2 * Copyright (C) 2001 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the LGPL.
8 #ifndef _LINUX_DEVICE_MAPPER_H
9 #define _LINUX_DEVICE_MAPPER_H
11 #include <linux/bio.h>
12 #include <linux/blkdev.h>
19 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
23 unsigned long long ll;
27 * In the constructor the target parameter will already have the
28 * table, type, begin and len fields filled in.
30 typedef int (*dm_ctr_fn) (struct dm_target *target,
31 unsigned int argc, char **argv);
34 * The destructor doesn't need to free the dm_target, just
35 * anything hidden ti->private.
37 typedef void (*dm_dtr_fn) (struct dm_target *ti);
40 * The map function must return:
42 * = 0: The target will handle the io by resubmitting it later
43 * = 1: simple remap complete
44 * = 2: The target wants to push back the io
46 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
47 union map_info *map_context);
48 typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
49 union map_info *map_context);
53 * < 0 : error (currently ignored)
54 * 0 : ended successfully
55 * 1 : for some reason the io has still not completed (eg,
56 * multipath target might want to requeue a failed io).
57 * 2 : The target wants to push back the io
59 typedef int (*dm_endio_fn) (struct dm_target *ti,
60 struct bio *bio, int error,
61 union map_info *map_context);
62 typedef int (*dm_request_endio_fn) (struct dm_target *ti,
63 struct request *clone, int error,
64 union map_info *map_context);
66 typedef void (*dm_flush_fn) (struct dm_target *ti);
67 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
68 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
69 typedef int (*dm_preresume_fn) (struct dm_target *ti);
70 typedef void (*dm_resume_fn) (struct dm_target *ti);
72 typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
73 char *result, unsigned int maxlen);
75 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
77 typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
80 typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
81 struct bio_vec *biovec, int max_size);
85 * 0: The target can handle the next I/O immediately.
86 * 1: The target can't handle the next I/O immediately.
88 typedef int (*dm_busy_fn) (struct dm_target *ti);
90 void dm_error(const char *message);
93 * Combine device limits.
95 void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev);
98 struct block_device *bdev;
104 * Constructors should call these functions to ensure destination devices
105 * are opened/closed correctly.
106 * FIXME: too many arguments.
108 int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
109 sector_t len, fmode_t mode, struct dm_dev **result);
110 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
113 * Information about a target type
117 struct module *module;
122 dm_map_request_fn map_rq;
124 dm_request_endio_fn rq_end_io;
126 dm_presuspend_fn presuspend;
127 dm_postsuspend_fn postsuspend;
128 dm_preresume_fn preresume;
131 dm_message_fn message;
137 struct io_restrictions {
138 unsigned long bounce_pfn;
139 unsigned long seg_boundary_mask;
140 unsigned max_hw_sectors;
141 unsigned max_sectors;
142 unsigned max_segment_size;
143 unsigned short hardsect_size;
144 unsigned short max_hw_segments;
145 unsigned short max_phys_segments;
146 unsigned char no_cluster; /* inverted so that 0 is default */
150 struct dm_table *table;
151 struct target_type *type;
157 /* FIXME: turn this into a mask, and merge with io_restrictions */
158 /* Always a power of 2 */
162 * These are automatically filled in by
163 * dm_table_get_device.
165 struct io_restrictions limits;
167 /* target specific data */
170 /* Used to provide an error string from the ctr */
174 int dm_register_target(struct target_type *t);
175 void dm_unregister_target(struct target_type *t);
177 /*-----------------------------------------------------------------
178 * Functions for creating and manipulating mapped devices.
179 * Drop the reference with dm_put when you finish with the object.
180 *---------------------------------------------------------------*/
183 * DM_ANY_MINOR chooses the next available minor number.
185 #define DM_ANY_MINOR (-1)
186 int dm_create(int minor, struct mapped_device **md);
189 * Reference counting for md.
191 struct mapped_device *dm_get_md(dev_t dev);
192 void dm_get(struct mapped_device *md);
193 void dm_put(struct mapped_device *md);
196 * An arbitrary pointer may be stored alongside a mapped device.
198 void dm_set_mdptr(struct mapped_device *md, void *ptr);
199 void *dm_get_mdptr(struct mapped_device *md);
202 * A device can still be used while suspended, but I/O is deferred.
204 int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
205 int dm_resume(struct mapped_device *md);
210 uint32_t dm_get_event_nr(struct mapped_device *md);
211 int dm_wait_event(struct mapped_device *md, int event_nr);
212 uint32_t dm_next_uevent_seq(struct mapped_device *md);
213 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
218 const char *dm_device_name(struct mapped_device *md);
219 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
220 struct gendisk *dm_disk(struct mapped_device *md);
221 int dm_suspended(struct mapped_device *md);
222 int dm_noflush_suspending(struct dm_target *ti);
223 union map_info *dm_get_mapinfo(struct bio *bio);
226 * Geometry functions.
228 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
229 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
232 /*-----------------------------------------------------------------
233 * Functions for manipulating device-mapper tables.
234 *---------------------------------------------------------------*/
237 * First create an empty table.
239 int dm_table_create(struct dm_table **result, fmode_t mode,
240 unsigned num_targets, struct mapped_device *md);
243 * Then call this once for each target.
245 int dm_table_add_target(struct dm_table *t, const char *type,
246 sector_t start, sector_t len, char *params);
249 * Finally call this to make the table ready for use.
251 int dm_table_complete(struct dm_table *t);
254 * Unplug all devices in a table.
256 void dm_table_unplug_all(struct dm_table *t);
259 * Table reference counting.
261 struct dm_table *dm_get_table(struct mapped_device *md);
262 void dm_table_get(struct dm_table *t);
263 void dm_table_put(struct dm_table *t);
268 sector_t dm_table_get_size(struct dm_table *t);
269 unsigned int dm_table_get_num_targets(struct dm_table *t);
270 fmode_t dm_table_get_mode(struct dm_table *t);
271 struct mapped_device *dm_table_get_md(struct dm_table *t);
276 void dm_table_event(struct dm_table *t);
279 * The device must be suspended before calling this method.
281 int dm_swap_table(struct mapped_device *md, struct dm_table *t);
284 * A wrapper around vmalloc.
286 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
288 /*-----------------------------------------------------------------
290 *---------------------------------------------------------------*/
291 #define DM_NAME "device-mapper"
293 #define DMCRIT(f, arg...) \
294 printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
296 #define DMERR(f, arg...) \
297 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
298 #define DMERR_LIMIT(f, arg...) \
300 if (printk_ratelimit()) \
301 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
305 #define DMWARN(f, arg...) \
306 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
307 #define DMWARN_LIMIT(f, arg...) \
309 if (printk_ratelimit()) \
310 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
314 #define DMINFO(f, arg...) \
315 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
316 #define DMINFO_LIMIT(f, arg...) \
318 if (printk_ratelimit()) \
319 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
323 #ifdef CONFIG_DM_DEBUG
324 # define DMDEBUG(f, arg...) \
325 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
326 # define DMDEBUG_LIMIT(f, arg...) \
328 if (printk_ratelimit()) \
329 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
333 # define DMDEBUG(f, arg...) do {} while (0)
334 # define DMDEBUG_LIMIT(f, arg...) do {} while (0)
337 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
338 0 : scnprintf(result + sz, maxlen - sz, x))
340 #define SECTOR_SHIFT 9
343 * Definitions of return values from target end_io function.
345 #define DM_ENDIO_INCOMPLETE 1
346 #define DM_ENDIO_REQUEUE 2
349 * Definitions of return values from target map function.
351 #define DM_MAPIO_SUBMITTED 0
352 #define DM_MAPIO_REMAPPED 1
353 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
358 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
360 #define dm_sector_div_up(n, sz) ( \
362 sector_t _r = ((n) + (sz) - 1); \
363 sector_div(_r, (sz)); \
369 * ceiling(n / size) * size
371 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
373 #define dm_array_too_big(fixed, obj, num) \
374 ((num) > (UINT_MAX - (fixed)) / (obj))
376 static inline sector_t to_sector(unsigned long n)
378 return (n >> SECTOR_SHIFT);
381 static inline unsigned long to_bytes(sector_t n)
383 return (n << SECTOR_SHIFT);
386 #endif /* _LINUX_DEVICE_MAPPER_H */