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Diffstat (limited to 'include/block/blockjob_int.h')
| -rw-r--r-- | include/block/blockjob_int.h | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h new file mode 100644 index 0000000000..82238229c6 --- /dev/null +++ b/include/block/blockjob_int.h @@ -0,0 +1,250 @@ +/* + * 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_INT_H +#define BLOCKJOB_INT_H + +#include "block/blockjob.h" +#include "block/block.h" + +/** + * BlockJobDriver: + * + * A class type for block job driver. + */ +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); + + /** Mandatory: Entrypoint for the Coroutine. */ + CoroutineEntry *start; + + /** + * Optional callback for job types whose completion must be triggered + * manually. + */ + void (*complete)(BlockJob *job, Error **errp); + + /** + * If the callback is not NULL, it will be invoked when all the jobs + * belonging to the same transaction complete; or upon this job's + * completion if it is not in a transaction. Skipped if NULL. + * + * All jobs will complete with a call to either .commit() or .abort() but + * never both. + */ + void (*commit)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked when any job in the + * same transaction fails; or upon this job's failure (due to error or + * cancellation) if it is not in a transaction. Skipped if NULL. + * + * All jobs will complete with a call to either .commit() or .abort() but + * never both. + */ + void (*abort)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked after a call to either + * .commit() or .abort(). Regardless of which callback is invoked after + * completion, .clean() will always be called, even if the job does not + * belong to a transaction group. + */ + void (*clean)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked when the job transitions + * into the paused state. Paused jobs must not perform any asynchronous + * I/O or event loop activity. This callback is used to quiesce jobs. + */ + void coroutine_fn (*pause)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked when the job transitions + * out of the paused state. Any asynchronous I/O or event loop activity + * should be restarted from this callback. + */ + void coroutine_fn (*resume)(BlockJob *job); + + /* + * If the callback is not NULL, it will be invoked before the job is + * resumed in a new AioContext. This is the place to move any resources + * besides job->blk to the new AioContext. + */ + void (*attached_aio_context)(BlockJob *job, AioContext *new_context); + + /* + * If the callback is not NULL, it will be invoked when the job has to be + * synchronously cancelled or completed; it should drain BlockDriverStates + * as required to ensure progress. + */ + void (*drain)(BlockJob *job); +}; + +/** + * block_job_create: + * @job_id: The id of the newly-created job, or %NULL to have one + * generated automatically. + * @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 char *job_id, const BlockJobDriver *driver, + BlockDriverState *bs, int64_t speed, int flags, + 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_ref: + * @bs: The block device. + * + * Grab a reference to the block job. Should be paired with block_job_unref. + */ +void block_job_ref(BlockJob *job); + +/** + * block_job_unref: + * @bs: The block device. + * + * Release reference to the block job and release resources if it is the last + * reference. + */ +void block_job_unref(BlockJob *job); + +/** + * 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_is_cancelled: + * @job: The job being queried. + * + * Returns whether the job is scheduled for cancellation. + */ +bool block_job_is_cancelled(BlockJob *job); + +/** + * block_job_pause_point: + * @job: The job that is ready to pause. + * + * Pause now if block_job_pause() has been called. Block jobs that perform + * lots of I/O must call this between requests so that the job can be paused. + */ +void coroutine_fn block_job_pause_point(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_ready: + * @job: The job which is now ready to be completed. + * + * Send a BLOCK_JOB_READY event for the specified job. + */ +void block_job_event_ready(BlockJob *job); + +/** + * block_job_error_action: + * @job: The job to signal an error for. + * @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, 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 |