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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 "qemu-common.h" | |
28 | #include "block/block.h" | |
29 | #include "block/blockjob_int.h" | |
30 | #include "block/block_int.h" | |
31 | #include "sysemu/block-backend.h" | |
32 | #include "qapi/error.h" | |
33 | #include "qapi/qapi-events-block-core.h" | |
34 | #include "qapi/qmp/qerror.h" | |
35 | #include "qemu/coroutine.h" | |
36 | #include "qemu/id.h" | |
37 | #include "qemu/timer.h" | |
38 | ||
39 | /* Right now, this mutex is only needed to synchronize accesses to job->busy | |
40 | * and job->sleep_timer, such as concurrent calls to block_job_do_yield and | |
41 | * block_job_enter. */ | |
42 | static QemuMutex block_job_mutex; | |
43 | ||
44 | static void block_job_lock(void) | |
45 | { | |
46 | qemu_mutex_lock(&block_job_mutex); | |
47 | } | |
48 | ||
49 | static void block_job_unlock(void) | |
50 | { | |
51 | qemu_mutex_unlock(&block_job_mutex); | |
52 | } | |
53 | ||
54 | static void __attribute__((__constructor__)) block_job_init(void) | |
55 | { | |
56 | qemu_mutex_init(&block_job_mutex); | |
57 | } | |
58 | ||
59 | static void block_job_event_cancelled(BlockJob *job); | |
60 | static void block_job_event_completed(BlockJob *job, const char *msg); | |
61 | static void block_job_enter_cond(BlockJob *job, bool(*fn)(BlockJob *job)); | |
62 | ||
63 | /* Transactional group of block jobs */ | |
64 | struct BlockJobTxn { | |
65 | ||
66 | /* Is this txn being cancelled? */ | |
67 | bool aborting; | |
68 | ||
69 | /* List of jobs */ | |
70 | QLIST_HEAD(, BlockJob) jobs; | |
71 | ||
72 | /* Reference count */ | |
73 | int refcnt; | |
74 | }; | |
75 | ||
76 | static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs); | |
77 | ||
78 | /* | |
79 | * The block job API is composed of two categories of functions. | |
80 | * | |
81 | * The first includes functions used by the monitor. The monitor is | |
82 | * peculiar in that it accesses the block job list with block_job_get, and | |
83 | * therefore needs consistency across block_job_get and the actual operation | |
84 | * (e.g. block_job_set_speed). The consistency is achieved with | |
85 | * aio_context_acquire/release. These functions are declared in blockjob.h. | |
86 | * | |
87 | * The second includes functions used by the block job drivers and sometimes | |
88 | * by the core block layer. These do not care about locking, because the | |
89 | * whole coroutine runs under the AioContext lock, and are declared in | |
90 | * blockjob_int.h. | |
91 | */ | |
92 | ||
93 | BlockJob *block_job_next(BlockJob *job) | |
94 | { | |
95 | if (!job) { | |
96 | return QLIST_FIRST(&block_jobs); | |
97 | } | |
98 | return QLIST_NEXT(job, job_list); | |
99 | } | |
100 | ||
101 | BlockJob *block_job_get(const char *id) | |
102 | { | |
103 | BlockJob *job; | |
104 | ||
105 | QLIST_FOREACH(job, &block_jobs, job_list) { | |
106 | if (job->id && !strcmp(id, job->id)) { | |
107 | return job; | |
108 | } | |
109 | } | |
110 | ||
111 | return NULL; | |
112 | } | |
113 | ||
114 | BlockJobTxn *block_job_txn_new(void) | |
115 | { | |
116 | BlockJobTxn *txn = g_new0(BlockJobTxn, 1); | |
117 | QLIST_INIT(&txn->jobs); | |
118 | txn->refcnt = 1; | |
119 | return txn; | |
120 | } | |
121 | ||
122 | static void block_job_txn_ref(BlockJobTxn *txn) | |
123 | { | |
124 | txn->refcnt++; | |
125 | } | |
126 | ||
127 | void block_job_txn_unref(BlockJobTxn *txn) | |
128 | { | |
129 | if (txn && --txn->refcnt == 0) { | |
130 | g_free(txn); | |
131 | } | |
132 | } | |
133 | ||
134 | void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job) | |
135 | { | |
136 | if (!txn) { | |
137 | return; | |
138 | } | |
139 | ||
140 | assert(!job->txn); | |
141 | job->txn = txn; | |
142 | ||
143 | QLIST_INSERT_HEAD(&txn->jobs, job, txn_list); | |
144 | block_job_txn_ref(txn); | |
145 | } | |
146 | ||
147 | static void block_job_pause(BlockJob *job) | |
148 | { | |
149 | job->pause_count++; | |
150 | } | |
151 | ||
152 | static void block_job_resume(BlockJob *job) | |
153 | { | |
154 | assert(job->pause_count > 0); | |
155 | job->pause_count--; | |
156 | if (job->pause_count) { | |
157 | return; | |
158 | } | |
159 | block_job_enter(job); | |
160 | } | |
161 | ||
162 | void block_job_ref(BlockJob *job) | |
163 | { | |
164 | ++job->refcnt; | |
165 | } | |
166 | ||
167 | static void block_job_attached_aio_context(AioContext *new_context, | |
168 | void *opaque); | |
169 | static void block_job_detach_aio_context(void *opaque); | |
170 | ||
171 | void block_job_unref(BlockJob *job) | |
172 | { | |
173 | if (--job->refcnt == 0) { | |
174 | BlockDriverState *bs = blk_bs(job->blk); | |
175 | QLIST_REMOVE(job, job_list); | |
176 | bs->job = NULL; | |
177 | block_job_remove_all_bdrv(job); | |
178 | blk_remove_aio_context_notifier(job->blk, | |
179 | block_job_attached_aio_context, | |
180 | block_job_detach_aio_context, job); | |
181 | blk_unref(job->blk); | |
182 | error_free(job->blocker); | |
183 | g_free(job->id); | |
184 | assert(!timer_pending(&job->sleep_timer)); | |
185 | g_free(job); | |
186 | } | |
187 | } | |
188 | ||
189 | static void block_job_attached_aio_context(AioContext *new_context, | |
190 | void *opaque) | |
191 | { | |
192 | BlockJob *job = opaque; | |
193 | ||
194 | if (job->driver->attached_aio_context) { | |
195 | job->driver->attached_aio_context(job, new_context); | |
196 | } | |
197 | ||
198 | block_job_resume(job); | |
199 | } | |
200 | ||
201 | static void block_job_drain(BlockJob *job) | |
202 | { | |
203 | /* If job is !job->busy this kicks it into the next pause point. */ | |
204 | block_job_enter(job); | |
205 | ||
206 | blk_drain(job->blk); | |
207 | if (job->driver->drain) { | |
208 | job->driver->drain(job); | |
209 | } | |
210 | } | |
211 | ||
212 | static void block_job_detach_aio_context(void *opaque) | |
213 | { | |
214 | BlockJob *job = opaque; | |
215 | ||
216 | /* In case the job terminates during aio_poll()... */ | |
217 | block_job_ref(job); | |
218 | ||
219 | block_job_pause(job); | |
220 | ||
221 | while (!job->paused && !job->completed) { | |
222 | block_job_drain(job); | |
223 | } | |
224 | ||
225 | block_job_unref(job); | |
226 | } | |
227 | ||
228 | static char *child_job_get_parent_desc(BdrvChild *c) | |
229 | { | |
230 | BlockJob *job = c->opaque; | |
231 | return g_strdup_printf("%s job '%s'", | |
232 | BlockJobType_str(job->driver->job_type), | |
233 | job->id); | |
234 | } | |
235 | ||
236 | static void child_job_drained_begin(BdrvChild *c) | |
237 | { | |
238 | BlockJob *job = c->opaque; | |
239 | block_job_pause(job); | |
240 | } | |
241 | ||
242 | static void child_job_drained_end(BdrvChild *c) | |
243 | { | |
244 | BlockJob *job = c->opaque; | |
245 | block_job_resume(job); | |
246 | } | |
247 | ||
248 | static const BdrvChildRole child_job = { | |
249 | .get_parent_desc = child_job_get_parent_desc, | |
250 | .drained_begin = child_job_drained_begin, | |
251 | .drained_end = child_job_drained_end, | |
252 | .stay_at_node = true, | |
253 | }; | |
254 | ||
255 | void block_job_remove_all_bdrv(BlockJob *job) | |
256 | { | |
257 | GSList *l; | |
258 | for (l = job->nodes; l; l = l->next) { | |
259 | BdrvChild *c = l->data; | |
260 | bdrv_op_unblock_all(c->bs, job->blocker); | |
261 | bdrv_root_unref_child(c); | |
262 | } | |
263 | g_slist_free(job->nodes); | |
264 | job->nodes = NULL; | |
265 | } | |
266 | ||
267 | int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, | |
268 | uint64_t perm, uint64_t shared_perm, Error **errp) | |
269 | { | |
270 | BdrvChild *c; | |
271 | ||
272 | c = bdrv_root_attach_child(bs, name, &child_job, perm, shared_perm, | |
273 | job, errp); | |
274 | if (c == NULL) { | |
275 | return -EPERM; | |
276 | } | |
277 | ||
278 | job->nodes = g_slist_prepend(job->nodes, c); | |
279 | bdrv_ref(bs); | |
280 | bdrv_op_block_all(bs, job->blocker); | |
281 | ||
282 | return 0; | |
283 | } | |
284 | ||
285 | bool block_job_is_internal(BlockJob *job) | |
286 | { | |
287 | return (job->id == NULL); | |
288 | } | |
289 | ||
290 | static bool block_job_started(BlockJob *job) | |
291 | { | |
292 | return job->co; | |
293 | } | |
294 | ||
295 | /** | |
296 | * All jobs must allow a pause point before entering their job proper. This | |
297 | * ensures that jobs can be paused prior to being started, then resumed later. | |
298 | */ | |
299 | static void coroutine_fn block_job_co_entry(void *opaque) | |
300 | { | |
301 | BlockJob *job = opaque; | |
302 | ||
303 | assert(job && job->driver && job->driver->start); | |
304 | block_job_pause_point(job); | |
305 | job->driver->start(job); | |
306 | } | |
307 | ||
308 | static void block_job_sleep_timer_cb(void *opaque) | |
309 | { | |
310 | BlockJob *job = opaque; | |
311 | ||
312 | block_job_enter(job); | |
313 | } | |
314 | ||
315 | void block_job_start(BlockJob *job) | |
316 | { | |
317 | assert(job && !block_job_started(job) && job->paused && | |
318 | job->driver && job->driver->start); | |
319 | job->co = qemu_coroutine_create(block_job_co_entry, job); | |
320 | job->pause_count--; | |
321 | job->busy = true; | |
322 | job->paused = false; | |
323 | bdrv_coroutine_enter(blk_bs(job->blk), job->co); | |
324 | } | |
325 | ||
326 | static void block_job_completed_single(BlockJob *job) | |
327 | { | |
328 | assert(job->completed); | |
329 | ||
330 | if (!job->ret) { | |
331 | if (job->driver->commit) { | |
332 | job->driver->commit(job); | |
333 | } | |
334 | } else { | |
335 | if (job->driver->abort) { | |
336 | job->driver->abort(job); | |
337 | } | |
338 | } | |
339 | if (job->driver->clean) { | |
340 | job->driver->clean(job); | |
341 | } | |
342 | ||
343 | if (job->cb) { | |
344 | job->cb(job->opaque, job->ret); | |
345 | } | |
346 | ||
347 | /* Emit events only if we actually started */ | |
348 | if (block_job_started(job)) { | |
349 | if (block_job_is_cancelled(job)) { | |
350 | block_job_event_cancelled(job); | |
351 | } else { | |
352 | const char *msg = NULL; | |
353 | if (job->ret < 0) { | |
354 | msg = strerror(-job->ret); | |
355 | } | |
356 | block_job_event_completed(job, msg); | |
357 | } | |
358 | } | |
359 | ||
360 | if (job->txn) { | |
361 | QLIST_REMOVE(job, txn_list); | |
362 | block_job_txn_unref(job->txn); | |
363 | } | |
364 | block_job_unref(job); | |
365 | } | |
366 | ||
367 | static void block_job_cancel_async(BlockJob *job) | |
368 | { | |
369 | if (job->iostatus != BLOCK_DEVICE_IO_STATUS_OK) { | |
370 | block_job_iostatus_reset(job); | |
371 | } | |
372 | if (job->user_paused) { | |
373 | /* Do not call block_job_enter here, the caller will handle it. */ | |
374 | job->user_paused = false; | |
375 | job->pause_count--; | |
376 | } | |
377 | job->cancelled = true; | |
378 | } | |
379 | ||
380 | static int block_job_finish_sync(BlockJob *job, | |
381 | void (*finish)(BlockJob *, Error **errp), | |
382 | Error **errp) | |
383 | { | |
384 | Error *local_err = NULL; | |
385 | int ret; | |
386 | ||
387 | assert(blk_bs(job->blk)->job == job); | |
388 | ||
389 | block_job_ref(job); | |
390 | ||
391 | if (finish) { | |
392 | finish(job, &local_err); | |
393 | } | |
394 | if (local_err) { | |
395 | error_propagate(errp, local_err); | |
396 | block_job_unref(job); | |
397 | return -EBUSY; | |
398 | } | |
399 | /* block_job_drain calls block_job_enter, and it should be enough to | |
400 | * induce progress until the job completes or moves to the main thread. | |
401 | */ | |
402 | while (!job->deferred_to_main_loop && !job->completed) { | |
403 | block_job_drain(job); | |
404 | } | |
405 | while (!job->completed) { | |
406 | aio_poll(qemu_get_aio_context(), true); | |
407 | } | |
408 | ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret; | |
409 | block_job_unref(job); | |
410 | return ret; | |
411 | } | |
412 | ||
413 | static void block_job_completed_txn_abort(BlockJob *job) | |
414 | { | |
415 | AioContext *ctx; | |
416 | BlockJobTxn *txn = job->txn; | |
417 | BlockJob *other_job; | |
418 | ||
419 | if (txn->aborting) { | |
420 | /* | |
421 | * We are cancelled by another job, which will handle everything. | |
422 | */ | |
423 | return; | |
424 | } | |
425 | txn->aborting = true; | |
426 | block_job_txn_ref(txn); | |
427 | ||
428 | /* We are the first failed job. Cancel other jobs. */ | |
429 | QLIST_FOREACH(other_job, &txn->jobs, txn_list) { | |
430 | ctx = blk_get_aio_context(other_job->blk); | |
431 | aio_context_acquire(ctx); | |
432 | } | |
433 | ||
434 | /* Other jobs are effectively cancelled by us, set the status for | |
435 | * them; this job, however, may or may not be cancelled, depending | |
436 | * on the caller, so leave it. */ | |
437 | QLIST_FOREACH(other_job, &txn->jobs, txn_list) { | |
438 | if (other_job != job) { | |
439 | block_job_cancel_async(other_job); | |
440 | } | |
441 | } | |
442 | while (!QLIST_EMPTY(&txn->jobs)) { | |
443 | other_job = QLIST_FIRST(&txn->jobs); | |
444 | ctx = blk_get_aio_context(other_job->blk); | |
445 | if (!other_job->completed) { | |
446 | assert(other_job->cancelled); | |
447 | block_job_finish_sync(other_job, NULL, NULL); | |
448 | } | |
449 | block_job_completed_single(other_job); | |
450 | aio_context_release(ctx); | |
451 | } | |
452 | ||
453 | block_job_txn_unref(txn); | |
454 | } | |
455 | ||
456 | static void block_job_completed_txn_success(BlockJob *job) | |
457 | { | |
458 | AioContext *ctx; | |
459 | BlockJobTxn *txn = job->txn; | |
460 | BlockJob *other_job, *next; | |
461 | /* | |
462 | * Successful completion, see if there are other running jobs in this | |
463 | * txn. | |
464 | */ | |
465 | QLIST_FOREACH(other_job, &txn->jobs, txn_list) { | |
466 | if (!other_job->completed) { | |
467 | return; | |
468 | } | |
469 | } | |
470 | /* We are the last completed job, commit the transaction. */ | |
471 | QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { | |
472 | ctx = blk_get_aio_context(other_job->blk); | |
473 | aio_context_acquire(ctx); | |
474 | assert(other_job->ret == 0); | |
475 | block_job_completed_single(other_job); | |
476 | aio_context_release(ctx); | |
477 | } | |
478 | } | |
479 | ||
480 | /* Assumes the block_job_mutex is held */ | |
481 | static bool block_job_timer_pending(BlockJob *job) | |
482 | { | |
483 | return timer_pending(&job->sleep_timer); | |
484 | } | |
485 | ||
486 | void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) | |
487 | { | |
488 | Error *local_err = NULL; | |
489 | int64_t old_speed = job->speed; | |
490 | ||
491 | if (!job->driver->set_speed) { | |
492 | error_setg(errp, QERR_UNSUPPORTED); | |
493 | return; | |
494 | } | |
495 | job->driver->set_speed(job, speed, &local_err); | |
496 | if (local_err) { | |
497 | error_propagate(errp, local_err); | |
498 | return; | |
499 | } | |
500 | ||
501 | job->speed = speed; | |
502 | if (speed && speed <= old_speed) { | |
503 | return; | |
504 | } | |
505 | ||
506 | /* kick only if a timer is pending */ | |
507 | block_job_enter_cond(job, block_job_timer_pending); | |
508 | } | |
509 | ||
510 | void block_job_complete(BlockJob *job, Error **errp) | |
511 | { | |
512 | /* Should not be reachable via external interface for internal jobs */ | |
513 | assert(job->id); | |
514 | if (job->pause_count || job->cancelled || | |
515 | !block_job_started(job) || !job->driver->complete) { | |
516 | error_setg(errp, "The active block job '%s' cannot be completed", | |
517 | job->id); | |
518 | return; | |
519 | } | |
520 | ||
521 | job->driver->complete(job, errp); | |
522 | } | |
523 | ||
524 | void block_job_user_pause(BlockJob *job) | |
525 | { | |
526 | job->user_paused = true; | |
527 | block_job_pause(job); | |
528 | } | |
529 | ||
530 | bool block_job_user_paused(BlockJob *job) | |
531 | { | |
532 | return job->user_paused; | |
533 | } | |
534 | ||
535 | void block_job_user_resume(BlockJob *job) | |
536 | { | |
537 | if (job && job->user_paused && job->pause_count > 0) { | |
538 | block_job_iostatus_reset(job); | |
539 | job->user_paused = false; | |
540 | block_job_resume(job); | |
541 | } | |
542 | } | |
543 | ||
544 | void block_job_cancel(BlockJob *job) | |
545 | { | |
546 | if (block_job_started(job)) { | |
547 | block_job_cancel_async(job); | |
548 | block_job_enter(job); | |
549 | } else { | |
550 | block_job_completed(job, -ECANCELED); | |
551 | } | |
552 | } | |
553 | ||
554 | /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be | |
555 | * used with block_job_finish_sync() without the need for (rather nasty) | |
556 | * function pointer casts there. */ | |
557 | static void block_job_cancel_err(BlockJob *job, Error **errp) | |
558 | { | |
559 | block_job_cancel(job); | |
560 | } | |
561 | ||
562 | int block_job_cancel_sync(BlockJob *job) | |
563 | { | |
564 | return block_job_finish_sync(job, &block_job_cancel_err, NULL); | |
565 | } | |
566 | ||
567 | void block_job_cancel_sync_all(void) | |
568 | { | |
569 | BlockJob *job; | |
570 | AioContext *aio_context; | |
571 | ||
572 | while ((job = QLIST_FIRST(&block_jobs))) { | |
573 | aio_context = blk_get_aio_context(job->blk); | |
574 | aio_context_acquire(aio_context); | |
575 | block_job_cancel_sync(job); | |
576 | aio_context_release(aio_context); | |
577 | } | |
578 | } | |
579 | ||
580 | int block_job_complete_sync(BlockJob *job, Error **errp) | |
581 | { | |
582 | return block_job_finish_sync(job, &block_job_complete, errp); | |
583 | } | |
584 | ||
585 | BlockJobInfo *block_job_query(BlockJob *job, Error **errp) | |
586 | { | |
587 | BlockJobInfo *info; | |
588 | ||
589 | if (block_job_is_internal(job)) { | |
590 | error_setg(errp, "Cannot query QEMU internal jobs"); | |
591 | return NULL; | |
592 | } | |
593 | info = g_new0(BlockJobInfo, 1); | |
594 | info->type = g_strdup(BlockJobType_str(job->driver->job_type)); | |
595 | info->device = g_strdup(job->id); | |
596 | info->len = job->len; | |
597 | info->busy = atomic_read(&job->busy); | |
598 | info->paused = job->pause_count > 0; | |
599 | info->offset = job->offset; | |
600 | info->speed = job->speed; | |
601 | info->io_status = job->iostatus; | |
602 | info->ready = job->ready; | |
603 | return info; | |
604 | } | |
605 | ||
606 | static void block_job_iostatus_set_err(BlockJob *job, int error) | |
607 | { | |
608 | if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
609 | job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : | |
610 | BLOCK_DEVICE_IO_STATUS_FAILED; | |
611 | } | |
612 | } | |
613 | ||
614 | static void block_job_event_cancelled(BlockJob *job) | |
615 | { | |
616 | if (block_job_is_internal(job)) { | |
617 | return; | |
618 | } | |
619 | ||
620 | qapi_event_send_block_job_cancelled(job->driver->job_type, | |
621 | job->id, | |
622 | job->len, | |
623 | job->offset, | |
624 | job->speed, | |
625 | &error_abort); | |
626 | } | |
627 | ||
628 | static void block_job_event_completed(BlockJob *job, const char *msg) | |
629 | { | |
630 | if (block_job_is_internal(job)) { | |
631 | return; | |
632 | } | |
633 | ||
634 | qapi_event_send_block_job_completed(job->driver->job_type, | |
635 | job->id, | |
636 | job->len, | |
637 | job->offset, | |
638 | job->speed, | |
639 | !!msg, | |
640 | msg, | |
641 | &error_abort); | |
642 | } | |
643 | ||
644 | /* | |
645 | * API for block job drivers and the block layer. These functions are | |
646 | * declared in blockjob_int.h. | |
647 | */ | |
648 | ||
649 | void *block_job_create(const char *job_id, const BlockJobDriver *driver, | |
650 | BlockDriverState *bs, uint64_t perm, | |
651 | uint64_t shared_perm, int64_t speed, int flags, | |
652 | BlockCompletionFunc *cb, void *opaque, Error **errp) | |
653 | { | |
654 | BlockBackend *blk; | |
655 | BlockJob *job; | |
656 | int ret; | |
657 | ||
658 | if (bs->job) { | |
659 | error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); | |
660 | return NULL; | |
661 | } | |
662 | ||
663 | if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) { | |
664 | job_id = bdrv_get_device_name(bs); | |
665 | if (!*job_id) { | |
666 | error_setg(errp, "An explicit job ID is required for this node"); | |
667 | return NULL; | |
668 | } | |
669 | } | |
670 | ||
671 | if (job_id) { | |
672 | if (flags & BLOCK_JOB_INTERNAL) { | |
673 | error_setg(errp, "Cannot specify job ID for internal block job"); | |
674 | return NULL; | |
675 | } | |
676 | ||
677 | if (!id_wellformed(job_id)) { | |
678 | error_setg(errp, "Invalid job ID '%s'", job_id); | |
679 | return NULL; | |
680 | } | |
681 | ||
682 | if (block_job_get(job_id)) { | |
683 | error_setg(errp, "Job ID '%s' already in use", job_id); | |
684 | return NULL; | |
685 | } | |
686 | } | |
687 | ||
688 | blk = blk_new(perm, shared_perm); | |
689 | ret = blk_insert_bs(blk, bs, errp); | |
690 | if (ret < 0) { | |
691 | blk_unref(blk); | |
692 | return NULL; | |
693 | } | |
694 | ||
695 | job = g_malloc0(driver->instance_size); | |
696 | job->driver = driver; | |
697 | job->id = g_strdup(job_id); | |
698 | job->blk = blk; | |
699 | job->cb = cb; | |
700 | job->opaque = opaque; | |
701 | job->busy = false; | |
702 | job->paused = true; | |
703 | job->pause_count = 1; | |
704 | job->refcnt = 1; | |
705 | aio_timer_init(qemu_get_aio_context(), &job->sleep_timer, | |
706 | QEMU_CLOCK_REALTIME, SCALE_NS, | |
707 | block_job_sleep_timer_cb, job); | |
708 | ||
709 | error_setg(&job->blocker, "block device is in use by block job: %s", | |
710 | BlockJobType_str(driver->job_type)); | |
711 | block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort); | |
712 | bs->job = job; | |
713 | ||
714 | bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker); | |
715 | ||
716 | QLIST_INSERT_HEAD(&block_jobs, job, job_list); | |
717 | ||
718 | blk_add_aio_context_notifier(blk, block_job_attached_aio_context, | |
719 | block_job_detach_aio_context, job); | |
720 | ||
721 | /* Only set speed when necessary to avoid NotSupported error */ | |
722 | if (speed != 0) { | |
723 | Error *local_err = NULL; | |
724 | ||
725 | block_job_set_speed(job, speed, &local_err); | |
726 | if (local_err) { | |
727 | block_job_unref(job); | |
728 | error_propagate(errp, local_err); | |
729 | return NULL; | |
730 | } | |
731 | } | |
732 | return job; | |
733 | } | |
734 | ||
735 | void block_job_pause_all(void) | |
736 | { | |
737 | BlockJob *job = NULL; | |
738 | while ((job = block_job_next(job))) { | |
739 | AioContext *aio_context = blk_get_aio_context(job->blk); | |
740 | ||
741 | aio_context_acquire(aio_context); | |
742 | block_job_ref(job); | |
743 | block_job_pause(job); | |
744 | aio_context_release(aio_context); | |
745 | } | |
746 | } | |
747 | ||
748 | void block_job_early_fail(BlockJob *job) | |
749 | { | |
750 | block_job_unref(job); | |
751 | } | |
752 | ||
753 | void block_job_completed(BlockJob *job, int ret) | |
754 | { | |
755 | assert(blk_bs(job->blk)->job == job); | |
756 | assert(!job->completed); | |
757 | job->completed = true; | |
758 | job->ret = ret; | |
759 | if (!job->txn) { | |
760 | block_job_completed_single(job); | |
761 | } else if (ret < 0 || block_job_is_cancelled(job)) { | |
762 | block_job_completed_txn_abort(job); | |
763 | } else { | |
764 | block_job_completed_txn_success(job); | |
765 | } | |
766 | } | |
767 | ||
768 | static bool block_job_should_pause(BlockJob *job) | |
769 | { | |
770 | return job->pause_count > 0; | |
771 | } | |
772 | ||
773 | /* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds. | |
774 | * Reentering the job coroutine with block_job_enter() before the timer has | |
775 | * expired is allowed and cancels the timer. | |
776 | * | |
777 | * If @ns is (uint64_t) -1, no timer is scheduled and block_job_enter() must be | |
778 | * called explicitly. */ | |
779 | static void block_job_do_yield(BlockJob *job, uint64_t ns) | |
780 | { | |
781 | block_job_lock(); | |
782 | if (ns != -1) { | |
783 | timer_mod(&job->sleep_timer, ns); | |
784 | } | |
785 | job->busy = false; | |
786 | block_job_unlock(); | |
787 | qemu_coroutine_yield(); | |
788 | ||
789 | /* Set by block_job_enter before re-entering the coroutine. */ | |
790 | assert(job->busy); | |
791 | } | |
792 | ||
793 | void coroutine_fn block_job_pause_point(BlockJob *job) | |
794 | { | |
795 | assert(job && block_job_started(job)); | |
796 | ||
797 | if (!block_job_should_pause(job)) { | |
798 | return; | |
799 | } | |
800 | if (block_job_is_cancelled(job)) { | |
801 | return; | |
802 | } | |
803 | ||
804 | if (job->driver->pause) { | |
805 | job->driver->pause(job); | |
806 | } | |
807 | ||
808 | if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { | |
809 | job->paused = true; | |
810 | block_job_do_yield(job, -1); | |
811 | job->paused = false; | |
812 | } | |
813 | ||
814 | if (job->driver->resume) { | |
815 | job->driver->resume(job); | |
816 | } | |
817 | } | |
818 | ||
819 | void block_job_resume_all(void) | |
820 | { | |
821 | BlockJob *job, *next; | |
822 | ||
823 | QLIST_FOREACH_SAFE(job, &block_jobs, job_list, next) { | |
824 | AioContext *aio_context = blk_get_aio_context(job->blk); | |
825 | ||
826 | aio_context_acquire(aio_context); | |
827 | block_job_resume(job); | |
828 | block_job_unref(job); | |
829 | aio_context_release(aio_context); | |
830 | } | |
831 | } | |
832 | ||
833 | /* | |
834 | * Conditionally enter a block_job pending a call to fn() while | |
835 | * under the block_job_lock critical section. | |
836 | */ | |
837 | static void block_job_enter_cond(BlockJob *job, bool(*fn)(BlockJob *job)) | |
838 | { | |
839 | if (!block_job_started(job)) { | |
840 | return; | |
841 | } | |
842 | if (job->deferred_to_main_loop) { | |
843 | return; | |
844 | } | |
845 | ||
846 | block_job_lock(); | |
847 | if (job->busy) { | |
848 | block_job_unlock(); | |
849 | return; | |
850 | } | |
851 | ||
852 | if (fn && !fn(job)) { | |
853 | block_job_unlock(); | |
854 | return; | |
855 | } | |
856 | ||
857 | assert(!job->deferred_to_main_loop); | |
858 | timer_del(&job->sleep_timer); | |
859 | job->busy = true; | |
860 | block_job_unlock(); | |
861 | aio_co_wake(job->co); | |
862 | } | |
863 | ||
864 | void block_job_enter(BlockJob *job) | |
865 | { | |
866 | block_job_enter_cond(job, NULL); | |
867 | } | |
868 | ||
869 | bool block_job_is_cancelled(BlockJob *job) | |
870 | { | |
871 | return job->cancelled; | |
872 | } | |
873 | ||
874 | void block_job_sleep_ns(BlockJob *job, int64_t ns) | |
875 | { | |
876 | assert(job->busy); | |
877 | ||
878 | /* Check cancellation *before* setting busy = false, too! */ | |
879 | if (block_job_is_cancelled(job)) { | |
880 | return; | |
881 | } | |
882 | ||
883 | if (!block_job_should_pause(job)) { | |
884 | block_job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns); | |
885 | } | |
886 | ||
887 | block_job_pause_point(job); | |
888 | } | |
889 | ||
890 | void block_job_yield(BlockJob *job) | |
891 | { | |
892 | assert(job->busy); | |
893 | ||
894 | /* Check cancellation *before* setting busy = false, too! */ | |
895 | if (block_job_is_cancelled(job)) { | |
896 | return; | |
897 | } | |
898 | ||
899 | if (!block_job_should_pause(job)) { | |
900 | block_job_do_yield(job, -1); | |
901 | } | |
902 | ||
903 | block_job_pause_point(job); | |
904 | } | |
905 | ||
906 | void block_job_iostatus_reset(BlockJob *job) | |
907 | { | |
908 | if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
909 | return; | |
910 | } | |
911 | assert(job->user_paused && job->pause_count > 0); | |
912 | job->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
913 | } | |
914 | ||
915 | void block_job_event_ready(BlockJob *job) | |
916 | { | |
917 | job->ready = true; | |
918 | ||
919 | if (block_job_is_internal(job)) { | |
920 | return; | |
921 | } | |
922 | ||
923 | qapi_event_send_block_job_ready(job->driver->job_type, | |
924 | job->id, | |
925 | job->len, | |
926 | job->offset, | |
927 | job->speed, &error_abort); | |
928 | } | |
929 | ||
930 | BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, | |
931 | int is_read, int error) | |
932 | { | |
933 | BlockErrorAction action; | |
934 | ||
935 | switch (on_err) { | |
936 | case BLOCKDEV_ON_ERROR_ENOSPC: | |
937 | case BLOCKDEV_ON_ERROR_AUTO: | |
938 | action = (error == ENOSPC) ? | |
939 | BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; | |
940 | break; | |
941 | case BLOCKDEV_ON_ERROR_STOP: | |
942 | action = BLOCK_ERROR_ACTION_STOP; | |
943 | break; | |
944 | case BLOCKDEV_ON_ERROR_REPORT: | |
945 | action = BLOCK_ERROR_ACTION_REPORT; | |
946 | break; | |
947 | case BLOCKDEV_ON_ERROR_IGNORE: | |
948 | action = BLOCK_ERROR_ACTION_IGNORE; | |
949 | break; | |
950 | default: | |
951 | abort(); | |
952 | } | |
953 | if (!block_job_is_internal(job)) { | |
954 | qapi_event_send_block_job_error(job->id, | |
955 | is_read ? IO_OPERATION_TYPE_READ : | |
956 | IO_OPERATION_TYPE_WRITE, | |
957 | action, &error_abort); | |
958 | } | |
959 | if (action == BLOCK_ERROR_ACTION_STOP) { | |
960 | /* make the pause user visible, which will be resumed from QMP. */ | |
961 | block_job_user_pause(job); | |
962 | block_job_iostatus_set_err(job, error); | |
963 | } | |
964 | return action; | |
965 | } | |
966 | ||
967 | typedef struct { | |
968 | BlockJob *job; | |
969 | AioContext *aio_context; | |
970 | BlockJobDeferToMainLoopFn *fn; | |
971 | void *opaque; | |
972 | } BlockJobDeferToMainLoopData; | |
973 | ||
974 | static void block_job_defer_to_main_loop_bh(void *opaque) | |
975 | { | |
976 | BlockJobDeferToMainLoopData *data = opaque; | |
977 | AioContext *aio_context; | |
978 | ||
979 | /* Prevent race with block_job_defer_to_main_loop() */ | |
980 | aio_context_acquire(data->aio_context); | |
981 | ||
982 | /* Fetch BDS AioContext again, in case it has changed */ | |
983 | aio_context = blk_get_aio_context(data->job->blk); | |
984 | if (aio_context != data->aio_context) { | |
985 | aio_context_acquire(aio_context); | |
986 | } | |
987 | ||
988 | data->fn(data->job, data->opaque); | |
989 | ||
990 | if (aio_context != data->aio_context) { | |
991 | aio_context_release(aio_context); | |
992 | } | |
993 | ||
994 | aio_context_release(data->aio_context); | |
995 | ||
996 | g_free(data); | |
997 | } | |
998 | ||
999 | void block_job_defer_to_main_loop(BlockJob *job, | |
1000 | BlockJobDeferToMainLoopFn *fn, | |
1001 | void *opaque) | |
1002 | { | |
1003 | BlockJobDeferToMainLoopData *data = g_malloc(sizeof(*data)); | |
1004 | data->job = job; | |
1005 | data->aio_context = blk_get_aio_context(job->blk); | |
1006 | data->fn = fn; | |
1007 | data->opaque = opaque; | |
1008 | job->deferred_to_main_loop = true; | |
1009 | ||
1010 | aio_bh_schedule_oneshot(qemu_get_aio_context(), | |
1011 | block_job_defer_to_main_loop_bh, data); | |
1012 | } |