/* * 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 #ifdef __KERNEL__ struct dm_target;struct dm_table;struct dm_dev;struct mapped_device; 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_flush_fn) (struct dm_target *ti);typedef void (*dm_presuspend_fn) (struct dm_target *ti);typedef void (*dm_postsuspend_fn) (struct dm_target *ti);typedef int (*dm_preresume_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); typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode,			    struct file *filp, unsigned int cmd,			    unsigned long arg); void dm_error(const char *message); /* * Combine device limits. */void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev); /* * 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_flush_fn flush;	dm_presuspend_fn presuspend;	dm_postsuspend_fn postsuspend;	dm_preresume_fn preresume;	dm_resume_fn resume;	dm_status_fn status;	dm_message_fn message;	dm_ioctl_fn ioctl;}; 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);  /*----------------------------------------------------------------- * Functions for creating and manipulating mapped devices. * Drop the reference with dm_put when you finish with the object. *---------------------------------------------------------------*/ /* * DM_ANY_MINOR chooses the next available minor number. */#define DM_ANY_MINOR (-1)int dm_create(int minor, struct mapped_device **md); /* * Reference counting for md. */struct mapped_device *dm_get_md(dev_t dev);void dm_get(struct mapped_device *md);void dm_put(struct mapped_device *md); /* * An arbitrary pointer may be stored alongside a mapped device. */void dm_set_mdptr(struct mapped_device *md, void *ptr);void *dm_get_mdptr(struct mapped_device *md); /* * A device can still be used while suspended, but I/O is deferred. */int dm_suspend(struct mapped_device *md, int with_lockfs);int dm_resume(struct mapped_device *md); /* * Event functions. */uint32_t dm_get_event_nr(struct mapped_device *md);int dm_wait_event(struct mapped_device *md, int event_nr); /* * Info functions. */const char *dm_device_name(struct mapped_device *md);struct gendisk *dm_disk(struct mapped_device *md);int dm_suspended(struct mapped_device *md); /* * Geometry functions. */int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);  /*----------------------------------------------------------------- * Functions for manipulating device-mapper tables. *---------------------------------------------------------------*/ /* * First create an empty table. */int dm_table_create(struct dm_table **result, int mode,		    unsigned num_targets, struct mapped_device *md); /* * Then call this once for each target. */int dm_table_add_target(struct dm_table *t, const char *type,			sector_t start, sector_t len, char *params); /* * Finally call this to make the table ready for use. */int dm_table_complete(struct dm_table *t); /* * Table reference counting. */struct dm_table *dm_get_table(struct mapped_device *md);void dm_table_get(struct dm_table *t);void dm_table_put(struct dm_table *t); /* * Queries */sector_t dm_table_get_size(struct dm_table *t);unsigned int dm_table_get_num_targets(struct dm_table *t);int dm_table_get_mode(struct dm_table *t);struct mapped_device *dm_table_get_md(struct dm_table *t); /* * Trigger an event. */void dm_table_event(struct dm_table *t); /* * The device must be suspended before calling this method. */int dm_swap_table(struct mapped_device *md, struct dm_table *t); /* * Prepare a table for a device that will error all I/O. * To make it active, call dm_suspend(), dm_swap_table() then dm_resume(). */int dm_create_error_table(struct dm_table **result, struct mapped_device *md); #endif	/* __KERNEL__ */#endif	/* _LINUX_DEVICE_MAPPER_H */