[deliverable/linux.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_target;
struct dm_table;
struct dm_dev;
struct mapped_device;
struct bio_vec;

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);

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

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;
	dm_merge_fn merge;
};

struct io_restrictions {
	unsigned long bounce_pfn;
	unsigned long seg_boundary_mask;
	unsigned max_hw_sectors;
	unsigned max_sectors;
	unsigned max_segment_size;
	unsigned short hardsect_size;
	unsigned short max_hw_segments;
	unsigned short max_phys_segments;
	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);
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 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);

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

#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))

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);
}

#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
1da177e4 LT	14	struct dm_target;
	15	struct dm_table;
	16	struct dm_dev;
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;
	25	};
	26
	27	/*
	28	* In the constructor the target parameter will already have the
	29	* table, type, begin and len fields filled in.
	30	*/
	31	typedef int (dm_ctr_fn) (struct dm_target target,
	32	unsigned int argc, char **argv);
	33
	34	/*
	35	* The destructor doesn't need to free the dm_target, just
	36	* anything hidden ti->private.
	37	*/
	38	typedef void (dm_dtr_fn) (struct dm_target ti);
	39
	40	/*
	41	* The map function must return:
	42	* < 0: error
	43	* = 0: The target will handle the io by resubmitting it later
45cbcd79	44	* = 1: simple remap complete
2e93ccc1	45	* = 2: The target wants to push back the io
1da177e4 LT	46	*/
	47	typedef int (dm_map_fn) (struct dm_target ti, struct bio *bio,
	48	union map_info *map_context);
	49
	50	/*
	51	* Returns:
	52	* < 0 : error (currently ignored)
	53	* 0 : ended successfully
	54	* 1 : for some reason the io has still not completed (eg,
	55	* multipath target might want to requeue a failed io).
2e93ccc1	56	* 2 : The target wants to push back the io
1da177e4 LT	57	*/
	58	typedef int (dm_endio_fn) (struct dm_target ti,
	59	struct bio *bio, int error,
	60	union map_info *map_context);
	61
999d8168	62	typedef void (dm_flush_fn) (struct dm_target ti);
1da177e4 LT	63	typedef void (dm_presuspend_fn) (struct dm_target ti);
1da177e4 LT	64	typedef void (dm_postsuspend_fn) (struct dm_target ti);
8757b776	65	typedef int (dm_preresume_fn) (struct dm_target ti);
1da177e4 LT	66	typedef void (dm_resume_fn) (struct dm_target ti);
	67
	68	typedef int (dm_status_fn) (struct dm_target ti, status_type_t status_type,
	69	char *result, unsigned int maxlen);
	70
	71	typedef int (dm_message_fn) (struct dm_target ti, unsigned argc, char **argv);
	72
aa129a22 MB	73	typedef int (dm_ioctl_fn) (struct dm_target ti, struct inode *inode,
	74	struct file *filp, unsigned int cmd,
	75	unsigned long arg);
	76
f6fccb12 MB	77	typedef int (dm_merge_fn) (struct dm_target ti, struct bvec_merge_data *bvm,
	78	struct bio_vec *biovec, int max_size);
	79
1da177e4 LT	80	void dm_error(const char *message);
1da177e4 LT	81
3cb40214 BR	82	/*
	83	* Combine device limits.
	84	*/
	85	void dm_set_device_limits(struct dm_target ti, struct block_device bdev);
	86
1da177e4 LT	87	/*
	88	* Constructors should call these functions to ensure destination devices
	89	* are opened/closed correctly.
	90	* FIXME: too many arguments.
	91	*/
	92	int dm_get_device(struct dm_target ti, const char path, sector_t start,
	93	sector_t len, int mode, struct dm_dev **result);
	94	void dm_put_device(struct dm_target ti, struct dm_dev d);
	95
	96	/*
	97	* Information about a target type
	98	*/
	99	struct target_type {
	100	const char *name;
	101	struct module *module;
17b2f66f	102	unsigned version[3];
1da177e4 LT	103	dm_ctr_fn ctr;
	104	dm_dtr_fn dtr;
	105	dm_map_fn map;
	106	dm_endio_fn end_io;
999d8168	107	dm_flush_fn flush;
1da177e4 LT	108	dm_presuspend_fn presuspend;
1da177e4 LT	109	dm_postsuspend_fn postsuspend;
8757b776	110	dm_preresume_fn preresume;
1da177e4 LT	111	dm_resume_fn resume;
	112	dm_status_fn status;
	113	dm_message_fn message;
aa129a22	114	dm_ioctl_fn ioctl;
f6fccb12	115	dm_merge_fn merge;
1da177e4 LT	116	};
	117
	118	struct io_restrictions {
4f41b09f VA	119	unsigned long bounce_pfn;
	120	unsigned long seg_boundary_mask;
	121	unsigned max_hw_sectors;
	122	unsigned max_sectors;
	123	unsigned max_segment_size;
	124	unsigned short hardsect_size;
	125	unsigned short max_hw_segments;
	126	unsigned short max_phys_segments;
	127	unsigned char no_cluster; /* inverted so that 0 is default */
1da177e4 LT	128	};
	129
	130	struct dm_target {
	131	struct dm_table *table;
	132	struct target_type *type;
	133
	134	/* target limits */
	135	sector_t begin;
	136	sector_t len;
	137
	138	/* FIXME: turn this into a mask, and merge with io_restrictions */
	139	/* Always a power of 2 */
	140	sector_t split_io;
	141
	142	/*
	143	* These are automatically filled in by
	144	* dm_table_get_device.
	145	*/
	146	struct io_restrictions limits;
	147
	148	/* target specific data */
	149	void *private;
	150
	151	/* Used to provide an error string from the ctr */
	152	char *error;
	153	};
	154
	155	int dm_register_target(struct target_type *t);
	156	int dm_unregister_target(struct target_type *t);
	157
17b2f66f AK	158
	159	/*-----------------------------------------------------------------
	160	* Functions for creating and manipulating mapped devices.
	161	* Drop the reference with dm_put when you finish with the object.
	162	---------------------------------------------------------------/
	163
	164	/*
	165	* DM_ANY_MINOR chooses the next available minor number.
	166	*/
	167	#define DM_ANY_MINOR (-1)
	168	int dm_create(int minor, struct mapped_device **md);
	169
	170	/*
	171	* Reference counting for md.
	172	*/
	173	struct mapped_device *dm_get_md(dev_t dev);
	174	void dm_get(struct mapped_device *md);
	175	void dm_put(struct mapped_device *md);
	176
	177	/*
	178	* An arbitrary pointer may be stored alongside a mapped device.
	179	*/
	180	void dm_set_mdptr(struct mapped_device md, void ptr);
	181	void dm_get_mdptr(struct mapped_device md);
	182
	183	/*
	184	* A device can still be used while suspended, but I/O is deferred.
	185	*/
a3d77d35	186	int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
17b2f66f AK	187	int dm_resume(struct mapped_device *md);
	188
	189	/*
	190	* Event functions.
	191	*/
	192	uint32_t dm_get_event_nr(struct mapped_device *md);
	193	int dm_wait_event(struct mapped_device *md, int event_nr);
7a8c3d3b MA	194	uint32_t dm_next_uevent_seq(struct mapped_device *md);
7a8c3d3b MA	195	void dm_uevent_add(struct mapped_device md, struct list_head elist);
17b2f66f AK	196
	197	/*
	198	* Info functions.
	199	*/
72d94861	200	const char dm_device_name(struct mapped_device md);
96a1f7db	201	int dm_copy_name_and_uuid(struct mapped_device md, char name, char *uuid);
17b2f66f AK	202	struct gendisk dm_disk(struct mapped_device md);
17b2f66f AK	203	int dm_suspended(struct mapped_device *md);
2e93ccc1	204	int dm_noflush_suspending(struct dm_target *ti);
17b2f66f AK	205
	206	/*
	207	* Geometry functions.
	208	*/
	209	int dm_get_geometry(struct mapped_device md, struct hd_geometry geo);
	210	int dm_set_geometry(struct mapped_device md, struct hd_geometry geo);
	211
	212
	213	/*-----------------------------------------------------------------
	214	* Functions for manipulating device-mapper tables.
	215	---------------------------------------------------------------/
	216
	217	/*
	218	* First create an empty table.
	219	*/
	220	int dm_table_create(struct dm_table **result, int mode,
	221	unsigned num_targets, struct mapped_device *md);
	222
	223	/*
	224	* Then call this once for each target.
	225	*/
	226	int dm_table_add_target(struct dm_table t, const char type,
	227	sector_t start, sector_t len, char *params);
	228
	229	/*
	230	* Finally call this to make the table ready for use.
	231	*/
	232	int dm_table_complete(struct dm_table *t);
	233
	234	/*
	235	* Table reference counting.
	236	*/
	237	struct dm_table dm_get_table(struct mapped_device md);
	238	void dm_table_get(struct dm_table *t);
	239	void dm_table_put(struct dm_table *t);
	240
	241	/*
	242	* Queries
	243	*/
	244	sector_t dm_table_get_size(struct dm_table *t);
	245	unsigned int dm_table_get_num_targets(struct dm_table *t);
	246	int dm_table_get_mode(struct dm_table *t);
	247	struct mapped_device dm_table_get_md(struct dm_table t);
	248
	249	/*
	250	* Trigger an event.
	251	*/
	252	void dm_table_event(struct dm_table *t);
	253
	254	/*
	255	* The device must be suspended before calling this method.
	256	*/
	257	int dm_swap_table(struct mapped_device md, struct dm_table t);
	258
0da336e5 AK	259	/*-----------------------------------------------------------------
	260	* Macros.
	261	---------------------------------------------------------------/
	262	#define DM_NAME "device-mapper"
	263
	264	#define DMERR(f, arg...) \
	265	printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	266	#define DMERR_LIMIT(f, arg...) \
	267	do { \
	268	if (printk_ratelimit()) \
	269	printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
	270	f "\n", ## arg); \
	271	} while (0)
	272
	273	#define DMWARN(f, arg...) \
	274	printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	275	#define DMWARN_LIMIT(f, arg...) \
	276	do { \
	277	if (printk_ratelimit()) \
	278	printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
	279	f "\n", ## arg); \
	280	} while (0)
	281
	282	#define DMINFO(f, arg...) \
	283	printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
	284	#define DMINFO_LIMIT(f, arg...) \
	285	do { \
	286	if (printk_ratelimit()) \
	287	printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
	288	"\n", ## arg); \
	289	} while (0)
	290
	291	#ifdef CONFIG_DM_DEBUG
	292	# define DMDEBUG(f, arg...) \
	293	printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
	294	# define DMDEBUG_LIMIT(f, arg...) \
	295	do { \
	296	if (printk_ratelimit()) \
	297	printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
	298	"\n", ## arg); \
	299	} while (0)
	300	#else
	301	# define DMDEBUG(f, arg...) do {} while (0)
	302	# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
	303	#endif
	304
	305	#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
	306	0 : scnprintf(result + sz, maxlen - sz, x))
	307
	308	#define SECTOR_SHIFT 9
	309
	310	/*
	311	* Definitions of return values from target end_io function.
	312	*/
	313	#define DM_ENDIO_INCOMPLETE 1
	314	#define DM_ENDIO_REQUEUE 2
	315
	316	/*
	317	* Definitions of return values from target map function.
	318	*/
	319	#define DM_MAPIO_SUBMITTED 0
	320	#define DM_MAPIO_REMAPPED 1
	321	#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
	322
323	/*
324	* Ceiling(n / sz)
325	*/
326	#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
327
328	#define dm_sector_div_up(n, sz) ( \
329	{ \
330	sector_t _r = ((n) + (sz) - 1); \
331	sector_div(_r, (sz)); \
332	_r; \
333	} \
334	)
335
336	/*
337	* ceiling(n / size) * size
338	*/
339	#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
340
341	static inline sector_t to_sector(unsigned long n)
342	{
343	return (n >> SECTOR_SHIFT);
344	}
345
346	static inline unsigned long to_bytes(sector_t n)
347	{
348	return (n << SECTOR_SHIFT);
349	}
350
17b2f66f	351	#endif /* _LINUX_DEVICE_MAPPER_H */