2 * Declarations for long-running block device operations
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5 * Copyright (c) 2012 Red Hat, Inc.
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26 #ifndef BLOCKJOB_INT_H
27 #define BLOCKJOB_INT_H
29 #include "block/blockjob.h"
30 #include "block/block.h"
35 * A class type for block job driver.
37 struct BlockJobDriver
{
38 /** Derived BlockJob struct size */
41 /** String describing the operation, part of query-block-jobs QMP API */
42 BlockJobType job_type
;
44 /** Mandatory: Entrypoint for the Coroutine. */
45 CoroutineEntry
*start
;
48 * Optional callback for job types whose completion must be triggered
51 void (*complete
)(BlockJob
*job
, Error
**errp
);
54 * If the callback is not NULL, prepare will be invoked when all the jobs
55 * belonging to the same transaction complete; or upon this job's completion
56 * if it is not in a transaction.
58 * This callback will not be invoked if the job has already failed.
59 * If it fails, abort and then clean will be called.
61 int (*prepare
)(BlockJob
*job
);
64 * If the callback is not NULL, it will be invoked when all the jobs
65 * belonging to the same transaction complete; or upon this job's
66 * completion if it is not in a transaction. Skipped if NULL.
68 * All jobs will complete with a call to either .commit() or .abort() but
71 void (*commit
)(BlockJob
*job
);
74 * If the callback is not NULL, it will be invoked when any job in the
75 * same transaction fails; or upon this job's failure (due to error or
76 * cancellation) if it is not in a transaction. Skipped if NULL.
78 * All jobs will complete with a call to either .commit() or .abort() but
81 void (*abort
)(BlockJob
*job
);
84 * If the callback is not NULL, it will be invoked after a call to either
85 * .commit() or .abort(). Regardless of which callback is invoked after
86 * completion, .clean() will always be called, even if the job does not
87 * belong to a transaction group.
89 void (*clean
)(BlockJob
*job
);
92 * If the callback is not NULL, it will be invoked when the job transitions
93 * into the paused state. Paused jobs must not perform any asynchronous
94 * I/O or event loop activity. This callback is used to quiesce jobs.
96 void coroutine_fn (*pause
)(BlockJob
*job
);
99 * If the callback is not NULL, it will be invoked when the job transitions
100 * out of the paused state. Any asynchronous I/O or event loop activity
101 * should be restarted from this callback.
103 void coroutine_fn (*resume
)(BlockJob
*job
);
106 * If the callback is not NULL, it will be invoked before the job is
107 * resumed in a new AioContext. This is the place to move any resources
108 * besides job->blk to the new AioContext.
110 void (*attached_aio_context
)(BlockJob
*job
, AioContext
*new_context
);
113 * If the callback is not NULL, it will be invoked when the job has to be
114 * synchronously cancelled or completed; it should drain BlockDriverStates
115 * as required to ensure progress.
117 void (*drain
)(BlockJob
*job
);
122 * @job_id: The id of the newly-created job, or %NULL to have one
123 * generated automatically.
124 * @driver: The class object for the newly-created job.
125 * @txn: The transaction this job belongs to, if any. %NULL otherwise.
127 * @perm, @shared_perm: Permissions to request for @bs
128 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
129 * @flags: Creation flags for the Block Job.
130 * See @BlockJobCreateFlags
131 * @cb: Completion function for the job.
132 * @opaque: Opaque pointer value passed to @cb.
133 * @errp: Error object.
135 * Create a new long-running block device job and return it. The job
136 * will call @cb asynchronously when the job completes. Note that
137 * @bs may have been closed at the time the @cb it is called. If
138 * this is the case, the job may be reported as either cancelled or
141 * This function is not part of the public job interface; it should be
142 * called from a wrapper that is specific to the job type.
144 void *block_job_create(const char *job_id
, const BlockJobDriver
*driver
,
145 BlockJobTxn
*txn
, BlockDriverState
*bs
, uint64_t perm
,
146 uint64_t shared_perm
, int64_t speed
, int flags
,
147 BlockCompletionFunc
*cb
, void *opaque
, Error
**errp
);
150 * block_job_sleep_ns:
151 * @job: The job that calls the function.
152 * @ns: How many nanoseconds to stop for.
154 * Put the job to sleep (assuming that it wasn't canceled) for @ns
155 * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will immediately
156 * interrupt the wait.
158 void block_job_sleep_ns(BlockJob
*job
, int64_t ns
);
162 * @job: The job that calls the function.
164 * Yield the block job coroutine.
166 void block_job_yield(BlockJob
*job
);
169 * block_job_ratelimit_get_delay:
171 * Calculate and return delay for the next request in ns. See the documentation
172 * of ratelimit_calculate_delay() for details.
174 int64_t block_job_ratelimit_get_delay(BlockJob
*job
, uint64_t n
);
177 * block_job_early_fail:
178 * @bs: The block device.
180 * The block job could not be started, free it.
182 void block_job_early_fail(BlockJob
*job
);
185 * block_job_completed:
186 * @job: The job being completed.
187 * @ret: The status code.
189 * Call the completion function that was registered at creation time, and
192 void block_job_completed(BlockJob
*job
, int ret
);
195 * block_job_is_cancelled:
196 * @job: The job being queried.
198 * Returns whether the job is scheduled for cancellation.
200 bool block_job_is_cancelled(BlockJob
*job
);
203 * block_job_pause_point:
204 * @job: The job that is ready to pause.
206 * Pause now if block_job_pause() has been called. Block jobs that perform
207 * lots of I/O must call this between requests so that the job can be paused.
209 void coroutine_fn
block_job_pause_point(BlockJob
*job
);
213 * @job: The job to enter.
215 * Continue the specified job by entering the coroutine.
217 void block_job_enter(BlockJob
*job
);
220 * block_job_event_ready:
221 * @job: The job which is now ready to be completed.
223 * Send a BLOCK_JOB_READY event for the specified job.
225 void block_job_event_ready(BlockJob
*job
);
228 * block_job_error_action:
229 * @job: The job to signal an error for.
230 * @on_err: The error action setting.
231 * @is_read: Whether the operation was a read.
232 * @error: The error that was reported.
234 * Report an I/O error for a block job and possibly stop the VM. Return the
235 * action that was selected based on @on_err and @error.
237 BlockErrorAction
block_job_error_action(BlockJob
*job
, BlockdevOnError on_err
,
238 int is_read
, int error
);
240 typedef void BlockJobDeferToMainLoopFn(BlockJob
*job
, void *opaque
);
243 * block_job_defer_to_main_loop:
245 * @fn: The function to run in the main loop
246 * @opaque: The opaque value that is passed to @fn
248 * This function must be called by the main job coroutine just before it
249 * returns. @fn is executed in the main loop with the BlockDriverState
250 * AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and
251 * anything that uses bdrv_drain_all() in the main loop.
253 * The @job AioContext is held while @fn executes.
255 void block_job_defer_to_main_loop(BlockJob
*job
,
256 BlockJobDeferToMainLoopFn
*fn
,