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