/* * 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 short		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;}; 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 */