qemu/include/block/blockjob_int.h
Kevin Wolf f3bbc53dc5 block: Mark block_job_add_bdrv() GRAPH_WRLOCK
Instead of taking the writer lock internally, require callers to already
hold it when calling block_job_add_bdrv(). These callers will typically
already hold the graph lock once the locking work is completed, which
means that they can't call functions that take it internally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-6-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00

169 lines
5.6 KiB
C

/*
* 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"
/**
* BlockJobDriver:
*
* A class type for block job driver.
*/
struct BlockJobDriver {
/** Generic JobDriver callbacks and settings */
JobDriver job_driver;
/*
* I/O API functions. These functions are thread-safe.
*
* See include/block/block-io.h for more information about
* the I/O API.
*/
/*
* Returns whether the job has pending requests for the child or will
* submit new requests before the next pause point. This callback is polled
* in the context of draining a job node after requesting that the job be
* paused, until all activity on the child has stopped.
*/
bool (*drained_poll)(BlockJob *job);
/*
* Global state (GS) API. These functions run under the BQL.
*
* See include/block/block-global-state.h for more information about
* the GS API.
*/
/*
* 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);
void (*set_speed)(BlockJob *job, int64_t speed);
/*
* Change the @job's options according to @opts.
*
* Note that this can already be called before the job coroutine is running.
*/
void (*change)(BlockJob *job, BlockJobChangeOptions *opts, Error **errp);
/*
* Query information specific to this kind of block job.
*/
void (*query)(BlockJob *job, BlockJobInfo *info);
};
/*
* Global state (GS) API. These functions run under the BQL.
*
* See include/block/block-global-state.h for more information about
* the GS API.
*/
/**
* block_job_create:
* @job_id: The id of the newly-created job, or %NULL to have one
* generated automatically.
* @driver: The class object for the newly-created job.
* @txn: The transaction this job belongs to, if any. %NULL otherwise.
* @bs: The block
* @perm, @shared_perm: Permissions to request for @bs
* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
* @flags: Creation flags for the Block Job. See @JobCreateFlags.
* @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 * GRAPH_UNLOCKED
block_job_create(const char *job_id, const BlockJobDriver *driver,
JobTxn *txn, BlockDriverState *bs, uint64_t perm,
uint64_t shared_perm, int64_t speed, int flags,
BlockCompletionFunc *cb, void *opaque, Error **errp);
/**
* block_job_free:
* Callback to be used for JobDriver.free in all block jobs. Frees block job
* specific resources in @job.
*/
void block_job_free(Job *job);
/**
* block_job_user_resume:
* Callback to be used for JobDriver.user_resume in all block jobs. Resets the
* iostatus when the user resumes @job.
*/
void block_job_user_resume(Job *job);
/*
* I/O API functions. These functions are thread-safe.
*
* See include/block/block-io.h for more information about
* the I/O API.
*/
/**
* block_job_ratelimit_processed_bytes:
*
* To be called after some work has been done. Adjusts the delay for the next
* request. See the documentation of ratelimit_calculate_delay() for details.
*/
void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n);
/**
* Put the job to sleep (assuming that it wasn't canceled) to throttle it to the
* right speed according to its rate limiting.
*/
void block_job_ratelimit_sleep(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);
#endif