Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. | |
3 | * Copyright (C) 2004 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include "dm.h" | |
9 | #include "dm-bio-list.h" | |
10 | ||
11 | #include <linux/init.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/moduleparam.h> | |
14 | #include <linux/blkpg.h> | |
15 | #include <linux/bio.h> | |
16 | #include <linux/buffer_head.h> | |
17 | #include <linux/mempool.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/idr.h> | |
2056a782 | 20 | #include <linux/blktrace_api.h> |
1da177e4 LT |
21 | |
22 | static const char *_name = DM_NAME; | |
23 | ||
24 | static unsigned int major = 0; | |
25 | static unsigned int _major = 0; | |
26 | ||
27 | /* | |
28 | * One of these is allocated per bio. | |
29 | */ | |
30 | struct dm_io { | |
31 | struct mapped_device *md; | |
32 | int error; | |
33 | struct bio *bio; | |
34 | atomic_t io_count; | |
3eaf840e | 35 | unsigned long start_time; |
1da177e4 LT |
36 | }; |
37 | ||
38 | /* | |
39 | * One of these is allocated per target within a bio. Hopefully | |
40 | * this will be simplified out one day. | |
41 | */ | |
42 | struct target_io { | |
43 | struct dm_io *io; | |
44 | struct dm_target *ti; | |
45 | union map_info info; | |
46 | }; | |
47 | ||
48 | union map_info *dm_get_mapinfo(struct bio *bio) | |
49 | { | |
50 | if (bio && bio->bi_private) | |
51 | return &((struct target_io *)bio->bi_private)->info; | |
52 | return NULL; | |
53 | } | |
54 | ||
55 | /* | |
56 | * Bits for the md->flags field. | |
57 | */ | |
58 | #define DMF_BLOCK_IO 0 | |
59 | #define DMF_SUSPENDED 1 | |
aa8d7c2f | 60 | #define DMF_FROZEN 2 |
1da177e4 LT |
61 | |
62 | struct mapped_device { | |
2ca3310e AK |
63 | struct rw_semaphore io_lock; |
64 | struct semaphore suspend_lock; | |
1da177e4 LT |
65 | rwlock_t map_lock; |
66 | atomic_t holders; | |
67 | ||
68 | unsigned long flags; | |
69 | ||
70 | request_queue_t *queue; | |
71 | struct gendisk *disk; | |
72 | ||
73 | void *interface_ptr; | |
74 | ||
75 | /* | |
76 | * A list of ios that arrived while we were suspended. | |
77 | */ | |
78 | atomic_t pending; | |
79 | wait_queue_head_t wait; | |
80 | struct bio_list deferred; | |
81 | ||
82 | /* | |
83 | * The current mapping. | |
84 | */ | |
85 | struct dm_table *map; | |
86 | ||
87 | /* | |
88 | * io objects are allocated from here. | |
89 | */ | |
90 | mempool_t *io_pool; | |
91 | mempool_t *tio_pool; | |
92 | ||
93 | /* | |
94 | * Event handling. | |
95 | */ | |
96 | atomic_t event_nr; | |
97 | wait_queue_head_t eventq; | |
98 | ||
99 | /* | |
100 | * freeze/thaw support require holding onto a super block | |
101 | */ | |
102 | struct super_block *frozen_sb; | |
e39e2e95 | 103 | struct block_device *suspended_bdev; |
1da177e4 LT |
104 | }; |
105 | ||
106 | #define MIN_IOS 256 | |
107 | static kmem_cache_t *_io_cache; | |
108 | static kmem_cache_t *_tio_cache; | |
109 | ||
110 | static struct bio_set *dm_set; | |
111 | ||
112 | static int __init local_init(void) | |
113 | { | |
114 | int r; | |
115 | ||
116 | dm_set = bioset_create(16, 16, 4); | |
117 | if (!dm_set) | |
118 | return -ENOMEM; | |
119 | ||
120 | /* allocate a slab for the dm_ios */ | |
121 | _io_cache = kmem_cache_create("dm_io", | |
122 | sizeof(struct dm_io), 0, 0, NULL, NULL); | |
123 | if (!_io_cache) | |
124 | return -ENOMEM; | |
125 | ||
126 | /* allocate a slab for the target ios */ | |
127 | _tio_cache = kmem_cache_create("dm_tio", sizeof(struct target_io), | |
128 | 0, 0, NULL, NULL); | |
129 | if (!_tio_cache) { | |
130 | kmem_cache_destroy(_io_cache); | |
131 | return -ENOMEM; | |
132 | } | |
133 | ||
134 | _major = major; | |
135 | r = register_blkdev(_major, _name); | |
136 | if (r < 0) { | |
137 | kmem_cache_destroy(_tio_cache); | |
138 | kmem_cache_destroy(_io_cache); | |
139 | return r; | |
140 | } | |
141 | ||
142 | if (!_major) | |
143 | _major = r; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | static void local_exit(void) | |
149 | { | |
150 | kmem_cache_destroy(_tio_cache); | |
151 | kmem_cache_destroy(_io_cache); | |
152 | ||
153 | bioset_free(dm_set); | |
154 | ||
155 | if (unregister_blkdev(_major, _name) < 0) | |
156 | DMERR("devfs_unregister_blkdev failed"); | |
157 | ||
158 | _major = 0; | |
159 | ||
160 | DMINFO("cleaned up"); | |
161 | } | |
162 | ||
163 | int (*_inits[])(void) __initdata = { | |
164 | local_init, | |
165 | dm_target_init, | |
166 | dm_linear_init, | |
167 | dm_stripe_init, | |
168 | dm_interface_init, | |
169 | }; | |
170 | ||
171 | void (*_exits[])(void) = { | |
172 | local_exit, | |
173 | dm_target_exit, | |
174 | dm_linear_exit, | |
175 | dm_stripe_exit, | |
176 | dm_interface_exit, | |
177 | }; | |
178 | ||
179 | static int __init dm_init(void) | |
180 | { | |
181 | const int count = ARRAY_SIZE(_inits); | |
182 | ||
183 | int r, i; | |
184 | ||
185 | for (i = 0; i < count; i++) { | |
186 | r = _inits[i](); | |
187 | if (r) | |
188 | goto bad; | |
189 | } | |
190 | ||
191 | return 0; | |
192 | ||
193 | bad: | |
194 | while (i--) | |
195 | _exits[i](); | |
196 | ||
197 | return r; | |
198 | } | |
199 | ||
200 | static void __exit dm_exit(void) | |
201 | { | |
202 | int i = ARRAY_SIZE(_exits); | |
203 | ||
204 | while (i--) | |
205 | _exits[i](); | |
206 | } | |
207 | ||
208 | /* | |
209 | * Block device functions | |
210 | */ | |
211 | static int dm_blk_open(struct inode *inode, struct file *file) | |
212 | { | |
213 | struct mapped_device *md; | |
214 | ||
215 | md = inode->i_bdev->bd_disk->private_data; | |
216 | dm_get(md); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static int dm_blk_close(struct inode *inode, struct file *file) | |
221 | { | |
222 | struct mapped_device *md; | |
223 | ||
224 | md = inode->i_bdev->bd_disk->private_data; | |
225 | dm_put(md); | |
226 | return 0; | |
227 | } | |
228 | ||
229 | static inline struct dm_io *alloc_io(struct mapped_device *md) | |
230 | { | |
231 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
232 | } | |
233 | ||
234 | static inline void free_io(struct mapped_device *md, struct dm_io *io) | |
235 | { | |
236 | mempool_free(io, md->io_pool); | |
237 | } | |
238 | ||
239 | static inline struct target_io *alloc_tio(struct mapped_device *md) | |
240 | { | |
241 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
242 | } | |
243 | ||
244 | static inline void free_tio(struct mapped_device *md, struct target_io *tio) | |
245 | { | |
246 | mempool_free(tio, md->tio_pool); | |
247 | } | |
248 | ||
3eaf840e JNN |
249 | static void start_io_acct(struct dm_io *io) |
250 | { | |
251 | struct mapped_device *md = io->md; | |
252 | ||
253 | io->start_time = jiffies; | |
254 | ||
255 | preempt_disable(); | |
256 | disk_round_stats(dm_disk(md)); | |
257 | preempt_enable(); | |
258 | dm_disk(md)->in_flight = atomic_inc_return(&md->pending); | |
259 | } | |
260 | ||
261 | static int end_io_acct(struct dm_io *io) | |
262 | { | |
263 | struct mapped_device *md = io->md; | |
264 | struct bio *bio = io->bio; | |
265 | unsigned long duration = jiffies - io->start_time; | |
266 | int pending; | |
267 | int rw = bio_data_dir(bio); | |
268 | ||
269 | preempt_disable(); | |
270 | disk_round_stats(dm_disk(md)); | |
271 | preempt_enable(); | |
272 | dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending); | |
273 | ||
274 | disk_stat_add(dm_disk(md), ticks[rw], duration); | |
275 | ||
276 | return !pending; | |
277 | } | |
278 | ||
1da177e4 LT |
279 | /* |
280 | * Add the bio to the list of deferred io. | |
281 | */ | |
282 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
283 | { | |
2ca3310e | 284 | down_write(&md->io_lock); |
1da177e4 LT |
285 | |
286 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 287 | up_write(&md->io_lock); |
1da177e4 LT |
288 | return 1; |
289 | } | |
290 | ||
291 | bio_list_add(&md->deferred, bio); | |
292 | ||
2ca3310e | 293 | up_write(&md->io_lock); |
1da177e4 LT |
294 | return 0; /* deferred successfully */ |
295 | } | |
296 | ||
297 | /* | |
298 | * Everyone (including functions in this file), should use this | |
299 | * function to access the md->map field, and make sure they call | |
300 | * dm_table_put() when finished. | |
301 | */ | |
302 | struct dm_table *dm_get_table(struct mapped_device *md) | |
303 | { | |
304 | struct dm_table *t; | |
305 | ||
306 | read_lock(&md->map_lock); | |
307 | t = md->map; | |
308 | if (t) | |
309 | dm_table_get(t); | |
310 | read_unlock(&md->map_lock); | |
311 | ||
312 | return t; | |
313 | } | |
314 | ||
315 | /*----------------------------------------------------------------- | |
316 | * CRUD START: | |
317 | * A more elegant soln is in the works that uses the queue | |
318 | * merge fn, unfortunately there are a couple of changes to | |
319 | * the block layer that I want to make for this. So in the | |
320 | * interests of getting something for people to use I give | |
321 | * you this clearly demarcated crap. | |
322 | *---------------------------------------------------------------*/ | |
323 | ||
324 | /* | |
325 | * Decrements the number of outstanding ios that a bio has been | |
326 | * cloned into, completing the original io if necc. | |
327 | */ | |
858119e1 | 328 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 LT |
329 | { |
330 | if (error) | |
331 | io->error = error; | |
332 | ||
333 | if (atomic_dec_and_test(&io->io_count)) { | |
3eaf840e | 334 | if (end_io_acct(io)) |
1da177e4 LT |
335 | /* nudge anyone waiting on suspend queue */ |
336 | wake_up(&io->md->wait); | |
337 | ||
2056a782 JA |
338 | blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); |
339 | ||
1da177e4 LT |
340 | bio_endio(io->bio, io->bio->bi_size, io->error); |
341 | free_io(io->md, io); | |
342 | } | |
343 | } | |
344 | ||
345 | static int clone_endio(struct bio *bio, unsigned int done, int error) | |
346 | { | |
347 | int r = 0; | |
348 | struct target_io *tio = bio->bi_private; | |
349 | struct dm_io *io = tio->io; | |
350 | dm_endio_fn endio = tio->ti->type->end_io; | |
351 | ||
352 | if (bio->bi_size) | |
353 | return 1; | |
354 | ||
355 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) | |
356 | error = -EIO; | |
357 | ||
358 | if (endio) { | |
359 | r = endio(tio->ti, bio, error, &tio->info); | |
360 | if (r < 0) | |
361 | error = r; | |
362 | ||
363 | else if (r > 0) | |
364 | /* the target wants another shot at the io */ | |
365 | return 1; | |
366 | } | |
367 | ||
368 | free_tio(io->md, tio); | |
369 | dec_pending(io, error); | |
370 | bio_put(bio); | |
371 | return r; | |
372 | } | |
373 | ||
374 | static sector_t max_io_len(struct mapped_device *md, | |
375 | sector_t sector, struct dm_target *ti) | |
376 | { | |
377 | sector_t offset = sector - ti->begin; | |
378 | sector_t len = ti->len - offset; | |
379 | ||
380 | /* | |
381 | * Does the target need to split even further ? | |
382 | */ | |
383 | if (ti->split_io) { | |
384 | sector_t boundary; | |
385 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
386 | - offset; | |
387 | if (len > boundary) | |
388 | len = boundary; | |
389 | } | |
390 | ||
391 | return len; | |
392 | } | |
393 | ||
394 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
395 | struct target_io *tio) | |
396 | { | |
397 | int r; | |
2056a782 | 398 | sector_t sector; |
1da177e4 LT |
399 | |
400 | /* | |
401 | * Sanity checks. | |
402 | */ | |
403 | BUG_ON(!clone->bi_size); | |
404 | ||
405 | clone->bi_end_io = clone_endio; | |
406 | clone->bi_private = tio; | |
407 | ||
408 | /* | |
409 | * Map the clone. If r == 0 we don't need to do | |
410 | * anything, the target has assumed ownership of | |
411 | * this io. | |
412 | */ | |
413 | atomic_inc(&tio->io->io_count); | |
2056a782 | 414 | sector = clone->bi_sector; |
1da177e4 | 415 | r = ti->type->map(ti, clone, &tio->info); |
2056a782 | 416 | if (r > 0) { |
1da177e4 | 417 | /* the bio has been remapped so dispatch it */ |
2056a782 JA |
418 | |
419 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, | |
420 | tio->io->bio->bi_bdev->bd_dev, sector, | |
421 | clone->bi_sector); | |
422 | ||
1da177e4 | 423 | generic_make_request(clone); |
2056a782 | 424 | } |
1da177e4 LT |
425 | |
426 | else if (r < 0) { | |
427 | /* error the io and bail out */ | |
428 | struct dm_io *io = tio->io; | |
429 | free_tio(tio->io->md, tio); | |
f6a80ea8 | 430 | dec_pending(io, r); |
1da177e4 LT |
431 | bio_put(clone); |
432 | } | |
433 | } | |
434 | ||
435 | struct clone_info { | |
436 | struct mapped_device *md; | |
437 | struct dm_table *map; | |
438 | struct bio *bio; | |
439 | struct dm_io *io; | |
440 | sector_t sector; | |
441 | sector_t sector_count; | |
442 | unsigned short idx; | |
443 | }; | |
444 | ||
3676347a PO |
445 | static void dm_bio_destructor(struct bio *bio) |
446 | { | |
447 | bio_free(bio, dm_set); | |
448 | } | |
449 | ||
1da177e4 LT |
450 | /* |
451 | * Creates a little bio that is just does part of a bvec. | |
452 | */ | |
453 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
454 | unsigned short idx, unsigned int offset, | |
455 | unsigned int len) | |
456 | { | |
457 | struct bio *clone; | |
458 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
459 | ||
460 | clone = bio_alloc_bioset(GFP_NOIO, 1, dm_set); | |
3676347a | 461 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
462 | *clone->bi_io_vec = *bv; |
463 | ||
464 | clone->bi_sector = sector; | |
465 | clone->bi_bdev = bio->bi_bdev; | |
466 | clone->bi_rw = bio->bi_rw; | |
467 | clone->bi_vcnt = 1; | |
468 | clone->bi_size = to_bytes(len); | |
469 | clone->bi_io_vec->bv_offset = offset; | |
470 | clone->bi_io_vec->bv_len = clone->bi_size; | |
471 | ||
472 | return clone; | |
473 | } | |
474 | ||
475 | /* | |
476 | * Creates a bio that consists of range of complete bvecs. | |
477 | */ | |
478 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
479 | unsigned short idx, unsigned short bv_count, | |
480 | unsigned int len) | |
481 | { | |
482 | struct bio *clone; | |
483 | ||
484 | clone = bio_clone(bio, GFP_NOIO); | |
485 | clone->bi_sector = sector; | |
486 | clone->bi_idx = idx; | |
487 | clone->bi_vcnt = idx + bv_count; | |
488 | clone->bi_size = to_bytes(len); | |
489 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
490 | ||
491 | return clone; | |
492 | } | |
493 | ||
494 | static void __clone_and_map(struct clone_info *ci) | |
495 | { | |
496 | struct bio *clone, *bio = ci->bio; | |
497 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
498 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
499 | struct target_io *tio; | |
500 | ||
501 | /* | |
502 | * Allocate a target io object. | |
503 | */ | |
504 | tio = alloc_tio(ci->md); | |
505 | tio->io = ci->io; | |
506 | tio->ti = ti; | |
507 | memset(&tio->info, 0, sizeof(tio->info)); | |
508 | ||
509 | if (ci->sector_count <= max) { | |
510 | /* | |
511 | * Optimise for the simple case where we can do all of | |
512 | * the remaining io with a single clone. | |
513 | */ | |
514 | clone = clone_bio(bio, ci->sector, ci->idx, | |
515 | bio->bi_vcnt - ci->idx, ci->sector_count); | |
516 | __map_bio(ti, clone, tio); | |
517 | ci->sector_count = 0; | |
518 | ||
519 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
520 | /* | |
521 | * There are some bvecs that don't span targets. | |
522 | * Do as many of these as possible. | |
523 | */ | |
524 | int i; | |
525 | sector_t remaining = max; | |
526 | sector_t bv_len; | |
527 | ||
528 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
529 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
530 | ||
531 | if (bv_len > remaining) | |
532 | break; | |
533 | ||
534 | remaining -= bv_len; | |
535 | len += bv_len; | |
536 | } | |
537 | ||
538 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len); | |
539 | __map_bio(ti, clone, tio); | |
540 | ||
541 | ci->sector += len; | |
542 | ci->sector_count -= len; | |
543 | ci->idx = i; | |
544 | ||
545 | } else { | |
546 | /* | |
d2044a94 | 547 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
548 | */ |
549 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
550 | sector_t remaining = to_sector(bv->bv_len); |
551 | unsigned int offset = 0; | |
1da177e4 | 552 | |
d2044a94 AK |
553 | do { |
554 | if (offset) { | |
555 | ti = dm_table_find_target(ci->map, ci->sector); | |
556 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 557 | |
d2044a94 AK |
558 | tio = alloc_tio(ci->md); |
559 | tio->io = ci->io; | |
560 | tio->ti = ti; | |
561 | memset(&tio->info, 0, sizeof(tio->info)); | |
562 | } | |
563 | ||
564 | len = min(remaining, max); | |
565 | ||
566 | clone = split_bvec(bio, ci->sector, ci->idx, | |
567 | bv->bv_offset + offset, len); | |
568 | ||
569 | __map_bio(ti, clone, tio); | |
570 | ||
571 | ci->sector += len; | |
572 | ci->sector_count -= len; | |
573 | offset += to_bytes(len); | |
574 | } while (remaining -= len); | |
1da177e4 | 575 | |
1da177e4 LT |
576 | ci->idx++; |
577 | } | |
578 | } | |
579 | ||
580 | /* | |
581 | * Split the bio into several clones. | |
582 | */ | |
583 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
584 | { | |
585 | struct clone_info ci; | |
586 | ||
587 | ci.map = dm_get_table(md); | |
588 | if (!ci.map) { | |
589 | bio_io_error(bio, bio->bi_size); | |
590 | return; | |
591 | } | |
592 | ||
593 | ci.md = md; | |
594 | ci.bio = bio; | |
595 | ci.io = alloc_io(md); | |
596 | ci.io->error = 0; | |
597 | atomic_set(&ci.io->io_count, 1); | |
598 | ci.io->bio = bio; | |
599 | ci.io->md = md; | |
600 | ci.sector = bio->bi_sector; | |
601 | ci.sector_count = bio_sectors(bio); | |
602 | ci.idx = bio->bi_idx; | |
603 | ||
3eaf840e | 604 | start_io_acct(ci.io); |
1da177e4 LT |
605 | while (ci.sector_count) |
606 | __clone_and_map(&ci); | |
607 | ||
608 | /* drop the extra reference count */ | |
609 | dec_pending(ci.io, 0); | |
610 | dm_table_put(ci.map); | |
611 | } | |
612 | /*----------------------------------------------------------------- | |
613 | * CRUD END | |
614 | *---------------------------------------------------------------*/ | |
615 | ||
616 | /* | |
617 | * The request function that just remaps the bio built up by | |
618 | * dm_merge_bvec. | |
619 | */ | |
620 | static int dm_request(request_queue_t *q, struct bio *bio) | |
621 | { | |
622 | int r; | |
12f03a49 | 623 | int rw = bio_data_dir(bio); |
1da177e4 LT |
624 | struct mapped_device *md = q->queuedata; |
625 | ||
2ca3310e | 626 | down_read(&md->io_lock); |
1da177e4 | 627 | |
12f03a49 KC |
628 | disk_stat_inc(dm_disk(md), ios[rw]); |
629 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
630 | ||
1da177e4 LT |
631 | /* |
632 | * If we're suspended we have to queue | |
633 | * this io for later. | |
634 | */ | |
635 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 636 | up_read(&md->io_lock); |
1da177e4 LT |
637 | |
638 | if (bio_rw(bio) == READA) { | |
639 | bio_io_error(bio, bio->bi_size); | |
640 | return 0; | |
641 | } | |
642 | ||
643 | r = queue_io(md, bio); | |
644 | if (r < 0) { | |
645 | bio_io_error(bio, bio->bi_size); | |
646 | return 0; | |
647 | ||
648 | } else if (r == 0) | |
649 | return 0; /* deferred successfully */ | |
650 | ||
651 | /* | |
652 | * We're in a while loop, because someone could suspend | |
653 | * before we get to the following read lock. | |
654 | */ | |
2ca3310e | 655 | down_read(&md->io_lock); |
1da177e4 LT |
656 | } |
657 | ||
658 | __split_bio(md, bio); | |
2ca3310e | 659 | up_read(&md->io_lock); |
1da177e4 LT |
660 | return 0; |
661 | } | |
662 | ||
663 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
664 | sector_t *error_sector) | |
665 | { | |
666 | struct mapped_device *md = q->queuedata; | |
667 | struct dm_table *map = dm_get_table(md); | |
668 | int ret = -ENXIO; | |
669 | ||
670 | if (map) { | |
cf222b37 | 671 | ret = dm_table_flush_all(map); |
1da177e4 LT |
672 | dm_table_put(map); |
673 | } | |
674 | ||
675 | return ret; | |
676 | } | |
677 | ||
678 | static void dm_unplug_all(request_queue_t *q) | |
679 | { | |
680 | struct mapped_device *md = q->queuedata; | |
681 | struct dm_table *map = dm_get_table(md); | |
682 | ||
683 | if (map) { | |
684 | dm_table_unplug_all(map); | |
685 | dm_table_put(map); | |
686 | } | |
687 | } | |
688 | ||
689 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
690 | { | |
691 | int r; | |
692 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
693 | struct dm_table *map = dm_get_table(md); | |
694 | ||
695 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
696 | r = bdi_bits; | |
697 | else | |
698 | r = dm_table_any_congested(map, bdi_bits); | |
699 | ||
700 | dm_table_put(map); | |
701 | return r; | |
702 | } | |
703 | ||
704 | /*----------------------------------------------------------------- | |
705 | * An IDR is used to keep track of allocated minor numbers. | |
706 | *---------------------------------------------------------------*/ | |
707 | static DECLARE_MUTEX(_minor_lock); | |
708 | static DEFINE_IDR(_minor_idr); | |
709 | ||
710 | static void free_minor(unsigned int minor) | |
711 | { | |
712 | down(&_minor_lock); | |
713 | idr_remove(&_minor_idr, minor); | |
714 | up(&_minor_lock); | |
715 | } | |
716 | ||
717 | /* | |
718 | * See if the device with a specific minor # is free. | |
719 | */ | |
720 | static int specific_minor(struct mapped_device *md, unsigned int minor) | |
721 | { | |
722 | int r, m; | |
723 | ||
724 | if (minor >= (1 << MINORBITS)) | |
725 | return -EINVAL; | |
726 | ||
727 | down(&_minor_lock); | |
728 | ||
729 | if (idr_find(&_minor_idr, minor)) { | |
730 | r = -EBUSY; | |
731 | goto out; | |
732 | } | |
733 | ||
734 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); | |
735 | if (!r) { | |
736 | r = -ENOMEM; | |
737 | goto out; | |
738 | } | |
739 | ||
740 | r = idr_get_new_above(&_minor_idr, md, minor, &m); | |
741 | if (r) { | |
742 | goto out; | |
743 | } | |
744 | ||
745 | if (m != minor) { | |
746 | idr_remove(&_minor_idr, m); | |
747 | r = -EBUSY; | |
748 | goto out; | |
749 | } | |
750 | ||
751 | out: | |
752 | up(&_minor_lock); | |
753 | return r; | |
754 | } | |
755 | ||
756 | static int next_free_minor(struct mapped_device *md, unsigned int *minor) | |
757 | { | |
758 | int r; | |
759 | unsigned int m; | |
760 | ||
761 | down(&_minor_lock); | |
762 | ||
763 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); | |
764 | if (!r) { | |
765 | r = -ENOMEM; | |
766 | goto out; | |
767 | } | |
768 | ||
769 | r = idr_get_new(&_minor_idr, md, &m); | |
770 | if (r) { | |
771 | goto out; | |
772 | } | |
773 | ||
774 | if (m >= (1 << MINORBITS)) { | |
775 | idr_remove(&_minor_idr, m); | |
776 | r = -ENOSPC; | |
777 | goto out; | |
778 | } | |
779 | ||
780 | *minor = m; | |
781 | ||
782 | out: | |
783 | up(&_minor_lock); | |
784 | return r; | |
785 | } | |
786 | ||
787 | static struct block_device_operations dm_blk_dops; | |
788 | ||
789 | /* | |
790 | * Allocate and initialise a blank device with a given minor. | |
791 | */ | |
792 | static struct mapped_device *alloc_dev(unsigned int minor, int persistent) | |
793 | { | |
794 | int r; | |
795 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
796 | ||
797 | if (!md) { | |
798 | DMWARN("unable to allocate device, out of memory."); | |
799 | return NULL; | |
800 | } | |
801 | ||
802 | /* get a minor number for the dev */ | |
803 | r = persistent ? specific_minor(md, minor) : next_free_minor(md, &minor); | |
804 | if (r < 0) | |
805 | goto bad1; | |
806 | ||
807 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
808 | init_rwsem(&md->io_lock); |
809 | init_MUTEX(&md->suspend_lock); | |
1da177e4 LT |
810 | rwlock_init(&md->map_lock); |
811 | atomic_set(&md->holders, 1); | |
812 | atomic_set(&md->event_nr, 0); | |
813 | ||
814 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
815 | if (!md->queue) | |
816 | goto bad1; | |
817 | ||
818 | md->queue->queuedata = md; | |
819 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
820 | md->queue->backing_dev_info.congested_data = md; | |
821 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 822 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
823 | md->queue->unplug_fn = dm_unplug_all; |
824 | md->queue->issue_flush_fn = dm_flush_all; | |
825 | ||
93d2341c | 826 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
1da177e4 LT |
827 | if (!md->io_pool) |
828 | goto bad2; | |
829 | ||
93d2341c | 830 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
831 | if (!md->tio_pool) |
832 | goto bad3; | |
833 | ||
834 | md->disk = alloc_disk(1); | |
835 | if (!md->disk) | |
836 | goto bad4; | |
837 | ||
838 | md->disk->major = _major; | |
839 | md->disk->first_minor = minor; | |
840 | md->disk->fops = &dm_blk_dops; | |
841 | md->disk->queue = md->queue; | |
842 | md->disk->private_data = md; | |
843 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
844 | add_disk(md->disk); | |
845 | ||
846 | atomic_set(&md->pending, 0); | |
847 | init_waitqueue_head(&md->wait); | |
848 | init_waitqueue_head(&md->eventq); | |
849 | ||
850 | return md; | |
851 | ||
852 | bad4: | |
853 | mempool_destroy(md->tio_pool); | |
854 | bad3: | |
855 | mempool_destroy(md->io_pool); | |
856 | bad2: | |
1312f40e | 857 | blk_cleanup_queue(md->queue); |
1da177e4 LT |
858 | free_minor(minor); |
859 | bad1: | |
860 | kfree(md); | |
861 | return NULL; | |
862 | } | |
863 | ||
864 | static void free_dev(struct mapped_device *md) | |
865 | { | |
63d94e48 JN |
866 | unsigned int minor = md->disk->first_minor; |
867 | ||
d9dde59b JN |
868 | if (md->suspended_bdev) { |
869 | thaw_bdev(md->suspended_bdev, NULL); | |
870 | bdput(md->suspended_bdev); | |
871 | } | |
1da177e4 LT |
872 | mempool_destroy(md->tio_pool); |
873 | mempool_destroy(md->io_pool); | |
874 | del_gendisk(md->disk); | |
63d94e48 | 875 | free_minor(minor); |
1da177e4 | 876 | put_disk(md->disk); |
1312f40e | 877 | blk_cleanup_queue(md->queue); |
1da177e4 LT |
878 | kfree(md); |
879 | } | |
880 | ||
881 | /* | |
882 | * Bind a table to the device. | |
883 | */ | |
884 | static void event_callback(void *context) | |
885 | { | |
886 | struct mapped_device *md = (struct mapped_device *) context; | |
887 | ||
888 | atomic_inc(&md->event_nr); | |
889 | wake_up(&md->eventq); | |
890 | } | |
891 | ||
4e90188b | 892 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 893 | { |
4e90188b | 894 | set_capacity(md->disk, size); |
1da177e4 | 895 | |
1b1dcc1b | 896 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 897 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 898 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
899 | } |
900 | ||
901 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
902 | { | |
903 | request_queue_t *q = md->queue; | |
904 | sector_t size; | |
905 | ||
906 | size = dm_table_get_size(t); | |
4e90188b | 907 | __set_size(md, size); |
1da177e4 LT |
908 | if (size == 0) |
909 | return 0; | |
910 | ||
2ca3310e AK |
911 | dm_table_get(t); |
912 | dm_table_event_callback(t, event_callback, md); | |
913 | ||
1da177e4 LT |
914 | write_lock(&md->map_lock); |
915 | md->map = t; | |
2ca3310e | 916 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
917 | write_unlock(&md->map_lock); |
918 | ||
1da177e4 LT |
919 | return 0; |
920 | } | |
921 | ||
922 | static void __unbind(struct mapped_device *md) | |
923 | { | |
924 | struct dm_table *map = md->map; | |
925 | ||
926 | if (!map) | |
927 | return; | |
928 | ||
929 | dm_table_event_callback(map, NULL, NULL); | |
930 | write_lock(&md->map_lock); | |
931 | md->map = NULL; | |
932 | write_unlock(&md->map_lock); | |
933 | dm_table_put(map); | |
934 | } | |
935 | ||
936 | /* | |
937 | * Constructor for a new device. | |
938 | */ | |
939 | static int create_aux(unsigned int minor, int persistent, | |
940 | struct mapped_device **result) | |
941 | { | |
942 | struct mapped_device *md; | |
943 | ||
944 | md = alloc_dev(minor, persistent); | |
945 | if (!md) | |
946 | return -ENXIO; | |
947 | ||
948 | *result = md; | |
949 | return 0; | |
950 | } | |
951 | ||
952 | int dm_create(struct mapped_device **result) | |
953 | { | |
954 | return create_aux(0, 0, result); | |
955 | } | |
956 | ||
957 | int dm_create_with_minor(unsigned int minor, struct mapped_device **result) | |
958 | { | |
959 | return create_aux(minor, 1, result); | |
960 | } | |
961 | ||
637842cf | 962 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
963 | { |
964 | struct mapped_device *md; | |
1da177e4 LT |
965 | unsigned minor = MINOR(dev); |
966 | ||
967 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
968 | return NULL; | |
969 | ||
970 | down(&_minor_lock); | |
971 | ||
972 | md = idr_find(&_minor_idr, minor); | |
637842cf DT |
973 | if (!md || (dm_disk(md)->first_minor != minor)) |
974 | md = NULL; | |
1da177e4 LT |
975 | |
976 | up(&_minor_lock); | |
977 | ||
637842cf DT |
978 | return md; |
979 | } | |
980 | ||
d229a958 DT |
981 | struct mapped_device *dm_get_md(dev_t dev) |
982 | { | |
983 | struct mapped_device *md = dm_find_md(dev); | |
984 | ||
985 | if (md) | |
986 | dm_get(md); | |
987 | ||
988 | return md; | |
989 | } | |
990 | ||
637842cf DT |
991 | void *dm_get_mdptr(dev_t dev) |
992 | { | |
993 | struct mapped_device *md; | |
994 | void *mdptr = NULL; | |
995 | ||
996 | md = dm_find_md(dev); | |
997 | if (md) | |
998 | mdptr = md->interface_ptr; | |
1da177e4 LT |
999 | return mdptr; |
1000 | } | |
1001 | ||
1002 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1003 | { | |
1004 | md->interface_ptr = ptr; | |
1005 | } | |
1006 | ||
1007 | void dm_get(struct mapped_device *md) | |
1008 | { | |
1009 | atomic_inc(&md->holders); | |
1010 | } | |
1011 | ||
1012 | void dm_put(struct mapped_device *md) | |
1013 | { | |
1014 | struct dm_table *map = dm_get_table(md); | |
1015 | ||
1016 | if (atomic_dec_and_test(&md->holders)) { | |
cf222b37 | 1017 | if (!dm_suspended(md)) { |
1da177e4 LT |
1018 | dm_table_presuspend_targets(map); |
1019 | dm_table_postsuspend_targets(map); | |
1020 | } | |
1021 | __unbind(md); | |
1022 | free_dev(md); | |
1023 | } | |
1024 | ||
1025 | dm_table_put(map); | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * Process the deferred bios | |
1030 | */ | |
1031 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1032 | { | |
1033 | struct bio *n; | |
1034 | ||
1035 | while (c) { | |
1036 | n = c->bi_next; | |
1037 | c->bi_next = NULL; | |
1038 | __split_bio(md, c); | |
1039 | c = n; | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | /* | |
1044 | * Swap in a new table (destroying old one). | |
1045 | */ | |
1046 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1047 | { | |
93c534ae | 1048 | int r = -EINVAL; |
1da177e4 | 1049 | |
2ca3310e | 1050 | down(&md->suspend_lock); |
1da177e4 LT |
1051 | |
1052 | /* device must be suspended */ | |
cf222b37 | 1053 | if (!dm_suspended(md)) |
93c534ae | 1054 | goto out; |
1da177e4 LT |
1055 | |
1056 | __unbind(md); | |
1057 | r = __bind(md, table); | |
1da177e4 | 1058 | |
93c534ae | 1059 | out: |
2ca3310e | 1060 | up(&md->suspend_lock); |
93c534ae | 1061 | return r; |
1da177e4 LT |
1062 | } |
1063 | ||
1064 | /* | |
1065 | * Functions to lock and unlock any filesystem running on the | |
1066 | * device. | |
1067 | */ | |
2ca3310e | 1068 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1069 | { |
e39e2e95 | 1070 | int r; |
1da177e4 LT |
1071 | |
1072 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1073 | |
e39e2e95 | 1074 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1075 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1076 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1077 | md->frozen_sb = NULL; |
1078 | return r; | |
dfbe03f6 AK |
1079 | } |
1080 | ||
aa8d7c2f AK |
1081 | set_bit(DMF_FROZEN, &md->flags); |
1082 | ||
1da177e4 | 1083 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1084 | * to go away while it is locked. |
1da177e4 LT |
1085 | */ |
1086 | return 0; | |
1087 | } | |
1088 | ||
2ca3310e | 1089 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1090 | { |
aa8d7c2f AK |
1091 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1092 | return; | |
1093 | ||
e39e2e95 | 1094 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1095 | md->frozen_sb = NULL; |
aa8d7c2f | 1096 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | /* | |
1100 | * We need to be able to change a mapping table under a mounted | |
1101 | * filesystem. For example we might want to move some data in | |
1102 | * the background. Before the table can be swapped with | |
1103 | * dm_bind_table, dm_suspend must be called to flush any in | |
1104 | * flight bios and ensure that any further io gets deferred. | |
1105 | */ | |
aa8d7c2f | 1106 | int dm_suspend(struct mapped_device *md, int do_lockfs) |
1da177e4 | 1107 | { |
2ca3310e | 1108 | struct dm_table *map = NULL; |
1da177e4 | 1109 | DECLARE_WAITQUEUE(wait, current); |
cf222b37 | 1110 | int r = -EINVAL; |
1da177e4 | 1111 | |
2ca3310e AK |
1112 | down(&md->suspend_lock); |
1113 | ||
1114 | if (dm_suspended(md)) | |
1115 | goto out; | |
1da177e4 LT |
1116 | |
1117 | map = dm_get_table(md); | |
1da177e4 | 1118 | |
cf222b37 AK |
1119 | /* This does not get reverted if there's an error later. */ |
1120 | dm_table_presuspend_targets(map); | |
1121 | ||
e39e2e95 AK |
1122 | md->suspended_bdev = bdget_disk(md->disk, 0); |
1123 | if (!md->suspended_bdev) { | |
1124 | DMWARN("bdget failed in dm_suspend"); | |
1125 | r = -ENOMEM; | |
1126 | goto out; | |
1127 | } | |
1128 | ||
cf222b37 | 1129 | /* Flush I/O to the device. */ |
aa8d7c2f AK |
1130 | if (do_lockfs) { |
1131 | r = lock_fs(md); | |
1132 | if (r) | |
1133 | goto out; | |
1134 | } | |
1da177e4 LT |
1135 | |
1136 | /* | |
354e0071 | 1137 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1138 | */ |
2ca3310e AK |
1139 | down_write(&md->io_lock); |
1140 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1141 | |
1da177e4 | 1142 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1143 | up_write(&md->io_lock); |
1da177e4 LT |
1144 | |
1145 | /* unplug */ | |
2ca3310e | 1146 | if (map) |
1da177e4 | 1147 | dm_table_unplug_all(map); |
1da177e4 LT |
1148 | |
1149 | /* | |
1150 | * Then we wait for the already mapped ios to | |
1151 | * complete. | |
1152 | */ | |
1153 | while (1) { | |
1154 | set_current_state(TASK_INTERRUPTIBLE); | |
1155 | ||
1156 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1157 | break; | |
1158 | ||
1159 | io_schedule(); | |
1160 | } | |
1161 | set_current_state(TASK_RUNNING); | |
1162 | ||
2ca3310e | 1163 | down_write(&md->io_lock); |
1da177e4 LT |
1164 | remove_wait_queue(&md->wait, &wait); |
1165 | ||
1166 | /* were we interrupted ? */ | |
cf222b37 | 1167 | r = -EINTR; |
2ca3310e AK |
1168 | if (atomic_read(&md->pending)) { |
1169 | up_write(&md->io_lock); | |
1170 | unlock_fs(md); | |
1171 | clear_bit(DMF_BLOCK_IO, &md->flags); | |
1172 | goto out; | |
1173 | } | |
1174 | up_write(&md->io_lock); | |
1da177e4 | 1175 | |
cf222b37 | 1176 | dm_table_postsuspend_targets(map); |
1da177e4 | 1177 | |
2ca3310e | 1178 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1179 | |
2ca3310e | 1180 | r = 0; |
b84b0287 | 1181 | |
2ca3310e | 1182 | out: |
e39e2e95 AK |
1183 | if (r && md->suspended_bdev) { |
1184 | bdput(md->suspended_bdev); | |
1185 | md->suspended_bdev = NULL; | |
1186 | } | |
1187 | ||
2ca3310e AK |
1188 | dm_table_put(map); |
1189 | up(&md->suspend_lock); | |
cf222b37 | 1190 | return r; |
1da177e4 LT |
1191 | } |
1192 | ||
1193 | int dm_resume(struct mapped_device *md) | |
1194 | { | |
cf222b37 | 1195 | int r = -EINVAL; |
1da177e4 | 1196 | struct bio *def; |
cf222b37 | 1197 | struct dm_table *map = NULL; |
1da177e4 | 1198 | |
2ca3310e AK |
1199 | down(&md->suspend_lock); |
1200 | if (!dm_suspended(md)) | |
cf222b37 | 1201 | goto out; |
cf222b37 AK |
1202 | |
1203 | map = dm_get_table(md); | |
2ca3310e | 1204 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1205 | goto out; |
1da177e4 LT |
1206 | |
1207 | dm_table_resume_targets(map); | |
2ca3310e AK |
1208 | |
1209 | down_write(&md->io_lock); | |
1da177e4 LT |
1210 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1211 | ||
1212 | def = bio_list_get(&md->deferred); | |
1213 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1214 | up_write(&md->io_lock); |
1215 | ||
1216 | unlock_fs(md); | |
1217 | ||
e39e2e95 AK |
1218 | bdput(md->suspended_bdev); |
1219 | md->suspended_bdev = NULL; | |
1220 | ||
2ca3310e AK |
1221 | clear_bit(DMF_SUSPENDED, &md->flags); |
1222 | ||
1da177e4 | 1223 | dm_table_unplug_all(map); |
1da177e4 | 1224 | |
cf222b37 | 1225 | r = 0; |
2ca3310e | 1226 | |
cf222b37 AK |
1227 | out: |
1228 | dm_table_put(map); | |
2ca3310e AK |
1229 | up(&md->suspend_lock); |
1230 | ||
cf222b37 | 1231 | return r; |
1da177e4 LT |
1232 | } |
1233 | ||
1234 | /*----------------------------------------------------------------- | |
1235 | * Event notification. | |
1236 | *---------------------------------------------------------------*/ | |
1237 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1238 | { | |
1239 | return atomic_read(&md->event_nr); | |
1240 | } | |
1241 | ||
1242 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1243 | { | |
1244 | return wait_event_interruptible(md->eventq, | |
1245 | (event_nr != atomic_read(&md->event_nr))); | |
1246 | } | |
1247 | ||
1248 | /* | |
1249 | * The gendisk is only valid as long as you have a reference | |
1250 | * count on 'md'. | |
1251 | */ | |
1252 | struct gendisk *dm_disk(struct mapped_device *md) | |
1253 | { | |
1254 | return md->disk; | |
1255 | } | |
1256 | ||
1257 | int dm_suspended(struct mapped_device *md) | |
1258 | { | |
1259 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1260 | } | |
1261 | ||
1262 | static struct block_device_operations dm_blk_dops = { | |
1263 | .open = dm_blk_open, | |
1264 | .release = dm_blk_close, | |
1265 | .owner = THIS_MODULE | |
1266 | }; | |
1267 | ||
1268 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1269 | ||
1270 | /* | |
1271 | * module hooks | |
1272 | */ | |
1273 | module_init(dm_init); | |
1274 | module_exit(dm_exit); | |
1275 | ||
1276 | module_param(major, uint, 0); | |
1277 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1278 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1279 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1280 | MODULE_LICENSE("GPL"); |