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1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2011 IBM Corp.
5 * Copyright (c) 2012 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26 #include "qemu/osdep.h"
27 #include "block/aio-wait.h"
28 #include "block/block.h"
29 #include "block/blockjob_int.h"
30 #include "block/block_int.h"
31 #include "block/trace.h"
32 #include "sysemu/block-backend.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-events-block-core.h"
35 #include "qapi/qmp/qerror.h"
36 #include "qemu/main-loop.h"
37 #include "qemu/timer.h"
38
39 static bool is_block_job(Job *job)
40 {
41 return job_type(job) == JOB_TYPE_BACKUP ||
42 job_type(job) == JOB_TYPE_COMMIT ||
43 job_type(job) == JOB_TYPE_MIRROR ||
44 job_type(job) == JOB_TYPE_STREAM;
45 }
46
47 BlockJob *block_job_next_locked(BlockJob *bjob)
48 {
49 Job *job = bjob ? &bjob->job : NULL;
50 GLOBAL_STATE_CODE();
51
52 do {
53 job = job_next_locked(job);
54 } while (job && !is_block_job(job));
55
56 return job ? container_of(job, BlockJob, job) : NULL;
57 }
58
59 BlockJob *block_job_get_locked(const char *id)
60 {
61 Job *job = job_get_locked(id);
62 GLOBAL_STATE_CODE();
63
64 if (job && is_block_job(job)) {
65 return container_of(job, BlockJob, job);
66 } else {
67 return NULL;
68 }
69 }
70
71 BlockJob *block_job_get(const char *id)
72 {
73 JOB_LOCK_GUARD();
74 return block_job_get_locked(id);
75 }
76
77 void block_job_free(Job *job)
78 {
79 BlockJob *bjob = container_of(job, BlockJob, job);
80 GLOBAL_STATE_CODE();
81
82 block_job_remove_all_bdrv(bjob);
83 ratelimit_destroy(&bjob->limit);
84 error_free(bjob->blocker);
85 }
86
87 static char *child_job_get_parent_desc(BdrvChild *c)
88 {
89 BlockJob *job = c->opaque;
90 return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id);
91 }
92
93 static void child_job_drained_begin(BdrvChild *c)
94 {
95 BlockJob *job = c->opaque;
96 job_pause(&job->job);
97 }
98
99 static bool child_job_drained_poll(BdrvChild *c)
100 {
101 BlockJob *bjob = c->opaque;
102 Job *job = &bjob->job;
103 const BlockJobDriver *drv = block_job_driver(bjob);
104
105 /* An inactive or completed job doesn't have any pending requests. Jobs
106 * with !job->busy are either already paused or have a pause point after
107 * being reentered, so no job driver code will run before they pause. */
108 WITH_JOB_LOCK_GUARD() {
109 if (!job->busy || job_is_completed_locked(job)) {
110 return false;
111 }
112 }
113
114 /* Otherwise, assume that it isn't fully stopped yet, but allow the job to
115 * override this assumption. */
116 if (drv->drained_poll) {
117 return drv->drained_poll(bjob);
118 } else {
119 return true;
120 }
121 }
122
123 static void child_job_drained_end(BdrvChild *c)
124 {
125 BlockJob *job = c->opaque;
126 job_resume(&job->job);
127 }
128
129 typedef struct BdrvStateChildJobContext {
130 AioContext *new_ctx;
131 BlockJob *job;
132 } BdrvStateChildJobContext;
133
134 static void child_job_set_aio_ctx_commit(void *opaque)
135 {
136 BdrvStateChildJobContext *s = opaque;
137 BlockJob *job = s->job;
138
139 job_set_aio_context(&job->job, s->new_ctx);
140 }
141
142 static TransactionActionDrv change_child_job_context = {
143 .commit = child_job_set_aio_ctx_commit,
144 .clean = g_free,
145 };
146
147 static bool child_job_change_aio_ctx(BdrvChild *c, AioContext *ctx,
148 GHashTable *visited, Transaction *tran,
149 Error **errp)
150 {
151 BlockJob *job = c->opaque;
152 BdrvStateChildJobContext *s;
153 GSList *l;
154
155 for (l = job->nodes; l; l = l->next) {
156 BdrvChild *sibling = l->data;
157 if (!bdrv_child_change_aio_context(sibling, ctx, visited,
158 tran, errp)) {
159 return false;
160 }
161 }
162
163 s = g_new(BdrvStateChildJobContext, 1);
164 *s = (BdrvStateChildJobContext) {
165 .new_ctx = ctx,
166 .job = job,
167 };
168
169 tran_add(tran, &change_child_job_context, s);
170 return true;
171 }
172
173 static AioContext *child_job_get_parent_aio_context(BdrvChild *c)
174 {
175 BlockJob *job = c->opaque;
176 IO_CODE();
177 JOB_LOCK_GUARD();
178
179 return job->job.aio_context;
180 }
181
182 static const BdrvChildClass child_job = {
183 .get_parent_desc = child_job_get_parent_desc,
184 .drained_begin = child_job_drained_begin,
185 .drained_poll = child_job_drained_poll,
186 .drained_end = child_job_drained_end,
187 .change_aio_ctx = child_job_change_aio_ctx,
188 .stay_at_node = true,
189 .get_parent_aio_context = child_job_get_parent_aio_context,
190 };
191
192 void block_job_remove_all_bdrv(BlockJob *job)
193 {
194 GLOBAL_STATE_CODE();
195 /*
196 * bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(),
197 * which will also traverse job->nodes, so consume the list one by
198 * one to make sure that such a concurrent access does not attempt
199 * to process an already freed BdrvChild.
200 */
201 aio_context_release(job->job.aio_context);
202 bdrv_graph_wrlock(NULL);
203 aio_context_acquire(job->job.aio_context);
204 while (job->nodes) {
205 GSList *l = job->nodes;
206 BdrvChild *c = l->data;
207
208 job->nodes = l->next;
209
210 bdrv_op_unblock_all(c->bs, job->blocker);
211 bdrv_root_unref_child(c);
212
213 g_slist_free_1(l);
214 }
215 bdrv_graph_wrunlock();
216 }
217
218 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
219 {
220 GSList *el;
221 GLOBAL_STATE_CODE();
222
223 for (el = job->nodes; el; el = el->next) {
224 BdrvChild *c = el->data;
225 if (c->bs == bs) {
226 return true;
227 }
228 }
229
230 return false;
231 }
232
233 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
234 uint64_t perm, uint64_t shared_perm, Error **errp)
235 {
236 BdrvChild *c;
237 AioContext *ctx = bdrv_get_aio_context(bs);
238 bool need_context_ops;
239 GLOBAL_STATE_CODE();
240
241 bdrv_ref(bs);
242
243 need_context_ops = ctx != job->job.aio_context;
244
245 if (need_context_ops) {
246 if (job->job.aio_context != qemu_get_aio_context()) {
247 aio_context_release(job->job.aio_context);
248 }
249 aio_context_acquire(ctx);
250 }
251 c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job,
252 errp);
253 if (need_context_ops) {
254 aio_context_release(ctx);
255 if (job->job.aio_context != qemu_get_aio_context()) {
256 aio_context_acquire(job->job.aio_context);
257 }
258 }
259 if (c == NULL) {
260 return -EPERM;
261 }
262
263 job->nodes = g_slist_prepend(job->nodes, c);
264 bdrv_op_block_all(bs, job->blocker);
265
266 return 0;
267 }
268
269 /* Called with job_mutex lock held. */
270 static void block_job_on_idle_locked(Notifier *n, void *opaque)
271 {
272 aio_wait_kick();
273 }
274
275 bool block_job_is_internal(BlockJob *job)
276 {
277 return (job->job.id == NULL);
278 }
279
280 const BlockJobDriver *block_job_driver(BlockJob *job)
281 {
282 return container_of(job->job.driver, BlockJobDriver, job_driver);
283 }
284
285 /* Assumes the job_mutex is held */
286 static bool job_timer_pending(Job *job)
287 {
288 return timer_pending(&job->sleep_timer);
289 }
290
291 bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp)
292 {
293 const BlockJobDriver *drv = block_job_driver(job);
294 int64_t old_speed = job->speed;
295
296 GLOBAL_STATE_CODE();
297
298 if (job_apply_verb_locked(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
299 return false;
300 }
301 if (speed < 0) {
302 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed",
303 "a non-negative value");
304 return false;
305 }
306
307 ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);
308
309 job->speed = speed;
310
311 if (drv->set_speed) {
312 job_unlock();
313 drv->set_speed(job, speed);
314 job_lock();
315 }
316
317 if (speed && speed <= old_speed) {
318 return true;
319 }
320
321 /* kick only if a timer is pending */
322 job_enter_cond_locked(&job->job, job_timer_pending);
323
324 return true;
325 }
326
327 static bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
328 {
329 JOB_LOCK_GUARD();
330 return block_job_set_speed_locked(job, speed, errp);
331 }
332
333 void block_job_change_locked(BlockJob *job, BlockJobChangeOptions *opts,
334 Error **errp)
335 {
336 const BlockJobDriver *drv = block_job_driver(job);
337
338 GLOBAL_STATE_CODE();
339
340 if (job_apply_verb_locked(&job->job, JOB_VERB_CHANGE, errp)) {
341 return;
342 }
343
344 if (drv->change) {
345 job_unlock();
346 drv->change(job, opts, errp);
347 job_lock();
348 } else {
349 error_setg(errp, "Job type does not support change");
350 }
351 }
352
353 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n)
354 {
355 IO_CODE();
356 ratelimit_calculate_delay(&job->limit, n);
357 }
358
359 void block_job_ratelimit_sleep(BlockJob *job)
360 {
361 uint64_t delay_ns;
362
363 /*
364 * Sleep at least once. If the job is reentered early, keep waiting until
365 * we've waited for the full time that is necessary to keep the job at the
366 * right speed.
367 *
368 * Make sure to recalculate the delay after each (possibly interrupted)
369 * sleep because the speed can change while the job has yielded.
370 */
371 do {
372 delay_ns = ratelimit_calculate_delay(&job->limit, 0);
373 job_sleep_ns(&job->job, delay_ns);
374 } while (delay_ns && !job_is_cancelled(&job->job));
375 }
376
377 BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp)
378 {
379 BlockJobInfo *info;
380 uint64_t progress_current, progress_total;
381 const BlockJobDriver *drv = block_job_driver(job);
382
383 GLOBAL_STATE_CODE();
384
385 if (block_job_is_internal(job)) {
386 error_setg(errp, "Cannot query QEMU internal jobs");
387 return NULL;
388 }
389
390 progress_get_snapshot(&job->job.progress, &progress_current,
391 &progress_total);
392
393 info = g_new0(BlockJobInfo, 1);
394 info->type = job_type(&job->job);
395 info->device = g_strdup(job->job.id);
396 info->busy = job->job.busy;
397 info->paused = job->job.pause_count > 0;
398 info->offset = progress_current;
399 info->len = progress_total;
400 info->speed = job->speed;
401 info->io_status = job->iostatus;
402 info->ready = job_is_ready_locked(&job->job),
403 info->status = job->job.status;
404 info->auto_finalize = job->job.auto_finalize;
405 info->auto_dismiss = job->job.auto_dismiss;
406 if (job->job.ret) {
407 info->error = job->job.err ?
408 g_strdup(error_get_pretty(job->job.err)) :
409 g_strdup(strerror(-job->job.ret));
410 }
411 if (drv->query) {
412 job_unlock();
413 drv->query(job, info);
414 job_lock();
415 }
416 return info;
417 }
418
419 /* Called with job lock held */
420 static void block_job_iostatus_set_err_locked(BlockJob *job, int error)
421 {
422 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
423 job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
424 BLOCK_DEVICE_IO_STATUS_FAILED;
425 }
426 }
427
428 /* Called with job_mutex lock held. */
429 static void block_job_event_cancelled_locked(Notifier *n, void *opaque)
430 {
431 BlockJob *job = opaque;
432 uint64_t progress_current, progress_total;
433
434 if (block_job_is_internal(job)) {
435 return;
436 }
437
438 progress_get_snapshot(&job->job.progress, &progress_current,
439 &progress_total);
440
441 qapi_event_send_block_job_cancelled(job_type(&job->job),
442 job->job.id,
443 progress_total,
444 progress_current,
445 job->speed);
446 }
447
448 /* Called with job_mutex lock held. */
449 static void block_job_event_completed_locked(Notifier *n, void *opaque)
450 {
451 BlockJob *job = opaque;
452 const char *msg = NULL;
453 uint64_t progress_current, progress_total;
454
455 if (block_job_is_internal(job)) {
456 return;
457 }
458
459 if (job->job.ret < 0) {
460 msg = error_get_pretty(job->job.err);
461 }
462
463 progress_get_snapshot(&job->job.progress, &progress_current,
464 &progress_total);
465
466 qapi_event_send_block_job_completed(job_type(&job->job),
467 job->job.id,
468 progress_total,
469 progress_current,
470 job->speed,
471 msg);
472 }
473
474 /* Called with job_mutex lock held. */
475 static void block_job_event_pending_locked(Notifier *n, void *opaque)
476 {
477 BlockJob *job = opaque;
478
479 if (block_job_is_internal(job)) {
480 return;
481 }
482
483 qapi_event_send_block_job_pending(job_type(&job->job),
484 job->job.id);
485 }
486
487 /* Called with job_mutex lock held. */
488 static void block_job_event_ready_locked(Notifier *n, void *opaque)
489 {
490 BlockJob *job = opaque;
491 uint64_t progress_current, progress_total;
492
493 if (block_job_is_internal(job)) {
494 return;
495 }
496
497 progress_get_snapshot(&job->job.progress, &progress_current,
498 &progress_total);
499
500 qapi_event_send_block_job_ready(job_type(&job->job),
501 job->job.id,
502 progress_total,
503 progress_current,
504 job->speed);
505 }
506
507
508 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
509 JobTxn *txn, BlockDriverState *bs, uint64_t perm,
510 uint64_t shared_perm, int64_t speed, int flags,
511 BlockCompletionFunc *cb, void *opaque, Error **errp)
512 {
513 BlockJob *job;
514 int ret;
515 GLOBAL_STATE_CODE();
516
517 bdrv_graph_wrlock(bs);
518
519 if (job_id == NULL && !(flags & JOB_INTERNAL)) {
520 job_id = bdrv_get_device_name(bs);
521 }
522
523 job = job_create(job_id, &driver->job_driver, txn, bdrv_get_aio_context(bs),
524 flags, cb, opaque, errp);
525 if (job == NULL) {
526 bdrv_graph_wrunlock();
527 return NULL;
528 }
529
530 assert(is_block_job(&job->job));
531 assert(job->job.driver->free == &block_job_free);
532 assert(job->job.driver->user_resume == &block_job_user_resume);
533
534 ratelimit_init(&job->limit);
535
536 job->finalize_cancelled_notifier.notify = block_job_event_cancelled_locked;
537 job->finalize_completed_notifier.notify = block_job_event_completed_locked;
538 job->pending_notifier.notify = block_job_event_pending_locked;
539 job->ready_notifier.notify = block_job_event_ready_locked;
540 job->idle_notifier.notify = block_job_on_idle_locked;
541
542 WITH_JOB_LOCK_GUARD() {
543 notifier_list_add(&job->job.on_finalize_cancelled,
544 &job->finalize_cancelled_notifier);
545 notifier_list_add(&job->job.on_finalize_completed,
546 &job->finalize_completed_notifier);
547 notifier_list_add(&job->job.on_pending, &job->pending_notifier);
548 notifier_list_add(&job->job.on_ready, &job->ready_notifier);
549 notifier_list_add(&job->job.on_idle, &job->idle_notifier);
550 }
551
552 error_setg(&job->blocker, "block device is in use by block job: %s",
553 job_type_str(&job->job));
554
555 ret = block_job_add_bdrv(job, "main node", bs, perm, shared_perm, errp);
556 if (ret < 0) {
557 goto fail;
558 }
559
560 bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
561
562 if (!block_job_set_speed(job, speed, errp)) {
563 goto fail;
564 }
565
566 bdrv_graph_wrunlock();
567 return job;
568
569 fail:
570 bdrv_graph_wrunlock();
571 job_early_fail(&job->job);
572 return NULL;
573 }
574
575 void block_job_iostatus_reset_locked(BlockJob *job)
576 {
577 GLOBAL_STATE_CODE();
578 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
579 return;
580 }
581 assert(job->job.user_paused && job->job.pause_count > 0);
582 job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
583 }
584
585 static void block_job_iostatus_reset(BlockJob *job)
586 {
587 JOB_LOCK_GUARD();
588 block_job_iostatus_reset_locked(job);
589 }
590
591 void block_job_user_resume(Job *job)
592 {
593 BlockJob *bjob = container_of(job, BlockJob, job);
594 GLOBAL_STATE_CODE();
595 block_job_iostatus_reset(bjob);
596 }
597
598 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
599 int is_read, int error)
600 {
601 BlockErrorAction action;
602 IO_CODE();
603
604 switch (on_err) {
605 case BLOCKDEV_ON_ERROR_ENOSPC:
606 case BLOCKDEV_ON_ERROR_AUTO:
607 action = (error == ENOSPC) ?
608 BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
609 break;
610 case BLOCKDEV_ON_ERROR_STOP:
611 action = BLOCK_ERROR_ACTION_STOP;
612 break;
613 case BLOCKDEV_ON_ERROR_REPORT:
614 action = BLOCK_ERROR_ACTION_REPORT;
615 break;
616 case BLOCKDEV_ON_ERROR_IGNORE:
617 action = BLOCK_ERROR_ACTION_IGNORE;
618 break;
619 default:
620 abort();
621 }
622 if (!block_job_is_internal(job)) {
623 qapi_event_send_block_job_error(job->job.id,
624 is_read ? IO_OPERATION_TYPE_READ :
625 IO_OPERATION_TYPE_WRITE,
626 action);
627 }
628 if (action == BLOCK_ERROR_ACTION_STOP) {
629 WITH_JOB_LOCK_GUARD() {
630 if (!job->job.user_paused) {
631 job_pause_locked(&job->job);
632 /*
633 * make the pause user visible, which will be
634 * resumed from QMP.
635 */
636 job->job.user_paused = true;
637 }
638 block_job_iostatus_set_err_locked(job, error);
639 }
640 }
641 return action;
642 }
643
644 AioContext *block_job_get_aio_context(BlockJob *job)
645 {
646 GLOBAL_STATE_CODE();
647 return job->job.aio_context;
648 }