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