| 1 | /* |
| 2 | * Declarations for background jobs |
| 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 | #ifndef JOB_H |
| 27 | #define JOB_H |
| 28 | |
| 29 | #include "qapi/qapi-types-job.h" |
| 30 | #include "qemu/aiocb.h" |
| 31 | #include "qemu/queue.h" |
| 32 | #include "qemu/progress_meter.h" |
| 33 | #include "qemu/coroutine.h" |
| 34 | #include "qemu/aio.h" |
| 35 | #include "block/graph-lock.h" |
| 36 | |
| 37 | typedef struct JobDriver JobDriver; |
| 38 | typedef struct JobTxn JobTxn; |
| 39 | |
| 40 | |
| 41 | /** |
| 42 | * Long-running operation. |
| 43 | */ |
| 44 | typedef struct Job { |
| 45 | |
| 46 | /* Fields set at initialization (job_create), and never modified */ |
| 47 | |
| 48 | /** The ID of the job. May be NULL for internal jobs. */ |
| 49 | char *id; |
| 50 | |
| 51 | /** |
| 52 | * The type of this job. |
| 53 | * All callbacks are called with job_mutex *not* held. |
| 54 | */ |
| 55 | const JobDriver *driver; |
| 56 | |
| 57 | /** |
| 58 | * The coroutine that executes the job. If not NULL, it is reentered when |
| 59 | * busy is false and the job is cancelled. |
| 60 | * Initialized in job_start() |
| 61 | */ |
| 62 | Coroutine *co; |
| 63 | |
| 64 | /** True if this job should automatically finalize itself */ |
| 65 | bool auto_finalize; |
| 66 | |
| 67 | /** True if this job should automatically dismiss itself */ |
| 68 | bool auto_dismiss; |
| 69 | |
| 70 | /** |
| 71 | * The completion function that will be called when the job completes. |
| 72 | */ |
| 73 | BlockCompletionFunc *cb; |
| 74 | |
| 75 | /** The opaque value that is passed to the completion function. */ |
| 76 | void *opaque; |
| 77 | |
| 78 | /* ProgressMeter API is thread-safe */ |
| 79 | ProgressMeter progress; |
| 80 | |
| 81 | /** |
| 82 | * AioContext to run the job coroutine in. |
| 83 | * The job Aiocontext can be read when holding *either* |
| 84 | * the BQL (so we are in the main loop) or the job_mutex. |
| 85 | * It can only be written when we hold *both* BQL |
| 86 | * and the job_mutex. |
| 87 | */ |
| 88 | AioContext *aio_context; |
| 89 | |
| 90 | |
| 91 | /** Protected by job_mutex */ |
| 92 | |
| 93 | /** Reference count of the block job */ |
| 94 | int refcnt; |
| 95 | |
| 96 | /** Current state; See @JobStatus for details. */ |
| 97 | JobStatus status; |
| 98 | |
| 99 | /** |
| 100 | * Timer that is used by @job_sleep_ns. Accessed under job_mutex (in |
| 101 | * job.c). |
| 102 | */ |
| 103 | QEMUTimer sleep_timer; |
| 104 | |
| 105 | /** |
| 106 | * Counter for pause request. If non-zero, the block job is either paused, |
| 107 | * or if busy == true will pause itself as soon as possible. |
| 108 | */ |
| 109 | int pause_count; |
| 110 | |
| 111 | /** |
| 112 | * Set to false by the job while the coroutine has yielded and may be |
| 113 | * re-entered by job_enter(). There may still be I/O or event loop activity |
| 114 | * pending. Accessed under job_mutex. |
| 115 | * |
| 116 | * When the job is deferred to the main loop, busy is true as long as the |
| 117 | * bottom half is still pending. |
| 118 | */ |
| 119 | bool busy; |
| 120 | |
| 121 | /** |
| 122 | * Set to true by the job while it is in a quiescent state, where |
| 123 | * no I/O or event loop activity is pending. |
| 124 | */ |
| 125 | bool paused; |
| 126 | |
| 127 | /** |
| 128 | * Set to true if the job is paused by user. Can be unpaused with the |
| 129 | * block-job-resume QMP command. |
| 130 | */ |
| 131 | bool user_paused; |
| 132 | |
| 133 | /** |
| 134 | * Set to true if the job should cancel itself. The flag must |
| 135 | * always be tested just before toggling the busy flag from false |
| 136 | * to true. After a job has been cancelled, it should only yield |
| 137 | * if #aio_poll will ("sooner or later") reenter the coroutine. |
| 138 | */ |
| 139 | bool cancelled; |
| 140 | |
| 141 | /** |
| 142 | * Set to true if the job should abort immediately without waiting |
| 143 | * for data to be in sync. |
| 144 | */ |
| 145 | bool force_cancel; |
| 146 | |
| 147 | /** Set to true when the job has deferred work to the main loop. */ |
| 148 | bool deferred_to_main_loop; |
| 149 | |
| 150 | /** |
| 151 | * Return code from @run and/or @prepare callback(s). |
| 152 | * Not final until the job has reached the CONCLUDED status. |
| 153 | * 0 on success, -errno on failure. |
| 154 | */ |
| 155 | int ret; |
| 156 | |
| 157 | /** |
| 158 | * Error object for a failed job. |
| 159 | * If job->ret is nonzero and an error object was not set, it will be set |
| 160 | * to strerror(-job->ret) during job_completed. |
| 161 | */ |
| 162 | Error *err; |
| 163 | |
| 164 | /** Notifiers called when a cancelled job is finalised */ |
| 165 | NotifierList on_finalize_cancelled; |
| 166 | |
| 167 | /** Notifiers called when a successfully completed job is finalised */ |
| 168 | NotifierList on_finalize_completed; |
| 169 | |
| 170 | /** Notifiers called when the job transitions to PENDING */ |
| 171 | NotifierList on_pending; |
| 172 | |
| 173 | /** Notifiers called when the job transitions to READY */ |
| 174 | NotifierList on_ready; |
| 175 | |
| 176 | /** Notifiers called when the job coroutine yields or terminates */ |
| 177 | NotifierList on_idle; |
| 178 | |
| 179 | /** Element of the list of jobs */ |
| 180 | QLIST_ENTRY(Job) job_list; |
| 181 | |
| 182 | /** Transaction this job is part of */ |
| 183 | JobTxn *txn; |
| 184 | |
| 185 | /** Element of the list of jobs in a job transaction */ |
| 186 | QLIST_ENTRY(Job) txn_list; |
| 187 | } Job; |
| 188 | |
| 189 | /** |
| 190 | * Callbacks and other information about a Job driver. |
| 191 | * All callbacks are invoked with job_mutex *not* held. |
| 192 | */ |
| 193 | struct JobDriver { |
| 194 | |
| 195 | /* |
| 196 | * These fields are initialized when this object is created, |
| 197 | * and are never changed afterwards |
| 198 | */ |
| 199 | |
| 200 | /** Derived Job struct size */ |
| 201 | size_t instance_size; |
| 202 | |
| 203 | /** Enum describing the operation */ |
| 204 | JobType job_type; |
| 205 | |
| 206 | /** |
| 207 | * Mandatory: Entrypoint for the Coroutine. |
| 208 | * |
| 209 | * This callback will be invoked when moving from CREATED to RUNNING. |
| 210 | * |
| 211 | * If this callback returns nonzero, the job transaction it is part of is |
| 212 | * aborted. If it returns zero, the job moves into the WAITING state. If it |
| 213 | * is the last job to complete in its transaction, all jobs in the |
| 214 | * transaction move from WAITING to PENDING. |
| 215 | * |
| 216 | * This callback must be run in the job's context. |
| 217 | */ |
| 218 | int coroutine_fn (*run)(Job *job, Error **errp); |
| 219 | |
| 220 | /* |
| 221 | * Functions run without regard to the BQL that may run in any |
| 222 | * arbitrary thread. These functions do not need to be thread-safe |
| 223 | * because the caller ensures that they are invoked from one |
| 224 | * thread at time. |
| 225 | */ |
| 226 | |
| 227 | /** |
| 228 | * If the callback is not NULL, it will be invoked when the job transitions |
| 229 | * into the paused state. Paused jobs must not perform any asynchronous |
| 230 | * I/O or event loop activity. This callback is used to quiesce jobs. |
| 231 | */ |
| 232 | void coroutine_fn (*pause)(Job *job); |
| 233 | |
| 234 | /** |
| 235 | * If the callback is not NULL, it will be invoked when the job transitions |
| 236 | * out of the paused state. Any asynchronous I/O or event loop activity |
| 237 | * should be restarted from this callback. |
| 238 | */ |
| 239 | void coroutine_fn (*resume)(Job *job); |
| 240 | |
| 241 | /* |
| 242 | * Global state (GS) API. These functions run under the BQL. |
| 243 | * |
| 244 | * See include/block/block-global-state.h for more information about |
| 245 | * the GS API. |
| 246 | */ |
| 247 | |
| 248 | /** |
| 249 | * Called when the job is resumed by the user (i.e. user_paused becomes |
| 250 | * false). .user_resume is called before .resume. |
| 251 | */ |
| 252 | void (*user_resume)(Job *job); |
| 253 | |
| 254 | /** |
| 255 | * Optional callback for job types whose completion must be triggered |
| 256 | * manually. |
| 257 | */ |
| 258 | void (*complete)(Job *job, Error **errp); |
| 259 | |
| 260 | /** |
| 261 | * If the callback is not NULL, prepare will be invoked when all the jobs |
| 262 | * belonging to the same transaction complete; or upon this job's completion |
| 263 | * if it is not in a transaction. |
| 264 | * |
| 265 | * This callback will not be invoked if the job has already failed. |
| 266 | * If it fails, abort and then clean will be called. |
| 267 | */ |
| 268 | int GRAPH_UNLOCKED_PTR (*prepare)(Job *job); |
| 269 | |
| 270 | /** |
| 271 | * If the callback is not NULL, it will be invoked when all the jobs |
| 272 | * belonging to the same transaction complete; or upon this job's |
| 273 | * completion if it is not in a transaction. Skipped if NULL. |
| 274 | * |
| 275 | * All jobs will complete with a call to either .commit() or .abort() but |
| 276 | * never both. |
| 277 | */ |
| 278 | void (*commit)(Job *job); |
| 279 | |
| 280 | /** |
| 281 | * If the callback is not NULL, it will be invoked when any job in the |
| 282 | * same transaction fails; or upon this job's failure (due to error or |
| 283 | * cancellation) if it is not in a transaction. Skipped if NULL. |
| 284 | * |
| 285 | * All jobs will complete with a call to either .commit() or .abort() but |
| 286 | * never both. |
| 287 | */ |
| 288 | void GRAPH_UNLOCKED_PTR (*abort)(Job *job); |
| 289 | |
| 290 | /** |
| 291 | * If the callback is not NULL, it will be invoked after a call to either |
| 292 | * .commit() or .abort(). Regardless of which callback is invoked after |
| 293 | * completion, .clean() will always be called, even if the job does not |
| 294 | * belong to a transaction group. |
| 295 | */ |
| 296 | void (*clean)(Job *job); |
| 297 | |
| 298 | /** |
| 299 | * If the callback is not NULL, it will be invoked in job_cancel_async |
| 300 | * |
| 301 | * This function must return true if the job will be cancelled |
| 302 | * immediately without any further I/O (mandatory if @force is |
| 303 | * true), and false otherwise. This lets the generic job layer |
| 304 | * know whether a job has been truly (force-)cancelled, or whether |
| 305 | * it is just in a special completion mode (like mirror after |
| 306 | * READY). |
| 307 | * (If the callback is NULL, the job is assumed to terminate |
| 308 | * without I/O.) |
| 309 | */ |
| 310 | bool (*cancel)(Job *job, bool force); |
| 311 | |
| 312 | |
| 313 | /** |
| 314 | * Called when the job is freed. |
| 315 | */ |
| 316 | void (*free)(Job *job); |
| 317 | }; |
| 318 | |
| 319 | typedef enum JobCreateFlags { |
| 320 | /* Default behavior */ |
| 321 | JOB_DEFAULT = 0x00, |
| 322 | /* Job is not QMP-created and should not send QMP events */ |
| 323 | JOB_INTERNAL = 0x01, |
| 324 | /* Job requires manual finalize step */ |
| 325 | JOB_MANUAL_FINALIZE = 0x02, |
| 326 | /* Job requires manual dismiss step */ |
| 327 | JOB_MANUAL_DISMISS = 0x04, |
| 328 | } JobCreateFlags; |
| 329 | |
| 330 | extern QemuMutex job_mutex; |
| 331 | |
| 332 | #define JOB_LOCK_GUARD() QEMU_LOCK_GUARD(&job_mutex) |
| 333 | |
| 334 | #define WITH_JOB_LOCK_GUARD() WITH_QEMU_LOCK_GUARD(&job_mutex) |
| 335 | |
| 336 | /** |
| 337 | * job_lock: |
| 338 | * |
| 339 | * Take the mutex protecting the list of jobs and their status. |
| 340 | * Most functions called by the monitor need to call job_lock |
| 341 | * and job_unlock manually. On the other hand, function called |
| 342 | * by the block jobs themselves and by the block layer will take the |
| 343 | * lock for you. |
| 344 | */ |
| 345 | void job_lock(void); |
| 346 | |
| 347 | /** |
| 348 | * job_unlock: |
| 349 | * |
| 350 | * Release the mutex protecting the list of jobs and their status. |
| 351 | */ |
| 352 | void job_unlock(void); |
| 353 | |
| 354 | /** |
| 355 | * Allocate and return a new job transaction. Jobs can be added to the |
| 356 | * transaction using job_txn_add_job(). |
| 357 | * |
| 358 | * The transaction is automatically freed when the last job completes or is |
| 359 | * cancelled. |
| 360 | * |
| 361 | * All jobs in the transaction either complete successfully or fail/cancel as a |
| 362 | * group. Jobs wait for each other before completing. Cancelling one job |
| 363 | * cancels all jobs in the transaction. |
| 364 | */ |
| 365 | JobTxn *job_txn_new(void); |
| 366 | |
| 367 | /** |
| 368 | * Release a reference that was previously acquired with job_txn_add_job or |
| 369 | * job_txn_new. If it's the last reference to the object, it will be freed. |
| 370 | * |
| 371 | * Called with job lock *not* held. |
| 372 | */ |
| 373 | void job_txn_unref(JobTxn *txn); |
| 374 | |
| 375 | /* |
| 376 | * Same as job_txn_unref(), but called with job lock held. |
| 377 | * Might release the lock temporarily. |
| 378 | */ |
| 379 | void job_txn_unref_locked(JobTxn *txn); |
| 380 | |
| 381 | /** |
| 382 | * Create a new long-running job and return it. |
| 383 | * Called with job_mutex *not* held. |
| 384 | * |
| 385 | * @job_id: The id of the newly-created job, or %NULL for internal jobs |
| 386 | * @driver: The class object for the newly-created job. |
| 387 | * @txn: The transaction this job belongs to, if any. %NULL otherwise. |
| 388 | * @ctx: The AioContext to run the job coroutine in. |
| 389 | * @flags: Creation flags for the job. See @JobCreateFlags. |
| 390 | * @cb: Completion function for the job. |
| 391 | * @opaque: Opaque pointer value passed to @cb. |
| 392 | * @errp: Error object. |
| 393 | */ |
| 394 | void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn, |
| 395 | AioContext *ctx, int flags, BlockCompletionFunc *cb, |
| 396 | void *opaque, Error **errp); |
| 397 | |
| 398 | /** |
| 399 | * Add a reference to Job refcnt, it will be decreased with job_unref, and then |
| 400 | * be freed if it comes to be the last reference. |
| 401 | * |
| 402 | * Called with job lock held. |
| 403 | */ |
| 404 | void job_ref_locked(Job *job); |
| 405 | |
| 406 | /** |
| 407 | * Release a reference that was previously acquired with job_ref_locked() or |
| 408 | * job_create(). If it's the last reference to the object, it will be freed. |
| 409 | * |
| 410 | * Called with job lock held. |
| 411 | */ |
| 412 | void job_unref_locked(Job *job); |
| 413 | |
| 414 | /** |
| 415 | * @job: The job that has made progress |
| 416 | * @done: How much progress the job made since the last call |
| 417 | * |
| 418 | * Updates the progress counter of the job. |
| 419 | * |
| 420 | * May be called with mutex held or not held. |
| 421 | */ |
| 422 | void job_progress_update(Job *job, uint64_t done); |
| 423 | |
| 424 | /** |
| 425 | * @job: The job whose expected progress end value is set |
| 426 | * @remaining: Missing progress (on top of the current progress counter value) |
| 427 | * until the new expected end value is reached |
| 428 | * |
| 429 | * Sets the expected end value of the progress counter of a job so that a |
| 430 | * completion percentage can be calculated when the progress is updated. |
| 431 | * |
| 432 | * May be called with mutex held or not held. |
| 433 | */ |
| 434 | void job_progress_set_remaining(Job *job, uint64_t remaining); |
| 435 | |
| 436 | /** |
| 437 | * @job: The job whose expected progress end value is updated |
| 438 | * @delta: Value which is to be added to the current expected end |
| 439 | * value |
| 440 | * |
| 441 | * Increases the expected end value of the progress counter of a job. |
| 442 | * This is useful for parenthesis operations: If a job has to |
| 443 | * conditionally perform a high-priority operation as part of its |
| 444 | * progress, it calls this function with the expected operation's |
| 445 | * length before, and job_progress_update() afterwards. |
| 446 | * (So the operation acts as a parenthesis in regards to the main job |
| 447 | * operation running in background.) |
| 448 | * |
| 449 | * May be called with mutex held or not held. |
| 450 | */ |
| 451 | void job_progress_increase_remaining(Job *job, uint64_t delta); |
| 452 | |
| 453 | /** |
| 454 | * Conditionally enter the job coroutine if the job is ready to run, not |
| 455 | * already busy and fn() returns true. fn() is called while under the job_lock |
| 456 | * critical section. |
| 457 | * |
| 458 | * Called with job lock held, but might release it temporarily. |
| 459 | */ |
| 460 | void job_enter_cond_locked(Job *job, bool(*fn)(Job *job)); |
| 461 | |
| 462 | /** |
| 463 | * @job: A job that has not yet been started. |
| 464 | * |
| 465 | * Begins execution of a job. |
| 466 | * Takes ownership of one reference to the job object. |
| 467 | * |
| 468 | * Called with job_mutex *not* held. |
| 469 | */ |
| 470 | void job_start(Job *job); |
| 471 | |
| 472 | /** |
| 473 | * @job: The job to enter. |
| 474 | * |
| 475 | * Continue the specified job by entering the coroutine. |
| 476 | * Called with job_mutex *not* held. |
| 477 | */ |
| 478 | void job_enter(Job *job); |
| 479 | |
| 480 | /** |
| 481 | * @job: The job that is ready to pause. |
| 482 | * |
| 483 | * Pause now if job_pause() has been called. Jobs that perform lots of I/O |
| 484 | * must call this between requests so that the job can be paused. |
| 485 | * |
| 486 | * Called with job_mutex *not* held. |
| 487 | */ |
| 488 | void coroutine_fn GRAPH_UNLOCKED job_pause_point(Job *job); |
| 489 | |
| 490 | /** |
| 491 | * @job: The job that calls the function. |
| 492 | * |
| 493 | * Yield the job coroutine. |
| 494 | * Called with job_mutex *not* held. |
| 495 | */ |
| 496 | void coroutine_fn job_yield(Job *job); |
| 497 | |
| 498 | /** |
| 499 | * @job: The job that calls the function. |
| 500 | * @ns: How many nanoseconds to stop for. |
| 501 | * |
| 502 | * Put the job to sleep (assuming that it wasn't canceled) for @ns |
| 503 | * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will immediately |
| 504 | * interrupt the wait. |
| 505 | * |
| 506 | * Called with job_mutex *not* held. |
| 507 | */ |
| 508 | void coroutine_fn job_sleep_ns(Job *job, int64_t ns); |
| 509 | |
| 510 | /** Returns the JobType of a given Job. */ |
| 511 | JobType job_type(const Job *job); |
| 512 | |
| 513 | /** Returns the enum string for the JobType of a given Job. */ |
| 514 | const char *job_type_str(const Job *job); |
| 515 | |
| 516 | /** Returns true if the job should not be visible to the management layer. */ |
| 517 | bool job_is_internal(Job *job); |
| 518 | |
| 519 | /** |
| 520 | * Returns whether the job is being cancelled. |
| 521 | * Called with job_mutex *not* held. |
| 522 | */ |
| 523 | bool job_is_cancelled(Job *job); |
| 524 | |
| 525 | /* Same as job_is_cancelled(), but called with job lock held. */ |
| 526 | bool job_is_cancelled_locked(Job *job); |
| 527 | |
| 528 | /** |
| 529 | * Returns whether the job is scheduled for cancellation (at an |
| 530 | * indefinite point). |
| 531 | * Called with job_mutex *not* held. |
| 532 | */ |
| 533 | bool job_cancel_requested(Job *job); |
| 534 | |
| 535 | /** |
| 536 | * Returns whether the job is in a completed state. |
| 537 | * Called with job lock held. |
| 538 | */ |
| 539 | bool job_is_completed_locked(Job *job); |
| 540 | |
| 541 | /** |
| 542 | * Returns whether the job is ready to be completed. |
| 543 | * Called with job_mutex *not* held. |
| 544 | */ |
| 545 | bool job_is_ready(Job *job); |
| 546 | |
| 547 | /* Same as job_is_ready(), but called with job lock held. */ |
| 548 | bool job_is_ready_locked(Job *job); |
| 549 | |
| 550 | /** Returns whether the job is paused. Called with job_mutex *not* held. */ |
| 551 | bool job_is_paused(Job *job); |
| 552 | |
| 553 | /** |
| 554 | * Request @job to pause at the next pause point. Must be paired with |
| 555 | * job_resume(). If the job is supposed to be resumed by user action, call |
| 556 | * job_user_pause_locked() instead. |
| 557 | * |
| 558 | * Called with job lock *not* held. |
| 559 | */ |
| 560 | void job_pause(Job *job); |
| 561 | |
| 562 | /* Same as job_pause(), but called with job lock held. */ |
| 563 | void job_pause_locked(Job *job); |
| 564 | |
| 565 | /** Resumes a @job paused with job_pause. Called with job lock *not* held. */ |
| 566 | void job_resume(Job *job); |
| 567 | |
| 568 | /* |
| 569 | * Same as job_resume(), but called with job lock held. |
| 570 | * Might release the lock temporarily. |
| 571 | */ |
| 572 | void job_resume_locked(Job *job); |
| 573 | |
| 574 | /** |
| 575 | * Asynchronously pause the specified @job. |
| 576 | * Do not allow a resume until a matching call to job_user_resume. |
| 577 | * Called with job lock held. |
| 578 | */ |
| 579 | void job_user_pause_locked(Job *job, Error **errp); |
| 580 | |
| 581 | /** |
| 582 | * Returns true if the job is user-paused. |
| 583 | * Called with job lock held. |
| 584 | */ |
| 585 | bool job_user_paused_locked(Job *job); |
| 586 | |
| 587 | /** |
| 588 | * Resume the specified @job. |
| 589 | * Must be paired with a preceding job_user_pause_locked. |
| 590 | * Called with job lock held, but might release it temporarily. |
| 591 | */ |
| 592 | void job_user_resume_locked(Job *job, Error **errp); |
| 593 | |
| 594 | /** |
| 595 | * Get the next element from the list of block jobs after @job, or the |
| 596 | * first one if @job is %NULL. |
| 597 | * |
| 598 | * Returns the requested job, or %NULL if there are no more jobs left. |
| 599 | * Called with job lock *not* held. |
| 600 | */ |
| 601 | Job *job_next(Job *job); |
| 602 | |
| 603 | /* Same as job_next(), but called with job lock held. */ |
| 604 | Job *job_next_locked(Job *job); |
| 605 | |
| 606 | /** |
| 607 | * Get the job identified by @id (which must not be %NULL). |
| 608 | * |
| 609 | * Returns the requested job, or %NULL if it doesn't exist. |
| 610 | * Called with job lock held. |
| 611 | */ |
| 612 | Job *job_get_locked(const char *id); |
| 613 | |
| 614 | /** |
| 615 | * Check whether the verb @verb can be applied to @job in its current state. |
| 616 | * Returns 0 if the verb can be applied; otherwise errp is set and -EPERM |
| 617 | * returned. |
| 618 | * |
| 619 | * Called with job lock held. |
| 620 | */ |
| 621 | int job_apply_verb_locked(Job *job, JobVerb verb, Error **errp); |
| 622 | |
| 623 | /** |
| 624 | * The @job could not be started, free it. |
| 625 | * Called with job_mutex *not* held. |
| 626 | */ |
| 627 | void job_early_fail(Job *job); |
| 628 | |
| 629 | /** |
| 630 | * Moves the @job from RUNNING to READY. |
| 631 | * Called with job_mutex *not* held. |
| 632 | */ |
| 633 | void job_transition_to_ready(Job *job); |
| 634 | |
| 635 | /** |
| 636 | * Asynchronously complete the specified @job. |
| 637 | * Called with job lock held, but might release it temporarily. |
| 638 | */ |
| 639 | void job_complete_locked(Job *job, Error **errp); |
| 640 | |
| 641 | /** |
| 642 | * Asynchronously cancel the specified @job. If @force is true, the job should |
| 643 | * be cancelled immediately without waiting for a consistent state. |
| 644 | * Called with job lock held. |
| 645 | */ |
| 646 | void job_cancel_locked(Job *job, bool force); |
| 647 | |
| 648 | /** |
| 649 | * Cancels the specified job like job_cancel_locked(), but may refuse |
| 650 | * to do so if the operation isn't meaningful in the current state of the job. |
| 651 | * Called with job lock held. |
| 652 | */ |
| 653 | void job_user_cancel_locked(Job *job, bool force, Error **errp); |
| 654 | |
| 655 | /** |
| 656 | * Synchronously cancel the @job. The completion callback is called |
| 657 | * before the function returns. If @force is false, the job may |
| 658 | * actually complete instead of canceling itself; the circumstances |
| 659 | * under which this happens depend on the kind of job that is active. |
| 660 | * |
| 661 | * Returns the return value from the job if the job actually completed |
| 662 | * during the call, or -ECANCELED if it was canceled. |
| 663 | * |
| 664 | * Called with job_lock *not* held. |
| 665 | */ |
| 666 | int job_cancel_sync(Job *job, bool force); |
| 667 | |
| 668 | /* Same as job_cancel_sync, but called with job lock held. */ |
| 669 | int job_cancel_sync_locked(Job *job, bool force); |
| 670 | |
| 671 | /** |
| 672 | * Synchronously force-cancels all jobs using job_cancel_sync_locked(). |
| 673 | * |
| 674 | * Called with job_lock *not* held. |
| 675 | */ |
| 676 | void job_cancel_sync_all(void); |
| 677 | |
| 678 | /** |
| 679 | * @job: The job to be completed. |
| 680 | * @errp: Error object which may be set by job_complete_locked(); this is not |
| 681 | * necessarily set on every error, the job return value has to be |
| 682 | * checked as well. |
| 683 | * |
| 684 | * Synchronously complete the job. The completion callback is called before the |
| 685 | * function returns, unless it is NULL (which is permissible when using this |
| 686 | * function). |
| 687 | * |
| 688 | * Returns the return value from the job. |
| 689 | * Called with job_lock held. |
| 690 | */ |
| 691 | int job_complete_sync_locked(Job *job, Error **errp); |
| 692 | |
| 693 | /** |
| 694 | * For a @job that has finished its work and is pending awaiting explicit |
| 695 | * acknowledgement to commit its work, this will commit that work. |
| 696 | * |
| 697 | * FIXME: Make the below statement universally true: |
| 698 | * For jobs that support the manual workflow mode, all graph changes that occur |
| 699 | * as a result will occur after this command and before a successful reply. |
| 700 | * |
| 701 | * Called with job lock held. |
| 702 | */ |
| 703 | void job_finalize_locked(Job *job, Error **errp); |
| 704 | |
| 705 | /** |
| 706 | * Remove the concluded @job from the query list and resets the passed pointer |
| 707 | * to %NULL. Returns an error if the job is not actually concluded. |
| 708 | * |
| 709 | * Called with job lock held. |
| 710 | */ |
| 711 | void job_dismiss_locked(Job **job, Error **errp); |
| 712 | |
| 713 | /** |
| 714 | * Synchronously finishes the given @job. If @finish is given, it is called to |
| 715 | * trigger completion or cancellation of the job. |
| 716 | * |
| 717 | * Returns 0 if the job is successfully completed, -ECANCELED if the job was |
| 718 | * cancelled before completing, and -errno in other error cases. |
| 719 | * |
| 720 | * Called with job_lock held, but might release it temporarily. |
| 721 | */ |
| 722 | int job_finish_sync_locked(Job *job, void (*finish)(Job *, Error **errp), |
| 723 | Error **errp); |
| 724 | |
| 725 | /** |
| 726 | * Sets the @job->aio_context. |
| 727 | * Called with job_mutex *not* held. |
| 728 | * |
| 729 | * This function must run in the main thread to protect against |
| 730 | * concurrent read in job_finish_sync_locked(), takes the job_mutex |
| 731 | * lock to protect against the read in job_do_yield_locked(), and must |
| 732 | * be called when the job is quiescent. |
| 733 | */ |
| 734 | void job_set_aio_context(Job *job, AioContext *ctx); |
| 735 | |
| 736 | #endif |