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33e9e9bd KW |
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 "qemu-common.h" | |
28 | #include "qapi/error.h" | |
29 | #include "qemu/job.h" | |
30 | #include "qemu/id.h" | |
1908a559 | 31 | #include "qemu/main-loop.h" |
a50c2ab8 | 32 | #include "trace-root.h" |
33e9e9bd | 33 | |
e7c1d78b KW |
34 | static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs); |
35 | ||
a50c2ab8 KW |
36 | /* Job State Transition Table */ |
37 | bool JobSTT[JOB_STATUS__MAX][JOB_STATUS__MAX] = { | |
38 | /* U, C, R, P, Y, S, W, D, X, E, N */ | |
39 | /* U: */ [JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}, | |
40 | /* C: */ [JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1}, | |
41 | /* R: */ [JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0}, | |
42 | /* P: */ [JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0}, | |
43 | /* Y: */ [JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0}, | |
44 | /* S: */ [JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0}, | |
45 | /* W: */ [JOB_STATUS_WAITING] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0}, | |
46 | /* D: */ [JOB_STATUS_PENDING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, | |
47 | /* X: */ [JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, | |
48 | /* E: */ [JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, | |
49 | /* N: */ [JOB_STATUS_NULL] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, | |
50 | }; | |
51 | ||
52 | bool JobVerbTable[JOB_VERB__MAX][JOB_STATUS__MAX] = { | |
53 | /* U, C, R, P, Y, S, W, D, X, E, N */ | |
54 | [JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0}, | |
55 | [JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, | |
56 | [JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, | |
57 | [JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, | |
58 | [JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0}, | |
59 | [JOB_VERB_FINALIZE] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0}, | |
60 | [JOB_VERB_DISMISS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0}, | |
61 | }; | |
62 | ||
da01ff7f KW |
63 | /* Right now, this mutex is only needed to synchronize accesses to job->busy |
64 | * and job->sleep_timer, such as concurrent calls to job_do_yield and | |
65 | * job_enter. */ | |
66 | static QemuMutex job_mutex; | |
67 | ||
68 | static void job_lock(void) | |
69 | { | |
70 | qemu_mutex_lock(&job_mutex); | |
71 | } | |
72 | ||
73 | static void job_unlock(void) | |
74 | { | |
75 | qemu_mutex_unlock(&job_mutex); | |
76 | } | |
77 | ||
78 | static void __attribute__((__constructor__)) job_init(void) | |
79 | { | |
80 | qemu_mutex_init(&job_mutex); | |
81 | } | |
82 | ||
a50c2ab8 KW |
83 | /* TODO Make static once the whole state machine is in job.c */ |
84 | void job_state_transition(Job *job, JobStatus s1) | |
85 | { | |
86 | JobStatus s0 = job->status; | |
87 | assert(s1 >= 0 && s1 <= JOB_STATUS__MAX); | |
88 | trace_job_state_transition(job, /* TODO re-enable: job->ret */ 0, | |
89 | JobSTT[s0][s1] ? "allowed" : "disallowed", | |
90 | JobStatus_str(s0), JobStatus_str(s1)); | |
91 | assert(JobSTT[s0][s1]); | |
92 | job->status = s1; | |
93 | } | |
94 | ||
95 | int job_apply_verb(Job *job, JobVerb verb, Error **errp) | |
96 | { | |
97 | JobStatus s0 = job->status; | |
98 | assert(verb >= 0 && verb <= JOB_VERB__MAX); | |
99 | trace_job_apply_verb(job, JobStatus_str(s0), JobVerb_str(verb), | |
100 | JobVerbTable[verb][s0] ? "allowed" : "prohibited"); | |
101 | if (JobVerbTable[verb][s0]) { | |
102 | return 0; | |
103 | } | |
104 | error_setg(errp, "Job '%s' in state '%s' cannot accept command verb '%s'", | |
105 | job->id, JobStatus_str(s0), JobVerb_str(verb)); | |
106 | return -EPERM; | |
107 | } | |
108 | ||
252291ea KW |
109 | JobType job_type(const Job *job) |
110 | { | |
111 | return job->driver->job_type; | |
112 | } | |
113 | ||
114 | const char *job_type_str(const Job *job) | |
115 | { | |
116 | return JobType_str(job_type(job)); | |
117 | } | |
118 | ||
daa7f2f9 KW |
119 | bool job_is_cancelled(Job *job) |
120 | { | |
121 | return job->cancelled; | |
122 | } | |
123 | ||
dbe5e6c1 KW |
124 | bool job_is_completed(Job *job) |
125 | { | |
126 | switch (job->status) { | |
127 | case JOB_STATUS_UNDEFINED: | |
128 | case JOB_STATUS_CREATED: | |
129 | case JOB_STATUS_RUNNING: | |
130 | case JOB_STATUS_PAUSED: | |
131 | case JOB_STATUS_READY: | |
132 | case JOB_STATUS_STANDBY: | |
133 | return false; | |
134 | case JOB_STATUS_WAITING: | |
135 | case JOB_STATUS_PENDING: | |
136 | case JOB_STATUS_ABORTING: | |
137 | case JOB_STATUS_CONCLUDED: | |
138 | case JOB_STATUS_NULL: | |
139 | return true; | |
140 | default: | |
141 | g_assert_not_reached(); | |
142 | } | |
143 | return false; | |
144 | } | |
145 | ||
da01ff7f KW |
146 | bool job_started(Job *job) |
147 | { | |
148 | return job->co; | |
149 | } | |
150 | ||
151 | bool job_should_pause(Job *job) | |
152 | { | |
153 | return job->pause_count > 0; | |
154 | } | |
155 | ||
e7c1d78b KW |
156 | Job *job_next(Job *job) |
157 | { | |
158 | if (!job) { | |
159 | return QLIST_FIRST(&jobs); | |
160 | } | |
161 | return QLIST_NEXT(job, job_list); | |
162 | } | |
163 | ||
164 | Job *job_get(const char *id) | |
165 | { | |
166 | Job *job; | |
167 | ||
168 | QLIST_FOREACH(job, &jobs, job_list) { | |
169 | if (job->id && !strcmp(id, job->id)) { | |
170 | return job; | |
171 | } | |
172 | } | |
173 | ||
174 | return NULL; | |
175 | } | |
176 | ||
5d43e86e KW |
177 | static void job_sleep_timer_cb(void *opaque) |
178 | { | |
179 | Job *job = opaque; | |
180 | ||
181 | job_enter(job); | |
182 | } | |
183 | ||
08be6fe2 | 184 | void *job_create(const char *job_id, const JobDriver *driver, AioContext *ctx, |
bb02b65c | 185 | int flags, Error **errp) |
33e9e9bd KW |
186 | { |
187 | Job *job; | |
188 | ||
189 | if (job_id) { | |
bb02b65c KW |
190 | if (flags & JOB_INTERNAL) { |
191 | error_setg(errp, "Cannot specify job ID for internal job"); | |
192 | return NULL; | |
193 | } | |
33e9e9bd KW |
194 | if (!id_wellformed(job_id)) { |
195 | error_setg(errp, "Invalid job ID '%s'", job_id); | |
196 | return NULL; | |
197 | } | |
e7c1d78b KW |
198 | if (job_get(job_id)) { |
199 | error_setg(errp, "Job ID '%s' already in use", job_id); | |
200 | return NULL; | |
201 | } | |
bb02b65c KW |
202 | } else if (!(flags & JOB_INTERNAL)) { |
203 | error_setg(errp, "An explicit job ID is required"); | |
204 | return NULL; | |
33e9e9bd KW |
205 | } |
206 | ||
207 | job = g_malloc0(driver->instance_size); | |
208 | job->driver = driver; | |
209 | job->id = g_strdup(job_id); | |
80fa2c75 | 210 | job->refcnt = 1; |
08be6fe2 | 211 | job->aio_context = ctx; |
da01ff7f KW |
212 | job->busy = false; |
213 | job->paused = true; | |
214 | job->pause_count = 1; | |
bb02b65c KW |
215 | job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE); |
216 | job->auto_dismiss = !(flags & JOB_MANUAL_DISMISS); | |
33e9e9bd | 217 | |
a50c2ab8 | 218 | job_state_transition(job, JOB_STATUS_CREATED); |
5d43e86e KW |
219 | aio_timer_init(qemu_get_aio_context(), &job->sleep_timer, |
220 | QEMU_CLOCK_REALTIME, SCALE_NS, | |
221 | job_sleep_timer_cb, job); | |
a50c2ab8 | 222 | |
e7c1d78b KW |
223 | QLIST_INSERT_HEAD(&jobs, job, job_list); |
224 | ||
33e9e9bd KW |
225 | return job; |
226 | } | |
fd61a701 | 227 | |
80fa2c75 | 228 | void job_ref(Job *job) |
fd61a701 | 229 | { |
80fa2c75 KW |
230 | ++job->refcnt; |
231 | } | |
232 | ||
233 | void job_unref(Job *job) | |
234 | { | |
235 | if (--job->refcnt == 0) { | |
236 | assert(job->status == JOB_STATUS_NULL); | |
5d43e86e | 237 | assert(!timer_pending(&job->sleep_timer)); |
e7c1d78b | 238 | |
80fa2c75 KW |
239 | if (job->driver->free) { |
240 | job->driver->free(job); | |
241 | } | |
242 | ||
243 | QLIST_REMOVE(job, job_list); | |
244 | ||
245 | g_free(job->id); | |
246 | g_free(job); | |
247 | } | |
fd61a701 | 248 | } |
1908a559 | 249 | |
da01ff7f KW |
250 | void job_enter_cond(Job *job, bool(*fn)(Job *job)) |
251 | { | |
252 | if (!job_started(job)) { | |
253 | return; | |
254 | } | |
255 | if (job->deferred_to_main_loop) { | |
256 | return; | |
257 | } | |
258 | ||
259 | job_lock(); | |
260 | if (job->busy) { | |
261 | job_unlock(); | |
262 | return; | |
263 | } | |
264 | ||
265 | if (fn && !fn(job)) { | |
266 | job_unlock(); | |
267 | return; | |
268 | } | |
269 | ||
270 | assert(!job->deferred_to_main_loop); | |
271 | timer_del(&job->sleep_timer); | |
272 | job->busy = true; | |
273 | job_unlock(); | |
274 | aio_co_wake(job->co); | |
275 | } | |
276 | ||
5d43e86e KW |
277 | void job_enter(Job *job) |
278 | { | |
279 | job_enter_cond(job, NULL); | |
280 | } | |
281 | ||
da01ff7f KW |
282 | /* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds. |
283 | * Reentering the job coroutine with block_job_enter() before the timer has | |
284 | * expired is allowed and cancels the timer. | |
285 | * | |
286 | * If @ns is (uint64_t) -1, no timer is scheduled and block_job_enter() must be | |
287 | * called explicitly. */ | |
288 | void coroutine_fn job_do_yield(Job *job, uint64_t ns) | |
289 | { | |
290 | job_lock(); | |
291 | if (ns != -1) { | |
292 | timer_mod(&job->sleep_timer, ns); | |
293 | } | |
294 | job->busy = false; | |
295 | job_unlock(); | |
296 | qemu_coroutine_yield(); | |
297 | ||
298 | /* Set by job_enter_cond() before re-entering the coroutine. */ | |
299 | assert(job->busy); | |
300 | } | |
301 | ||
302 | void coroutine_fn job_pause_point(Job *job) | |
303 | { | |
304 | assert(job && job_started(job)); | |
305 | ||
306 | if (!job_should_pause(job)) { | |
307 | return; | |
308 | } | |
309 | if (job_is_cancelled(job)) { | |
310 | return; | |
311 | } | |
312 | ||
313 | if (job->driver->pause) { | |
314 | job->driver->pause(job); | |
315 | } | |
316 | ||
317 | if (job_should_pause(job) && !job_is_cancelled(job)) { | |
318 | JobStatus status = job->status; | |
319 | job_state_transition(job, status == JOB_STATUS_READY | |
320 | ? JOB_STATUS_STANDBY | |
321 | : JOB_STATUS_PAUSED); | |
322 | job->paused = true; | |
323 | job_do_yield(job, -1); | |
324 | job->paused = false; | |
325 | job_state_transition(job, status); | |
326 | } | |
327 | ||
328 | if (job->driver->resume) { | |
329 | job->driver->resume(job); | |
330 | } | |
331 | } | |
332 | ||
5d43e86e KW |
333 | void coroutine_fn job_sleep_ns(Job *job, int64_t ns) |
334 | { | |
335 | assert(job->busy); | |
336 | ||
337 | /* Check cancellation *before* setting busy = false, too! */ | |
338 | if (job_is_cancelled(job)) { | |
339 | return; | |
340 | } | |
341 | ||
342 | if (!job_should_pause(job)) { | |
343 | job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns); | |
344 | } | |
345 | ||
346 | job_pause_point(job); | |
347 | } | |
348 | ||
da01ff7f KW |
349 | /** |
350 | * All jobs must allow a pause point before entering their job proper. This | |
351 | * ensures that jobs can be paused prior to being started, then resumed later. | |
352 | */ | |
353 | static void coroutine_fn job_co_entry(void *opaque) | |
354 | { | |
355 | Job *job = opaque; | |
356 | ||
357 | assert(job && job->driver && job->driver->start); | |
358 | job_pause_point(job); | |
359 | job->driver->start(job); | |
360 | } | |
361 | ||
362 | ||
363 | void job_start(Job *job) | |
364 | { | |
365 | assert(job && !job_started(job) && job->paused && | |
366 | job->driver && job->driver->start); | |
367 | job->co = qemu_coroutine_create(job_co_entry, job); | |
368 | job->pause_count--; | |
369 | job->busy = true; | |
370 | job->paused = false; | |
371 | job_state_transition(job, JOB_STATUS_RUNNING); | |
372 | aio_co_enter(job->aio_context, job->co); | |
373 | } | |
374 | ||
b15de828 KW |
375 | /* Assumes the block_job_mutex is held */ |
376 | static bool job_timer_not_pending(Job *job) | |
377 | { | |
378 | return !timer_pending(&job->sleep_timer); | |
379 | } | |
380 | ||
381 | void job_pause(Job *job) | |
382 | { | |
383 | job->pause_count++; | |
384 | } | |
385 | ||
386 | void job_resume(Job *job) | |
387 | { | |
388 | assert(job->pause_count > 0); | |
389 | job->pause_count--; | |
390 | if (job->pause_count) { | |
391 | return; | |
392 | } | |
393 | ||
394 | /* kick only if no timer is pending */ | |
395 | job_enter_cond(job, job_timer_not_pending); | |
396 | } | |
397 | ||
398 | void job_user_pause(Job *job, Error **errp) | |
399 | { | |
400 | if (job_apply_verb(job, JOB_VERB_PAUSE, errp)) { | |
401 | return; | |
402 | } | |
403 | if (job->user_paused) { | |
404 | error_setg(errp, "Job is already paused"); | |
405 | return; | |
406 | } | |
407 | job->user_paused = true; | |
408 | job_pause(job); | |
409 | } | |
410 | ||
411 | bool job_user_paused(Job *job) | |
412 | { | |
413 | return job->user_paused; | |
414 | } | |
415 | ||
416 | void job_user_resume(Job *job, Error **errp) | |
417 | { | |
418 | assert(job); | |
419 | if (!job->user_paused || job->pause_count <= 0) { | |
420 | error_setg(errp, "Can't resume a job that was not paused"); | |
421 | return; | |
422 | } | |
423 | if (job_apply_verb(job, JOB_VERB_RESUME, errp)) { | |
424 | return; | |
425 | } | |
426 | if (job->driver->user_resume) { | |
427 | job->driver->user_resume(job); | |
428 | } | |
429 | job->user_paused = false; | |
430 | job_resume(job); | |
431 | } | |
432 | ||
433 | ||
1908a559 KW |
434 | typedef struct { |
435 | Job *job; | |
436 | JobDeferToMainLoopFn *fn; | |
437 | void *opaque; | |
438 | } JobDeferToMainLoopData; | |
439 | ||
440 | static void job_defer_to_main_loop_bh(void *opaque) | |
441 | { | |
442 | JobDeferToMainLoopData *data = opaque; | |
443 | Job *job = data->job; | |
444 | AioContext *aio_context = job->aio_context; | |
445 | ||
446 | aio_context_acquire(aio_context); | |
447 | data->fn(data->job, data->opaque); | |
448 | aio_context_release(aio_context); | |
449 | ||
450 | g_free(data); | |
451 | } | |
452 | ||
453 | void job_defer_to_main_loop(Job *job, JobDeferToMainLoopFn *fn, void *opaque) | |
454 | { | |
455 | JobDeferToMainLoopData *data = g_malloc(sizeof(*data)); | |
456 | data->job = job; | |
457 | data->fn = fn; | |
458 | data->opaque = opaque; | |
459 | job->deferred_to_main_loop = true; | |
460 | ||
461 | aio_bh_schedule_oneshot(qemu_get_aio_context(), | |
462 | job_defer_to_main_loop_bh, data); | |
463 | } |