL;
 298     }
 299     info = g_new0(BlockJobInfo, 1);
 300     info->type      = g_strdup(job_type_str(&job->job));
 301     info->device    = g_strdup(job->job.id);
 302     info->busy      = atomic_read(&job->job.busy);
 303     info->paused    = job->job.pause_count > 0;
 304     info->offset    = job->job.progress_current;
 305     info->len       = job->job.progress_total;
 306     info->speed     = job->speed;
 307     info->io_status = job->iostatus;
 308     info->ready     = job_is_ready(&job->job),
 309     info->status    = job->job.status;
 310     info->auto_finalize = job->job.auto_finalize;
 311     info->auto_dismiss  = job->job.auto_dismiss;
 312     info->has_error = job->job.ret != 0;
 313     info->error     = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL;
 314     return info;
 315 }
 316
 317 static void block_job_iostatus_set_err(BlockJob *job, int error)
 318 {
 319     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 320         job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
 321                                           BLOCK_DEVICE_IO_STATUS_FAILED;
 322     }
 323 }
 324
 325 static void block_job_event_cancelled(Notifier *n, void *opaque)
 326 {
 327     BlockJob *job = opaque;
 328
 329     if (block_job_is_internal(job)) {
 330         return;
 331     }
 332
 333     qapi_event_send_block_job_cancelled(job_type(&job->job),
 334                                         job->job.id,
 335                                         job->job.progress_total,
 336                                         job->job.progress_current,
 337                                         job->speed);
 338 }
 339
 340 static void block_job_event_completed(Notifier *n, void *opaque)
 341 {
 342     BlockJob *job = opaque;
 343     const char *msg = NULL;
 344
 345     if (block_job_is_internal(job)) {
 346         return;
 347     }
 348
 349     if (job->job.ret < 0) {
 350         msg = strerror(-job->job.ret);
 351     }
 352
 353     qapi_event_send_block_job_completed(job_type(&job->job),
 354                                         job->job.id,
 355                                         job->job.progress_total,
 356                                         job->job.progress_current,
 357                                         job->speed,
 358                                         !!msg,
 359                                         msg);
 360 }
 361
 362 static void block_job_event_pending(Notifier *n, void *opaque)
 363 {
 364     BlockJob *job = opaque;
 365
 366     if (block_job_is_internal(job)) {
 367         return;
 368     }
 369
 370     qapi_event_send_block_job_pending(job_type(&job->job),
 371                                       job->job.id);
 372 }
 373
 374 static void block_job_event_ready(Notifier *n, void *opaque)
 375 {
 376     BlockJob *job = opaque;
 377
 378     if (block_job_is_internal(job)) {
 379         return;
 380     }
 381
 382     qapi_event_send_block_job_ready(job_type(&job->job),
 383                                     job->job.id,
 384                                     job->job.progress_total,
 385                                     job->job.progress_current,
 386                                     job->speed);
 387 }
 388
 389
 390 /*
 391  * API for block job drivers and the block layer.  These functions are
 392  * declared in blockjob_int.h.
 393  */
 394
 395 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
 396                        JobTxn *txn, BlockDriverState *bs, uint64_t perm,
 397                        uint64_t shared_perm, int64_t speed, int flags,
 398                        BlockCompletionFunc *cb, void *opaque, Error **errp)
 399 {
 400     BlockBackend *blk;
 401     BlockJob *job;
 402     int ret;
 403
 404     if (job_id == NULL && !(flags & JOB_INTERNAL)) {
 405         job_id = bdrv_get_device_name(bs);
 406     }
 407
 408     blk = blk_new(bdrv_get_aio_context(bs), perm, shared_perm);
 409     ret = blk_insert_bs(blk, bs, errp);
 410     if (ret < 0) {
 411         blk_unref(blk);
 412         return NULL;
 413     }
 414
 415     job = job_create(job_id, &driver->job_driver, txn, blk_get_aio_context(blk),
 416                      flags, cb, opaque, errp);
 417     if (job == NULL) {
 418         blk_unref(blk);
 419         return NULL;
 420     }
 421
 422     assert(is_block_job(&job->job));
 423     assert(job->job.driver->free == &block_job_free);
 424     assert(job->job.driver->user_resume == &block_job_user_resume);
 425     assert(job->job.driver->drain == &block_job_drain);
 426
 427     job->blk = blk;
 428
 429     job->finalize_cancelled_notifier.notify = block_job_event_cancelled;
 430     job->finalize_completed_notifier.notify = block_job_event_completed;
 431     job->pending_notifier.notify = block_job_event_pending;
 432     job->ready_notifier.notify = block_job_event_ready;
 433     job->idle_notifier.notify = block_job_on_idle;
 434
 435     notifier_list_add(&job->job.on_finalize_cancelled,
 436                       &job->finalize_cancelled_notifier);
 437     notifier_list_add(&job->job.on_finalize_completed,
 438                       &job->finalize_completed_notifier);
 439     notifier_list_add(&job->job.on_pending, &job->pending_notifier);
 440     notifier_list_add(&job->job.on_ready, &job->ready_notifier);
 441     notifier_list_add(&job->job.on_idle, &job->idle_notifier);
 442
 443     error_setg(&job->blocker, "block device is in use by block job: %s",
 444                job_type_str(&job->job));
 445     block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
 446
 447     bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
 448
 449     /* Disable request queuing in the BlockBackend to avoid deadlocks on drain:
 450      * The job reports that it's busy until it reaches a pause point. */
 451     blk_set_disable_request_queuing(blk, true);
 452     blk_set_allow_aio_context_change(blk, true);
 453
 454     /* Only set speed when necessary to avoid NotSupported error */
 455     if (speed != 0) {
 456         Error *local_err = NULL;
 457
 458         block_job_set_speed(job, speed, &local_err);
 459         if (local_err) {
 460             job_early_fail(&job->job);
 461             error_propagate(errp, local_err);
 462             return NULL;
 463         }
 464     }
 465
 466     return job;
 467 }
 468
 469 void block_job_iostatus_reset(BlockJob *job)
 470 {
 471     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 472         return;
 473     }
 474     assert(job->job.user_paused && job->job.pause_count > 0);
 475     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 476 }
 477
 478 void block_job_user_resume(Job *job)
 479 {
 480     BlockJob *bjob = container_of(job, BlockJob, job);
 481     block_job_iostatus_reset(bjob);
 482 }
 483
 484 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
 485                                         int is_read, int error)
 486 {
 487     BlockErrorAction action;
 488
 489     switch (on_err) {
 490     case BLOCKDEV_ON_ERROR_ENOSPC:
 491     case BLOCKDEV_ON_ERROR_AUTO:
 492         action = (error == ENOSPC) ?
 493                  BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
 494         break;
 495     case BLOCKDEV_ON_ERROR_STOP:
 496         action = BLOCK_ERROR_ACTION_STOP;
 497         break;
 498     case BLOCKDEV_ON_ERROR_REPORT:
 499         action = BLOCK_ERROR_ACTION_REPORT;
 500         break;
 501     case BLOCKDEV_ON_ERROR_IGNORE:
 502         action = BLOCK_ERROR_ACTION_IGNORE;
 503         break;
 504     default:
 505         abort();
 506     }
 507     if (!block_job_is_internal(job)) {
 508         qapi_event_send_block_job_error(job->job.id,
 509                                         is_read ? IO_OPERATION_TYPE_READ :
 510                                         IO_OPERATION_TYPE_WRITE,
 511                                         action);
 512     }
 513     if (action == BLOCK_ERROR_ACTION_STOP) {
 514         if (!job->job.user_paused) {
 515             job_pause(&job->job);
 516             /* make the pause user visible, which will be resumed from QMP. */
 517             job->job.user_paused = true;
 518         }
 519         block_job_iostatus_set_err(job, error);
 520     }
 521     return action;
 522 }