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/*
* Copyright (C) 2001 - 2003 Sistina Software
* Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
*
* kcopyd provides a simple interface for copying an area of one
* block-device to one or more other block-devices, either synchronous
* or with an asynchronous completion notification.
*
* This file is released under the GPL.
*/
#ifndef _LINUX_DM_KCOPYD_H
#define _LINUX_DM_KCOPYD_H
#ifdef __KERNEL__
#include <linux/dm-io.h>
/* FIXME: make this configurable */
#define DM_KCOPYD_MAX_REGIONS 8
#define DM_KCOPYD_IGNORE_ERROR 1
/*
* To use kcopyd you must first create a dm_kcopyd_client object.
*/
struct dm_kcopyd_client;
struct dm_kcopyd_client *dm_kcopyd_client_create(void);
void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
/*
* Submit a copy job to kcopyd. This is built on top of the
* previous three fns.
*
* read_err is a boolean,
* write_err is a bitset, with 1 bit for each destination region
*/
typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
void *context);
int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
unsigned num_dests, struct dm_io_region *dests,
unsigned flags, dm_kcopyd_notify_fn fn, void *context);
/*
* Prepare a callback and submit it via the kcopyd thread.
*
* dm_kcopyd_prepare_callback allocates a callback structure and returns it.
* It must not be called from interrupt context.
* The returned value should be passed into dm_kcopyd_do_callback.
*
* dm_kcopyd_do_callback submits the callback.
* It may be called from interrupt context.
* The callback is issued from the kcopyd thread.
*/
void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
dm_kcopyd_notify_fn fn, void *context);
void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
#endif /* __KERNEL__ */
#endif /* _LINUX_DM_KCOPYD_H */
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