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- /*
- * 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
- * = 1: simple remap complete
- * = 2: The target wants to push back the io
- */
- 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).
- * 2 : The target wants to push back the 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, unsigned suspend_flags);
- 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);
- int dm_noflush_suspending(struct dm_target *ti);
- /*
- * 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 */
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