[linux-block.git] / 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 block_device *bdev;
	sector_t sector;
	sector_t count;		/* If this is zero the region is ignored. */
};

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

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

enum dm_io_mem_type {
	DM_IO_PAGE_LIST,/* Page list */
	DM_IO_BIO,	/* Bio vector */
	DM_IO_VMA,	/* Virtual memory area */
	DM_IO_KMEM,	/* Kernel memory */
};

struct dm_io_memory {
	enum dm_io_mem_type type;

	unsigned int offset;

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

struct dm_io_notify {
	io_notify_fn fn;	/* Callback for asynchronous requests */
	void *context;		/* Passed to callback */
};

/*
 * IO request structure
 */
struct dm_io_client;
struct dm_io_request {
	blk_opf_t	    bi_opf;	/* Request type and flags */
	struct dm_io_memory mem;	/* Memory to use for io */
	struct dm_io_notify notify;	/* Synchronous if notify.fn is NULL */
	struct dm_io_client *client;	/* Client memory handler */
};

/*
 * 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);

#endif	/* __KERNEL__ */
#endif	/* _LINUX_DM_IO_H */
Commit	Line	Data
3bd94003	1	/* SPDX-License-Identifier: GPL-2.0-only */
1da177e4 LT	2	/*
1da177e4 LT	3	* Copyright (C) 2003 Sistina Software
22a1ceb1 HM	4	* Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
	5	*
	6	* Device-Mapper low-level I/O.
1da177e4 LT	7	*
	8	* This file is released under the GPL.
	9	*/
	10
22a1ceb1 HM	11	#ifndef _LINUX_DM_IO_H
	12	#define _LINUX_DM_IO_H
	13
	14	#ifdef __KERNEL__
1da177e4	15
22a1ceb1	16	#include <linux/types.h>
581075e4	17	#include <linux/blk_types.h>
1da177e4	18
22a1ceb1	19	struct dm_io_region {
1da177e4 LT	20	struct block_device *bdev;
1da177e4 LT	21	sector_t sector;
bf17ce3a	22	sector_t count; /* If this is zero the region is ignored. */
1da177e4 LT	23	};
	24
	25	struct page_list {
	26	struct page_list *next;
	27	struct page *page;
	28	};
	29
86a3238c	30	typedef void (io_notify_fn)(unsigned int long error, void context);
1da177e4	31
c8b03afe HM	32	enum dm_io_mem_type {
c8b03afe HM	33	DM_IO_PAGE_LIST,/* Page list */
003b5c57	34	DM_IO_BIO, /* Bio vector */
c8b03afe HM	35	DM_IO_VMA, /* Virtual memory area */
	36	DM_IO_KMEM, /* Kernel memory */
	37	};
	38
	39	struct dm_io_memory {
	40	enum dm_io_mem_type type;
	41
86a3238c	42	unsigned int offset;
924e600d	43
c8b03afe HM	44	union {
c8b03afe HM	45	struct page_list *pl;
003b5c57	46	struct bio *bio;
c8b03afe HM	47	void *vma;
	48	void *addr;
	49	} ptr;
c8b03afe HM	50	};
	51
	52	struct dm_io_notify {
	53	io_notify_fn fn; /* Callback for asynchronous requests */
	54	void context; / Passed to callback */
	55	};
	56
	57	/*
	58	* IO request structure
	59	*/
	60	struct dm_io_client;
	61	struct dm_io_request {
581075e4	62	blk_opf_t bi_opf; /* Request type and flags */
c8b03afe HM	63	struct dm_io_memory mem; /* Memory to use for io */
	64	struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
	65	struct dm_io_client client; / Client memory handler */
	66	};
1da177e4	67
c8b03afe HM	68	/*
	69	* For async io calls, users can alternatively use the dm_io() function below
	70	* and dm_io_client_create() to create private mempools for the client.
	71	*
	72	* Create/destroy may block.
	73	*/
bda8efec	74	struct dm_io_client *dm_io_client_create(void);
c8b03afe HM	75	void dm_io_client_destroy(struct dm_io_client *client);
c8b03afe HM	76
c8b03afe HM	77	/*
c8b03afe HM	78	* IO interface using private per-client pools.
bf17ce3a MB	79	* Each bit in the optional 'sync_error_bits' bitset indicates whether an
bf17ce3a MB	80	* error occurred doing io to the corresponding region.
c8b03afe	81	*/
86a3238c HM	82	int dm_io(struct dm_io_request *io_req, unsigned int num_regions,
86a3238c HM	83	struct dm_io_region region, unsigned int long sync_error_bits);
c8b03afe	84
22a1ceb1 HM	85	#endif /* __KERNEL__ */
22a1ceb1 HM	86	#endif /* _LINUX_DM_IO_H */