/*
 * Copyright (C) 2003 Sistina Software
 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
 *
 * Device-Mapper low-level I/O.
 *
 * This file is released under the GPL.
 */

#ifndef _LINUX_DM_IO_H
#define _LINUX_DM_IO_H

#ifdef __KERNEL__

#include <linux/types.h>

struct dm_io_region {
	struct block_device *bdev;
	sector_t sector;
	sector_t count;		
};

struct page_list {
	struct page_list *next;
	struct page *page;
};

typedef void (*io_notify_fn)(unsigned long error, void *context);

enum dm_io_mem_type {
	DM_IO_PAGE_LIST,
	DM_IO_BVEC,	
	DM_IO_VMA,	
	DM_IO_KMEM,	
};

struct dm_io_memory {
	enum dm_io_mem_type type;

	unsigned offset;

	union {
		struct page_list *pl;
		struct bio_vec *bvec;
		void *vma;
		void *addr;
	} ptr;
};

struct dm_io_notify {
	io_notify_fn fn;	
	void *context;		
};

struct dm_io_client;
struct dm_io_request {
	int bi_rw;			
	struct dm_io_memory mem;	
	struct dm_io_notify notify;	
	struct dm_io_client *client;	
};

struct dm_io_client *dm_io_client_create(void);
void dm_io_client_destroy(struct dm_io_client *client);

int dm_io(struct dm_io_request *io_req, unsigned num_regions,
	  struct dm_io_region *region, unsigned long *sync_error_bits);

#endif	
#endif