2 * Declarations for long-running block device operations
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29 #include "block/block.h"
34 * A class type for block job driver.
36 typedef struct BlockJobDriver
{
37 /** Derived BlockJob struct size */
40 /** String describing the operation, part of query-block-jobs QMP API */
41 BlockJobType job_type
;
43 /** Optional callback for job types that support setting a speed limit */
44 void (*set_speed
)(BlockJob
*job
, int64_t speed
, Error
**errp
);
46 /** Optional callback for job types that need to forward I/O status reset */
47 void (*iostatus_reset
)(BlockJob
*job
);
50 * Optional callback for job types whose completion must be triggered
53 void (*complete
)(BlockJob
*job
, Error
**errp
);
56 * If the callback is not NULL, it will be invoked when all the jobs
57 * belonging to the same transaction complete; or upon this job's
58 * completion if it is not in a transaction. Skipped if NULL.
60 * All jobs will complete with a call to either .commit() or .abort() but
63 void (*commit
)(BlockJob
*job
);
66 * If the callback is not NULL, it will be invoked when any job in the
67 * same transaction fails; or upon this job's failure (due to error or
68 * cancellation) if it is not in a transaction. Skipped if NULL.
70 * All jobs will complete with a call to either .commit() or .abort() but
73 void (*abort
)(BlockJob
*job
);
76 * If the callback is not NULL, it will be invoked when the job transitions
77 * into the paused state. Paused jobs must not perform any asynchronous
78 * I/O or event loop activity. This callback is used to quiesce jobs.
80 void coroutine_fn (*pause
)(BlockJob
*job
);
83 * If the callback is not NULL, it will be invoked when the job transitions
84 * out of the paused state. Any asynchronous I/O or event loop activity
85 * should be restarted from this callback.
87 void coroutine_fn (*resume
)(BlockJob
*job
);
90 * If the callback is not NULL, it will be invoked before the job is
91 * resumed in a new AioContext. This is the place to move any resources
92 * besides job->blk to the new AioContext.
94 void (*attached_aio_context
)(BlockJob
*job
, AioContext
*new_context
);
97 * If the callback is not NULL, it will be invoked when the job has to be
98 * synchronously cancelled or completed; it should drain BlockDriverStates
99 * as required to ensure progress.
101 void (*drain
)(BlockJob
*job
);
107 * Long-running operation on a BlockDriverState.
110 /** The job type, including the job vtable. */
111 const BlockJobDriver
*driver
;
113 /** The block device on which the job is operating. */
117 * The ID of the block job. May be NULL for internal jobs.
122 * The coroutine that executes the job. If not NULL, it is
123 * reentered when busy is false and the job is cancelled.
128 * Set to true if the job should cancel itself. The flag must
129 * always be tested just before toggling the busy flag from false
130 * to true. After a job has been cancelled, it should only yield
131 * if #aio_poll will ("sooner or later") reenter the coroutine.
136 * Counter for pause request. If non-zero, the block job is either paused,
137 * or if busy == true will pause itself as soon as possible.
142 * Set to true if the job is paused by user. Can be unpaused with the
143 * block-job-resume QMP command.
148 * Set to false by the job while the coroutine has yielded and may be
149 * re-entered by block_job_enter(). There may still be I/O or event loop
155 * Set to true by the job while it is in a quiescent state, where
156 * no I/O or event loop activity is pending.
161 * Set to true when the job is ready to be completed.
166 * Set to true when the job has deferred work to the main loop.
168 bool deferred_to_main_loop
;
170 /** Element of the list of block jobs */
171 QLIST_ENTRY(BlockJob
) job_list
;
173 /** Status that is published by the query-block-jobs QMP API */
174 BlockDeviceIoStatus iostatus
;
176 /** Offset that is published by the query-block-jobs QMP API */
179 /** Length that is published by the query-block-jobs QMP API */
182 /** Speed that was set with @block_job_set_speed. */
185 /** The completion function that will be called when the job completes. */
186 BlockCompletionFunc
*cb
;
188 /** Block other operations when block job is running */
191 /** BlockDriverStates that are involved in this block job */
194 /** The opaque value that is passed to the completion function. */
197 /** Reference count of the block job */
200 /* True if this job has reported completion by calling block_job_completed.
204 /* ret code passed to block_job_completed.
208 /** Non-NULL if this job is part of a transaction */
210 QLIST_ENTRY(BlockJob
) txn_list
;
213 typedef enum BlockJobCreateFlags
{
214 BLOCK_JOB_DEFAULT
= 0x00,
215 BLOCK_JOB_INTERNAL
= 0x01,
216 } BlockJobCreateFlags
;
220 * @job: A block job, or %NULL.
222 * Get the next element from the list of block jobs after @job, or the
223 * first one if @job is %NULL.
225 * Returns the requested job, or %NULL if there are no more jobs left.
227 BlockJob
*block_job_next(BlockJob
*job
);
231 * @id: The id of the block job.
233 * Get the block job identified by @id (which must not be %NULL).
235 * Returns the requested job, or %NULL if it doesn't exist.
237 BlockJob
*block_job_get(const char *id
);
241 * @job_id: The id of the newly-created job, or %NULL to have one
242 * generated automatically.
243 * @job_type: The class object for the newly-created job.
245 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
246 * @cb: Completion function for the job.
247 * @opaque: Opaque pointer value passed to @cb.
248 * @errp: Error object.
250 * Create a new long-running block device job and return it. The job
251 * will call @cb asynchronously when the job completes. Note that
252 * @bs may have been closed at the time the @cb it is called. If
253 * this is the case, the job may be reported as either cancelled or
256 * This function is not part of the public job interface; it should be
257 * called from a wrapper that is specific to the job type.
259 void *block_job_create(const char *job_id
, const BlockJobDriver
*driver
,
260 BlockDriverState
*bs
, int64_t speed
, int flags
,
261 BlockCompletionFunc
*cb
, void *opaque
, Error
**errp
);
264 * block_job_add_bdrv:
266 * @bs: A BlockDriverState that is involved in @job
268 * Add @bs to the list of BlockDriverState that are involved in
269 * @job. This means that all operations will be blocked on @bs while
272 void block_job_add_bdrv(BlockJob
*job
, BlockDriverState
*bs
);
275 * block_job_sleep_ns:
276 * @job: The job that calls the function.
277 * @clock: The clock to sleep on.
278 * @ns: How many nanoseconds to stop for.
280 * Put the job to sleep (assuming that it wasn't canceled) for @ns
281 * nanoseconds. Canceling the job will interrupt the wait immediately.
283 void block_job_sleep_ns(BlockJob
*job
, QEMUClockType type
, int64_t ns
);
287 * @job: The job that calls the function.
289 * Yield the block job coroutine.
291 void block_job_yield(BlockJob
*job
);
295 * @bs: The block device.
297 * Grab a reference to the block job. Should be paired with block_job_unref.
299 void block_job_ref(BlockJob
*job
);
303 * @bs: The block device.
305 * Release reference to the block job and release resources if it is the last
308 void block_job_unref(BlockJob
*job
);
311 * block_job_completed:
312 * @job: The job being completed.
313 * @ret: The status code.
315 * Call the completion function that was registered at creation time, and
318 void block_job_completed(BlockJob
*job
, int ret
);
321 * block_job_set_speed:
322 * @job: The job to set the speed for.
323 * @speed: The new value
324 * @errp: Error object.
326 * Set a rate-limiting parameter for the job; the actual meaning may
327 * vary depending on the job type.
329 void block_job_set_speed(BlockJob
*job
, int64_t speed
, Error
**errp
);
333 * @job: The job to be canceled.
335 * Asynchronously cancel the specified job.
337 void block_job_cancel(BlockJob
*job
);
340 * block_job_complete:
341 * @job: The job to be completed.
342 * @errp: Error object.
344 * Asynchronously complete the specified job.
346 void block_job_complete(BlockJob
*job
, Error
**errp
);
349 * block_job_is_cancelled:
350 * @job: The job being queried.
352 * Returns whether the job is scheduled for cancellation.
354 bool block_job_is_cancelled(BlockJob
*job
);
358 * @job: The job to get information about.
360 * Return information about a job.
362 BlockJobInfo
*block_job_query(BlockJob
*job
, Error
**errp
);
365 * block_job_pause_point:
366 * @job: The job that is ready to pause.
368 * Pause now if block_job_pause() has been called. Block jobs that perform
369 * lots of I/O must call this between requests so that the job can be paused.
371 void coroutine_fn
block_job_pause_point(BlockJob
*job
);
375 * @job: The job to be paused.
377 * Asynchronously pause the specified job.
379 void block_job_pause(BlockJob
*job
);
383 * @job: The job to be resumed.
385 * Resume the specified job. Must be paired with a preceding block_job_pause.
387 void block_job_resume(BlockJob
*job
);
391 * @job: The job to enter.
393 * Continue the specified job by entering the coroutine.
395 void block_job_enter(BlockJob
*job
);
399 * @job: The job which is now ready to complete.
401 * Send a BLOCK_JOB_READY event for the specified job.
403 void block_job_event_ready(BlockJob
*job
);
406 * block_job_cancel_sync:
407 * @job: The job to be canceled.
409 * Synchronously cancel the job. The completion callback is called
410 * before the function returns. The job may actually complete
411 * instead of canceling itself; the circumstances under which this
412 * happens depend on the kind of job that is active.
414 * Returns the return value from the job if the job actually completed
415 * during the call, or -ECANCELED if it was canceled.
417 int block_job_cancel_sync(BlockJob
*job
);
420 * block_job_cancel_sync_all:
422 * Synchronously cancels all jobs using block_job_cancel_sync().
424 void block_job_cancel_sync_all(void);
427 * block_job_complete_sync:
428 * @job: The job to be completed.
429 * @errp: Error object which may be set by block_job_complete(); this is not
430 * necessarily set on every error, the job return value has to be
433 * Synchronously complete the job. The completion callback is called before the
434 * function returns, unless it is NULL (which is permissible when using this
437 * Returns the return value from the job.
439 int block_job_complete_sync(BlockJob
*job
, Error
**errp
);
442 * block_job_iostatus_reset:
443 * @job: The job whose I/O status should be reset.
445 * Reset I/O status on @job and on BlockDriverState objects it uses,
446 * other than job->blk.
448 void block_job_iostatus_reset(BlockJob
*job
);
451 * block_job_error_action:
452 * @job: The job to signal an error for.
453 * @on_err: The error action setting.
454 * @is_read: Whether the operation was a read.
455 * @error: The error that was reported.
457 * Report an I/O error for a block job and possibly stop the VM. Return the
458 * action that was selected based on @on_err and @error.
460 BlockErrorAction
block_job_error_action(BlockJob
*job
, BlockdevOnError on_err
,
461 int is_read
, int error
);
463 typedef void BlockJobDeferToMainLoopFn(BlockJob
*job
, void *opaque
);
466 * block_job_defer_to_main_loop:
468 * @fn: The function to run in the main loop
469 * @opaque: The opaque value that is passed to @fn
471 * Execute a given function in the main loop with the BlockDriverState
472 * AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and
473 * anything that uses bdrv_drain_all() in the main loop.
475 * The @job AioContext is held while @fn executes.
477 void block_job_defer_to_main_loop(BlockJob
*job
,
478 BlockJobDeferToMainLoopFn
*fn
,
484 * Allocate and return a new block job transaction. Jobs can be added to the
485 * transaction using block_job_txn_add_job().
487 * The transaction is automatically freed when the last job completes or is
490 * All jobs in the transaction either complete successfully or fail/cancel as a
491 * group. Jobs wait for each other before completing. Cancelling one job
492 * cancels all jobs in the transaction.
494 BlockJobTxn
*block_job_txn_new(void);
497 * block_job_txn_unref:
499 * Release a reference that was previously acquired with block_job_txn_add_job
500 * or block_job_txn_new. If it's the last reference to the object, it will be
503 void block_job_txn_unref(BlockJobTxn
*txn
);
506 * block_job_txn_add_job:
507 * @txn: The transaction (may be NULL)
508 * @job: Job to add to the transaction
510 * Add @job to the transaction. The @job must not already be in a transaction.
511 * The caller must call either block_job_txn_unref() or block_job_completed()
512 * to release the reference that is automatically grabbed here.
514 void block_job_txn_add_job(BlockJobTxn
*txn
, BlockJob
*job
);
517 * block_job_is_internal:
518 * @job: The job to determine if it is user-visible or not.
520 * Returns true if the job should not be visible to the management layer.
522 bool block_job_is_internal(BlockJob
*job
);