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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/block.h" | |
28 | #include "block/blockjob_int.h" | |
29 | #include "block/block_int.h" | |
30 | #include "block/trace.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/main-loop.h" | |
37 | #include "qemu/timer.h" | |
38 | ||
39 | /* | |
40 | * The block job API is composed of two categories of functions. | |
41 | * | |
42 | * The first includes functions used by the monitor. The monitor is | |
43 | * peculiar in that it accesses the block job list with block_job_get, and | |
44 | * therefore needs consistency across block_job_get and the actual operation | |
45 | * (e.g. block_job_set_speed). The consistency is achieved with | |
46 | * aio_context_acquire/release. These functions are declared in blockjob.h. | |
47 | * | |
48 | * The second includes functions used by the block job drivers and sometimes | |
49 | * by the core block layer. These do not care about locking, because the | |
50 | * whole coroutine runs under the AioContext lock, and are declared in | |
51 | * blockjob_int.h. | |
52 | */ | |
53 | ||
54 | static bool is_block_job(Job *job) | |
55 | { | |
56 | return job_type(job) == JOB_TYPE_BACKUP || | |
57 | job_type(job) == JOB_TYPE_COMMIT || | |
58 | job_type(job) == JOB_TYPE_MIRROR || | |
59 | job_type(job) == JOB_TYPE_STREAM; | |
60 | } | |
61 | ||
62 | BlockJob *block_job_next(BlockJob *bjob) | |
63 | { | |
64 | Job *job = bjob ? &bjob->job : NULL; | |
65 | GLOBAL_STATE_CODE(); | |
66 | ||
67 | do { | |
68 | job = job_next(job); | |
69 | } while (job && !is_block_job(job)); | |
70 | ||
71 | return job ? container_of(job, BlockJob, job) : NULL; | |
72 | } | |
73 | ||
74 | BlockJob *block_job_get(const char *id) | |
75 | { | |
76 | Job *job = job_get(id); | |
77 | GLOBAL_STATE_CODE(); | |
78 | ||
79 | if (job && is_block_job(job)) { | |
80 | return container_of(job, BlockJob, job); | |
81 | } else { | |
82 | return NULL; | |
83 | } | |
84 | } | |
85 | ||
86 | void block_job_free(Job *job) | |
87 | { | |
88 | BlockJob *bjob = container_of(job, BlockJob, job); | |
89 | GLOBAL_STATE_CODE(); | |
90 | ||
91 | block_job_remove_all_bdrv(bjob); | |
92 | ratelimit_destroy(&bjob->limit); | |
93 | error_free(bjob->blocker); | |
94 | } | |
95 | ||
96 | static char *child_job_get_parent_desc(BdrvChild *c) | |
97 | { | |
98 | BlockJob *job = c->opaque; | |
99 | return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id); | |
100 | } | |
101 | ||
102 | static void child_job_drained_begin(BdrvChild *c) | |
103 | { | |
104 | BlockJob *job = c->opaque; | |
105 | job_pause(&job->job); | |
106 | } | |
107 | ||
108 | static bool child_job_drained_poll(BdrvChild *c) | |
109 | { | |
110 | BlockJob *bjob = c->opaque; | |
111 | Job *job = &bjob->job; | |
112 | const BlockJobDriver *drv = block_job_driver(bjob); | |
113 | ||
114 | /* An inactive or completed job doesn't have any pending requests. Jobs | |
115 | * with !job->busy are either already paused or have a pause point after | |
116 | * being reentered, so no job driver code will run before they pause. */ | |
117 | if (!job->busy || job_is_completed(job)) { | |
118 | return false; | |
119 | } | |
120 | ||
121 | /* Otherwise, assume that it isn't fully stopped yet, but allow the job to | |
122 | * override this assumption. */ | |
123 | if (drv->drained_poll) { | |
124 | return drv->drained_poll(bjob); | |
125 | } else { | |
126 | return true; | |
127 | } | |
128 | } | |
129 | ||
130 | static void child_job_drained_end(BdrvChild *c, int *drained_end_counter) | |
131 | { | |
132 | BlockJob *job = c->opaque; | |
133 | job_resume(&job->job); | |
134 | } | |
135 | ||
136 | static bool child_job_can_set_aio_ctx(BdrvChild *c, AioContext *ctx, | |
137 | GSList **ignore, Error **errp) | |
138 | { | |
139 | BlockJob *job = c->opaque; | |
140 | GSList *l; | |
141 | ||
142 | for (l = job->nodes; l; l = l->next) { | |
143 | BdrvChild *sibling = l->data; | |
144 | if (!bdrv_child_can_set_aio_context(sibling, ctx, ignore, errp)) { | |
145 | return false; | |
146 | } | |
147 | } | |
148 | return true; | |
149 | } | |
150 | ||
151 | static void child_job_set_aio_ctx(BdrvChild *c, AioContext *ctx, | |
152 | GSList **ignore) | |
153 | { | |
154 | BlockJob *job = c->opaque; | |
155 | GSList *l; | |
156 | ||
157 | for (l = job->nodes; l; l = l->next) { | |
158 | BdrvChild *sibling = l->data; | |
159 | if (g_slist_find(*ignore, sibling)) { | |
160 | continue; | |
161 | } | |
162 | *ignore = g_slist_prepend(*ignore, sibling); | |
163 | bdrv_set_aio_context_ignore(sibling->bs, ctx, ignore); | |
164 | } | |
165 | ||
166 | job->job.aio_context = ctx; | |
167 | } | |
168 | ||
169 | static AioContext *child_job_get_parent_aio_context(BdrvChild *c) | |
170 | { | |
171 | BlockJob *job = c->opaque; | |
172 | ||
173 | return job->job.aio_context; | |
174 | } | |
175 | ||
176 | static const BdrvChildClass child_job = { | |
177 | .get_parent_desc = child_job_get_parent_desc, | |
178 | .drained_begin = child_job_drained_begin, | |
179 | .drained_poll = child_job_drained_poll, | |
180 | .drained_end = child_job_drained_end, | |
181 | .can_set_aio_ctx = child_job_can_set_aio_ctx, | |
182 | .set_aio_ctx = child_job_set_aio_ctx, | |
183 | .stay_at_node = true, | |
184 | .get_parent_aio_context = child_job_get_parent_aio_context, | |
185 | }; | |
186 | ||
187 | void block_job_remove_all_bdrv(BlockJob *job) | |
188 | { | |
189 | GLOBAL_STATE_CODE(); | |
190 | /* | |
191 | * bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(), | |
192 | * which will also traverse job->nodes, so consume the list one by | |
193 | * one to make sure that such a concurrent access does not attempt | |
194 | * to process an already freed BdrvChild. | |
195 | */ | |
196 | while (job->nodes) { | |
197 | GSList *l = job->nodes; | |
198 | BdrvChild *c = l->data; | |
199 | ||
200 | job->nodes = l->next; | |
201 | ||
202 | bdrv_op_unblock_all(c->bs, job->blocker); | |
203 | bdrv_root_unref_child(c); | |
204 | ||
205 | g_slist_free_1(l); | |
206 | } | |
207 | } | |
208 | ||
209 | bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs) | |
210 | { | |
211 | GSList *el; | |
212 | GLOBAL_STATE_CODE(); | |
213 | ||
214 | for (el = job->nodes; el; el = el->next) { | |
215 | BdrvChild *c = el->data; | |
216 | if (c->bs == bs) { | |
217 | return true; | |
218 | } | |
219 | } | |
220 | ||
221 | return false; | |
222 | } | |
223 | ||
224 | int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, | |
225 | uint64_t perm, uint64_t shared_perm, Error **errp) | |
226 | { | |
227 | BdrvChild *c; | |
228 | bool need_context_ops; | |
229 | GLOBAL_STATE_CODE(); | |
230 | ||
231 | bdrv_ref(bs); | |
232 | ||
233 | need_context_ops = bdrv_get_aio_context(bs) != job->job.aio_context; | |
234 | ||
235 | if (need_context_ops && job->job.aio_context != qemu_get_aio_context()) { | |
236 | aio_context_release(job->job.aio_context); | |
237 | } | |
238 | c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job, | |
239 | errp); | |
240 | if (need_context_ops && job->job.aio_context != qemu_get_aio_context()) { | |
241 | aio_context_acquire(job->job.aio_context); | |
242 | } | |
243 | if (c == NULL) { | |
244 | return -EPERM; | |
245 | } | |
246 | ||
247 | job->nodes = g_slist_prepend(job->nodes, c); | |
248 | bdrv_op_block_all(bs, job->blocker); | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
253 | static void block_job_on_idle(Notifier *n, void *opaque) | |
254 | { | |
255 | aio_wait_kick(); | |
256 | } | |
257 | ||
258 | bool block_job_is_internal(BlockJob *job) | |
259 | { | |
260 | return (job->job.id == NULL); | |
261 | } | |
262 | ||
263 | const BlockJobDriver *block_job_driver(BlockJob *job) | |
264 | { | |
265 | return container_of(job->job.driver, BlockJobDriver, job_driver); | |
266 | } | |
267 | ||
268 | /* Assumes the job_mutex is held */ | |
269 | static bool job_timer_pending(Job *job) | |
270 | { | |
271 | return timer_pending(&job->sleep_timer); | |
272 | } | |
273 | ||
274 | bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) | |
275 | { | |
276 | const BlockJobDriver *drv = block_job_driver(job); | |
277 | int64_t old_speed = job->speed; | |
278 | ||
279 | GLOBAL_STATE_CODE(); | |
280 | ||
281 | if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp) < 0) { | |
282 | return false; | |
283 | } | |
284 | if (speed < 0) { | |
285 | error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed", | |
286 | "a non-negative value"); | |
287 | return false; | |
288 | } | |
289 | ||
290 | ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME); | |
291 | ||
292 | job->speed = speed; | |
293 | ||
294 | if (drv->set_speed) { | |
295 | drv->set_speed(job, speed); | |
296 | } | |
297 | ||
298 | if (speed && speed <= old_speed) { | |
299 | return true; | |
300 | } | |
301 | ||
302 | /* kick only if a timer is pending */ | |
303 | job_enter_cond(&job->job, job_timer_pending); | |
304 | ||
305 | return true; | |
306 | } | |
307 | ||
308 | int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n) | |
309 | { | |
310 | IO_CODE(); | |
311 | return ratelimit_calculate_delay(&job->limit, n); | |
312 | } | |
313 | ||
314 | BlockJobInfo *block_job_query(BlockJob *job, Error **errp) | |
315 | { | |
316 | BlockJobInfo *info; | |
317 | uint64_t progress_current, progress_total; | |
318 | ||
319 | GLOBAL_STATE_CODE(); | |
320 | ||
321 | if (block_job_is_internal(job)) { | |
322 | error_setg(errp, "Cannot query QEMU internal jobs"); | |
323 | return NULL; | |
324 | } | |
325 | ||
326 | progress_get_snapshot(&job->job.progress, &progress_current, | |
327 | &progress_total); | |
328 | ||
329 | info = g_new0(BlockJobInfo, 1); | |
330 | info->type = g_strdup(job_type_str(&job->job)); | |
331 | info->device = g_strdup(job->job.id); | |
332 | info->busy = qatomic_read(&job->job.busy); | |
333 | info->paused = job->job.pause_count > 0; | |
334 | info->offset = progress_current; | |
335 | info->len = progress_total; | |
336 | info->speed = job->speed; | |
337 | info->io_status = job->iostatus; | |
338 | info->ready = job_is_ready(&job->job), | |
339 | info->status = job->job.status; | |
340 | info->auto_finalize = job->job.auto_finalize; | |
341 | info->auto_dismiss = job->job.auto_dismiss; | |
342 | if (job->job.ret) { | |
343 | info->has_error = true; | |
344 | info->error = job->job.err ? | |
345 | g_strdup(error_get_pretty(job->job.err)) : | |
346 | g_strdup(strerror(-job->job.ret)); | |
347 | } | |
348 | return info; | |
349 | } | |
350 | ||
351 | static void block_job_iostatus_set_err(BlockJob *job, int error) | |
352 | { | |
353 | if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
354 | job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : | |
355 | BLOCK_DEVICE_IO_STATUS_FAILED; | |
356 | } | |
357 | } | |
358 | ||
359 | static void block_job_event_cancelled(Notifier *n, void *opaque) | |
360 | { | |
361 | BlockJob *job = opaque; | |
362 | uint64_t progress_current, progress_total; | |
363 | ||
364 | if (block_job_is_internal(job)) { | |
365 | return; | |
366 | } | |
367 | ||
368 | progress_get_snapshot(&job->job.progress, &progress_current, | |
369 | &progress_total); | |
370 | ||
371 | qapi_event_send_block_job_cancelled(job_type(&job->job), | |
372 | job->job.id, | |
373 | progress_total, | |
374 | progress_current, | |
375 | job->speed); | |
376 | } | |
377 | ||
378 | static void block_job_event_completed(Notifier *n, void *opaque) | |
379 | { | |
380 | BlockJob *job = opaque; | |
381 | const char *msg = NULL; | |
382 | uint64_t progress_current, progress_total; | |
383 | ||
384 | if (block_job_is_internal(job)) { | |
385 | return; | |
386 | } | |
387 | ||
388 | if (job->job.ret < 0) { | |
389 | msg = error_get_pretty(job->job.err); | |
390 | } | |
391 | ||
392 | progress_get_snapshot(&job->job.progress, &progress_current, | |
393 | &progress_total); | |
394 | ||
395 | qapi_event_send_block_job_completed(job_type(&job->job), | |
396 | job->job.id, | |
397 | progress_total, | |
398 | progress_current, | |
399 | job->speed, | |
400 | !!msg, | |
401 | msg); | |
402 | } | |
403 | ||
404 | static void block_job_event_pending(Notifier *n, void *opaque) | |
405 | { | |
406 | BlockJob *job = opaque; | |
407 | ||
408 | if (block_job_is_internal(job)) { | |
409 | return; | |
410 | } | |
411 | ||
412 | qapi_event_send_block_job_pending(job_type(&job->job), | |
413 | job->job.id); | |
414 | } | |
415 | ||
416 | static void block_job_event_ready(Notifier *n, void *opaque) | |
417 | { | |
418 | BlockJob *job = opaque; | |
419 | uint64_t progress_current, progress_total; | |
420 | ||
421 | if (block_job_is_internal(job)) { | |
422 | return; | |
423 | } | |
424 | ||
425 | progress_get_snapshot(&job->job.progress, &progress_current, | |
426 | &progress_total); | |
427 | ||
428 | qapi_event_send_block_job_ready(job_type(&job->job), | |
429 | job->job.id, | |
430 | progress_total, | |
431 | progress_current, | |
432 | job->speed); | |
433 | } | |
434 | ||
435 | ||
436 | /* | |
437 | * API for block job drivers and the block layer. These functions are | |
438 | * declared in blockjob_int.h. | |
439 | */ | |
440 | ||
441 | void *block_job_create(const char *job_id, const BlockJobDriver *driver, | |
442 | JobTxn *txn, BlockDriverState *bs, uint64_t perm, | |
443 | uint64_t shared_perm, int64_t speed, int flags, | |
444 | BlockCompletionFunc *cb, void *opaque, Error **errp) | |
445 | { | |
446 | BlockJob *job; | |
447 | int ret; | |
448 | GLOBAL_STATE_CODE(); | |
449 | ||
450 | if (job_id == NULL && !(flags & JOB_INTERNAL)) { | |
451 | job_id = bdrv_get_device_name(bs); | |
452 | } | |
453 | ||
454 | job = job_create(job_id, &driver->job_driver, txn, bdrv_get_aio_context(bs), | |
455 | flags, cb, opaque, errp); | |
456 | if (job == NULL) { | |
457 | return NULL; | |
458 | } | |
459 | ||
460 | assert(is_block_job(&job->job)); | |
461 | assert(job->job.driver->free == &block_job_free); | |
462 | assert(job->job.driver->user_resume == &block_job_user_resume); | |
463 | ||
464 | ratelimit_init(&job->limit); | |
465 | ||
466 | job->finalize_cancelled_notifier.notify = block_job_event_cancelled; | |
467 | job->finalize_completed_notifier.notify = block_job_event_completed; | |
468 | job->pending_notifier.notify = block_job_event_pending; | |
469 | job->ready_notifier.notify = block_job_event_ready; | |
470 | job->idle_notifier.notify = block_job_on_idle; | |
471 | ||
472 | notifier_list_add(&job->job.on_finalize_cancelled, | |
473 | &job->finalize_cancelled_notifier); | |
474 | notifier_list_add(&job->job.on_finalize_completed, | |
475 | &job->finalize_completed_notifier); | |
476 | notifier_list_add(&job->job.on_pending, &job->pending_notifier); | |
477 | notifier_list_add(&job->job.on_ready, &job->ready_notifier); | |
478 | notifier_list_add(&job->job.on_idle, &job->idle_notifier); | |
479 | ||
480 | error_setg(&job->blocker, "block device is in use by block job: %s", | |
481 | job_type_str(&job->job)); | |
482 | ||
483 | ret = block_job_add_bdrv(job, "main node", bs, perm, shared_perm, errp); | |
484 | if (ret < 0) { | |
485 | goto fail; | |
486 | } | |
487 | ||
488 | bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker); | |
489 | ||
490 | if (!block_job_set_speed(job, speed, errp)) { | |
491 | goto fail; | |
492 | } | |
493 | ||
494 | return job; | |
495 | ||
496 | fail: | |
497 | job_early_fail(&job->job); | |
498 | return NULL; | |
499 | } | |
500 | ||
501 | void block_job_iostatus_reset(BlockJob *job) | |
502 | { | |
503 | GLOBAL_STATE_CODE(); | |
504 | if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
505 | return; | |
506 | } | |
507 | assert(job->job.user_paused && job->job.pause_count > 0); | |
508 | job->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
509 | } | |
510 | ||
511 | void block_job_user_resume(Job *job) | |
512 | { | |
513 | BlockJob *bjob = container_of(job, BlockJob, job); | |
514 | GLOBAL_STATE_CODE(); | |
515 | block_job_iostatus_reset(bjob); | |
516 | } | |
517 | ||
518 | BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, | |
519 | int is_read, int error) | |
520 | { | |
521 | BlockErrorAction action; | |
522 | IO_CODE(); | |
523 | ||
524 | switch (on_err) { | |
525 | case BLOCKDEV_ON_ERROR_ENOSPC: | |
526 | case BLOCKDEV_ON_ERROR_AUTO: | |
527 | action = (error == ENOSPC) ? | |
528 | BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; | |
529 | break; | |
530 | case BLOCKDEV_ON_ERROR_STOP: | |
531 | action = BLOCK_ERROR_ACTION_STOP; | |
532 | break; | |
533 | case BLOCKDEV_ON_ERROR_REPORT: | |
534 | action = BLOCK_ERROR_ACTION_REPORT; | |
535 | break; | |
536 | case BLOCKDEV_ON_ERROR_IGNORE: | |
537 | action = BLOCK_ERROR_ACTION_IGNORE; | |
538 | break; | |
539 | default: | |
540 | abort(); | |
541 | } | |
542 | if (!block_job_is_internal(job)) { | |
543 | qapi_event_send_block_job_error(job->job.id, | |
544 | is_read ? IO_OPERATION_TYPE_READ : | |
545 | IO_OPERATION_TYPE_WRITE, | |
546 | action); | |
547 | } | |
548 | if (action == BLOCK_ERROR_ACTION_STOP) { | |
549 | if (!job->job.user_paused) { | |
550 | job_pause(&job->job); | |
551 | /* make the pause user visible, which will be resumed from QMP. */ | |
552 | job->job.user_paused = true; | |
553 | } | |
554 | block_job_iostatus_set_err(job, error); | |
555 | } | |
556 | return action; | |
557 | } | |
558 | ||
559 | AioContext *block_job_get_aio_context(BlockJob *job) | |
560 | { | |
561 | GLOBAL_STATE_CODE(); | |
562 | return job->job.aio_context; | |
563 | } |