Merge remote-tracking branch 'remotes/alistair23/tags/pull-riscv-to-apply-20210921...
[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 "qapi/error.h"
28 #include "qemu/job.h"
29 #include "qemu/id.h"
30 #include "qemu/main-loop.h"
31 #include "block/aio-wait.h"
32 #include "trace/trace-root.h"
33 #include "qapi/qapi-events-job.h"
34
35 static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs);
36
37 /* Job State Transition Table */
38 bool JobSTT[JOB_STATUS__MAX][JOB_STATUS__MAX] = {
39 /* U, C, R, P, Y, S, W, D, X, E, N */
40 /* U: */ [JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
41 /* C: */ [JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1},
42 /* R: */ [JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0},
43 /* P: */ [JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
44 /* Y: */ [JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0},
45 /* S: */ [JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
46 /* W: */ [JOB_STATUS_WAITING] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0},
47 /* D: */ [JOB_STATUS_PENDING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
48 /* X: */ [JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
49 /* E: */ [JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
50 /* N: */ [JOB_STATUS_NULL] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
51 };
52
53 bool JobVerbTable[JOB_VERB__MAX][JOB_STATUS__MAX] = {
54 /* U, C, R, P, Y, S, W, D, X, E, N */
55 [JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0},
56 [JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
57 [JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
58 [JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
59 [JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0},
60 [JOB_VERB_FINALIZE] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0},
61 [JOB_VERB_DISMISS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
62 };
63
64 /* Transactional group of jobs */
65 struct JobTxn {
66
67 /* Is this txn being cancelled? */
68 bool aborting;
69
70 /* List of jobs */
71 QLIST_HEAD(, Job) jobs;
72
73 /* Reference count */
74 int refcnt;
75 };
76
77 /* Right now, this mutex is only needed to synchronize accesses to job->busy
78 * and job->sleep_timer, such as concurrent calls to job_do_yield and
79 * job_enter. */
80 static QemuMutex job_mutex;
81
82 static void job_lock(void)
83 {
84 qemu_mutex_lock(&job_mutex);
85 }
86
87 static void job_unlock(void)
88 {
89 qemu_mutex_unlock(&job_mutex);
90 }
91
92 static void __attribute__((__constructor__)) job_init(void)
93 {
94 qemu_mutex_init(&job_mutex);
95 }
96
97 JobTxn *job_txn_new(void)
98 {
99 JobTxn *txn = g_new0(JobTxn, 1);
100 QLIST_INIT(&txn->jobs);
101 txn->refcnt = 1;
102 return txn;
103 }
104
105 static void job_txn_ref(JobTxn *txn)
106 {
107 txn->refcnt++;
108 }
109
110 void job_txn_unref(JobTxn *txn)
111 {
112 if (txn && --txn->refcnt == 0) {
113 g_free(txn);
114 }
115 }
116
117 void job_txn_add_job(JobTxn *txn, Job *job)
118 {
119 if (!txn) {
120 return;
121 }
122
123 assert(!job->txn);
124 job->txn = txn;
125
126 QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
127 job_txn_ref(txn);
128 }
129
130 static void job_txn_del_job(Job *job)
131 {
132 if (job->txn) {
133 QLIST_REMOVE(job, txn_list);
134 job_txn_unref(job->txn);
135 job->txn = NULL;
136 }
137 }
138
139 static int job_txn_apply(Job *job, int fn(Job *))
140 {
141 AioContext *inner_ctx;
142 Job *other_job, *next;
143 JobTxn *txn = job->txn;
144 int rc = 0;
145
146 /*
147 * Similar to job_completed_txn_abort, we take each job's lock before
148 * applying fn, but since we assume that outer_ctx is held by the caller,
149 * we need to release it here to avoid holding the lock twice - which would
150 * break AIO_WAIT_WHILE from within fn.
151 */
152 job_ref(job);
153 aio_context_release(job->aio_context);
154
155 QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
156 inner_ctx = other_job->aio_context;
157 aio_context_acquire(inner_ctx);
158 rc = fn(other_job);
159 aio_context_release(inner_ctx);
160 if (rc) {
161 break;
162 }
163 }
164
165 /*
166 * Note that job->aio_context might have been changed by calling fn, so we
167 * can't use a local variable to cache it.
168 */
169 aio_context_acquire(job->aio_context);
170 job_unref(job);
171 return rc;
172 }
173
174 bool job_is_internal(Job *job)
175 {
176 return (job->id == NULL);
177 }
178
179 static void job_state_transition(Job *job, JobStatus s1)
180 {
181 JobStatus s0 = job->status;
182 assert(s1 >= 0 && s1 < JOB_STATUS__MAX);
183 trace_job_state_transition(job, job->ret,
184 JobSTT[s0][s1] ? "allowed" : "disallowed",
185 JobStatus_str(s0), JobStatus_str(s1));
186 assert(JobSTT[s0][s1]);
187 job->status = s1;
188
189 if (!job_is_internal(job) && s1 != s0) {
190 qapi_event_send_job_status_change(job->id, job->status);
191 }
192 }
193
194 int job_apply_verb(Job *job, JobVerb verb, Error **errp)
195 {
196 JobStatus s0 = job->status;
197 assert(verb >= 0 && verb < JOB_VERB__MAX);
198 trace_job_apply_verb(job, JobStatus_str(s0), JobVerb_str(verb),
199 JobVerbTable[verb][s0] ? "allowed" : "prohibited");
200 if (JobVerbTable[verb][s0]) {
201 return 0;
202 }
203 error_setg(errp, "Job '%s' in state '%s' cannot accept command verb '%s'",
204 job->id, JobStatus_str(s0), JobVerb_str(verb));
205 return -EPERM;
206 }
207
208 JobType job_type(const Job *job)
209 {
210 return job->driver->job_type;
211 }
212
213 const char *job_type_str(const Job *job)
214 {
215 return JobType_str(job_type(job));
216 }
217
218 bool job_is_cancelled(Job *job)
219 {
220 return job->cancelled;
221 }
222
223 bool job_is_ready(Job *job)
224 {
225 switch (job->status) {
226 case JOB_STATUS_UNDEFINED:
227 case JOB_STATUS_CREATED:
228 case JOB_STATUS_RUNNING:
229 case JOB_STATUS_PAUSED:
230 case JOB_STATUS_WAITING:
231 case JOB_STATUS_PENDING:
232 case JOB_STATUS_ABORTING:
233 case JOB_STATUS_CONCLUDED:
234 case JOB_STATUS_NULL:
235 return false;
236 case JOB_STATUS_READY:
237 case JOB_STATUS_STANDBY:
238 return true;
239 default:
240 g_assert_not_reached();
241 }
242 return false;
243 }
244
245 bool job_is_completed(Job *job)
246 {
247 switch (job->status) {
248 case JOB_STATUS_UNDEFINED:
249 case JOB_STATUS_CREATED:
250 case JOB_STATUS_RUNNING:
251 case JOB_STATUS_PAUSED:
252 case JOB_STATUS_READY:
253 case JOB_STATUS_STANDBY:
254 return false;
255 case JOB_STATUS_WAITING:
256 case JOB_STATUS_PENDING:
257 case JOB_STATUS_ABORTING:
258 case JOB_STATUS_CONCLUDED:
259 case JOB_STATUS_NULL:
260 return true;
261 default:
262 g_assert_not_reached();
263 }
264 return false;
265 }
266
267 static bool job_started(Job *job)
268 {
269 return job->co;
270 }
271
272 static bool job_should_pause(Job *job)
273 {
274 return job->pause_count > 0;
275 }
276
277 Job *job_next(Job *job)
278 {
279 if (!job) {
280 return QLIST_FIRST(&jobs);
281 }
282 return QLIST_NEXT(job, job_list);
283 }
284
285 Job *job_get(const char *id)
286 {
287 Job *job;
288
289 QLIST_FOREACH(job, &jobs, job_list) {
290 if (job->id && !strcmp(id, job->id)) {
291 return job;
292 }
293 }
294
295 return NULL;
296 }
297
298 static void job_sleep_timer_cb(void *opaque)
299 {
300 Job *job = opaque;
301
302 job_enter(job);
303 }
304
305 void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
306 AioContext *ctx, int flags, BlockCompletionFunc *cb,
307 void *opaque, Error **errp)
308 {
309 Job *job;
310
311 if (job_id) {
312 if (flags & JOB_INTERNAL) {
313 error_setg(errp, "Cannot specify job ID for internal job");
314 return NULL;
315 }
316 if (!id_wellformed(job_id)) {
317 error_setg(errp, "Invalid job ID '%s'", job_id);
318 return NULL;
319 }
320 if (job_get(job_id)) {
321 error_setg(errp, "Job ID '%s' already in use", job_id);
322 return NULL;
323 }
324 } else if (!(flags & JOB_INTERNAL)) {
325 error_setg(errp, "An explicit job ID is required");
326 return NULL;
327 }
328
329 job = g_malloc0(driver->instance_size);
330 job->driver = driver;
331 job->id = g_strdup(job_id);
332 job->refcnt = 1;
333 job->aio_context = ctx;
334 job->busy = false;
335 job->paused = true;
336 job->pause_count = 1;
337 job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE);
338 job->auto_dismiss = !(flags & JOB_MANUAL_DISMISS);
339 job->cb = cb;
340 job->opaque = opaque;
341
342 notifier_list_init(&job->on_finalize_cancelled);
343 notifier_list_init(&job->on_finalize_completed);
344 notifier_list_init(&job->on_pending);
345 notifier_list_init(&job->on_ready);
346
347 job_state_transition(job, JOB_STATUS_CREATED);
348 aio_timer_init(qemu_get_aio_context(), &job->sleep_timer,
349 QEMU_CLOCK_REALTIME, SCALE_NS,
350 job_sleep_timer_cb, job);
351
352 QLIST_INSERT_HEAD(&jobs, job, job_list);
353
354 /* Single jobs are modeled as single-job transactions for sake of
355 * consolidating the job management logic */
356 if (!txn) {
357 txn = job_txn_new();
358 job_txn_add_job(txn, job);
359 job_txn_unref(txn);
360 } else {
361 job_txn_add_job(txn, job);
362 }
363
364 return job;
365 }
366
367 void job_ref(Job *job)
368 {
369 ++job->refcnt;
370 }
371
372 void job_unref(Job *job)
373 {
374 if (--job->refcnt == 0) {
375 assert(job->status == JOB_STATUS_NULL);
376 assert(!timer_pending(&job->sleep_timer));
377 assert(!job->txn);
378
379 if (job->driver->free) {
380 job->driver->free(job);
381 }
382
383 QLIST_REMOVE(job, job_list);
384
385 error_free(job->err);
386 g_free(job->id);
387 g_free(job);
388 }
389 }
390
391 void job_progress_update(Job *job, uint64_t done)
392 {
393 progress_work_done(&job->progress, done);
394 }
395
396 void job_progress_set_remaining(Job *job, uint64_t remaining)
397 {
398 progress_set_remaining(&job->progress, remaining);
399 }
400
401 void job_progress_increase_remaining(Job *job, uint64_t delta)
402 {
403 progress_increase_remaining(&job->progress, delta);
404 }
405
406 void job_event_cancelled(Job *job)
407 {
408 notifier_list_notify(&job->on_finalize_cancelled, job);
409 }
410
411 void job_event_completed(Job *job)
412 {
413 notifier_list_notify(&job->on_finalize_completed, job);
414 }
415
416 static void job_event_pending(Job *job)
417 {
418 notifier_list_notify(&job->on_pending, job);
419 }
420
421 static void job_event_ready(Job *job)
422 {
423 notifier_list_notify(&job->on_ready, job);
424 }
425
426 static void job_event_idle(Job *job)
427 {
428 notifier_list_notify(&job->on_idle, job);
429 }
430
431 void job_enter_cond(Job *job, bool(*fn)(Job *job))
432 {
433 if (!job_started(job)) {
434 return;
435 }
436 if (job->deferred_to_main_loop) {
437 return;
438 }
439
440 job_lock();
441 if (job->busy) {
442 job_unlock();
443 return;
444 }
445
446 if (fn && !fn(job)) {
447 job_unlock();
448 return;
449 }
450
451 assert(!job->deferred_to_main_loop);
452 timer_del(&job->sleep_timer);
453 job->busy = true;
454 job_unlock();
455 aio_co_enter(job->aio_context, job->co);
456 }
457
458 void job_enter(Job *job)
459 {
460 job_enter_cond(job, NULL);
461 }
462
463 /* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds.
464 * Reentering the job coroutine with job_enter() before the timer has expired
465 * is allowed and cancels the timer.
466 *
467 * If @ns is (uint64_t) -1, no timer is scheduled and job_enter() must be
468 * called explicitly. */
469 static void coroutine_fn job_do_yield(Job *job, uint64_t ns)
470 {
471 job_lock();
472 if (ns != -1) {
473 timer_mod(&job->sleep_timer, ns);
474 }
475 job->busy = false;
476 job_event_idle(job);
477 job_unlock();
478 qemu_coroutine_yield();
479
480 /* Set by job_enter_cond() before re-entering the coroutine. */
481 assert(job->busy);
482 }
483
484 void coroutine_fn job_pause_point(Job *job)
485 {
486 assert(job && job_started(job));
487
488 if (!job_should_pause(job)) {
489 return;
490 }
491 if (job_is_cancelled(job)) {
492 return;
493 }
494
495 if (job->driver->pause) {
496 job->driver->pause(job);
497 }
498
499 if (job_should_pause(job) && !job_is_cancelled(job)) {
500 JobStatus status = job->status;
501 job_state_transition(job, status == JOB_STATUS_READY
502 ? JOB_STATUS_STANDBY
503 : JOB_STATUS_PAUSED);
504 job->paused = true;
505 job_do_yield(job, -1);
506 job->paused = false;
507 job_state_transition(job, status);
508 }
509
510 if (job->driver->resume) {
511 job->driver->resume(job);
512 }
513 }
514
515 void job_yield(Job *job)
516 {
517 assert(job->busy);
518
519 /* Check cancellation *before* setting busy = false, too! */
520 if (job_is_cancelled(job)) {
521 return;
522 }
523
524 if (!job_should_pause(job)) {
525 job_do_yield(job, -1);
526 }
527
528 job_pause_point(job);
529 }
530
531 void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
532 {
533 assert(job->busy);
534
535 /* Check cancellation *before* setting busy = false, too! */
536 if (job_is_cancelled(job)) {
537 return;
538 }
539
540 if (!job_should_pause(job)) {
541 job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
542 }
543
544 job_pause_point(job);
545 }
546
547 /* Assumes the block_job_mutex is held */
548 static bool job_timer_not_pending(Job *job)
549 {
550 return !timer_pending(&job->sleep_timer);
551 }
552
553 void job_pause(Job *job)
554 {
555 job->pause_count++;
556 if (!job->paused) {
557 job_enter(job);
558 }
559 }
560
561 void job_resume(Job *job)
562 {
563 assert(job->pause_count > 0);
564 job->pause_count--;
565 if (job->pause_count) {
566 return;
567 }
568
569 /* kick only if no timer is pending */
570 job_enter_cond(job, job_timer_not_pending);
571 }
572
573 void job_user_pause(Job *job, Error **errp)
574 {
575 if (job_apply_verb(job, JOB_VERB_PAUSE, errp)) {
576 return;
577 }
578 if (job->user_paused) {
579 error_setg(errp, "Job is already paused");
580 return;
581 }
582 job->user_paused = true;
583 job_pause(job);
584 }
585
586 bool job_user_paused(Job *job)
587 {
588 return job->user_paused;
589 }
590
591 void job_user_resume(Job *job, Error **errp)
592 {
593 assert(job);
594 if (!job->user_paused || job->pause_count <= 0) {
595 error_setg(errp, "Can't resume a job that was not paused");
596 return;
597 }
598 if (job_apply_verb(job, JOB_VERB_RESUME, errp)) {
599 return;
600 }
601 if (job->driver->user_resume) {
602 job->driver->user_resume(job);
603 }
604 job->user_paused = false;
605 job_resume(job);
606 }
607
608 static void job_do_dismiss(Job *job)
609 {
610 assert(job);
611 job->busy = false;
612 job->paused = false;
613 job->deferred_to_main_loop = true;
614
615 job_txn_del_job(job);
616
617 job_state_transition(job, JOB_STATUS_NULL);
618 job_unref(job);
619 }
620
621 void job_dismiss(Job **jobptr, Error **errp)
622 {
623 Job *job = *jobptr;
624 /* similarly to _complete, this is QMP-interface only. */
625 assert(job->id);
626 if (job_apply_verb(job, JOB_VERB_DISMISS, errp)) {
627 return;
628 }
629
630 job_do_dismiss(job);
631 *jobptr = NULL;
632 }
633
634 void job_early_fail(Job *job)
635 {
636 assert(job->status == JOB_STATUS_CREATED);
637 job_do_dismiss(job);
638 }
639
640 static void job_conclude(Job *job)
641 {
642 job_state_transition(job, JOB_STATUS_CONCLUDED);
643 if (job->auto_dismiss || !job_started(job)) {
644 job_do_dismiss(job);
645 }
646 }
647
648 static void job_update_rc(Job *job)
649 {
650 if (!job->ret && job_is_cancelled(job)) {
651 job->ret = -ECANCELED;
652 }
653 if (job->ret) {
654 if (!job->err) {
655 error_setg(&job->err, "%s", strerror(-job->ret));
656 }
657 job_state_transition(job, JOB_STATUS_ABORTING);
658 }
659 }
660
661 static void job_commit(Job *job)
662 {
663 assert(!job->ret);
664 if (job->driver->commit) {
665 job->driver->commit(job);
666 }
667 }
668
669 static void job_abort(Job *job)
670 {
671 assert(job->ret);
672 if (job->driver->abort) {
673 job->driver->abort(job);
674 }
675 }
676
677 static void job_clean(Job *job)
678 {
679 if (job->driver->clean) {
680 job->driver->clean(job);
681 }
682 }
683
684 static int job_finalize_single(Job *job)
685 {
686 assert(job_is_completed(job));
687
688 /* Ensure abort is called for late-transactional failures */
689 job_update_rc(job);
690
691 if (!job->ret) {
692 job_commit(job);
693 } else {
694 job_abort(job);
695 }
696 job_clean(job);
697
698 if (job->cb) {
699 job->cb(job->opaque, job->ret);
700 }
701
702 /* Emit events only if we actually started */
703 if (job_started(job)) {
704 if (job_is_cancelled(job)) {
705 job_event_cancelled(job);
706 } else {
707 job_event_completed(job);
708 }
709 }
710
711 job_txn_del_job(job);
712 job_conclude(job);
713 return 0;
714 }
715
716 static void job_cancel_async(Job *job, bool force)
717 {
718 if (job->driver->cancel) {
719 job->driver->cancel(job, force);
720 }
721 if (job->user_paused) {
722 /* Do not call job_enter here, the caller will handle it. */
723 if (job->driver->user_resume) {
724 job->driver->user_resume(job);
725 }
726 job->user_paused = false;
727 assert(job->pause_count > 0);
728 job->pause_count--;
729 }
730 job->cancelled = true;
731 /* To prevent 'force == false' overriding a previous 'force == true' */
732 job->force_cancel |= force;
733 }
734
735 static void job_completed_txn_abort(Job *job)
736 {
737 AioContext *outer_ctx = job->aio_context;
738 AioContext *ctx;
739 JobTxn *txn = job->txn;
740 Job *other_job;
741
742 if (txn->aborting) {
743 /*
744 * We are cancelled by another job, which will handle everything.
745 */
746 return;
747 }
748 txn->aborting = true;
749 job_txn_ref(txn);
750
751 /* We can only hold the single job's AioContext lock while calling
752 * job_finalize_single() because the finalization callbacks can involve
753 * calls of AIO_WAIT_WHILE(), which could deadlock otherwise. */
754 aio_context_release(outer_ctx);
755
756 /* Other jobs are effectively cancelled by us, set the status for
757 * them; this job, however, may or may not be cancelled, depending
758 * on the caller, so leave it. */
759 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
760 if (other_job != job) {
761 ctx = other_job->aio_context;
762 aio_context_acquire(ctx);
763 job_cancel_async(other_job, false);
764 aio_context_release(ctx);
765 }
766 }
767 while (!QLIST_EMPTY(&txn->jobs)) {
768 other_job = QLIST_FIRST(&txn->jobs);
769 ctx = other_job->aio_context;
770 aio_context_acquire(ctx);
771 if (!job_is_completed(other_job)) {
772 assert(job_is_cancelled(other_job));
773 job_finish_sync(other_job, NULL, NULL);
774 }
775 job_finalize_single(other_job);
776 aio_context_release(ctx);
777 }
778
779 aio_context_acquire(outer_ctx);
780
781 job_txn_unref(txn);
782 }
783
784 static int job_prepare(Job *job)
785 {
786 if (job->ret == 0 && job->driver->prepare) {
787 job->ret = job->driver->prepare(job);
788 job_update_rc(job);
789 }
790 return job->ret;
791 }
792
793 static int job_needs_finalize(Job *job)
794 {
795 return !job->auto_finalize;
796 }
797
798 static void job_do_finalize(Job *job)
799 {
800 int rc;
801 assert(job && job->txn);
802
803 /* prepare the transaction to complete */
804 rc = job_txn_apply(job, job_prepare);
805 if (rc) {
806 job_completed_txn_abort(job);
807 } else {
808 job_txn_apply(job, job_finalize_single);
809 }
810 }
811
812 void job_finalize(Job *job, Error **errp)
813 {
814 assert(job && job->id);
815 if (job_apply_verb(job, JOB_VERB_FINALIZE, errp)) {
816 return;
817 }
818 job_do_finalize(job);
819 }
820
821 static int job_transition_to_pending(Job *job)
822 {
823 job_state_transition(job, JOB_STATUS_PENDING);
824 if (!job->auto_finalize) {
825 job_event_pending(job);
826 }
827 return 0;
828 }
829
830 void job_transition_to_ready(Job *job)
831 {
832 job_state_transition(job, JOB_STATUS_READY);
833 job_event_ready(job);
834 }
835
836 static void job_completed_txn_success(Job *job)
837 {
838 JobTxn *txn = job->txn;
839 Job *other_job;
840
841 job_state_transition(job, JOB_STATUS_WAITING);
842
843 /*
844 * Successful completion, see if there are other running jobs in this
845 * txn.
846 */
847 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
848 if (!job_is_completed(other_job)) {
849 return;
850 }
851 assert(other_job->ret == 0);
852 }
853
854 job_txn_apply(job, job_transition_to_pending);
855
856 /* If no jobs need manual finalization, automatically do so */
857 if (job_txn_apply(job, job_needs_finalize) == 0) {
858 job_do_finalize(job);
859 }
860 }
861
862 static void job_completed(Job *job)
863 {
864 assert(job && job->txn && !job_is_completed(job));
865
866 job_update_rc(job);
867 trace_job_completed(job, job->ret);
868 if (job->ret) {
869 job_completed_txn_abort(job);
870 } else {
871 job_completed_txn_success(job);
872 }
873 }
874
875 /** Useful only as a type shim for aio_bh_schedule_oneshot. */
876 static void job_exit(void *opaque)
877 {
878 Job *job = (Job *)opaque;
879 AioContext *ctx;
880
881 job_ref(job);
882 aio_context_acquire(job->aio_context);
883
884 /* This is a lie, we're not quiescent, but still doing the completion
885 * callbacks. However, completion callbacks tend to involve operations that
886 * drain block nodes, and if .drained_poll still returned true, we would
887 * deadlock. */
888 job->busy = false;
889 job_event_idle(job);
890
891 job_completed(job);
892
893 /*
894 * Note that calling job_completed can move the job to a different
895 * aio_context, so we cannot cache from above. job_txn_apply takes care of
896 * acquiring the new lock, and we ref/unref to avoid job_completed freeing
897 * the job underneath us.
898 */
899 ctx = job->aio_context;
900 job_unref(job);
901 aio_context_release(ctx);
902 }
903
904 /**
905 * All jobs must allow a pause point before entering their job proper. This
906 * ensures that jobs can be paused prior to being started, then resumed later.
907 */
908 static void coroutine_fn job_co_entry(void *opaque)
909 {
910 Job *job = opaque;
911
912 assert(job && job->driver && job->driver->run);
913 job_pause_point(job);
914 job->ret = job->driver->run(job, &job->err);
915 job->deferred_to_main_loop = true;
916 job->busy = true;
917 aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
918 }
919
920 void job_start(Job *job)
921 {
922 assert(job && !job_started(job) && job->paused &&
923 job->driver && job->driver->run);
924 job->co = qemu_coroutine_create(job_co_entry, job);
925 job->pause_count--;
926 job->busy = true;
927 job->paused = false;
928 job_state_transition(job, JOB_STATUS_RUNNING);
929 aio_co_enter(job->aio_context, job->co);
930 }
931
932 void job_cancel(Job *job, bool force)
933 {
934 if (job->status == JOB_STATUS_CONCLUDED) {
935 job_do_dismiss(job);
936 return;
937 }
938 job_cancel_async(job, force);
939 if (!job_started(job)) {
940 job_completed(job);
941 } else if (job->deferred_to_main_loop) {
942 job_completed_txn_abort(job);
943 } else {
944 job_enter(job);
945 }
946 }
947
948 void job_user_cancel(Job *job, bool force, Error **errp)
949 {
950 if (job_apply_verb(job, JOB_VERB_CANCEL, errp)) {
951 return;
952 }
953 job_cancel(job, force);
954 }
955
956 /* A wrapper around job_cancel() taking an Error ** parameter so it may be
957 * used with job_finish_sync() without the need for (rather nasty) function
958 * pointer casts there. */
959 static void job_cancel_err(Job *job, Error **errp)
960 {
961 job_cancel(job, false);
962 }
963
964 int job_cancel_sync(Job *job)
965 {
966 return job_finish_sync(job, &job_cancel_err, NULL);
967 }
968
969 void job_cancel_sync_all(void)
970 {
971 Job *job;
972 AioContext *aio_context;
973
974 while ((job = job_next(NULL))) {
975 aio_context = job->aio_context;
976 aio_context_acquire(aio_context);
977 job_cancel_sync(job);
978 aio_context_release(aio_context);
979 }
980 }
981
982 int job_complete_sync(Job *job, Error **errp)
983 {
984 return job_finish_sync(job, job_complete, errp);
985 }
986
987 void job_complete(Job *job, Error **errp)
988 {
989 /* Should not be reachable via external interface for internal jobs */
990 assert(job->id);
991 if (job_apply_verb(job, JOB_VERB_COMPLETE, errp)) {
992 return;
993 }
994 if (job_is_cancelled(job) || !job->driver->complete) {
995 error_setg(errp, "The active block job '%s' cannot be completed",
996 job->id);
997 return;
998 }
999
1000 job->driver->complete(job, errp);
1001 }
1002
1003 int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp)
1004 {
1005 Error *local_err = NULL;
1006 int ret;
1007
1008 job_ref(job);
1009
1010 if (finish) {
1011 finish(job, &local_err);
1012 }
1013 if (local_err) {
1014 error_propagate(errp, local_err);
1015 job_unref(job);
1016 return -EBUSY;
1017 }
1018
1019 AIO_WAIT_WHILE(job->aio_context,
1020 (job_enter(job), !job_is_completed(job)));
1021
1022 ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret;
1023 job_unref(job);
1024 return ret;
1025 }