Merge remote-tracking branch 'remotes/kraxel/tags/seabios-20220118-pull-request'...
[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 /* force_cancel may be true only if cancelled is true, too */
221 assert(job->cancelled || !job->force_cancel);
222 return job->force_cancel;
223 }
224
225 bool job_cancel_requested(Job *job)
226 {
227 return job->cancelled;
228 }
229
230 bool job_is_ready(Job *job)
231 {
232 switch (job->status) {
233 case JOB_STATUS_UNDEFINED:
234 case JOB_STATUS_CREATED:
235 case JOB_STATUS_RUNNING:
236 case JOB_STATUS_PAUSED:
237 case JOB_STATUS_WAITING:
238 case JOB_STATUS_PENDING:
239 case JOB_STATUS_ABORTING:
240 case JOB_STATUS_CONCLUDED:
241 case JOB_STATUS_NULL:
242 return false;
243 case JOB_STATUS_READY:
244 case JOB_STATUS_STANDBY:
245 return true;
246 default:
247 g_assert_not_reached();
248 }
249 return false;
250 }
251
252 bool job_is_completed(Job *job)
253 {
254 switch (job->status) {
255 case JOB_STATUS_UNDEFINED:
256 case JOB_STATUS_CREATED:
257 case JOB_STATUS_RUNNING:
258 case JOB_STATUS_PAUSED:
259 case JOB_STATUS_READY:
260 case JOB_STATUS_STANDBY:
261 return false;
262 case JOB_STATUS_WAITING:
263 case JOB_STATUS_PENDING:
264 case JOB_STATUS_ABORTING:
265 case JOB_STATUS_CONCLUDED:
266 case JOB_STATUS_NULL:
267 return true;
268 default:
269 g_assert_not_reached();
270 }
271 return false;
272 }
273
274 static bool job_started(Job *job)
275 {
276 return job->co;
277 }
278
279 static bool job_should_pause(Job *job)
280 {
281 return job->pause_count > 0;
282 }
283
284 Job *job_next(Job *job)
285 {
286 if (!job) {
287 return QLIST_FIRST(&jobs);
288 }
289 return QLIST_NEXT(job, job_list);
290 }
291
292 Job *job_get(const char *id)
293 {
294 Job *job;
295
296 QLIST_FOREACH(job, &jobs, job_list) {
297 if (job->id && !strcmp(id, job->id)) {
298 return job;
299 }
300 }
301
302 return NULL;
303 }
304
305 static void job_sleep_timer_cb(void *opaque)
306 {
307 Job *job = opaque;
308
309 job_enter(job);
310 }
311
312 void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
313 AioContext *ctx, int flags, BlockCompletionFunc *cb,
314 void *opaque, Error **errp)
315 {
316 Job *job;
317
318 if (job_id) {
319 if (flags & JOB_INTERNAL) {
320 error_setg(errp, "Cannot specify job ID for internal job");
321 return NULL;
322 }
323 if (!id_wellformed(job_id)) {
324 error_setg(errp, "Invalid job ID '%s'", job_id);
325 return NULL;
326 }
327 if (job_get(job_id)) {
328 error_setg(errp, "Job ID '%s' already in use", job_id);
329 return NULL;
330 }
331 } else if (!(flags & JOB_INTERNAL)) {
332 error_setg(errp, "An explicit job ID is required");
333 return NULL;
334 }
335
336 job = g_malloc0(driver->instance_size);
337 job->driver = driver;
338 job->id = g_strdup(job_id);
339 job->refcnt = 1;
340 job->aio_context = ctx;
341 job->busy = false;
342 job->paused = true;
343 job->pause_count = 1;
344 job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE);
345 job->auto_dismiss = !(flags & JOB_MANUAL_DISMISS);
346 job->cb = cb;
347 job->opaque = opaque;
348
349 progress_init(&job->progress);
350
351 notifier_list_init(&job->on_finalize_cancelled);
352 notifier_list_init(&job->on_finalize_completed);
353 notifier_list_init(&job->on_pending);
354 notifier_list_init(&job->on_ready);
355
356 job_state_transition(job, JOB_STATUS_CREATED);
357 aio_timer_init(qemu_get_aio_context(), &job->sleep_timer,
358 QEMU_CLOCK_REALTIME, SCALE_NS,
359 job_sleep_timer_cb, job);
360
361 QLIST_INSERT_HEAD(&jobs, job, job_list);
362
363 /* Single jobs are modeled as single-job transactions for sake of
364 * consolidating the job management logic */
365 if (!txn) {
366 txn = job_txn_new();
367 job_txn_add_job(txn, job);
368 job_txn_unref(txn);
369 } else {
370 job_txn_add_job(txn, job);
371 }
372
373 return job;
374 }
375
376 void job_ref(Job *job)
377 {
378 ++job->refcnt;
379 }
380
381 void job_unref(Job *job)
382 {
383 if (--job->refcnt == 0) {
384 assert(job->status == JOB_STATUS_NULL);
385 assert(!timer_pending(&job->sleep_timer));
386 assert(!job->txn);
387
388 if (job->driver->free) {
389 job->driver->free(job);
390 }
391
392 QLIST_REMOVE(job, job_list);
393
394 progress_destroy(&job->progress);
395 error_free(job->err);
396 g_free(job->id);
397 g_free(job);
398 }
399 }
400
401 void job_progress_update(Job *job, uint64_t done)
402 {
403 progress_work_done(&job->progress, done);
404 }
405
406 void job_progress_set_remaining(Job *job, uint64_t remaining)
407 {
408 progress_set_remaining(&job->progress, remaining);
409 }
410
411 void job_progress_increase_remaining(Job *job, uint64_t delta)
412 {
413 progress_increase_remaining(&job->progress, delta);
414 }
415
416 void job_event_cancelled(Job *job)
417 {
418 notifier_list_notify(&job->on_finalize_cancelled, job);
419 }
420
421 void job_event_completed(Job *job)
422 {
423 notifier_list_notify(&job->on_finalize_completed, job);
424 }
425
426 static void job_event_pending(Job *job)
427 {
428 notifier_list_notify(&job->on_pending, job);
429 }
430
431 static void job_event_ready(Job *job)
432 {
433 notifier_list_notify(&job->on_ready, job);
434 }
435
436 static void job_event_idle(Job *job)
437 {
438 notifier_list_notify(&job->on_idle, job);
439 }
440
441 void job_enter_cond(Job *job, bool(*fn)(Job *job))
442 {
443 if (!job_started(job)) {
444 return;
445 }
446 if (job->deferred_to_main_loop) {
447 return;
448 }
449
450 job_lock();
451 if (job->busy) {
452 job_unlock();
453 return;
454 }
455
456 if (fn && !fn(job)) {
457 job_unlock();
458 return;
459 }
460
461 assert(!job->deferred_to_main_loop);
462 timer_del(&job->sleep_timer);
463 job->busy = true;
464 job_unlock();
465 aio_co_enter(job->aio_context, job->co);
466 }
467
468 void job_enter(Job *job)
469 {
470 job_enter_cond(job, NULL);
471 }
472
473 /* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds.
474 * Reentering the job coroutine with job_enter() before the timer has expired
475 * is allowed and cancels the timer.
476 *
477 * If @ns is (uint64_t) -1, no timer is scheduled and job_enter() must be
478 * called explicitly. */
479 static void coroutine_fn job_do_yield(Job *job, uint64_t ns)
480 {
481 job_lock();
482 if (ns != -1) {
483 timer_mod(&job->sleep_timer, ns);
484 }
485 job->busy = false;
486 job_event_idle(job);
487 job_unlock();
488 qemu_coroutine_yield();
489
490 /* Set by job_enter_cond() before re-entering the coroutine. */
491 assert(job->busy);
492 }
493
494 void coroutine_fn job_pause_point(Job *job)
495 {
496 assert(job && job_started(job));
497
498 if (!job_should_pause(job)) {
499 return;
500 }
501 if (job_is_cancelled(job)) {
502 return;
503 }
504
505 if (job->driver->pause) {
506 job->driver->pause(job);
507 }
508
509 if (job_should_pause(job) && !job_is_cancelled(job)) {
510 JobStatus status = job->status;
511 job_state_transition(job, status == JOB_STATUS_READY
512 ? JOB_STATUS_STANDBY
513 : JOB_STATUS_PAUSED);
514 job->paused = true;
515 job_do_yield(job, -1);
516 job->paused = false;
517 job_state_transition(job, status);
518 }
519
520 if (job->driver->resume) {
521 job->driver->resume(job);
522 }
523 }
524
525 void job_yield(Job *job)
526 {
527 assert(job->busy);
528
529 /* Check cancellation *before* setting busy = false, too! */
530 if (job_is_cancelled(job)) {
531 return;
532 }
533
534 if (!job_should_pause(job)) {
535 job_do_yield(job, -1);
536 }
537
538 job_pause_point(job);
539 }
540
541 void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
542 {
543 assert(job->busy);
544
545 /* Check cancellation *before* setting busy = false, too! */
546 if (job_is_cancelled(job)) {
547 return;
548 }
549
550 if (!job_should_pause(job)) {
551 job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
552 }
553
554 job_pause_point(job);
555 }
556
557 /* Assumes the block_job_mutex is held */
558 static bool job_timer_not_pending(Job *job)
559 {
560 return !timer_pending(&job->sleep_timer);
561 }
562
563 void job_pause(Job *job)
564 {
565 job->pause_count++;
566 if (!job->paused) {
567 job_enter(job);
568 }
569 }
570
571 void job_resume(Job *job)
572 {
573 assert(job->pause_count > 0);
574 job->pause_count--;
575 if (job->pause_count) {
576 return;
577 }
578
579 /* kick only if no timer is pending */
580 job_enter_cond(job, job_timer_not_pending);
581 }
582
583 void job_user_pause(Job *job, Error **errp)
584 {
585 if (job_apply_verb(job, JOB_VERB_PAUSE, errp)) {
586 return;
587 }
588 if (job->user_paused) {
589 error_setg(errp, "Job is already paused");
590 return;
591 }
592 job->user_paused = true;
593 job_pause(job);
594 }
595
596 bool job_user_paused(Job *job)
597 {
598 return job->user_paused;
599 }
600
601 void job_user_resume(Job *job, Error **errp)
602 {
603 assert(job);
604 if (!job->user_paused || job->pause_count <= 0) {
605 error_setg(errp, "Can't resume a job that was not paused");
606 return;
607 }
608 if (job_apply_verb(job, JOB_VERB_RESUME, errp)) {
609 return;
610 }
611 if (job->driver->user_resume) {
612 job->driver->user_resume(job);
613 }
614 job->user_paused = false;
615 job_resume(job);
616 }
617
618 static void job_do_dismiss(Job *job)
619 {
620 assert(job);
621 job->busy = false;
622 job->paused = false;
623 job->deferred_to_main_loop = true;
624
625 job_txn_del_job(job);
626
627 job_state_transition(job, JOB_STATUS_NULL);
628 job_unref(job);
629 }
630
631 void job_dismiss(Job **jobptr, Error **errp)
632 {
633 Job *job = *jobptr;
634 /* similarly to _complete, this is QMP-interface only. */
635 assert(job->id);
636 if (job_apply_verb(job, JOB_VERB_DISMISS, errp)) {
637 return;
638 }
639
640 job_do_dismiss(job);
641 *jobptr = NULL;
642 }
643
644 void job_early_fail(Job *job)
645 {
646 assert(job->status == JOB_STATUS_CREATED);
647 job_do_dismiss(job);
648 }
649
650 static void job_conclude(Job *job)
651 {
652 job_state_transition(job, JOB_STATUS_CONCLUDED);
653 if (job->auto_dismiss || !job_started(job)) {
654 job_do_dismiss(job);
655 }
656 }
657
658 static void job_update_rc(Job *job)
659 {
660 if (!job->ret && job_is_cancelled(job)) {
661 job->ret = -ECANCELED;
662 }
663 if (job->ret) {
664 if (!job->err) {
665 error_setg(&job->err, "%s", strerror(-job->ret));
666 }
667 job_state_transition(job, JOB_STATUS_ABORTING);
668 }
669 }
670
671 static void job_commit(Job *job)
672 {
673 assert(!job->ret);
674 if (job->driver->commit) {
675 job->driver->commit(job);
676 }
677 }
678
679 static void job_abort(Job *job)
680 {
681 assert(job->ret);
682 if (job->driver->abort) {
683 job->driver->abort(job);
684 }
685 }
686
687 static void job_clean(Job *job)
688 {
689 if (job->driver->clean) {
690 job->driver->clean(job);
691 }
692 }
693
694 static int job_finalize_single(Job *job)
695 {
696 assert(job_is_completed(job));
697
698 /* Ensure abort is called for late-transactional failures */
699 job_update_rc(job);
700
701 if (!job->ret) {
702 job_commit(job);
703 } else {
704 job_abort(job);
705 }
706 job_clean(job);
707
708 if (job->cb) {
709 job->cb(job->opaque, job->ret);
710 }
711
712 /* Emit events only if we actually started */
713 if (job_started(job)) {
714 if (job_is_cancelled(job)) {
715 job_event_cancelled(job);
716 } else {
717 job_event_completed(job);
718 }
719 }
720
721 job_txn_del_job(job);
722 job_conclude(job);
723 return 0;
724 }
725
726 static void job_cancel_async(Job *job, bool force)
727 {
728 if (job->driver->cancel) {
729 force = job->driver->cancel(job, force);
730 } else {
731 /* No .cancel() means the job will behave as if force-cancelled */
732 force = true;
733 }
734
735 if (job->user_paused) {
736 /* Do not call job_enter here, the caller will handle it. */
737 if (job->driver->user_resume) {
738 job->driver->user_resume(job);
739 }
740 job->user_paused = false;
741 assert(job->pause_count > 0);
742 job->pause_count--;
743 }
744
745 /*
746 * Ignore soft cancel requests after the job is already done
747 * (We will still invoke job->driver->cancel() above, but if the
748 * job driver supports soft cancelling and the job is done, that
749 * should be a no-op, too. We still call it so it can override
750 * @force.)
751 */
752 if (force || !job->deferred_to_main_loop) {
753 job->cancelled = true;
754 /* To prevent 'force == false' overriding a previous 'force == true' */
755 job->force_cancel |= force;
756 }
757 }
758
759 static void job_completed_txn_abort(Job *job)
760 {
761 AioContext *ctx;
762 JobTxn *txn = job->txn;
763 Job *other_job;
764
765 if (txn->aborting) {
766 /*
767 * We are cancelled by another job, which will handle everything.
768 */
769 return;
770 }
771 txn->aborting = true;
772 job_txn_ref(txn);
773
774 /*
775 * We can only hold the single job's AioContext lock while calling
776 * job_finalize_single() because the finalization callbacks can involve
777 * calls of AIO_WAIT_WHILE(), which could deadlock otherwise.
778 * Note that the job's AioContext may change when it is finalized.
779 */
780 job_ref(job);
781 aio_context_release(job->aio_context);
782
783 /* Other jobs are effectively cancelled by us, set the status for
784 * them; this job, however, may or may not be cancelled, depending
785 * on the caller, so leave it. */
786 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
787 if (other_job != job) {
788 ctx = other_job->aio_context;
789 aio_context_acquire(ctx);
790 /*
791 * This is a transaction: If one job failed, no result will matter.
792 * Therefore, pass force=true to terminate all other jobs as quickly
793 * as possible.
794 */
795 job_cancel_async(other_job, true);
796 aio_context_release(ctx);
797 }
798 }
799 while (!QLIST_EMPTY(&txn->jobs)) {
800 other_job = QLIST_FIRST(&txn->jobs);
801 /*
802 * The job's AioContext may change, so store it in @ctx so we
803 * release the same context that we have acquired before.
804 */
805 ctx = other_job->aio_context;
806 aio_context_acquire(ctx);
807 if (!job_is_completed(other_job)) {
808 assert(job_cancel_requested(other_job));
809 job_finish_sync(other_job, NULL, NULL);
810 }
811 job_finalize_single(other_job);
812 aio_context_release(ctx);
813 }
814
815 /*
816 * Use job_ref()/job_unref() so we can read the AioContext here
817 * even if the job went away during job_finalize_single().
818 */
819 aio_context_acquire(job->aio_context);
820 job_unref(job);
821
822 job_txn_unref(txn);
823 }
824
825 static int job_prepare(Job *job)
826 {
827 if (job->ret == 0 && job->driver->prepare) {
828 job->ret = job->driver->prepare(job);
829 job_update_rc(job);
830 }
831 return job->ret;
832 }
833
834 static int job_needs_finalize(Job *job)
835 {
836 return !job->auto_finalize;
837 }
838
839 static void job_do_finalize(Job *job)
840 {
841 int rc;
842 assert(job && job->txn);
843
844 /* prepare the transaction to complete */
845 rc = job_txn_apply(job, job_prepare);
846 if (rc) {
847 job_completed_txn_abort(job);
848 } else {
849 job_txn_apply(job, job_finalize_single);
850 }
851 }
852
853 void job_finalize(Job *job, Error **errp)
854 {
855 assert(job && job->id);
856 if (job_apply_verb(job, JOB_VERB_FINALIZE, errp)) {
857 return;
858 }
859 job_do_finalize(job);
860 }
861
862 static int job_transition_to_pending(Job *job)
863 {
864 job_state_transition(job, JOB_STATUS_PENDING);
865 if (!job->auto_finalize) {
866 job_event_pending(job);
867 }
868 return 0;
869 }
870
871 void job_transition_to_ready(Job *job)
872 {
873 job_state_transition(job, JOB_STATUS_READY);
874 job_event_ready(job);
875 }
876
877 static void job_completed_txn_success(Job *job)
878 {
879 JobTxn *txn = job->txn;
880 Job *other_job;
881
882 job_state_transition(job, JOB_STATUS_WAITING);
883
884 /*
885 * Successful completion, see if there are other running jobs in this
886 * txn.
887 */
888 QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
889 if (!job_is_completed(other_job)) {
890 return;
891 }
892 assert(other_job->ret == 0);
893 }
894
895 job_txn_apply(job, job_transition_to_pending);
896
897 /* If no jobs need manual finalization, automatically do so */
898 if (job_txn_apply(job, job_needs_finalize) == 0) {
899 job_do_finalize(job);
900 }
901 }
902
903 static void job_completed(Job *job)
904 {
905 assert(job && job->txn && !job_is_completed(job));
906
907 job_update_rc(job);
908 trace_job_completed(job, job->ret);
909 if (job->ret) {
910 job_completed_txn_abort(job);
911 } else {
912 job_completed_txn_success(job);
913 }
914 }
915
916 /** Useful only as a type shim for aio_bh_schedule_oneshot. */
917 static void job_exit(void *opaque)
918 {
919 Job *job = (Job *)opaque;
920 AioContext *ctx;
921
922 job_ref(job);
923 aio_context_acquire(job->aio_context);
924
925 /* This is a lie, we're not quiescent, but still doing the completion
926 * callbacks. However, completion callbacks tend to involve operations that
927 * drain block nodes, and if .drained_poll still returned true, we would
928 * deadlock. */
929 job->busy = false;
930 job_event_idle(job);
931
932 job_completed(job);
933
934 /*
935 * Note that calling job_completed can move the job to a different
936 * aio_context, so we cannot cache from above. job_txn_apply takes care of
937 * acquiring the new lock, and we ref/unref to avoid job_completed freeing
938 * the job underneath us.
939 */
940 ctx = job->aio_context;
941 job_unref(job);
942 aio_context_release(ctx);
943 }
944
945 /**
946 * All jobs must allow a pause point before entering their job proper. This
947 * ensures that jobs can be paused prior to being started, then resumed later.
948 */
949 static void coroutine_fn job_co_entry(void *opaque)
950 {
951 Job *job = opaque;
952
953 assert(job && job->driver && job->driver->run);
954 job_pause_point(job);
955 job->ret = job->driver->run(job, &job->err);
956 job->deferred_to_main_loop = true;
957 job->busy = true;
958 aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
959 }
960
961 void job_start(Job *job)
962 {
963 assert(job && !job_started(job) && job->paused &&
964 job->driver && job->driver->run);
965 job->co = qemu_coroutine_create(job_co_entry, job);
966 job->pause_count--;
967 job->busy = true;
968 job->paused = false;
969 job_state_transition(job, JOB_STATUS_RUNNING);
970 aio_co_enter(job->aio_context, job->co);
971 }
972
973 void job_cancel(Job *job, bool force)
974 {
975 if (job->status == JOB_STATUS_CONCLUDED) {
976 job_do_dismiss(job);
977 return;
978 }
979 job_cancel_async(job, force);
980 if (!job_started(job)) {
981 job_completed(job);
982 } else if (job->deferred_to_main_loop) {
983 /*
984 * job_cancel_async() ignores soft-cancel requests for jobs
985 * that are already done (i.e. deferred to the main loop). We
986 * have to check again whether the job is really cancelled.
987 * (job_cancel_requested() and job_is_cancelled() are equivalent
988 * here, because job_cancel_async() will make soft-cancel
989 * requests no-ops when deferred_to_main_loop is true. We
990 * choose to call job_is_cancelled() to show that we invoke
991 * job_completed_txn_abort() only for force-cancelled jobs.)
992 */
993 if (job_is_cancelled(job)) {
994 job_completed_txn_abort(job);
995 }
996 } else {
997 job_enter(job);
998 }
999 }
1000
1001 void job_user_cancel(Job *job, bool force, Error **errp)
1002 {
1003 if (job_apply_verb(job, JOB_VERB_CANCEL, errp)) {
1004 return;
1005 }
1006 job_cancel(job, force);
1007 }
1008
1009 /* A wrapper around job_cancel() taking an Error ** parameter so it may be
1010 * used with job_finish_sync() without the need for (rather nasty) function
1011 * pointer casts there. */
1012 static void job_cancel_err(Job *job, Error **errp)
1013 {
1014 job_cancel(job, false);
1015 }
1016
1017 /**
1018 * Same as job_cancel_err(), but force-cancel.
1019 */
1020 static void job_force_cancel_err(Job *job, Error **errp)
1021 {
1022 job_cancel(job, true);
1023 }
1024
1025 int job_cancel_sync(Job *job, bool force)
1026 {
1027 if (force) {
1028 return job_finish_sync(job, &job_force_cancel_err, NULL);
1029 } else {
1030 return job_finish_sync(job, &job_cancel_err, NULL);
1031 }
1032 }
1033
1034 void job_cancel_sync_all(void)
1035 {
1036 Job *job;
1037 AioContext *aio_context;
1038
1039 while ((job = job_next(NULL))) {
1040 aio_context = job->aio_context;
1041 aio_context_acquire(aio_context);
1042 job_cancel_sync(job, true);
1043 aio_context_release(aio_context);
1044 }
1045 }
1046
1047 int job_complete_sync(Job *job, Error **errp)
1048 {
1049 return job_finish_sync(job, job_complete, errp);
1050 }
1051
1052 void job_complete(Job *job, Error **errp)
1053 {
1054 /* Should not be reachable via external interface for internal jobs */
1055 assert(job->id);
1056 if (job_apply_verb(job, JOB_VERB_COMPLETE, errp)) {
1057 return;
1058 }
1059 if (job_cancel_requested(job) || !job->driver->complete) {
1060 error_setg(errp, "The active block job '%s' cannot be completed",
1061 job->id);
1062 return;
1063 }
1064
1065 job->driver->complete(job, errp);
1066 }
1067
1068 int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp)
1069 {
1070 Error *local_err = NULL;
1071 int ret;
1072
1073 job_ref(job);
1074
1075 if (finish) {
1076 finish(job, &local_err);
1077 }
1078 if (local_err) {
1079 error_propagate(errp, local_err);
1080 job_unref(job);
1081 return -EBUSY;
1082 }
1083
1084 AIO_WAIT_WHILE(job->aio_context,
1085 (job_enter(job), !job_is_completed(job)));
1086
1087 ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret;
1088 job_unref(job);
1089 return ret;
1090 }