[linux-2.6-block.git] / include / linux / device-mapper.h

/*
 * Copyright (C) 2001 Sistina Software (UK) Limited.
 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef _LINUX_DEVICE_MAPPER_H
#define _LINUX_DEVICE_MAPPER_H

#include <linux/bio.h>
#include <linux/blkdev.h>

struct dm_dev;
struct dm_target;
struct dm_table;
struct mapped_device;
struct bio_vec;

typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;

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

/*
 * 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);
typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
				  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 int (*dm_request_endio_fn) (struct dm_target *ti,
				    struct request *clone, 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, unsigned int cmd,
			    unsigned long arg);

typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
			    struct bio_vec *biovec, int max_size);

typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
					   struct dm_dev *dev,
					   sector_t start, sector_t len,
					   void *data);

typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
				      iterate_devices_callout_fn fn,
				      void *data);

typedef void (*dm_io_hints_fn) (struct dm_target *ti,
				struct queue_limits *limits);

/*
 * Returns:
 *    0: The target can handle the next I/O immediately.
 *    1: The target can't handle the next I/O immediately.
 */
typedef int (*dm_busy_fn) (struct dm_target *ti);

void dm_error(const char *message);

/*
 * Combine device limits.
 */
int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
			 sector_t start, sector_t len, void *data);

struct dm_dev {
	struct block_device *bdev;
	fmode_t mode;
	char name[16];
};

/*
 * Constructors should call these functions to ensure destination devices
 * are opened/closed correctly.
 */
int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
						 struct dm_dev **result);
void dm_put_device(struct dm_target *ti, struct dm_dev *d);

/*
 * Information about a target type
 */

/*
 * Target features
 */

struct target_type {
	uint64_t features;
	const char *name;
	struct module *module;
	unsigned version[3];
	dm_ctr_fn ctr;
	dm_dtr_fn dtr;
	dm_map_fn map;
	dm_map_request_fn map_rq;
	dm_endio_fn end_io;
	dm_request_endio_fn rq_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;
	dm_merge_fn merge;
	dm_busy_fn busy;
	dm_iterate_devices_fn iterate_devices;
	dm_io_hints_fn io_hints;

	/* For internal device-mapper use. */
	struct list_head list;
};

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

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

	/* Always a power of 2 */
	sector_t split_io;

	/*
	 * A number of zero-length barrier requests that will be submitted
	 * to the target for the purpose of flushing cache.
	 *
	 * The request number will be placed in union map_info->target_request_nr.
	 * It is a responsibility of the target driver to remap these requests
	 * to the real underlying devices.
	 */
	unsigned num_flush_requests;

	/*
	 * The number of discard requests that will be submitted to the
	 * target.  map_info->request_nr is used just like num_flush_requests.
	 */
	unsigned num_discard_requests;

	/* target specific data */
	void *private;

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

	/*
	 * Set if this target needs to receive discards regardless of
	 * whether or not its underlying devices have support.
	 */
	unsigned discards_supported:1;
};

/* Each target can link one of these into the table */
struct dm_target_callbacks {
	struct list_head list;
	int (*congested_fn) (struct dm_target_callbacks *, int);
};

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

/*
 * Target argument parsing.
 */
struct dm_arg_set {
	unsigned argc;
	char **argv;
};

/*
 * The minimum and maximum value of a numeric argument, together with
 * the error message to use if the number is found to be outside that range.
 */
struct dm_arg {
	unsigned min;
	unsigned max;
	char *error;
};

/*
 * Validate the next argument, either returning it as *value or, if invalid,
 * returning -EINVAL and setting *error.
 */
int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
		unsigned *value, char **error);

/*
 * Process the next argument as the start of a group containing between
 * arg->min and arg->max further arguments. Either return the size as
 * *num_args or, if invalid, return -EINVAL and set *error.
 */
int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
		      unsigned *num_args, char **error);

/*
 * Return the current argument and shift to the next.
 */
const char *dm_shift_arg(struct dm_arg_set *as);

/*
 * Move through num_args arguments.
 */
void dm_consume_args(struct dm_arg_set *as, unsigned num_args);

/*-----------------------------------------------------------------
 * 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);
uint32_t dm_next_uevent_seq(struct mapped_device *md);
void dm_uevent_add(struct mapped_device *md, struct list_head *elist);

/*
 * Info functions.
 */
const char *dm_device_name(struct mapped_device *md);
int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct dm_target *ti);
int dm_noflush_suspending(struct dm_target *ti);
union map_info *dm_get_mapinfo(struct bio *bio);
union map_info *dm_get_rq_mapinfo(struct request *rq);

/*
 * 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, fmode_t 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);

/*
 * Target_ctr should call this if it needs to add any callbacks.
 */
void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);

/*
 * 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_live_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);
fmode_t 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.
 * Returns the previous table, which the caller must destroy.
 */
struct dm_table *dm_swap_table(struct mapped_device *md,
			       struct dm_table *t);

/*
 * A wrapper around vmalloc.
 */
void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);

/*-----------------------------------------------------------------
 * Macros.
 *---------------------------------------------------------------*/
#define DM_NAME "device-mapper"

#define DMCRIT(f, arg...) \
	printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)

#define DMERR(f, arg...) \
	printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
#define DMERR_LIMIT(f, arg...) \
	do { \
		if (printk_ratelimit())	\
			printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
			       f "\n", ## arg); \
	} while (0)

#define DMWARN(f, arg...) \
	printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
#define DMWARN_LIMIT(f, arg...) \
	do { \
		if (printk_ratelimit())	\
			printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
			       f "\n", ## arg); \
	} while (0)

#define DMINFO(f, arg...) \
	printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
#define DMINFO_LIMIT(f, arg...) \
	do { \
		if (printk_ratelimit())	\
			printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
			       "\n", ## arg); \
	} while (0)

#ifdef CONFIG_DM_DEBUG
#  define DMDEBUG(f, arg...) \
	printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
#  define DMDEBUG_LIMIT(f, arg...) \
	do { \
		if (printk_ratelimit())	\
			printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
			       "\n", ## arg); \
	} while (0)
#else
#  define DMDEBUG(f, arg...) do {} while (0)
#  define DMDEBUG_LIMIT(f, arg...) do {} while (0)
#endif

#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
			  0 : scnprintf(result + sz, maxlen - sz, x))

#define SECTOR_SHIFT 9

/*
 * Definitions of return values from target end_io function.
 */
#define DM_ENDIO_INCOMPLETE	1
#define DM_ENDIO_REQUEUE	2

/*
 * Definitions of return values from target map function.
 */
#define DM_MAPIO_SUBMITTED	0
#define DM_MAPIO_REMAPPED	1
#define DM_MAPIO_REQUEUE	DM_ENDIO_REQUEUE

/*
 * Ceiling(n / sz)
 */
#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))

#define dm_sector_div_up(n, sz) ( \
{ \
	sector_t _r = ((n) + (sz) - 1); \
	sector_div(_r, (sz)); \
	_r; \
} \
)

/*
 * ceiling(n / size) * size
 */
#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))

#define dm_array_too_big(fixed, obj, num) \
	((num) > (UINT_MAX - (fixed)) / (obj))

/*
 * Sector offset taken relative to the start of the target instead of
 * relative to the start of the device.
 */
#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)

static inline sector_t to_sector(unsigned long n)
{
	return (n >> SECTOR_SHIFT);
}

static inline unsigned long to_bytes(sector_t n)
{
	return (n << SECTOR_SHIFT);
}

/*-----------------------------------------------------------------
 * Helper for block layer and dm core operations
 *---------------------------------------------------------------*/
void dm_dispatch_request(struct request *rq);
void dm_requeue_unmapped_request(struct request *rq);
void dm_kill_unmapped_request(struct request *rq, int error);
int dm_underlying_device_busy(struct request_queue *q);

#endif	/* _LINUX_DEVICE_MAPPER_H */
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Copyright (C) 2001 Sistina Software (UK) Limited.
0da336e5	3	* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
1da177e4 LT	4	*
	5	* This file is released under the LGPL.
	6	*/
	7
	8	#ifndef _LINUX_DEVICE_MAPPER_H
	9	#define _LINUX_DEVICE_MAPPER_H
	10
416cd17b	11	#include <linux/bio.h>
f6fccb12	12	#include <linux/blkdev.h>
416cd17b	13
af4874e0	14	struct dm_dev;
1da177e4 LT	15	struct dm_target;
1da177e4 LT	16	struct dm_table;
17b2f66f	17	struct mapped_device;
f6fccb12	18	struct bio_vec;
1da177e4 LT	19
	20	typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
	21
	22	union map_info {
	23	void *ptr;
	24	unsigned long long ll;
57cba5d3	25	unsigned target_request_nr;
1da177e4 LT	26	};
	27
	28	/*
	29	* In the constructor the target parameter will already have the
	30	* table, type, begin and len fields filled in.
	31	*/
	32	typedef int (dm_ctr_fn) (struct dm_target target,
	33	unsigned int argc, char **argv);
	34
	35	/*
	36	* The destructor doesn't need to free the dm_target, just
	37	* anything hidden ti->private.
	38	*/
	39	typedef void (dm_dtr_fn) (struct dm_target ti);
	40
	41	/*
	42	* The map function must return:
	43	* < 0: error
	44	* = 0: The target will handle the io by resubmitting it later
45cbcd79	45	* = 1: simple remap complete
2e93ccc1	46	* = 2: The target wants to push back the io
1da177e4 LT	47	*/
	48	typedef int (dm_map_fn) (struct dm_target ti, struct bio *bio,
	49	union map_info *map_context);
7d76345d KU	50	typedef int (dm_map_request_fn) (struct dm_target ti, struct request *clone,
7d76345d KU	51	union map_info *map_context);
1da177e4 LT	52
	53	/*
	54	* Returns:
	55	* < 0 : error (currently ignored)
	56	* 0 : ended successfully
	57	* 1 : for some reason the io has still not completed (eg,
	58	* multipath target might want to requeue a failed io).
2e93ccc1	59	* 2 : The target wants to push back the io
1da177e4 LT	60	*/
	61	typedef int (dm_endio_fn) (struct dm_target ti,
	62	struct bio *bio, int error,
	63	union map_info *map_context);
7d76345d KU	64	typedef int (dm_request_endio_fn) (struct dm_target ti,
	65	struct request *clone, int error,
	66	union map_info *map_context);
1da177e4	67
999d8168	68	typedef void (dm_flush_fn) (struct dm_target ti);
1da177e4 LT	69	typedef void (dm_presuspend_fn) (struct dm_target ti);
1da177e4 LT	70	typedef void (dm_postsuspend_fn) (struct dm_target ti);
8757b776	71	typedef int (dm_preresume_fn) (struct dm_target ti);
1da177e4 LT	72	typedef void (dm_resume_fn) (struct dm_target ti);
	73
	74	typedef int (dm_status_fn) (struct dm_target ti, status_type_t status_type,
	75	char *result, unsigned int maxlen);
	76
	77	typedef int (dm_message_fn) (struct dm_target ti, unsigned argc, char **argv);
	78
647b3d00	79	typedef int (dm_ioctl_fn) (struct dm_target ti, unsigned int cmd,
aa129a22 MB	80	unsigned long arg);
aa129a22 MB	81
f6fccb12 MB	82	typedef int (dm_merge_fn) (struct dm_target ti, struct bvec_merge_data *bvm,
	83	struct bio_vec *biovec, int max_size);
	84
af4874e0 MS	85	typedef int (iterate_devices_callout_fn) (struct dm_target ti,
af4874e0 MS	86	struct dm_dev *dev,
5dea271b	87	sector_t start, sector_t len,
af4874e0 MS	88	void *data);
	89
	90	typedef int (dm_iterate_devices_fn) (struct dm_target ti,
	91	iterate_devices_callout_fn fn,
	92	void *data);
	93
40bea431 MS	94	typedef void (dm_io_hints_fn) (struct dm_target ti,
	95	struct queue_limits *limits);
	96
7d76345d KU	97	/*
	98	* Returns:
	99	* 0: The target can handle the next I/O immediately.
	100	* 1: The target can't handle the next I/O immediately.
	101	*/
	102	typedef int (dm_busy_fn) (struct dm_target ti);
	103
1da177e4 LT	104	void dm_error(const char *message);
1da177e4 LT	105
3cb40214 BR	106	/*
	107	* Combine device limits.
	108	*/
754c5fc7	109	int dm_set_device_limits(struct dm_target ti, struct dm_dev dev,
5dea271b	110	sector_t start, sector_t len, void *data);
3cb40214	111
82b1519b MP	112	struct dm_dev {
82b1519b MP	113	struct block_device *bdev;
aeb5d727	114	fmode_t mode;
82b1519b MP	115	char name[16];
	116	};
	117
1da177e4 LT	118	/*
	119	* Constructors should call these functions to ensure destination devices
	120	* are opened/closed correctly.
1da177e4	121	*/
8215d6ec NK	122	int dm_get_device(struct dm_target ti, const char path, fmode_t mode,
8215d6ec NK	123	struct dm_dev **result);
1da177e4 LT	124	void dm_put_device(struct dm_target ti, struct dm_dev d);
	125
	126	/*
	127	* Information about a target type
	128	*/
ab4c1424 AK	129
	130	/*
	131	* Target features
	132	*/
ab4c1424	133
1da177e4	134	struct target_type {
ab4c1424	135	uint64_t features;
1da177e4 LT	136	const char *name;
1da177e4 LT	137	struct module *module;
17b2f66f	138	unsigned version[3];
1da177e4 LT	139	dm_ctr_fn ctr;
	140	dm_dtr_fn dtr;
	141	dm_map_fn map;
7d76345d	142	dm_map_request_fn map_rq;
1da177e4	143	dm_endio_fn end_io;
7d76345d	144	dm_request_endio_fn rq_end_io;
999d8168	145	dm_flush_fn flush;
1da177e4 LT	146	dm_presuspend_fn presuspend;
1da177e4 LT	147	dm_postsuspend_fn postsuspend;
8757b776	148	dm_preresume_fn preresume;
1da177e4 LT	149	dm_resume_fn resume;
	150	dm_status_fn status;
	151	dm_message_fn message;
aa129a22	152	dm_ioctl_fn ioctl;
f6fccb12	153	dm_merge_fn merge;
7d76345d	154	dm_busy_fn busy;
af4874e0	155	dm_iterate_devices_fn iterate_devices;
40bea431	156	dm_io_hints_fn io_hints;
45194e4f CR	157
	158	/* For internal device-mapper use. */
	159	struct list_head list;
1da177e4 LT	160	};
1da177e4 LT	161
1da177e4 LT	162	struct dm_target {
	163	struct dm_table *table;
	164	struct target_type *type;
	165
	166	/* target limits */
	167	sector_t begin;
	168	sector_t len;
	169
1da177e4 LT	170	/* Always a power of 2 */
	171	sector_t split_io;
	172
f9ab94ce MP	173	/*
	174	* A number of zero-length barrier requests that will be submitted
	175	* to the target for the purpose of flushing cache.
	176	*
57cba5d3	177	* The request number will be placed in union map_info->target_request_nr.
f9ab94ce MP	178	* It is a responsibility of the target driver to remap these requests
	179	* to the real underlying devices.
	180	*/
	181	unsigned num_flush_requests;
	182
5ae89a87 MS	183	/*
	184	* The number of discard requests that will be submitted to the
	185	* target. map_info->request_nr is used just like num_flush_requests.
	186	*/
	187	unsigned num_discard_requests;
	188
1da177e4 LT	189	/* target specific data */
	190	void *private;
	191
	192	/* Used to provide an error string from the ctr */
	193	char *error;
4c259327 MS	194
	195	/*
	196	* Set if this target needs to receive discards regardless of
	197	* whether or not its underlying devices have support.
	198	*/
	199	unsigned discards_supported:1;
1da177e4 LT	200	};
1da177e4 LT	201
9d357b07 N	202	/* Each target can link one of these into the table */
	203	struct dm_target_callbacks {
	204	struct list_head list;
	205	int (congested_fn) (struct dm_target_callbacks , int);
	206	};
	207
1da177e4	208	int dm_register_target(struct target_type *t);
10d3bd09	209	void dm_unregister_target(struct target_type *t);
17b2f66f	210
498f0103 MS	211	/*
	212	* Target argument parsing.
	213	*/
	214	struct dm_arg_set {
	215	unsigned argc;
	216	char **argv;
	217	};
	218
	219	/*
	220	* The minimum and maximum value of a numeric argument, together with
	221	* the error message to use if the number is found to be outside that range.
	222	*/
	223	struct dm_arg {
	224	unsigned min;
	225	unsigned max;
	226	char *error;
	227	};
	228
	229	/*
	230	* Validate the next argument, either returning it as *value or, if invalid,
	231	* returning -EINVAL and setting *error.
	232	*/
	233	int dm_read_arg(struct dm_arg arg, struct dm_arg_set arg_set,
	234	unsigned value, char *error);
	235
	236	/*
	237	* Process the next argument as the start of a group containing between
	238	* arg->min and arg->max further arguments. Either return the size as
	239	* num_args or, if invalid, return -EINVAL and set error.
	240	*/
	241	int dm_read_arg_group(struct dm_arg arg, struct dm_arg_set arg_set,
	242	unsigned num_args, char *error);
	243
	244	/*
	245	* Return the current argument and shift to the next.
	246	*/
	247	const char dm_shift_arg(struct dm_arg_set as);
	248
	249	/*
	250	* Move through num_args arguments.
	251	*/
	252	void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
	253
17b2f66f AK	254	/*-----------------------------------------------------------------
	255	* Functions for creating and manipulating mapped devices.
	256	* Drop the reference with dm_put when you finish with the object.
	257	---------------------------------------------------------------/
	258
	259	/*
	260	* DM_ANY_MINOR chooses the next available minor number.
	261	*/
	262	#define DM_ANY_MINOR (-1)
	263	int dm_create(int minor, struct mapped_device **md);
	264
	265	/*
	266	* Reference counting for md.
	267	*/
	268	struct mapped_device *dm_get_md(dev_t dev);
	269	void dm_get(struct mapped_device *md);
	270	void dm_put(struct mapped_device *md);
	271
	272	/*
	273	* An arbitrary pointer may be stored alongside a mapped device.
	274	*/
	275	void dm_set_mdptr(struct mapped_device md, void ptr);
	276	void dm_get_mdptr(struct mapped_device md);
	277
	278	/*
	279	* A device can still be used while suspended, but I/O is deferred.
	280	*/
a3d77d35	281	int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
17b2f66f AK	282	int dm_resume(struct mapped_device *md);
	283
	284	/*
	285	* Event functions.
	286	*/
	287	uint32_t dm_get_event_nr(struct mapped_device *md);
	288	int dm_wait_event(struct mapped_device *md, int event_nr);
7a8c3d3b MA	289	uint32_t dm_next_uevent_seq(struct mapped_device *md);
7a8c3d3b MA	290	void dm_uevent_add(struct mapped_device md, struct list_head elist);
17b2f66f AK	291
	292	/*
	293	* Info functions.
	294	*/
72d94861	295	const char dm_device_name(struct mapped_device md);
96a1f7db	296	int dm_copy_name_and_uuid(struct mapped_device md, char name, char *uuid);
17b2f66f	297	struct gendisk dm_disk(struct mapped_device md);
64dbce58	298	int dm_suspended(struct dm_target *ti);
2e93ccc1	299	int dm_noflush_suspending(struct dm_target *ti);
89343da0	300	union map_info dm_get_mapinfo(struct bio bio);
cec47e3d	301	union map_info dm_get_rq_mapinfo(struct request rq);
17b2f66f AK	302
	303	/*
	304	* Geometry functions.
	305	*/
	306	int dm_get_geometry(struct mapped_device md, struct hd_geometry geo);
	307	int dm_set_geometry(struct mapped_device md, struct hd_geometry geo);
	308
	309
	310	/*-----------------------------------------------------------------
	311	* Functions for manipulating device-mapper tables.
	312	---------------------------------------------------------------/
	313
	314	/*
	315	* First create an empty table.
	316	*/
aeb5d727	317	int dm_table_create(struct dm_table **result, fmode_t mode,
17b2f66f AK	318	unsigned num_targets, struct mapped_device *md);
	319
	320	/*
	321	* Then call this once for each target.
	322	*/
	323	int dm_table_add_target(struct dm_table t, const char type,
	324	sector_t start, sector_t len, char *params);
	325
9d357b07 N	326	/*
	327	* Target_ctr should call this if it needs to add any callbacks.
	328	*/
	329	void dm_table_add_target_callbacks(struct dm_table t, struct dm_target_callbacks cb);
	330
17b2f66f AK	331	/*
	332	* Finally call this to make the table ready for use.
	333	*/
	334	int dm_table_complete(struct dm_table *t);
	335
	336	/*
	337	* Table reference counting.
	338	*/
7c666411	339	struct dm_table dm_get_live_table(struct mapped_device md);
17b2f66f AK	340	void dm_table_get(struct dm_table *t);
	341	void dm_table_put(struct dm_table *t);
	342
	343	/*
	344	* Queries
	345	*/
	346	sector_t dm_table_get_size(struct dm_table *t);
	347	unsigned int dm_table_get_num_targets(struct dm_table *t);
aeb5d727	348	fmode_t dm_table_get_mode(struct dm_table *t);
17b2f66f AK	349	struct mapped_device dm_table_get_md(struct dm_table t);
	350
	351	/*
	352	* Trigger an event.
	353	*/
	354	void dm_table_event(struct dm_table *t);
	355
	356	/*
	357	* The device must be suspended before calling this method.
042d2a9b	358	* Returns the previous table, which the caller must destroy.
17b2f66f	359	*/
042d2a9b AK	360	struct dm_table dm_swap_table(struct mapped_device md,
042d2a9b AK	361	struct dm_table *t);
17b2f66f	362
54160904 MP	363	/*
	364	* A wrapper around vmalloc.
	365	*/
	366	void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
	367
0da336e5 AK	368	/*-----------------------------------------------------------------
	369	* Macros.
	370	---------------------------------------------------------------/
	371	#define DM_NAME "device-mapper"
	372
10d3bd09 MP	373	#define DMCRIT(f, arg...) \
	374	printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	375
0da336e5 AK	376	#define DMERR(f, arg...) \
	377	printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	378	#define DMERR_LIMIT(f, arg...) \
	379	do { \
	380	if (printk_ratelimit()) \
	381	printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
	382	f "\n", ## arg); \
	383	} while (0)
	384
	385	#define DMWARN(f, arg...) \
	386	printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	387	#define DMWARN_LIMIT(f, arg...) \
	388	do { \
	389	if (printk_ratelimit()) \
	390	printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
	391	f "\n", ## arg); \
	392	} while (0)
	393
	394	#define DMINFO(f, arg...) \
	395	printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	396	#define DMINFO_LIMIT(f, arg...) \
	397	do { \
	398	if (printk_ratelimit()) \
	399	printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
	400	"\n", ## arg); \
	401	} while (0)
	402
	403	#ifdef CONFIG_DM_DEBUG
	404	# define DMDEBUG(f, arg...) \
	405	printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
	406	# define DMDEBUG_LIMIT(f, arg...) \
	407	do { \
	408	if (printk_ratelimit()) \
	409	printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
	410	"\n", ## arg); \
	411	} while (0)
	412	#else
	413	# define DMDEBUG(f, arg...) do {} while (0)
	414	# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
	415	#endif
	416
	417	#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
	418	0 : scnprintf(result + sz, maxlen - sz, x))
	419
	420	#define SECTOR_SHIFT 9
	421
	422	/*
	423	* Definitions of return values from target end_io function.
	424	*/
	425	#define DM_ENDIO_INCOMPLETE 1
	426	#define DM_ENDIO_REQUEUE 2
	427
	428	/*
	429	* Definitions of return values from target map function.
	430	*/
	431	#define DM_MAPIO_SUBMITTED 0
	432	#define DM_MAPIO_REMAPPED 1
	433	#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
	434
	435	/*
	436	* Ceiling(n / sz)
	437	*/
	438	#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
	439
440	#define dm_sector_div_up(n, sz) ( \
441	{ \
442	sector_t _r = ((n) + (sz) - 1); \
443	sector_div(_r, (sz)); \
444	_r; \
445	} \
446	)
447
448	/*
449	* ceiling(n / size) * size
450	*/
451	#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
452
d63a5ce3 MP	453	#define dm_array_too_big(fixed, obj, num) \
	454	((num) > (UINT_MAX - (fixed)) / (obj))
	455
56a67df7 MS	456	/*
	457	* Sector offset taken relative to the start of the target instead of
	458	* relative to the start of the device.
	459	*/
	460	#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
	461
0da336e5 AK	462	static inline sector_t to_sector(unsigned long n)
	463	{
	464	return (n >> SECTOR_SHIFT);
	465	}
	466
	467	static inline unsigned long to_bytes(sector_t n)
	468	{
	469	return (n << SECTOR_SHIFT);
	470	}
	471
cec47e3d KU	472	/*-----------------------------------------------------------------
	473	* Helper for block layer and dm core operations
	474	---------------------------------------------------------------/
	475	void dm_dispatch_request(struct request *rq);
	476	void dm_requeue_unmapped_request(struct request *rq);
	477	void dm_kill_unmapped_request(struct request *rq, int error);
	478	int dm_underlying_device_busy(struct request_queue *q);
	479
17b2f66f	480	#endif /* _LINUX_DEVICE_MAPPER_H */