linux/include/linux/dm-io.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * 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>
#include <linux/blk_types.h>

struct dm_io_region { … };

struct page_list { … };

io_notify_fn;

enum dm_io_mem_type { … };

struct dm_io_memory { … };

struct dm_io_notify { … };

/*
 * IO request structure
 */
struct dm_io_client;
struct dm_io_request { … };

/*
 * For async io calls, users can alternatively use the dm_io() function below
 * and dm_io_client_create() to create private mempools for the client.
 *
 * Create/destroy may block.
 */
struct dm_io_client *dm_io_client_create(void);
void dm_io_client_destroy(struct dm_io_client *client);

/*
 * IO interface using private per-client pools.
 * Each bit in the optional 'sync_error_bits' bitset indicates whether an
 * error occurred doing io to the corresponding region.
 */
int dm_io(struct dm_io_request *io_req, unsigned int num_regions,
	  struct dm_io_region *region, unsigned int long *sync_error_bits,
	  unsigned short ioprio);

#endif	/* __KERNEL__ */
#endif	/* _LINUX_DM_IO_H */