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