qxl: check release info object
[qemu.git] / job.c
1 /*
2 * Background jobs (long-running operations)
3 *
4 * Copyright (c) 2011 IBM Corp.
5 * Copyright (c) 2012, 2018 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 "qemu-common.h"
28 #include "qapi/error.h"
29 #include "qemu/job.h"
30 #include "qemu/id.h"
31 #include "qemu/main-loop.h"
32 #include "block/aio-wait.h"
33 #include "trace-root.h"
34 #include "qapi/qapi-events-job.h"
35
36 static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs);
37
38 /* Job State Transition Table */
39 bool JobSTT[JOB_STATUS__MAX][JOB_STATUS__MAX] = {
40 /* U, C, R, P, Y, S, W, D, X, E, N */
41 /* U: */ [JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
42 /* C: */ [JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1},
43 /* R: */ [JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0},
44 /* P: */ [JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
45 /* Y: */ [JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0},
46 /* S: */ [JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
47 /* W: */ [JOB_STATUS_WAITING] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0},
48 /* D: */ [JOB_STATUS_PENDING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
49 /* X: */ [JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
50 /* E: */ [JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
51 /* N: */ [JOB_STATUS_NULL] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
52 };
53
54 bool JobVerbTable[JOB_VERB__MAX][JOB_STATUS__MAX] = {
55 /* U, C, R, P, Y, S, W, D, X, E, N */
56 [JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0},
57 [JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
58 [JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
59 [JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
60 [JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
61 [JOB_VERB_FINALIZE] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0},
62 [JOB_VERB_DISMISS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
63 };
64
65 /* Transactional group of jobs */
66 struct JobTxn {
67
68 /* Is this txn being cancelled? */
69 bool aborting;
70
71 /* List of jobs */
72 QLIST_HEAD(, Job) jobs;
73
74 /* Reference count */
75 int refcnt;
76 };
77
78 /* Right now, this mutex is only needed to synchronize accesses to job->busy
79 * and job->sleep_timer, such as concurrent calls to job_do_yield and
80 * job_enter. */
81 static QemuMutex job_mutex;
82
83 static void job_lock(void)
84 {
85 qemu_mutex_lock(&job_mutex);
86 }
87
88 static void job_unlock(void)
89 {
90 qemu_mutex_unlock(&job_mutex);
91 }
92
93 static void __attribute__((__constructor__)) job_init(void)
94 {
95 qemu_mutex_init(&job_mutex);
96 }
97
98 JobTxn *job_txn_new(void)
99 {
100 JobTxn *txn = g_new0(JobTxn, 1);
101 QLIST_INIT(&txn->jobs);
102 txn->refcnt = 1;
103 return txn;
104 }
105
106 static void job_txn_ref(JobTxn *txn)
107 {
108 txn->refcnt++;
109 }
110
111 void job_txn_unref(JobTxn *txn)
112 {
113 if (txn && --txn->refcnt == 0) {
114 g_free(txn);
115 }
116 }
117
118 void job_txn_add_job(JobTxn *txn, Job *job)
119 {
120 if (!txn) {
121 return;
122 }
123
124 assert(!job->txn);
125 job->txn = txn;
126
127 QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
128 job_txn_ref(txn);
129 }
130
131 static void job_txn_del_job(Job *job)
132 {
133 if (job->txn) {
134 QLIST_REMOVE(job, txn_list);
135 job_txn_unref(job->txn);
136 job->txn = NULL;
137 }
138 }
139
140 static int job_txn_apply(JobTxn *txn, int fn(Job *))
141 {
142 Job *job, *next;
143 int rc = 0;
144
145 QLIST_FOREACH_SAFE(job, &txn->jobs, txn_list, next) {
146 rc = fn(job);
147 if (rc) {
148 break;
149 }
150 }
151 return rc;
152 }
153
154 bool job_is_internal(Job *job)
155 {
156 return (job->id == NULL);
157 }
158
159 static void job_state_transition(Job *job, JobStatus s1)
160 {
161 JobStatus s0 = job->status;
162 assert(s1 >= 0 && s1 < JOB_STATUS__MAX);
163 trace_job_state_transition(job, job->ret,
164 JobSTT[s0][s1] ? "allowed" : "disallowed",
165 JobStatus_str(s0), JobStatus_str(s1));
166 assert(JobSTT[s0][s1]);
167 job->status = s1;
168
169 if (!job_is_internal(job) && s1 != s0) {
170 qapi_event_send_job_status_change(job->id, job->status);
171 }
172 }
173
174 int job_apply_verb(Job *job, JobVerb verb, Error **errp)
175 {
176 JobStatus s0 = job->status;
177 assert(verb >= 0 && verb < JOB_VERB__MAX);
178 trace_job_apply_verb(job, JobStatus_str(s0), JobVerb_str(verb),
179 JobVerbTable[verb][s0] ? "allowed" : "prohibited");
180 if (JobVerbTable[verb][s0]) {
181 return 0;
182 }
183 error_setg(errp, "Job '%s' in state '%s' cannot accept command verb '%s'",
184 job->id, JobStatus_str(s0), JobVerb_str(verb));
185 return -EPERM;
186 }
187
188 JobType job_type(const Job *job)
189 {
190 return job->driver->job_type;
191 }
192
193 const char *job_type_str(const Job *job)
194 {
195 return JobType_str(job_type(job));
196 }
197
198 bool job_is_cancelled(Job *job)
199 {
200 return job->cancelled;
201 }
202
203 bool job_is_ready(Job *job)
204 {
205 switch (job->status) {
206 case JOB_STATUS_UNDEFINED:
207 case JOB_STATUS_CREATED:
208 case JOB_STATUS_RUNNING:
209 case JOB_STATUS_PAUSED:
210 case JOB_STATUS_WAITING:
211 case JOB_STATUS_PENDING:
212 case JOB_STATUS_ABORTING:
213 case JOB_STATUS_CONCLUDED:
214 case JOB_STATUS_NULL:
215 return false;
216 case JOB_STATUS_READY:
217 case JOB_STATUS_STANDBY:
218 return true;
219 default:
220 g_assert_not_reached();
221 }
222 return false;
223 }
224
225 bool job_is_completed(Job *job)
226 {
227 switch (job->status) {
228 case JOB_STATUS_UNDEFINED:
229 case JOB_STATUS_CREATED:
230 case JOB_STATUS_RUNNING:
231 case JOB_STATUS_PAUSED:
232 case JOB_STATUS_READY:
233 case JOB_STATUS_STANDBY:
234 return false;
235 case JOB_STATUS_WAITING:
236 case JOB_STATUS_PENDING:
237 case JOB_STATUS_ABORTING:
238 case JOB_STATUS_CONCLUDED:
239 case JOB_STATUS_NULL:
240 return true;
241 default:
242 g_assert_not_reached();
243 }
244 return false;
245 }
246
247 static bool job_started(Job *job)
248 {
249 return job->co;
250 }
251
252 static bool job_should_pause(Job *job)
253 {
254 return job->pause_count > 0;
255 }
256
257 Job *job_next(Job *job)
258 {
259 if (!job) {
260 return QLIST_FIRST(&jobs);
261 }
262 return QLIST_NEXT(job, job_list);
263 }
264
265 Job *job_get(const char *id)
266 {
267 Job *job;
268
269 QLIST_FOREACH(job, &jobs, job_list) {
270 if (job->id && !strcmp(id, job->id)) {
271 return job;
272 }
273 }
274
275 return NULL;
276 }
277
278 static void job_sleep_timer_cb(void *opaque)
279 {
280 Job *job = opaque;
281
282 job_enter(job);
283 }
284
285 void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
286 AioContext *ctx, int flags, BlockCompletionFunc *cb,
287 void *opaque, Error **errp)
288 {
289 Job *job;
290
291 if (job_id) {
292 if (flags & JOB_INTERNAL) {
293 error_setg(errp, "Cannot specify job ID for internal job");
294 return NULL;
295 }
296 if (!id_wellformed(job_id)) {
297 error_setg(errp, "Invalid job ID '%s'", job_id);
298 return NULL;
299 }
300 if (job_get(job_id)) {
301 error_setg(errp, "Job ID '%s' already in use", job_id);
302 return NULL;
303 }
304 } else if (!(flags & JOB_INTERNAL)) {
305 error_setg(errp, "An explicit job ID is required");
306 return NULL;
307 }
308
309 job = g_malloc0(driver->instance_size);
310 job->driver = driver;
311 job->id = g_strdup(job_id);
312 job->refcnt = 1;
313 job->aio_context = ctx;
314 job->busy = false;
315 job->paused = true;
316 job->pause_count = 1;
317 job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE);
318 job->auto_dismiss = !(flags & JOB_MANUAL_DISMISS);
319 job->cb = cb;
320 job->opaque = opaque;
321
322 notifier_list_init(&job->on_finalize_cancelled);
323 notifier_list_init(&job->on_finalize_completed);
324 notifier_list_init(&job->on_pending);
325 notifier_list_init(&job->on_ready);
326
327 job_state_transition(job, JOB_STATUS_CREATED);
328 aio_timer_init(qemu_get_aio_context(), &job->sleep_timer,
329 QEMU_CLOCK_REALTIME, SCALE_NS,
330 job_sleep_timer_cb, job);
331
332 QLIST_INSERT_HEAD(&jobs, job, job_list);
333
334 /* Single jobs are modeled as single-job transactions for sake of
335 * consolidating the job management logic */
336 if (!txn) {
337 txn = job_txn_new();
338 job_txn_add_job(txn, job);
339 job_txn_unref(txn);
340 } else {
341 job_txn_add_job(txn, job);
342 }
343
344 return job;
345 }
346
347 void job_ref(Job *job)
348 {
349 ++job->refcnt;
350 }
351
352 void job_unref(Job *job)
353 {
354 if (--job->refcnt == 0) {
355 assert(job->status == JOB_STATUS_NULL);
356 assert(!timer_pending(&job->sleep_timer));
357 assert(!job->txn);
358
359 if (job->driver->free) {
360 job->driver->free(job);
361 }
362
363 QLIST_REMOVE(job, job_list);
364
365 error_free(job->err);
366 g_free(job->id);
367 g_free(job);
368 }
369 }
370
371 void job_progress_update(Job *job, uint64_t done)
372 {
373 job->progress_current += done;
374 }
375
376 void job_progress_set_remaining(Job *job, uint64_t remaining)
377 {
378 job->progress_total = job->progress_current + remaining;
379 }
380
381 void job_progress_increase_remaining(Job *job, uint64_t delta)
382 {
383 job->progress_total += delta;
384 }
385
386 void job_event_cancelled(Job *job)
387 {
388 notifier_list_notify(&job->on_finalize_cancelled, job);
389 }
390
391 void job_event_completed(Job *job)
392 {
393 notifier_list_notify(&job->on_finalize_completed, job);
394 }
395
396 static void job_event_pending(Job *job)
397 {
398 notifier_list_notify(&job->on_pending, job);
399 }
400
401 static void job_event_ready(Job *job)
402 {
403 notifier_list_notify(&job->on_ready, job);
404 }
405
406 static void job_event_idle(Job *job)
407 {
408 notifier_list_notify(&job->on_idle, job);
409 }
410
411 void job_enter_cond(Job *job, bool(*fn)(Job *job))
412 {
413 if (!job_started(job)) {
414 return;
415 }
416 if (job->deferred_to_main_loop) {
417 return;
418 }
419
420 job_lock();
421 if (job->busy) {
422 job_unlock();
423 return;
424 }
425
426 if (fn && !fn(job)) {
427 job_unlock();
428 return;
429 }
430
431 assert(!job->deferred_to_main_loop);
432 timer_del(&job->sleep_timer);
433 job->busy = true;
434 job_unlock();
435 aio_co_wake(job->co);
436 }
437
438 void job_enter(Job *job)
439 {
440 job_enter_cond(job, NULL);
441 }
442
443 /* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds.
444 * Reentering the job coroutine with job_enter() before the timer has expired
445 * is allowed and cancels the timer.
446 *
447 * If @ns is (uint64_t) -1, no timer is scheduled and job_enter() must be
448 * called explicitly. */
449 static void coroutine_fn job_do_yield(Job *job, uint64_t ns)
450 {
451 job_lock();
452 if (ns != -1) {
453 timer_mod(&job->sleep_timer, ns);
454 }
455 job->busy = false;
456 job_event_idle(job);
457 job_unlock();
458 qemu_coroutine_yield();
459
460 /* Set by job_enter_cond() before re-entering the coroutine. */
461 assert(job->busy);
462 }
463
464 void coroutine_fn job_pause_point(Job *job)
465 {
466 assert(job && job_started(job));
467
468 if (!job_should_pause(job)) {
469 return;
470 }
471 if (job_is_cancelled(job)) {
472 return;
473 }
474
475 if (job->driver->pause) {
476 job->driver->pause(job);
477 }
478
479 if (job_should_pause(job) && !job_is_cancelled(job)) {
480 JobStatus status = job->status;
481 job_state_transition(job, status == JOB_STATUS_READY
482 ? JOB_STATUS_STANDBY
483 : JOB_STATUS_PAUSED);
484 job->paused = true;
485 job_do_yield(job, -1);
486 job->paused = false;
487 job_state_transition(job, status);
488 }
489
490 if (job->driver->resume) {
491 job->driver->resume(job);
492 }
493 }
494
495 void job_yield(Job *job)
496 {
497 assert(job->busy);
498
499 /* Check cancellation *before* setting busy = false, too! */
500 if (job_is_cancelled(job)) {
501 return;
502 }
503
504 if (!job_should_pause(job)) {
505 job_do_yield(job, -1);
506 }
507
508 job_pause_point(job);
509 }
510
511 void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
512 {
513 assert(job->busy);
514
515 /* Check cancellation *before* setting busy = false, too! */
516 if (job_is_cancelled(job)) {
517 return;
518 }
519
520 if (!job_should_pause(job)) {
521 job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
522 }
523
524 job_pause_point(job);
525 }
526
527 void job_drain(Job *job)
528 {
529 /* If job is !busy this kicks it into the next pause point. */
530 job_enter(job);
531
532 if (job->driver->drain) {
533 job->driver->drain(job);
534 }
535 }
536
537 /* Assumes the block_job_mutex is held */
538 static bool job_timer_not_pending(Job *job)
539 {
540 return !timer_pending(&job->sleep_timer);
541 }
542
543 void job_pause(Job *job)
544 {
545 job->pause_count++;
546 }
547
548 void job_resume(Job *job)
549 {
550 assert(job->pause_count > 0);
551 job->pause_count--;
552 if (job->pause_count) {
553 return;
554 }
555
556 /* kick only if no timer is pending */
557 job_enter_cond(job, job_timer_not_pending);
558 }
559
560 void job_user_pause(Job *job, Error **errp)
561 {
562 if (job_apply_verb(job, JOB_VERB_PAUSE, errp)) {
563 return;
564 }
565 if (job->user_paused) {
566 error_setg(errp, "Job is already paused");
567 return;
568 }
569 job->user_paused = true;
570 job_pause(job);
571 }
572
573 bool job_user_paused(Job *job)
574 {
575 return job->user_paused;
576 }
577
578 void job_user_resume(Job *job, Error **errp)
579 {
580 assert(job);
581 if (!job->user_paused || job->pause_count <= 0) {
582 error_setg(errp, "Can't resume a job that was not paused");
583 return;
584 }
585 if (job_apply_verb(job, JOB_VERB_RESUME, errp)) {
586 return;
587 }
588 if (job->driver->user_resume) {
589 job->driver->user_resume(job);
590 }
591 job->user_paused = false;
592 job_resume(job);
593 }
594
595 static void job_do_dismiss(Job *job)
596 {
597 assert(job);
598 job->busy = false;
599 job->paused = false;
600 job->deferred_to_main_loop = true;
601
602 job_txn_del_job(job);
603
604 job_state_transition(job, JOB_STATUS_NULL);
605 job_unref(job);
606 }
607
608 void job_dismiss(Job **jobptr, Error **errp)
609 {
610 Job *job = *jobptr;
611 /* similarly to _complete, this is QMP-interface only. */
612 assert(job->id);
613 if (job_apply_verb(job, JOB_VERB_DISMISS, errp)) {
614 return;
615 }
616
617 job_do_dismiss(job);
618 *jobptr = NULL;
619 }
620
621 void job_early_fail(Job *job)
622 {
623 assert(job->status == JOB_STATUS_CREATED);
624 job_do_dismiss(job);
625 }
626
627 static void job_conclude(Job *job)
628 {
629 job_state_transition(job, JOB_STATUS_CONCLUDED);
630 if (job->auto_dismiss || !job_started(job)) {
631 job_do_dismiss(job);
632 }
633 }
634
635 static void job_update_rc(Job *job)
636 {
637 if (!job->ret && job_is_cancelled(job)) {
638 job->ret = -ECANCELED;
639 }
640 if (job->ret) {
641 if (!job->err) {
642 error_setg(&job->err, "%s", strerror(-job->ret));
643 }
644 job_state_transition(job, JOB_STATUS_ABORTING);
645 }
646 }
647
648 static void job_commit(Job *job)
649 {
650 assert(!job->ret);
651 if (job->driver->commit) {
652 job->driver->commit(job);
653 }
654 }
655
656 static void job_abort(Job *job)
657 {
658 assert(job->ret);
659 if (job->driver->abort) {
660 job->driver->abort(job);
661 }
662 }
663
664 static void job_clean(Job *job)
665 {
666 if (job->driver->clean) {
667 job->driver->clean(job);
668 }
669 }
670
671 static int job_finalize_single(Job *job)
672 {
673 assert(job_is_completed(job));
674
675 /* Ensure abort is called for late-transactional failures */
676 job_update_rc(job);
677
678 if (!job->ret) {
679 job_commit(job);
680 } else {
681 job_abort(job);
682 }
683 job_clean(job);
684
685 if (job->cb) {
686 job->cb(job->opaque, job->ret);
687 }
688
689 /* Emit events only if we actually started */
690 if (job_started(job)) {
691 if (job_is_cancelled(job)) {
692 job_event_cancelled(job);
693 } else {
694 job_event_completed(job);
695 }
696 }
697
698 job_txn_del_job(job);
699 job_conclude(job);
700 return 0;
701 }
702
703 static void job_cancel_async(Job *job, bool force)
704 {
705 if (job->user_paused) {
706 /* Do not call job_enter here, the caller will handle it. */
707 if (job->driver->user_resume) {
708 job->driver->user_resume(job);
709 }
710 job->user_paused = false;
711 assert(job->pause_count > 0);
712 job->pause_count--;
713 }
714 job->cancelled = true;
715 /* To prevent 'force == false' overriding a previous 'force == true' */
716 job->force_cancel |= force;
717 }
718
719 static void job_completed_txn_abort(Job *job)
720 {
721 AioContext *outer_ctx = job->aio_context;
722 AioContext *ctx;
723 JobTxn *txn = job->txn;
724 Job *other_job;
725
726 if (txn->aborting) {
727 /*
728 * We are cancelled by another job, which will handle everything.
729 */
730 return;
731 }
732 txn->aborting = true;
733 job_txn_ref(txn);
734
735 /* We can only hold the single job's AioContext lock while calling
736 * job_finalize_single() because the finalization callbacks can involve
737 * calls of AIO_WAIT_WHILE(), which could deadlock otherwise. */
738 aio_context_release(outer_ctx);
739
740 /* Other jobs are effectively cancelled by us, set the status for
741 * them; this job, however, may or may not be cancelled, depending
742 * on the caller, so leave it. */
743 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
744 if (other_job != job) {
745 ctx = other_job->aio_context;
746 aio_context_acquire(ctx);
747 job_cancel_async(other_job, false);
748 aio_context_release(ctx);
749 }
750 }
751 while (!QLIST_EMPTY(&txn->jobs)) {
752 other_job = QLIST_FIRST(&txn->jobs);
753 ctx = other_job->aio_context;
754 aio_context_acquire(ctx);
755 if (!job_is_completed(other_job)) {
756 assert(job_is_cancelled(other_job));
757 job_finish_sync(other_job, NULL, NULL);
758 }
759 job_finalize_single(other_job);
760 aio_context_release(ctx);
761 }
762
763 aio_context_acquire(outer_ctx);
764
765 job_txn_unref(txn);
766 }
767
768 static int job_prepare(Job *job)
769 {
770 if (job->ret == 0 && job->driver->prepare) {
771 job->ret = job->driver->prepare(job);
772 job_update_rc(job);
773 }
774 return job->ret;
775 }
776
777 static int job_needs_finalize(Job *job)
778 {
779 return !job->auto_finalize;
780 }
781
782 static void job_do_finalize(Job *job)
783 {
784 int rc;
785 assert(job && job->txn);
786
787 /* prepare the transaction to complete */
788 rc = job_txn_apply(job->txn, job_prepare);
789 if (rc) {
790 job_completed_txn_abort(job);
791 } else {
792 job_txn_apply(job->txn, job_finalize_single);
793 }
794 }
795
796 void job_finalize(Job *job, Error **errp)
797 {
798 assert(job && job->id);
799 if (job_apply_verb(job, JOB_VERB_FINALIZE, errp)) {
800 return;
801 }
802 job_do_finalize(job);
803 }
804
805 static int job_transition_to_pending(Job *job)
806 {
807 job_state_transition(job, JOB_STATUS_PENDING);
808 if (!job->auto_finalize) {
809 job_event_pending(job);
810 }
811 return 0;
812 }
813
814 void job_transition_to_ready(Job *job)
815 {
816 job_state_transition(job, JOB_STATUS_READY);
817 job_event_ready(job);
818 }
819
820 static void job_completed_txn_success(Job *job)
821 {
822 JobTxn *txn = job->txn;
823 Job *other_job;
824
825 job_state_transition(job, JOB_STATUS_WAITING);
826
827 /*
828 * Successful completion, see if there are other running jobs in this
829 * txn.
830 */
831 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
832 if (!job_is_completed(other_job)) {
833 return;
834 }
835 assert(other_job->ret == 0);
836 }
837
838 job_txn_apply(txn, job_transition_to_pending);
839
840 /* If no jobs need manual finalization, automatically do so */
841 if (job_txn_apply(txn, job_needs_finalize) == 0) {
842 job_do_finalize(job);
843 }
844 }
845
846 static void job_completed(Job *job)
847 {
848 assert(job && job->txn && !job_is_completed(job));
849
850 job_update_rc(job);
851 trace_job_completed(job, job->ret);
852 if (job->ret) {
853 job_completed_txn_abort(job);
854 } else {
855 job_completed_txn_success(job);
856 }
857 }
858
859 /** Useful only as a type shim for aio_bh_schedule_oneshot. */
860 static void job_exit(void *opaque)
861 {
862 Job *job = (Job *)opaque;
863 AioContext *ctx = job->aio_context;
864
865 aio_context_acquire(ctx);
866
867 /* This is a lie, we're not quiescent, but still doing the completion
868 * callbacks. However, completion callbacks tend to involve operations that
869 * drain block nodes, and if .drained_poll still returned true, we would
870 * deadlock. */
871 job->busy = false;
872 job_event_idle(job);
873
874 job_completed(job);
875
876 aio_context_release(ctx);
877 }
878
879 /**
880 * All jobs must allow a pause point before entering their job proper. This
881 * ensures that jobs can be paused prior to being started, then resumed later.
882 */
883 static void coroutine_fn job_co_entry(void *opaque)
884 {
885 Job *job = opaque;
886
887 assert(job && job->driver && job->driver->run);
888 job_pause_point(job);
889 job->ret = job->driver->run(job, &job->err);
890 job->deferred_to_main_loop = true;
891 job->busy = true;
892 aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
893 }
894
895 void job_start(Job *job)
896 {
897 assert(job && !job_started(job) && job->paused &&
898 job->driver && job->driver->run);
899 job->co = qemu_coroutine_create(job_co_entry, job);
900 job->pause_count--;
901 job->busy = true;
902 job->paused = false;
903 job_state_transition(job, JOB_STATUS_RUNNING);
904 aio_co_enter(job->aio_context, job->co);
905 }
906
907 void job_cancel(Job *job, bool force)
908 {
909 if (job->status == JOB_STATUS_CONCLUDED) {
910 job_do_dismiss(job);
911 return;
912 }
913 job_cancel_async(job, force);
914 if (!job_started(job)) {
915 job_completed(job);
916 } else if (job->deferred_to_main_loop) {
917 job_completed_txn_abort(job);
918 } else {
919 job_enter(job);
920 }
921 }
922
923 void job_user_cancel(Job *job, bool force, Error **errp)
924 {
925 if (job_apply_verb(job, JOB_VERB_CANCEL, errp)) {
926 return;
927 }
928 job_cancel(job, force);
929 }
930
931 /* A wrapper around job_cancel() taking an Error ** parameter so it may be
932 * used with job_finish_sync() without the need for (rather nasty) function
933 * pointer casts there. */
934 static void job_cancel_err(Job *job, Error **errp)
935 {
936 job_cancel(job, false);
937 }
938
939 int job_cancel_sync(Job *job)
940 {
941 return job_finish_sync(job, &job_cancel_err, NULL);
942 }
943
944 void job_cancel_sync_all(void)
945 {
946 Job *job;
947 AioContext *aio_context;
948
949 while ((job = job_next(NULL))) {
950 aio_context = job->aio_context;
951 aio_context_acquire(aio_context);
952 job_cancel_sync(job);
953 aio_context_release(aio_context);
954 }
955 }
956
957 int job_complete_sync(Job *job, Error **errp)
958 {
959 return job_finish_sync(job, job_complete, errp);
960 }
961
962 void job_complete(Job *job, Error **errp)
963 {
964 /* Should not be reachable via external interface for internal jobs */
965 assert(job->id);
966 if (job_apply_verb(job, JOB_VERB_COMPLETE, errp)) {
967 return;
968 }
969 if (job->pause_count || job_is_cancelled(job) || !job->driver->complete) {
970 error_setg(errp, "The active block job '%s' cannot be completed",
971 job->id);
972 return;
973 }
974
975 job->driver->complete(job, errp);
976 }
977
978 int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp)
979 {
980 Error *local_err = NULL;
981 int ret;
982
983 job_ref(job);
984
985 if (finish) {
986 finish(job, &local_err);
987 }
988 if (local_err) {
989 error_propagate(errp, local_err);
990 job_unref(job);
991 return -EBUSY;
992 }
993
994 AIO_WAIT_WHILE(job->aio_context,
995 (job_drain(job), !job_is_completed(job)));
996
997 ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret;
998 job_unref(job);
999 return ret;
1000 }