/*
* 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
#include "block/block.h"
typedef struct BlockJobDriver BlockJobDriver;
typedef struct BlockJobTxn BlockJobTxn;
/**
* BlockJob:
*
* Long-running operation on a BlockDriverState.
*/
typedef struct BlockJob {
/** The job type, including the job vtable. */
const BlockJobDriver *driver;
/** The block device on which the job is operating. */
BlockBackend *blk;
/**
* The ID of the block job. May be NULL for internal jobs.
*/
char *id;
/**
* 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 the coroutine has yielded and may be
* re-entered by block_job_enter(). There may still be I/O or event loop
* activity pending.
*/
bool busy;
/**
* Set to true by the job while it is in a quiescent state, where
* no I/O or event loop activity is pending.
*/
bool paused;
/**
* Set to true when the job is ready to be completed.
*/
bool ready;
/**
* Set to true when the job has deferred work to the main loop.
*/
bool deferred_to_main_loop;
/** Element of the list of block jobs */
QLIST_ENTRY(BlockJob) job_list;
/** 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;
/** BlockDriverStates that are involved in this block job */
GSList *nodes;
/** The opaque value that is passed to the completion function. */
void *opaque;
/** Reference count of the block job */
int refcnt;
/* True if this job has reported completion by calling block_job_completed.
*/
bool completed;
/* ret code passed to block_job_completed.
*/
int ret;
/** Non-NULL if this job is part of a transaction */
BlockJobTxn *txn;
QLIST_ENTRY(BlockJob) txn_list;
} BlockJob;
typedef enum BlockJobCreateFlags {
BLOCK_JOB_DEFAULT = 0x00,
BLOCK_JOB_INTERNAL = 0x01,
} BlockJobCreateFlags;
/**
* block_job_next:
* @job: A block job, or %NULL.
*
* Get the next element from the list of block jobs after @job, or the
* first one if @job is %NULL.
*
* Returns the requested job, or %NULL if there are no more jobs left.
*/
BlockJob *block_job_next(BlockJob *job);
/**
* block_job_get:
* @id: The id of the block job.
*
* Get the block job identified by @id (which must not be %NULL).
*
* Returns the requested job, or %NULL if it doesn't exist.
*/
BlockJob *block_job_get(const char *id);
/**
* block_job_add_bdrv:
* @job: A block job
* @bs: A BlockDriverState that is involved in @job
*
* Add @bs to the list of BlockDriverState that are involved in
* @job. This means that all operations will be blocked on @bs while
* @job exists.
*/
void block_job_add_bdrv(BlockJob *job, BlockDriverState *bs);
/**
* 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_start:
* @job: A job that has not yet been started.
*
* Begins execution of a block job.
* Takes ownership of one reference to the job object.
*/
void block_job_start(BlockJob *job);
/**
* 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_query:
* @job: The job to get information about.
*
* Return information about a job.
*/
BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
/**
* block_job_pause:
* @job: The job to be paused.
*
* Asynchronously pause the specified job.
*/
void block_job_pause(BlockJob *job);
/**
* block_job_user_pause:
* @job: The job to be paused.
*
* Asynchronously pause the specified job.
* Do not allow a resume until a matching call to block_job_user_resume.
*/
void block_job_user_pause(BlockJob *job);
/**
* block_job_paused:
* @job: The job to query.
*
* Returns true if the job is user-paused.
*/
bool block_job_user_paused(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_user_resume:
* @job: The job to be resumed.
*
* Resume the specified job.
* Must be paired with a preceding block_job_user_pause.
*/
void block_job_user_resume(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_cancel_sync_all:
*
* Synchronously cancels all jobs using block_job_cancel_sync().
*/
void block_job_cancel_sync_all(void);
/**
* 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->blk.
*/
void block_job_iostatus_reset(BlockJob *job);
/**
* block_job_txn_new:
*
* Allocate and return a new block job transaction. Jobs can be added to the
* transaction using block_job_txn_add_job().
*
* The transaction is automatically freed when the last job completes or is
* cancelled.
*
* All jobs in the transaction either complete successfully or fail/cancel as a
* group. Jobs wait for each other before completing. Cancelling one job
* cancels all jobs in the transaction.
*/
BlockJobTxn *block_job_txn_new(void);
/**
* block_job_txn_unref:
*
* Release a reference that was previously acquired with block_job_txn_add_job
* or block_job_txn_new. If it's the last reference to the object, it will be
* freed.
*/
void block_job_txn_unref(BlockJobTxn *txn);
/**
* block_job_txn_add_job:
* @txn: The transaction (may be NULL)
* @job: Job to add to the transaction
*
* Add @job to the transaction. The @job must not already be in a transaction.
* The caller must call either block_job_txn_unref() or block_job_completed()
* to release the reference that is automatically grabbed here.
*/
void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
/**
* block_job_is_internal:
* @job: The job to determine if it is user-visible or not.
*
* Returns true if the job should not be visible to the management layer.
*/
bool block_job_is_internal(BlockJob *job);
#endif
