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/*
* Declarations for block exports
*
* Copyright (c) 2012, 2020 Red Hat, Inc.
*
* Authors:
* Paolo Bonzini <pbonzini@redhat.com>
* Kevin Wolf <kwolf@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#ifndef BLOCK_EXPORT_H
#define BLOCK_EXPORT_H
#include "qapi/qapi-types-block-export.h"
#include "qemu/queue.h"
typedef struct BlockExport BlockExport;
typedef struct BlockExportDriver {
/* The export type that this driver services */
BlockExportType type;
/*
* The size of the driver-specific state that contains BlockExport as its
* first field.
*/
size_t instance_size;
/* Creates and starts a new block export */
int (*create)(BlockExport *, BlockExportOptions *, Error **);
/*
* Frees a removed block export. This function is only called after all
* references have been dropped.
*/
void (*delete)(BlockExport *);
/*
* Start to disconnect all clients and drop other references held
* internally by the export driver. When the function returns, there may
* still be active references while the export is in the process of
* shutting down.
*/
void (*request_shutdown)(BlockExport *);
} BlockExportDriver;
struct BlockExport {
const BlockExportDriver *drv;
/* Unique identifier for the export */
char *id;
/*
* Reference count for this block export. This includes strong references
* both from the owner (qemu-nbd or the monitor) and clients connected to
* the export.
*
* Use atomics to access this field.
*/
int refcount;
/*
* True if one of the references in refcount belongs to the user. After the
* user has dropped their reference, they may not e.g. remove the same
* export a second time (which would decrease the refcount without having
* it incremented first).
*/
bool user_owned;
/* The AioContext whose lock protects this BlockExport object. */
AioContext *ctx;
/* The block device to export */
BlockBackend *blk;
/* List entry for block_exports */
QLIST_ENTRY(BlockExport) next;
};
BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp);
BlockExport *blk_exp_find(const char *id);
void blk_exp_ref(BlockExport *exp);
void blk_exp_unref(BlockExport *exp);
void blk_exp_request_shutdown(BlockExport *exp);
void blk_exp_close_all(void);
void blk_exp_close_all_type(BlockExportType type);
#endif
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