root / include / block / blockjob.h @ b94a2610
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/*
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* Declarations for long-running block device operations
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*
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* Copyright (c) 2011 IBM Corp.
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* Copyright (c) 2012 Red Hat, Inc.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef BLOCKJOB_H
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#define BLOCKJOB_H 1 |
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#include "block/block.h" |
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/**
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* BlockJobDriver:
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*
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* A class type for block job driver.
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*/
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typedef struct BlockJobDriver { |
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/** Derived BlockJob struct size */
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size_t instance_size; |
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/** String describing the operation, part of query-block-jobs QMP API */
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BlockJobType job_type; |
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/** Optional callback for job types that support setting a speed limit */
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void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
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/** Optional callback for job types that need to forward I/O status reset */
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void (*iostatus_reset)(BlockJob *job);
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/**
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* Optional callback for job types whose completion must be triggered
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* manually.
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*/
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void (*complete)(BlockJob *job, Error **errp);
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} BlockJobDriver; |
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/**
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* BlockJob:
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*
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* Long-running operation on a BlockDriverState.
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*/
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struct BlockJob {
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/** The job type, including the job vtable. */
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const BlockJobDriver *driver;
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/** The block device on which the job is operating. */
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BlockDriverState *bs; |
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/**
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* The coroutine that executes the job. If not NULL, it is
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* reentered when busy is false and the job is cancelled.
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*/
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Coroutine *co; |
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/**
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* Set to true if the job should cancel itself. The flag must
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* always be tested just before toggling the busy flag from false
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* to true. After a job has been cancelled, it should only yield
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* if #qemu_aio_wait will ("sooner or later") reenter the coroutine.
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*/
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bool cancelled;
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/**
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* Set to true if the job is either paused, or will pause itself
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* as soon as possible (if busy == true).
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*/
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bool paused;
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/**
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* Set to false by the job while it is in a quiescent state, where
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* no I/O is pending and the job has yielded on any condition
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* that is not detected by #qemu_aio_wait, such as a timer.
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*/
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bool busy;
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/** Status that is published by the query-block-jobs QMP API */
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BlockDeviceIoStatus iostatus; |
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/** Offset that is published by the query-block-jobs QMP API */
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int64_t offset; |
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/** Length that is published by the query-block-jobs QMP API */
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int64_t len; |
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/** Speed that was set with @block_job_set_speed. */
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int64_t speed; |
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/** The completion function that will be called when the job completes. */
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BlockDriverCompletionFunc *cb; |
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/** The opaque value that is passed to the completion function. */
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void *opaque;
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}; |
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/**
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* block_job_create:
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* @job_type: The class object for the newly-created job.
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* @bs: The block
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* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
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* @cb: Completion function for the job.
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* @opaque: Opaque pointer value passed to @cb.
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* @errp: Error object.
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*
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* Create a new long-running block device job and return it. The job
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* will call @cb asynchronously when the job completes. Note that
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* @bs may have been closed at the time the @cb it is called. If
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* this is the case, the job may be reported as either cancelled or
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* completed.
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*
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* This function is not part of the public job interface; it should be
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* called from a wrapper that is specific to the job type.
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*/
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void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, |
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int64_t speed, BlockDriverCompletionFunc *cb, |
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void *opaque, Error **errp);
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/**
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* block_job_sleep_ns:
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* @job: The job that calls the function.
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* @clock: The clock to sleep on.
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* @ns: How many nanoseconds to stop for.
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*
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* Put the job to sleep (assuming that it wasn't canceled) for @ns
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* nanoseconds. Canceling the job will interrupt the wait immediately.
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*/
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void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
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/**
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* block_job_completed:
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* @job: The job being completed.
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* @ret: The status code.
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*
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* Call the completion function that was registered at creation time, and
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* free @job.
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*/
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void block_job_completed(BlockJob *job, int ret); |
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/**
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* block_job_set_speed:
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* @job: The job to set the speed for.
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* @speed: The new value
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* @errp: Error object.
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*
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* Set a rate-limiting parameter for the job; the actual meaning may
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* vary depending on the job type.
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*/
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void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
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/**
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* block_job_cancel:
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* @job: The job to be canceled.
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*
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* Asynchronously cancel the specified job.
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*/
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void block_job_cancel(BlockJob *job);
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/**
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* block_job_complete:
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* @job: The job to be completed.
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* @errp: Error object.
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*
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* Asynchronously complete the specified job.
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*/
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void block_job_complete(BlockJob *job, Error **errp);
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/**
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* block_job_is_cancelled:
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* @job: The job being queried.
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*
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* Returns whether the job is scheduled for cancellation.
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*/
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bool block_job_is_cancelled(BlockJob *job);
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/**
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* block_job_query:
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* @job: The job to get information about.
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*
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* Return information about a job.
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*/
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BlockJobInfo *block_job_query(BlockJob *job); |
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/**
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* block_job_pause:
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* @job: The job to be paused.
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*
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* Asynchronously pause the specified job.
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*/
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void block_job_pause(BlockJob *job);
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/**
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* block_job_resume:
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* @job: The job to be resumed.
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*
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* Resume the specified job.
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*/
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void block_job_resume(BlockJob *job);
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/**
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* qobject_from_block_job:
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* @job: The job whose information is requested.
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*
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* Return a QDict corresponding to @job's query-block-jobs entry.
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*/
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QObject *qobject_from_block_job(BlockJob *job); |
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/**
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* block_job_ready:
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* @job: The job which is now ready to complete.
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*
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* Send a BLOCK_JOB_READY event for the specified job.
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*/
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void block_job_ready(BlockJob *job);
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/**
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* block_job_is_paused:
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* @job: The job being queried.
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*
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* Returns whether the job is currently paused, or will pause
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* as soon as it reaches a sleeping point.
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*/
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bool block_job_is_paused(BlockJob *job);
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/**
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* block_job_cancel_sync:
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* @job: The job to be canceled.
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*
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* Synchronously cancel the job. The completion callback is called
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* before the function returns. The job may actually complete
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* instead of canceling itself; the circumstances under which this
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* happens depend on the kind of job that is active.
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*
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* Returns the return value from the job if the job actually completed
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* during the call, or -ECANCELED if it was canceled.
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*/
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int block_job_cancel_sync(BlockJob *job);
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/**
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* block_job_iostatus_reset:
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* @job: The job whose I/O status should be reset.
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*
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* Reset I/O status on @job and on BlockDriverState objects it uses,
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* other than job->bs.
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*/
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void block_job_iostatus_reset(BlockJob *job);
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/**
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* block_job_error_action:
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* @job: The job to signal an error for.
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* @bs: The block device on which to set an I/O error.
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* @on_err: The error action setting.
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* @is_read: Whether the operation was a read.
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* @error: The error that was reported.
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*
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* Report an I/O error for a block job and possibly stop the VM. Return the
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* action that was selected based on @on_err and @error.
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*/
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BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, |
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BlockdevOnError on_err, |
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int is_read, int error); |
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#endif
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