blob: 38d27a10aa5d9f922a14dd5746b9e29f34bce633 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2001 Sistina Software (UK) Limited.
Alasdair G Kergon0da336e2008-04-24 21:43:52 +01003 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * This file is released under the LGPL.
6 */
7
8#ifndef _LINUX_DEVICE_MAPPER_H
9#define _LINUX_DEVICE_MAPPER_H
10
Heinz Mauelshagen416cd172008-04-24 21:43:35 +010011#include <linux/bio.h>
Milan Brozf6fccb12008-07-21 12:00:37 +010012#include <linux/blkdev.h>
Namhyung Kim71a16732011-10-31 20:18:54 +000013#include <linux/ratelimit.h>
Heinz Mauelshagen416cd172008-04-24 21:43:35 +010014
Mike Snitzeraf4874e2009-06-22 10:12:33 +010015struct dm_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070016struct dm_target;
17struct dm_table;
Alasdair G Kergon17b2f662006-06-26 00:27:33 -070018struct mapped_device;
Milan Brozf6fccb12008-07-21 12:00:37 +010019struct bio_vec;
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
22
23union map_info {
24 void *ptr;
25 unsigned long long ll;
Mike Snitzer57cba5d2010-08-12 04:14:04 +010026 unsigned target_request_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070027};
28
29/*
30 * In the constructor the target parameter will already have the
31 * table, type, begin and len fields filled in.
32 */
33typedef int (*dm_ctr_fn) (struct dm_target *target,
34 unsigned int argc, char **argv);
35
36/*
37 * The destructor doesn't need to free the dm_target, just
38 * anything hidden ti->private.
39 */
40typedef void (*dm_dtr_fn) (struct dm_target *ti);
41
42/*
43 * The map function must return:
44 * < 0: error
45 * = 0: The target will handle the io by resubmitting it later
Kiyoshi Ueda45cbcd72006-12-08 02:41:05 -080046 * = 1: simple remap complete
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -080047 * = 2: The target wants to push back the io
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 */
49typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
50 union map_info *map_context);
Kiyoshi Ueda7d763452009-01-06 03:05:07 +000051typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
52 union map_info *map_context);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54/*
55 * Returns:
56 * < 0 : error (currently ignored)
57 * 0 : ended successfully
58 * 1 : for some reason the io has still not completed (eg,
59 * multipath target might want to requeue a failed io).
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -080060 * 2 : The target wants to push back the io
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 */
62typedef int (*dm_endio_fn) (struct dm_target *ti,
63 struct bio *bio, int error,
64 union map_info *map_context);
Kiyoshi Ueda7d763452009-01-06 03:05:07 +000065typedef int (*dm_request_endio_fn) (struct dm_target *ti,
66 struct request *clone, int error,
67 union map_info *map_context);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69typedef void (*dm_presuspend_fn) (struct dm_target *ti);
70typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
Milan Broz8757b772006-10-03 01:15:36 -070071typedef int (*dm_preresume_fn) (struct dm_target *ti);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072typedef void (*dm_resume_fn) (struct dm_target *ti);
73
74typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +010075 unsigned status_flags, char *result, unsigned maxlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
78
Al Viro647b3d02007-08-28 22:15:59 -040079typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
Milan Brozaa129a22006-10-03 01:15:15 -070080 unsigned long arg);
81
Milan Brozf6fccb12008-07-21 12:00:37 +010082typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
83 struct bio_vec *biovec, int max_size);
84
Mike Snitzeraf4874e2009-06-22 10:12:33 +010085typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
86 struct dm_dev *dev,
Mike Snitzer5dea2712009-07-23 20:30:42 +010087 sector_t start, sector_t len,
Mike Snitzeraf4874e2009-06-22 10:12:33 +010088 void *data);
89
90typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
91 iterate_devices_callout_fn fn,
92 void *data);
93
Mike Snitzer40bea432009-09-04 20:40:25 +010094typedef void (*dm_io_hints_fn) (struct dm_target *ti,
95 struct queue_limits *limits);
96
Kiyoshi Ueda7d763452009-01-06 03:05:07 +000097/*
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 */
102typedef int (*dm_busy_fn) (struct dm_target *ti);
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104void dm_error(const char *message);
105
106/*
Bryn Reeves3cb40212006-10-03 01:15:42 -0700107 * Combine device limits.
108 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100109int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
Mike Snitzer5dea2712009-07-23 20:30:42 +0100110 sector_t start, sector_t len, void *data);
Bryn Reeves3cb40212006-10-03 01:15:42 -0700111
Mikulas Patocka82b15192008-10-10 13:37:09 +0100112struct dm_dev {
113 struct block_device *bdev;
Al Viroaeb5d722008-09-02 15:28:45 -0400114 fmode_t mode;
Mikulas Patocka82b15192008-10-10 13:37:09 +0100115 char name[16];
116};
117
Bryn Reeves3cb40212006-10-03 01:15:42 -0700118/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 * Constructors should call these functions to ensure destination devices
120 * are opened/closed correctly.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 */
Nikanth Karthikesan8215d6e2010-03-06 02:32:27 +0000122int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
123 struct dm_dev **result);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124void dm_put_device(struct dm_target *ti, struct dm_dev *d);
125
126/*
127 * Information about a target type
128 */
Andi Kleenab4c142482009-01-06 03:05:09 +0000129
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130struct target_type {
Andi Kleenab4c142482009-01-06 03:05:09 +0000131 uint64_t features;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 const char *name;
133 struct module *module;
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700134 unsigned version[3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 dm_ctr_fn ctr;
136 dm_dtr_fn dtr;
137 dm_map_fn map;
Kiyoshi Ueda7d763452009-01-06 03:05:07 +0000138 dm_map_request_fn map_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 dm_endio_fn end_io;
Kiyoshi Ueda7d763452009-01-06 03:05:07 +0000140 dm_request_endio_fn rq_end_io;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 dm_presuspend_fn presuspend;
142 dm_postsuspend_fn postsuspend;
Milan Broz8757b772006-10-03 01:15:36 -0700143 dm_preresume_fn preresume;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 dm_resume_fn resume;
145 dm_status_fn status;
146 dm_message_fn message;
Milan Brozaa129a22006-10-03 01:15:15 -0700147 dm_ioctl_fn ioctl;
Milan Brozf6fccb12008-07-21 12:00:37 +0100148 dm_merge_fn merge;
Kiyoshi Ueda7d763452009-01-06 03:05:07 +0000149 dm_busy_fn busy;
Mike Snitzeraf4874e2009-06-22 10:12:33 +0100150 dm_iterate_devices_fn iterate_devices;
Mike Snitzer40bea432009-09-04 20:40:25 +0100151 dm_io_hints_fn io_hints;
Cheng Renquan45194e42009-04-02 19:55:28 +0100152
153 /* For internal device-mapper use. */
154 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155};
156
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +0000157/*
158 * Target features
159 */
160
161/*
162 * Any table that contains an instance of this target must have only one.
163 */
164#define DM_TARGET_SINGLETON 0x00000001
165#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
166
Alasdair G Kergoncc6cbe12011-10-31 20:19:02 +0000167/*
168 * Indicates that a target does not support read-only devices.
169 */
170#define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
171#define dm_target_always_writeable(type) \
172 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
173
Alasdair G Kergon36a04562011-10-31 20:19:04 +0000174/*
175 * Any device that contains a table with an instance of this target may never
176 * have tables containing any different target type.
177 */
178#define DM_TARGET_IMMUTABLE 0x00000004
179#define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181struct dm_target {
182 struct dm_table *table;
183 struct target_type *type;
184
185 /* target limits */
186 sector_t begin;
187 sector_t len;
188
Mike Snitzer542f9032012-07-27 15:08:00 +0100189 /* If non-zero, maximum size of I/O submitted to a target. */
190 uint32_t max_io_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 /*
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +0100193 * A number of zero-length barrier requests that will be submitted
194 * to the target for the purpose of flushing cache.
195 *
Mike Snitzer57cba5d2010-08-12 04:14:04 +0100196 * The request number will be placed in union map_info->target_request_nr.
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +0100197 * It is a responsibility of the target driver to remap these requests
198 * to the real underlying devices.
199 */
200 unsigned num_flush_requests;
201
Mike Snitzer5ae89a82010-08-12 04:14:08 +0100202 /*
203 * The number of discard requests that will be submitted to the
204 * target. map_info->request_nr is used just like num_flush_requests.
205 */
206 unsigned num_discard_requests;
207
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 /* target specific data */
209 void *private;
210
211 /* Used to provide an error string from the ctr */
212 char *error;
Mike Snitzer4c259322011-05-29 12:52:55 +0100213
214 /*
Joe Thornber0e9c24e2012-07-27 15:08:07 +0100215 * Set if this target needs to receive flushes regardless of
216 * whether or not its underlying devices have support.
217 */
218 bool flush_supported:1;
219
220 /*
Mike Snitzer4c259322011-05-29 12:52:55 +0100221 * Set if this target needs to receive discards regardless of
222 * whether or not its underlying devices have support.
223 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +0100224 bool discards_supported:1;
Milan Broz983c7db2011-09-25 23:26:21 +0100225
226 /*
Mikulas Patocka7acf0272012-07-27 15:08:03 +0100227 * Set if the target required discard request to be split
228 * on max_io_len boundary.
229 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +0100230 bool split_discard_requests:1;
Mikulas Patocka7acf0272012-07-27 15:08:03 +0100231
232 /*
Milan Broz983c7db2011-09-25 23:26:21 +0100233 * Set if this target does not return zeroes on discarded blocks.
234 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +0100235 bool discard_zeroes_data_unsupported:1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236};
237
NeilBrown9d357b02011-01-13 20:00:01 +0000238/* Each target can link one of these into the table */
239struct dm_target_callbacks {
240 struct list_head list;
241 int (*congested_fn) (struct dm_target_callbacks *, int);
242};
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244int dm_register_target(struct target_type *t);
Mikulas Patocka10d3bd02009-01-06 03:04:58 +0000245void dm_unregister_target(struct target_type *t);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700246
Mike Snitzer498f0102011-08-02 12:32:04 +0100247/*
248 * Target argument parsing.
249 */
250struct dm_arg_set {
251 unsigned argc;
252 char **argv;
253};
254
255/*
256 * The minimum and maximum value of a numeric argument, together with
257 * the error message to use if the number is found to be outside that range.
258 */
259struct dm_arg {
260 unsigned min;
261 unsigned max;
262 char *error;
263};
264
265/*
266 * Validate the next argument, either returning it as *value or, if invalid,
267 * returning -EINVAL and setting *error.
268 */
269int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
270 unsigned *value, char **error);
271
272/*
273 * Process the next argument as the start of a group containing between
274 * arg->min and arg->max further arguments. Either return the size as
275 * *num_args or, if invalid, return -EINVAL and set *error.
276 */
277int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
278 unsigned *num_args, char **error);
279
280/*
281 * Return the current argument and shift to the next.
282 */
283const char *dm_shift_arg(struct dm_arg_set *as);
284
285/*
286 * Move through num_args arguments.
287 */
288void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
289
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700290/*-----------------------------------------------------------------
291 * Functions for creating and manipulating mapped devices.
292 * Drop the reference with dm_put when you finish with the object.
293 *---------------------------------------------------------------*/
294
295/*
296 * DM_ANY_MINOR chooses the next available minor number.
297 */
298#define DM_ANY_MINOR (-1)
299int dm_create(int minor, struct mapped_device **md);
300
301/*
302 * Reference counting for md.
303 */
304struct mapped_device *dm_get_md(dev_t dev);
305void dm_get(struct mapped_device *md);
306void dm_put(struct mapped_device *md);
307
308/*
309 * An arbitrary pointer may be stored alongside a mapped device.
310 */
311void dm_set_mdptr(struct mapped_device *md, void *ptr);
312void *dm_get_mdptr(struct mapped_device *md);
313
314/*
315 * A device can still be used while suspended, but I/O is deferred.
316 */
Kiyoshi Uedaa3d77d32006-12-08 02:41:04 -0800317int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700318int dm_resume(struct mapped_device *md);
319
320/*
321 * Event functions.
322 */
323uint32_t dm_get_event_nr(struct mapped_device *md);
324int dm_wait_event(struct mapped_device *md, int event_nr);
Mike Anderson7a8c3d32007-10-19 22:48:01 +0100325uint32_t dm_next_uevent_seq(struct mapped_device *md);
326void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700327
328/*
329 * Info functions.
330 */
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700331const char *dm_device_name(struct mapped_device *md);
Mike Anderson96a1f7d2007-10-19 22:47:59 +0100332int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700333struct gendisk *dm_disk(struct mapped_device *md);
Kiyoshi Ueda64dbce52009-12-10 23:52:27 +0000334int dm_suspended(struct dm_target *ti);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800335int dm_noflush_suspending(struct dm_target *ti);
Mikulas Patocka89343da2008-10-10 13:37:10 +0100336union map_info *dm_get_mapinfo(struct bio *bio);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100337union map_info *dm_get_rq_mapinfo(struct request *rq);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700338
339/*
340 * Geometry functions.
341 */
342int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
343int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
344
345
346/*-----------------------------------------------------------------
347 * Functions for manipulating device-mapper tables.
348 *---------------------------------------------------------------*/
349
350/*
351 * First create an empty table.
352 */
Al Viroaeb5d722008-09-02 15:28:45 -0400353int dm_table_create(struct dm_table **result, fmode_t mode,
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700354 unsigned num_targets, struct mapped_device *md);
355
356/*
357 * Then call this once for each target.
358 */
359int dm_table_add_target(struct dm_table *t, const char *type,
360 sector_t start, sector_t len, char *params);
361
362/*
NeilBrown9d357b02011-01-13 20:00:01 +0000363 * Target_ctr should call this if it needs to add any callbacks.
364 */
365void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
366
367/*
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700368 * Finally call this to make the table ready for use.
369 */
370int dm_table_complete(struct dm_table *t);
371
372/*
Mike Snitzer542f9032012-07-27 15:08:00 +0100373 * Target may require that it is never sent I/O larger than len.
374 */
375int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
376
377/*
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700378 * Table reference counting.
379 */
Alasdair G Kergon7c666412009-12-10 23:52:19 +0000380struct dm_table *dm_get_live_table(struct mapped_device *md);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700381void dm_table_get(struct dm_table *t);
382void dm_table_put(struct dm_table *t);
383
384/*
385 * Queries
386 */
387sector_t dm_table_get_size(struct dm_table *t);
388unsigned int dm_table_get_num_targets(struct dm_table *t);
Al Viroaeb5d722008-09-02 15:28:45 -0400389fmode_t dm_table_get_mode(struct dm_table *t);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700390struct mapped_device *dm_table_get_md(struct dm_table *t);
391
392/*
393 * Trigger an event.
394 */
395void dm_table_event(struct dm_table *t);
396
397/*
398 * The device must be suspended before calling this method.
Alasdair G Kergon042d2a92009-12-10 23:52:24 +0000399 * Returns the previous table, which the caller must destroy.
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700400 */
Alasdair G Kergon042d2a92009-12-10 23:52:24 +0000401struct dm_table *dm_swap_table(struct mapped_device *md,
402 struct dm_table *t);
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700403
Mikulas Patocka54160902008-10-10 13:37:12 +0100404/*
405 * A wrapper around vmalloc.
406 */
407void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
408
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100409/*-----------------------------------------------------------------
410 * Macros.
411 *---------------------------------------------------------------*/
412#define DM_NAME "device-mapper"
413
Namhyung Kim71a16732011-10-31 20:18:54 +0000414#ifdef CONFIG_PRINTK
415extern struct ratelimit_state dm_ratelimit_state;
416
417#define dm_ratelimit() __ratelimit(&dm_ratelimit_state)
418#else
419#define dm_ratelimit() 0
420#endif
421
Mikulas Patocka10d3bd02009-01-06 03:04:58 +0000422#define DMCRIT(f, arg...) \
423 printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
424
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100425#define DMERR(f, arg...) \
426 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
427#define DMERR_LIMIT(f, arg...) \
428 do { \
Namhyung Kim71a16732011-10-31 20:18:54 +0000429 if (dm_ratelimit()) \
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100430 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
431 f "\n", ## arg); \
432 } while (0)
433
434#define DMWARN(f, arg...) \
435 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
436#define DMWARN_LIMIT(f, arg...) \
437 do { \
Namhyung Kim71a16732011-10-31 20:18:54 +0000438 if (dm_ratelimit()) \
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100439 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
440 f "\n", ## arg); \
441 } while (0)
442
443#define DMINFO(f, arg...) \
444 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
445#define DMINFO_LIMIT(f, arg...) \
446 do { \
Namhyung Kim71a16732011-10-31 20:18:54 +0000447 if (dm_ratelimit()) \
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100448 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
449 "\n", ## arg); \
450 } while (0)
451
452#ifdef CONFIG_DM_DEBUG
453# define DMDEBUG(f, arg...) \
454 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
455# define DMDEBUG_LIMIT(f, arg...) \
456 do { \
Namhyung Kim71a16732011-10-31 20:18:54 +0000457 if (dm_ratelimit()) \
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100458 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
459 "\n", ## arg); \
460 } while (0)
461#else
462# define DMDEBUG(f, arg...) do {} while (0)
463# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
464#endif
465
466#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
467 0 : scnprintf(result + sz, maxlen - sz, x))
468
469#define SECTOR_SHIFT 9
470
471/*
472 * Definitions of return values from target end_io function.
473 */
474#define DM_ENDIO_INCOMPLETE 1
475#define DM_ENDIO_REQUEUE 2
476
477/*
478 * Definitions of return values from target map function.
479 */
480#define DM_MAPIO_SUBMITTED 0
481#define DM_MAPIO_REMAPPED 1
482#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
483
484/*
485 * Ceiling(n / sz)
486 */
487#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
488
489#define dm_sector_div_up(n, sz) ( \
490{ \
491 sector_t _r = ((n) + (sz) - 1); \
492 sector_div(_r, (sz)); \
493 _r; \
494} \
495)
496
497/*
498 * ceiling(n / size) * size
499 */
500#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
501
Mikulas Patockad63a5ce2008-10-21 17:44:57 +0100502#define dm_array_too_big(fixed, obj, num) \
503 ((num) > (UINT_MAX - (fixed)) / (obj))
504
Mike Snitzer56a67df2010-08-12 04:14:10 +0100505/*
506 * Sector offset taken relative to the start of the target instead of
507 * relative to the start of the device.
508 */
509#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
510
Alasdair G Kergon0da336e2008-04-24 21:43:52 +0100511static inline sector_t to_sector(unsigned long n)
512{
513 return (n >> SECTOR_SHIFT);
514}
515
516static inline unsigned long to_bytes(sector_t n)
517{
518 return (n << SECTOR_SHIFT);
519}
520
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100521/*-----------------------------------------------------------------
522 * Helper for block layer and dm core operations
523 *---------------------------------------------------------------*/
524void dm_dispatch_request(struct request *rq);
525void dm_requeue_unmapped_request(struct request *rq);
526void dm_kill_unmapped_request(struct request *rq, int error);
527int dm_underlying_device_busy(struct request_queue *q);
528
Alasdair G Kergon17b2f662006-06-26 00:27:33 -0700529#endif /* _LINUX_DEVICE_MAPPER_H */