[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / device-mapper.h

/*
 * Copyright (C) 2001 Sistina Software (UK) Limited.
 * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef _LINUX_DEVICE_MAPPER_H
#define _LINUX_DEVICE_MAPPER_H

struct dm_target;
struct dm_table;
struct dm_dev;

typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;

union map_info {
	void *ptr;
	unsigned long long ll;
};

/*
 * In the constructor the target parameter will already have the
 * table, type, begin and len fields filled in.
 */
typedef int (*dm_ctr_fn) (struct dm_target *target,
			  unsigned int argc, char **argv);

/*
 * The destructor doesn't need to free the dm_target, just
 * anything hidden ti->private.
 */
typedef void (*dm_dtr_fn) (struct dm_target *ti);

/*
 * The map function must return:
 * < 0: error
 * = 0: The target will handle the io by resubmitting it later
 * > 0: simple remap complete
 */
typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
			  union map_info *map_context);

/*
 * Returns:
 * < 0 : error (currently ignored)
 * 0   : ended successfully
 * 1   : for some reason the io has still not completed (eg,
 *       multipath target might want to requeue a failed io).
 */
typedef int (*dm_endio_fn) (struct dm_target *ti,
			    struct bio *bio, int error,
			    union map_info *map_context);

typedef void (*dm_presuspend_fn) (struct dm_target *ti);
typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
typedef void (*dm_resume_fn) (struct dm_target *ti);

typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
			     char *result, unsigned int maxlen);

typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);

void dm_error(const char *message);

/*
 * Constructors should call these functions to ensure destination devices
 * are opened/closed correctly.
 * FIXME: too many arguments.
 */
int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
		  sector_t len, int mode, struct dm_dev **result);
void dm_put_device(struct dm_target *ti, struct dm_dev *d);

/*
 * Information about a target type
 */
struct target_type {
	const char *name;
	struct module *module;
        unsigned version[3];
	dm_ctr_fn ctr;
	dm_dtr_fn dtr;
	dm_map_fn map;
	dm_endio_fn end_io;
	dm_presuspend_fn presuspend;
	dm_postsuspend_fn postsuspend;
	dm_resume_fn resume;
	dm_status_fn status;
	dm_message_fn message;
};

struct io_restrictions {
	unsigned int		max_sectors;
	unsigned short		max_phys_segments;
	unsigned short		max_hw_segments;
	unsigned short		hardsect_size;
	unsigned int		max_segment_size;
	unsigned long		seg_boundary_mask;
	unsigned char		no_cluster; /* inverted so that 0 is default */
};

struct dm_target {
	struct dm_table *table;
	struct target_type *type;

	/* target limits */
	sector_t begin;
	sector_t len;

	/* FIXME: turn this into a mask, and merge with io_restrictions */
	/* Always a power of 2 */
	sector_t split_io;

	/*
	 * These are automatically filled in by
	 * dm_table_get_device.
	 */
	struct io_restrictions limits;

	/* target specific data */
	void *private;

	/* Used to provide an error string from the ctr */
	char *error;
};

int dm_register_target(struct target_type *t);
int dm_unregister_target(struct target_type *t);

#endif				/* _LINUX_DEVICE_MAPPER_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2001 Sistina Software (UK) Limited.
	3	* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
	4	*
	5	* This file is released under the LGPL.
	6	*/
	7
	8	#ifndef _LINUX_DEVICE_MAPPER_H
	9	#define _LINUX_DEVICE_MAPPER_H
	10
	11	struct dm_target;
	12	struct dm_table;
	13	struct dm_dev;
	14
	15	typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
	16
	17	union map_info {
	18	void *ptr;
	19	unsigned long long ll;
	20	};
	21
	22	/*
	23	* In the constructor the target parameter will already have the
	24	* table, type, begin and len fields filled in.
	25	*/
	26	typedef int (dm_ctr_fn) (struct dm_target target,
	27	unsigned int argc, char **argv);
	28
	29	/*
	30	* The destructor doesn't need to free the dm_target, just
	31	* anything hidden ti->private.
	32	*/
	33	typedef void (dm_dtr_fn) (struct dm_target ti);
	34
	35	/*
	36	* The map function must return:
	37	* < 0: error
	38	* = 0: The target will handle the io by resubmitting it later
	39	* > 0: simple remap complete
	40	*/
	41	typedef int (dm_map_fn) (struct dm_target ti, struct bio *bio,
	42	union map_info *map_context);
	43
	44	/*
	45	* Returns:
	46	* < 0 : error (currently ignored)
	47	* 0 : ended successfully
	48	* 1 : for some reason the io has still not completed (eg,
	49	* multipath target might want to requeue a failed io).
	50	*/
	51	typedef int (dm_endio_fn) (struct dm_target ti,
	52	struct bio *bio, int error,
	53	union map_info *map_context);
	54
	55	typedef void (dm_presuspend_fn) (struct dm_target ti);
	56	typedef void (dm_postsuspend_fn) (struct dm_target ti);
	57	typedef void (dm_resume_fn) (struct dm_target ti);
	58
	59	typedef int (dm_status_fn) (struct dm_target ti, status_type_t status_type,
	60	char *result, unsigned int maxlen);
	61
	62	typedef int (dm_message_fn) (struct dm_target ti, unsigned argc, char **argv);
	63
	64	void dm_error(const char *message);
65
66	/*
67	* Constructors should call these functions to ensure destination devices
68	* are opened/closed correctly.
69	* FIXME: too many arguments.
70	*/
71	int dm_get_device(struct dm_target ti, const char path, sector_t start,
72	sector_t len, int mode, struct dm_dev **result);
73	void dm_put_device(struct dm_target ti, struct dm_dev d);
74
75	/*
76	* Information about a target type
77	*/
78	struct target_type {
79	const char *name;
80	struct module *module;
81	unsigned version[3];
82	dm_ctr_fn ctr;
83	dm_dtr_fn dtr;
84	dm_map_fn map;
85	dm_endio_fn end_io;
86	dm_presuspend_fn presuspend;
87	dm_postsuspend_fn postsuspend;
88	dm_resume_fn resume;
89	dm_status_fn status;
90	dm_message_fn message;
91	};
92
93	struct io_restrictions {
3ee247eb	94	unsigned int max_sectors;
1da177e4 LT	95	unsigned short max_phys_segments;
	96	unsigned short max_hw_segments;
	97	unsigned short hardsect_size;
	98	unsigned int max_segment_size;
	99	unsigned long seg_boundary_mask;
969429b5	100	unsigned char no_cluster; /* inverted so that 0 is default */
1da177e4 LT	101	};
	102
	103	struct dm_target {
	104	struct dm_table *table;
	105	struct target_type *type;
	106
	107	/* target limits */
	108	sector_t begin;
	109	sector_t len;
	110
	111	/* FIXME: turn this into a mask, and merge with io_restrictions */
	112	/* Always a power of 2 */
	113	sector_t split_io;
	114
	115	/*
	116	* These are automatically filled in by
	117	* dm_table_get_device.
	118	*/
	119	struct io_restrictions limits;
	120
	121	/* target specific data */
	122	void *private;
	123
	124	/* Used to provide an error string from the ctr */
	125	char *error;
	126	};
	127
	128	int dm_register_target(struct target_type *t);
	129	int dm_unregister_target(struct target_type *t);
	130
	131	#endif /* _LINUX_DEVICE_MAPPER_H */