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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. | |
2b06cfff | 3 | * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
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> | |
48c9c27b | 13 | #include <linux/mutex.h> |
1da177e4 LT |
14 | #include <linux/moduleparam.h> |
15 | #include <linux/blkpg.h> | |
16 | #include <linux/bio.h> | |
17 | #include <linux/buffer_head.h> | |
18 | #include <linux/mempool.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/idr.h> | |
3ac51e74 | 21 | #include <linux/hdreg.h> |
2056a782 | 22 | #include <linux/blktrace_api.h> |
1da177e4 LT |
23 | |
24 | static const char *_name = DM_NAME; | |
25 | ||
26 | static unsigned int major = 0; | |
27 | static unsigned int _major = 0; | |
28 | ||
f32c10b0 | 29 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 LT |
30 | /* |
31 | * One of these is allocated per bio. | |
32 | */ | |
33 | struct dm_io { | |
34 | struct mapped_device *md; | |
35 | int error; | |
36 | struct bio *bio; | |
37 | atomic_t io_count; | |
3eaf840e | 38 | unsigned long start_time; |
1da177e4 LT |
39 | }; |
40 | ||
41 | /* | |
42 | * One of these is allocated per target within a bio. Hopefully | |
43 | * this will be simplified out one day. | |
44 | */ | |
45 | struct target_io { | |
46 | struct dm_io *io; | |
47 | struct dm_target *ti; | |
48 | union map_info info; | |
49 | }; | |
50 | ||
51 | union map_info *dm_get_mapinfo(struct bio *bio) | |
52 | { | |
17b2f66f AK |
53 | if (bio && bio->bi_private) |
54 | return &((struct target_io *)bio->bi_private)->info; | |
55 | return NULL; | |
1da177e4 LT |
56 | } |
57 | ||
ba61fdd1 JM |
58 | #define MINOR_ALLOCED ((void *)-1) |
59 | ||
1da177e4 LT |
60 | /* |
61 | * Bits for the md->flags field. | |
62 | */ | |
63 | #define DMF_BLOCK_IO 0 | |
64 | #define DMF_SUSPENDED 1 | |
aa8d7c2f | 65 | #define DMF_FROZEN 2 |
fba9f90e | 66 | #define DMF_FREEING 3 |
1da177e4 LT |
67 | |
68 | struct mapped_device { | |
2ca3310e AK |
69 | struct rw_semaphore io_lock; |
70 | struct semaphore suspend_lock; | |
1da177e4 LT |
71 | rwlock_t map_lock; |
72 | atomic_t holders; | |
73 | ||
74 | unsigned long flags; | |
75 | ||
76 | request_queue_t *queue; | |
77 | struct gendisk *disk; | |
7e51f257 | 78 | char name[16]; |
1da177e4 LT |
79 | |
80 | void *interface_ptr; | |
81 | ||
82 | /* | |
83 | * A list of ios that arrived while we were suspended. | |
84 | */ | |
85 | atomic_t pending; | |
86 | wait_queue_head_t wait; | |
87 | struct bio_list deferred; | |
88 | ||
89 | /* | |
90 | * The current mapping. | |
91 | */ | |
92 | struct dm_table *map; | |
93 | ||
94 | /* | |
95 | * io objects are allocated from here. | |
96 | */ | |
97 | mempool_t *io_pool; | |
98 | mempool_t *tio_pool; | |
99 | ||
100 | /* | |
101 | * Event handling. | |
102 | */ | |
103 | atomic_t event_nr; | |
104 | wait_queue_head_t eventq; | |
105 | ||
106 | /* | |
107 | * freeze/thaw support require holding onto a super block | |
108 | */ | |
109 | struct super_block *frozen_sb; | |
e39e2e95 | 110 | struct block_device *suspended_bdev; |
3ac51e74 DW |
111 | |
112 | /* forced geometry settings */ | |
113 | struct hd_geometry geometry; | |
1da177e4 LT |
114 | }; |
115 | ||
116 | #define MIN_IOS 256 | |
117 | static kmem_cache_t *_io_cache; | |
118 | static kmem_cache_t *_tio_cache; | |
119 | ||
120 | static struct bio_set *dm_set; | |
121 | ||
122 | static int __init local_init(void) | |
123 | { | |
124 | int r; | |
125 | ||
126 | dm_set = bioset_create(16, 16, 4); | |
127 | if (!dm_set) | |
128 | return -ENOMEM; | |
129 | ||
130 | /* allocate a slab for the dm_ios */ | |
131 | _io_cache = kmem_cache_create("dm_io", | |
132 | sizeof(struct dm_io), 0, 0, NULL, NULL); | |
133 | if (!_io_cache) | |
134 | return -ENOMEM; | |
135 | ||
136 | /* allocate a slab for the target ios */ | |
137 | _tio_cache = kmem_cache_create("dm_tio", sizeof(struct target_io), | |
138 | 0, 0, NULL, NULL); | |
139 | if (!_tio_cache) { | |
140 | kmem_cache_destroy(_io_cache); | |
141 | return -ENOMEM; | |
142 | } | |
143 | ||
144 | _major = major; | |
145 | r = register_blkdev(_major, _name); | |
146 | if (r < 0) { | |
147 | kmem_cache_destroy(_tio_cache); | |
148 | kmem_cache_destroy(_io_cache); | |
149 | return r; | |
150 | } | |
151 | ||
152 | if (!_major) | |
153 | _major = r; | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static void local_exit(void) | |
159 | { | |
160 | kmem_cache_destroy(_tio_cache); | |
161 | kmem_cache_destroy(_io_cache); | |
162 | ||
163 | bioset_free(dm_set); | |
164 | ||
165 | if (unregister_blkdev(_major, _name) < 0) | |
166 | DMERR("devfs_unregister_blkdev failed"); | |
167 | ||
168 | _major = 0; | |
169 | ||
170 | DMINFO("cleaned up"); | |
171 | } | |
172 | ||
173 | int (*_inits[])(void) __initdata = { | |
174 | local_init, | |
175 | dm_target_init, | |
176 | dm_linear_init, | |
177 | dm_stripe_init, | |
178 | dm_interface_init, | |
179 | }; | |
180 | ||
181 | void (*_exits[])(void) = { | |
182 | local_exit, | |
183 | dm_target_exit, | |
184 | dm_linear_exit, | |
185 | dm_stripe_exit, | |
186 | dm_interface_exit, | |
187 | }; | |
188 | ||
189 | static int __init dm_init(void) | |
190 | { | |
191 | const int count = ARRAY_SIZE(_inits); | |
192 | ||
193 | int r, i; | |
194 | ||
195 | for (i = 0; i < count; i++) { | |
196 | r = _inits[i](); | |
197 | if (r) | |
198 | goto bad; | |
199 | } | |
200 | ||
201 | return 0; | |
202 | ||
203 | bad: | |
204 | while (i--) | |
205 | _exits[i](); | |
206 | ||
207 | return r; | |
208 | } | |
209 | ||
210 | static void __exit dm_exit(void) | |
211 | { | |
212 | int i = ARRAY_SIZE(_exits); | |
213 | ||
214 | while (i--) | |
215 | _exits[i](); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Block device functions | |
220 | */ | |
221 | static int dm_blk_open(struct inode *inode, struct file *file) | |
222 | { | |
223 | struct mapped_device *md; | |
224 | ||
fba9f90e JM |
225 | spin_lock(&_minor_lock); |
226 | ||
1da177e4 | 227 | md = inode->i_bdev->bd_disk->private_data; |
fba9f90e JM |
228 | if (!md) |
229 | goto out; | |
230 | ||
231 | if (test_bit(DMF_FREEING, &md->flags)) { | |
232 | md = NULL; | |
233 | goto out; | |
234 | } | |
235 | ||
1da177e4 | 236 | dm_get(md); |
fba9f90e JM |
237 | |
238 | out: | |
239 | spin_unlock(&_minor_lock); | |
240 | ||
241 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
242 | } |
243 | ||
244 | static int dm_blk_close(struct inode *inode, struct file *file) | |
245 | { | |
246 | struct mapped_device *md; | |
247 | ||
248 | md = inode->i_bdev->bd_disk->private_data; | |
249 | dm_put(md); | |
250 | return 0; | |
251 | } | |
252 | ||
3ac51e74 DW |
253 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
254 | { | |
255 | struct mapped_device *md = bdev->bd_disk->private_data; | |
256 | ||
257 | return dm_get_geometry(md, geo); | |
258 | } | |
259 | ||
1da177e4 LT |
260 | static inline struct dm_io *alloc_io(struct mapped_device *md) |
261 | { | |
262 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
263 | } | |
264 | ||
265 | static inline void free_io(struct mapped_device *md, struct dm_io *io) | |
266 | { | |
267 | mempool_free(io, md->io_pool); | |
268 | } | |
269 | ||
270 | static inline struct target_io *alloc_tio(struct mapped_device *md) | |
271 | { | |
272 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
273 | } | |
274 | ||
275 | static inline void free_tio(struct mapped_device *md, struct target_io *tio) | |
276 | { | |
277 | mempool_free(tio, md->tio_pool); | |
278 | } | |
279 | ||
3eaf840e JNN |
280 | static void start_io_acct(struct dm_io *io) |
281 | { | |
282 | struct mapped_device *md = io->md; | |
283 | ||
284 | io->start_time = jiffies; | |
285 | ||
286 | preempt_disable(); | |
287 | disk_round_stats(dm_disk(md)); | |
288 | preempt_enable(); | |
289 | dm_disk(md)->in_flight = atomic_inc_return(&md->pending); | |
290 | } | |
291 | ||
292 | static int end_io_acct(struct dm_io *io) | |
293 | { | |
294 | struct mapped_device *md = io->md; | |
295 | struct bio *bio = io->bio; | |
296 | unsigned long duration = jiffies - io->start_time; | |
297 | int pending; | |
298 | int rw = bio_data_dir(bio); | |
299 | ||
300 | preempt_disable(); | |
301 | disk_round_stats(dm_disk(md)); | |
302 | preempt_enable(); | |
303 | dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending); | |
304 | ||
305 | disk_stat_add(dm_disk(md), ticks[rw], duration); | |
306 | ||
307 | return !pending; | |
308 | } | |
309 | ||
1da177e4 LT |
310 | /* |
311 | * Add the bio to the list of deferred io. | |
312 | */ | |
313 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
314 | { | |
2ca3310e | 315 | down_write(&md->io_lock); |
1da177e4 LT |
316 | |
317 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 318 | up_write(&md->io_lock); |
1da177e4 LT |
319 | return 1; |
320 | } | |
321 | ||
322 | bio_list_add(&md->deferred, bio); | |
323 | ||
2ca3310e | 324 | up_write(&md->io_lock); |
1da177e4 LT |
325 | return 0; /* deferred successfully */ |
326 | } | |
327 | ||
328 | /* | |
329 | * Everyone (including functions in this file), should use this | |
330 | * function to access the md->map field, and make sure they call | |
331 | * dm_table_put() when finished. | |
332 | */ | |
333 | struct dm_table *dm_get_table(struct mapped_device *md) | |
334 | { | |
335 | struct dm_table *t; | |
336 | ||
337 | read_lock(&md->map_lock); | |
338 | t = md->map; | |
339 | if (t) | |
340 | dm_table_get(t); | |
341 | read_unlock(&md->map_lock); | |
342 | ||
343 | return t; | |
344 | } | |
345 | ||
3ac51e74 DW |
346 | /* |
347 | * Get the geometry associated with a dm device | |
348 | */ | |
349 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
350 | { | |
351 | *geo = md->geometry; | |
352 | ||
353 | return 0; | |
354 | } | |
355 | ||
356 | /* | |
357 | * Set the geometry of a device. | |
358 | */ | |
359 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
360 | { | |
361 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
362 | ||
363 | if (geo->start > sz) { | |
364 | DMWARN("Start sector is beyond the geometry limits."); | |
365 | return -EINVAL; | |
366 | } | |
367 | ||
368 | md->geometry = *geo; | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
1da177e4 LT |
373 | /*----------------------------------------------------------------- |
374 | * CRUD START: | |
375 | * A more elegant soln is in the works that uses the queue | |
376 | * merge fn, unfortunately there are a couple of changes to | |
377 | * the block layer that I want to make for this. So in the | |
378 | * interests of getting something for people to use I give | |
379 | * you this clearly demarcated crap. | |
380 | *---------------------------------------------------------------*/ | |
381 | ||
382 | /* | |
383 | * Decrements the number of outstanding ios that a bio has been | |
384 | * cloned into, completing the original io if necc. | |
385 | */ | |
858119e1 | 386 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 LT |
387 | { |
388 | if (error) | |
389 | io->error = error; | |
390 | ||
391 | if (atomic_dec_and_test(&io->io_count)) { | |
3eaf840e | 392 | if (end_io_acct(io)) |
1da177e4 LT |
393 | /* nudge anyone waiting on suspend queue */ |
394 | wake_up(&io->md->wait); | |
395 | ||
2056a782 JA |
396 | blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); |
397 | ||
1da177e4 LT |
398 | bio_endio(io->bio, io->bio->bi_size, io->error); |
399 | free_io(io->md, io); | |
400 | } | |
401 | } | |
402 | ||
403 | static int clone_endio(struct bio *bio, unsigned int done, int error) | |
404 | { | |
405 | int r = 0; | |
406 | struct target_io *tio = bio->bi_private; | |
407 | struct dm_io *io = tio->io; | |
408 | dm_endio_fn endio = tio->ti->type->end_io; | |
409 | ||
410 | if (bio->bi_size) | |
411 | return 1; | |
412 | ||
413 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) | |
414 | error = -EIO; | |
415 | ||
416 | if (endio) { | |
417 | r = endio(tio->ti, bio, error, &tio->info); | |
418 | if (r < 0) | |
419 | error = r; | |
420 | ||
421 | else if (r > 0) | |
422 | /* the target wants another shot at the io */ | |
423 | return 1; | |
424 | } | |
425 | ||
426 | free_tio(io->md, tio); | |
427 | dec_pending(io, error); | |
428 | bio_put(bio); | |
429 | return r; | |
430 | } | |
431 | ||
432 | static sector_t max_io_len(struct mapped_device *md, | |
433 | sector_t sector, struct dm_target *ti) | |
434 | { | |
435 | sector_t offset = sector - ti->begin; | |
436 | sector_t len = ti->len - offset; | |
437 | ||
438 | /* | |
439 | * Does the target need to split even further ? | |
440 | */ | |
441 | if (ti->split_io) { | |
442 | sector_t boundary; | |
443 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
444 | - offset; | |
445 | if (len > boundary) | |
446 | len = boundary; | |
447 | } | |
448 | ||
449 | return len; | |
450 | } | |
451 | ||
452 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
453 | struct target_io *tio) | |
454 | { | |
455 | int r; | |
2056a782 | 456 | sector_t sector; |
1da177e4 LT |
457 | |
458 | /* | |
459 | * Sanity checks. | |
460 | */ | |
461 | BUG_ON(!clone->bi_size); | |
462 | ||
463 | clone->bi_end_io = clone_endio; | |
464 | clone->bi_private = tio; | |
465 | ||
466 | /* | |
467 | * Map the clone. If r == 0 we don't need to do | |
468 | * anything, the target has assumed ownership of | |
469 | * this io. | |
470 | */ | |
471 | atomic_inc(&tio->io->io_count); | |
2056a782 | 472 | sector = clone->bi_sector; |
1da177e4 | 473 | r = ti->type->map(ti, clone, &tio->info); |
2056a782 | 474 | if (r > 0) { |
1da177e4 | 475 | /* the bio has been remapped so dispatch it */ |
2056a782 | 476 | |
17b2f66f AK |
477 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, |
478 | tio->io->bio->bi_bdev->bd_dev, sector, | |
2056a782 JA |
479 | clone->bi_sector); |
480 | ||
1da177e4 | 481 | generic_make_request(clone); |
2056a782 | 482 | } |
1da177e4 LT |
483 | |
484 | else if (r < 0) { | |
485 | /* error the io and bail out */ | |
486 | struct dm_io *io = tio->io; | |
487 | free_tio(tio->io->md, tio); | |
f6a80ea8 | 488 | dec_pending(io, r); |
1da177e4 LT |
489 | bio_put(clone); |
490 | } | |
491 | } | |
492 | ||
493 | struct clone_info { | |
494 | struct mapped_device *md; | |
495 | struct dm_table *map; | |
496 | struct bio *bio; | |
497 | struct dm_io *io; | |
498 | sector_t sector; | |
499 | sector_t sector_count; | |
500 | unsigned short idx; | |
501 | }; | |
502 | ||
3676347a PO |
503 | static void dm_bio_destructor(struct bio *bio) |
504 | { | |
505 | bio_free(bio, dm_set); | |
506 | } | |
507 | ||
1da177e4 LT |
508 | /* |
509 | * Creates a little bio that is just does part of a bvec. | |
510 | */ | |
511 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
512 | unsigned short idx, unsigned int offset, | |
513 | unsigned int len) | |
514 | { | |
515 | struct bio *clone; | |
516 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
517 | ||
518 | clone = bio_alloc_bioset(GFP_NOIO, 1, dm_set); | |
3676347a | 519 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
520 | *clone->bi_io_vec = *bv; |
521 | ||
522 | clone->bi_sector = sector; | |
523 | clone->bi_bdev = bio->bi_bdev; | |
524 | clone->bi_rw = bio->bi_rw; | |
525 | clone->bi_vcnt = 1; | |
526 | clone->bi_size = to_bytes(len); | |
527 | clone->bi_io_vec->bv_offset = offset; | |
528 | clone->bi_io_vec->bv_len = clone->bi_size; | |
529 | ||
530 | return clone; | |
531 | } | |
532 | ||
533 | /* | |
534 | * Creates a bio that consists of range of complete bvecs. | |
535 | */ | |
536 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
537 | unsigned short idx, unsigned short bv_count, | |
538 | unsigned int len) | |
539 | { | |
540 | struct bio *clone; | |
541 | ||
542 | clone = bio_clone(bio, GFP_NOIO); | |
543 | clone->bi_sector = sector; | |
544 | clone->bi_idx = idx; | |
545 | clone->bi_vcnt = idx + bv_count; | |
546 | clone->bi_size = to_bytes(len); | |
547 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
548 | ||
549 | return clone; | |
550 | } | |
551 | ||
552 | static void __clone_and_map(struct clone_info *ci) | |
553 | { | |
554 | struct bio *clone, *bio = ci->bio; | |
555 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
556 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
557 | struct target_io *tio; | |
558 | ||
559 | /* | |
560 | * Allocate a target io object. | |
561 | */ | |
562 | tio = alloc_tio(ci->md); | |
563 | tio->io = ci->io; | |
564 | tio->ti = ti; | |
565 | memset(&tio->info, 0, sizeof(tio->info)); | |
566 | ||
567 | if (ci->sector_count <= max) { | |
568 | /* | |
569 | * Optimise for the simple case where we can do all of | |
570 | * the remaining io with a single clone. | |
571 | */ | |
572 | clone = clone_bio(bio, ci->sector, ci->idx, | |
573 | bio->bi_vcnt - ci->idx, ci->sector_count); | |
574 | __map_bio(ti, clone, tio); | |
575 | ci->sector_count = 0; | |
576 | ||
577 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
578 | /* | |
579 | * There are some bvecs that don't span targets. | |
580 | * Do as many of these as possible. | |
581 | */ | |
582 | int i; | |
583 | sector_t remaining = max; | |
584 | sector_t bv_len; | |
585 | ||
586 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
587 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
588 | ||
589 | if (bv_len > remaining) | |
590 | break; | |
591 | ||
592 | remaining -= bv_len; | |
593 | len += bv_len; | |
594 | } | |
595 | ||
596 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len); | |
597 | __map_bio(ti, clone, tio); | |
598 | ||
599 | ci->sector += len; | |
600 | ci->sector_count -= len; | |
601 | ci->idx = i; | |
602 | ||
603 | } else { | |
604 | /* | |
d2044a94 | 605 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
606 | */ |
607 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
608 | sector_t remaining = to_sector(bv->bv_len); |
609 | unsigned int offset = 0; | |
1da177e4 | 610 | |
d2044a94 AK |
611 | do { |
612 | if (offset) { | |
613 | ti = dm_table_find_target(ci->map, ci->sector); | |
614 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 615 | |
d2044a94 AK |
616 | tio = alloc_tio(ci->md); |
617 | tio->io = ci->io; | |
618 | tio->ti = ti; | |
619 | memset(&tio->info, 0, sizeof(tio->info)); | |
620 | } | |
621 | ||
622 | len = min(remaining, max); | |
623 | ||
624 | clone = split_bvec(bio, ci->sector, ci->idx, | |
625 | bv->bv_offset + offset, len); | |
626 | ||
627 | __map_bio(ti, clone, tio); | |
628 | ||
629 | ci->sector += len; | |
630 | ci->sector_count -= len; | |
631 | offset += to_bytes(len); | |
632 | } while (remaining -= len); | |
1da177e4 | 633 | |
1da177e4 LT |
634 | ci->idx++; |
635 | } | |
636 | } | |
637 | ||
638 | /* | |
639 | * Split the bio into several clones. | |
640 | */ | |
641 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
642 | { | |
643 | struct clone_info ci; | |
644 | ||
645 | ci.map = dm_get_table(md); | |
646 | if (!ci.map) { | |
647 | bio_io_error(bio, bio->bi_size); | |
648 | return; | |
649 | } | |
650 | ||
651 | ci.md = md; | |
652 | ci.bio = bio; | |
653 | ci.io = alloc_io(md); | |
654 | ci.io->error = 0; | |
655 | atomic_set(&ci.io->io_count, 1); | |
656 | ci.io->bio = bio; | |
657 | ci.io->md = md; | |
658 | ci.sector = bio->bi_sector; | |
659 | ci.sector_count = bio_sectors(bio); | |
660 | ci.idx = bio->bi_idx; | |
661 | ||
3eaf840e | 662 | start_io_acct(ci.io); |
1da177e4 LT |
663 | while (ci.sector_count) |
664 | __clone_and_map(&ci); | |
665 | ||
666 | /* drop the extra reference count */ | |
667 | dec_pending(ci.io, 0); | |
668 | dm_table_put(ci.map); | |
669 | } | |
670 | /*----------------------------------------------------------------- | |
671 | * CRUD END | |
672 | *---------------------------------------------------------------*/ | |
673 | ||
674 | /* | |
675 | * The request function that just remaps the bio built up by | |
676 | * dm_merge_bvec. | |
677 | */ | |
678 | static int dm_request(request_queue_t *q, struct bio *bio) | |
679 | { | |
680 | int r; | |
12f03a49 | 681 | int rw = bio_data_dir(bio); |
1da177e4 LT |
682 | struct mapped_device *md = q->queuedata; |
683 | ||
2ca3310e | 684 | down_read(&md->io_lock); |
1da177e4 | 685 | |
12f03a49 KC |
686 | disk_stat_inc(dm_disk(md), ios[rw]); |
687 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
688 | ||
1da177e4 LT |
689 | /* |
690 | * If we're suspended we have to queue | |
691 | * this io for later. | |
692 | */ | |
693 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 694 | up_read(&md->io_lock); |
1da177e4 LT |
695 | |
696 | if (bio_rw(bio) == READA) { | |
697 | bio_io_error(bio, bio->bi_size); | |
698 | return 0; | |
699 | } | |
700 | ||
701 | r = queue_io(md, bio); | |
702 | if (r < 0) { | |
703 | bio_io_error(bio, bio->bi_size); | |
704 | return 0; | |
705 | ||
706 | } else if (r == 0) | |
707 | return 0; /* deferred successfully */ | |
708 | ||
709 | /* | |
710 | * We're in a while loop, because someone could suspend | |
711 | * before we get to the following read lock. | |
712 | */ | |
2ca3310e | 713 | down_read(&md->io_lock); |
1da177e4 LT |
714 | } |
715 | ||
716 | __split_bio(md, bio); | |
2ca3310e | 717 | up_read(&md->io_lock); |
1da177e4 LT |
718 | return 0; |
719 | } | |
720 | ||
721 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
722 | sector_t *error_sector) | |
723 | { | |
724 | struct mapped_device *md = q->queuedata; | |
725 | struct dm_table *map = dm_get_table(md); | |
726 | int ret = -ENXIO; | |
727 | ||
728 | if (map) { | |
cf222b37 | 729 | ret = dm_table_flush_all(map); |
1da177e4 LT |
730 | dm_table_put(map); |
731 | } | |
732 | ||
733 | return ret; | |
734 | } | |
735 | ||
736 | static void dm_unplug_all(request_queue_t *q) | |
737 | { | |
738 | struct mapped_device *md = q->queuedata; | |
739 | struct dm_table *map = dm_get_table(md); | |
740 | ||
741 | if (map) { | |
742 | dm_table_unplug_all(map); | |
743 | dm_table_put(map); | |
744 | } | |
745 | } | |
746 | ||
747 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
748 | { | |
749 | int r; | |
750 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
751 | struct dm_table *map = dm_get_table(md); | |
752 | ||
753 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
754 | r = bdi_bits; | |
755 | else | |
756 | r = dm_table_any_congested(map, bdi_bits); | |
757 | ||
758 | dm_table_put(map); | |
759 | return r; | |
760 | } | |
761 | ||
762 | /*----------------------------------------------------------------- | |
763 | * An IDR is used to keep track of allocated minor numbers. | |
764 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
765 | static DEFINE_IDR(_minor_idr); |
766 | ||
2b06cfff | 767 | static void free_minor(int minor) |
1da177e4 | 768 | { |
f32c10b0 | 769 | spin_lock(&_minor_lock); |
1da177e4 | 770 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 771 | spin_unlock(&_minor_lock); |
1da177e4 LT |
772 | } |
773 | ||
774 | /* | |
775 | * See if the device with a specific minor # is free. | |
776 | */ | |
2b06cfff | 777 | static int specific_minor(struct mapped_device *md, int minor) |
1da177e4 LT |
778 | { |
779 | int r, m; | |
780 | ||
781 | if (minor >= (1 << MINORBITS)) | |
782 | return -EINVAL; | |
783 | ||
62f75c2f JM |
784 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
785 | if (!r) | |
786 | return -ENOMEM; | |
787 | ||
f32c10b0 | 788 | spin_lock(&_minor_lock); |
1da177e4 LT |
789 | |
790 | if (idr_find(&_minor_idr, minor)) { | |
791 | r = -EBUSY; | |
792 | goto out; | |
793 | } | |
794 | ||
ba61fdd1 | 795 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 796 | if (r) |
1da177e4 | 797 | goto out; |
1da177e4 LT |
798 | |
799 | if (m != minor) { | |
800 | idr_remove(&_minor_idr, m); | |
801 | r = -EBUSY; | |
802 | goto out; | |
803 | } | |
804 | ||
805 | out: | |
f32c10b0 | 806 | spin_unlock(&_minor_lock); |
1da177e4 LT |
807 | return r; |
808 | } | |
809 | ||
2b06cfff | 810 | static int next_free_minor(struct mapped_device *md, int *minor) |
1da177e4 | 811 | { |
2b06cfff | 812 | int r, m; |
1da177e4 | 813 | |
1da177e4 | 814 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
815 | if (!r) |
816 | return -ENOMEM; | |
817 | ||
f32c10b0 | 818 | spin_lock(&_minor_lock); |
1da177e4 | 819 | |
ba61fdd1 | 820 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
1da177e4 LT |
821 | if (r) { |
822 | goto out; | |
823 | } | |
824 | ||
825 | if (m >= (1 << MINORBITS)) { | |
826 | idr_remove(&_minor_idr, m); | |
827 | r = -ENOSPC; | |
828 | goto out; | |
829 | } | |
830 | ||
831 | *minor = m; | |
832 | ||
833 | out: | |
f32c10b0 | 834 | spin_unlock(&_minor_lock); |
1da177e4 LT |
835 | return r; |
836 | } | |
837 | ||
838 | static struct block_device_operations dm_blk_dops; | |
839 | ||
840 | /* | |
841 | * Allocate and initialise a blank device with a given minor. | |
842 | */ | |
2b06cfff | 843 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
844 | { |
845 | int r; | |
846 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
ba61fdd1 | 847 | void *old_md; |
1da177e4 LT |
848 | |
849 | if (!md) { | |
850 | DMWARN("unable to allocate device, out of memory."); | |
851 | return NULL; | |
852 | } | |
853 | ||
10da4f79 JM |
854 | if (!try_module_get(THIS_MODULE)) |
855 | goto bad0; | |
856 | ||
1da177e4 | 857 | /* get a minor number for the dev */ |
2b06cfff AK |
858 | if (minor == DM_ANY_MINOR) |
859 | r = next_free_minor(md, &minor); | |
860 | else | |
861 | r = specific_minor(md, minor); | |
1da177e4 LT |
862 | if (r < 0) |
863 | goto bad1; | |
864 | ||
865 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
866 | init_rwsem(&md->io_lock); |
867 | init_MUTEX(&md->suspend_lock); | |
1da177e4 LT |
868 | rwlock_init(&md->map_lock); |
869 | atomic_set(&md->holders, 1); | |
870 | atomic_set(&md->event_nr, 0); | |
871 | ||
872 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
873 | if (!md->queue) | |
874 | goto bad1; | |
875 | ||
876 | md->queue->queuedata = md; | |
877 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
878 | md->queue->backing_dev_info.congested_data = md; | |
879 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 880 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
881 | md->queue->unplug_fn = dm_unplug_all; |
882 | md->queue->issue_flush_fn = dm_flush_all; | |
883 | ||
93d2341c | 884 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
1da177e4 LT |
885 | if (!md->io_pool) |
886 | goto bad2; | |
887 | ||
93d2341c | 888 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
889 | if (!md->tio_pool) |
890 | goto bad3; | |
891 | ||
892 | md->disk = alloc_disk(1); | |
893 | if (!md->disk) | |
894 | goto bad4; | |
895 | ||
f0b04115 JM |
896 | atomic_set(&md->pending, 0); |
897 | init_waitqueue_head(&md->wait); | |
898 | init_waitqueue_head(&md->eventq); | |
899 | ||
1da177e4 LT |
900 | md->disk->major = _major; |
901 | md->disk->first_minor = minor; | |
902 | md->disk->fops = &dm_blk_dops; | |
903 | md->disk->queue = md->queue; | |
904 | md->disk->private_data = md; | |
905 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
906 | add_disk(md->disk); | |
7e51f257 | 907 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 908 | |
ba61fdd1 | 909 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 910 | spin_lock(&_minor_lock); |
ba61fdd1 | 911 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 912 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
913 | |
914 | BUG_ON(old_md != MINOR_ALLOCED); | |
915 | ||
1da177e4 LT |
916 | return md; |
917 | ||
918 | bad4: | |
919 | mempool_destroy(md->tio_pool); | |
920 | bad3: | |
921 | mempool_destroy(md->io_pool); | |
922 | bad2: | |
1312f40e | 923 | blk_cleanup_queue(md->queue); |
1da177e4 LT |
924 | free_minor(minor); |
925 | bad1: | |
10da4f79 JM |
926 | module_put(THIS_MODULE); |
927 | bad0: | |
1da177e4 LT |
928 | kfree(md); |
929 | return NULL; | |
930 | } | |
931 | ||
932 | static void free_dev(struct mapped_device *md) | |
933 | { | |
2b06cfff | 934 | int minor = md->disk->first_minor; |
63d94e48 | 935 | |
d9dde59b JN |
936 | if (md->suspended_bdev) { |
937 | thaw_bdev(md->suspended_bdev, NULL); | |
938 | bdput(md->suspended_bdev); | |
939 | } | |
1da177e4 LT |
940 | mempool_destroy(md->tio_pool); |
941 | mempool_destroy(md->io_pool); | |
942 | del_gendisk(md->disk); | |
63d94e48 | 943 | free_minor(minor); |
fba9f90e JM |
944 | |
945 | spin_lock(&_minor_lock); | |
946 | md->disk->private_data = NULL; | |
947 | spin_unlock(&_minor_lock); | |
948 | ||
1da177e4 | 949 | put_disk(md->disk); |
1312f40e | 950 | blk_cleanup_queue(md->queue); |
10da4f79 | 951 | module_put(THIS_MODULE); |
1da177e4 LT |
952 | kfree(md); |
953 | } | |
954 | ||
955 | /* | |
956 | * Bind a table to the device. | |
957 | */ | |
958 | static void event_callback(void *context) | |
959 | { | |
960 | struct mapped_device *md = (struct mapped_device *) context; | |
961 | ||
962 | atomic_inc(&md->event_nr); | |
963 | wake_up(&md->eventq); | |
964 | } | |
965 | ||
4e90188b | 966 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 967 | { |
4e90188b | 968 | set_capacity(md->disk, size); |
1da177e4 | 969 | |
1b1dcc1b | 970 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 971 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 972 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
973 | } |
974 | ||
975 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
976 | { | |
977 | request_queue_t *q = md->queue; | |
978 | sector_t size; | |
979 | ||
980 | size = dm_table_get_size(t); | |
3ac51e74 DW |
981 | |
982 | /* | |
983 | * Wipe any geometry if the size of the table changed. | |
984 | */ | |
985 | if (size != get_capacity(md->disk)) | |
986 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
987 | ||
4e90188b | 988 | __set_size(md, size); |
1da177e4 LT |
989 | if (size == 0) |
990 | return 0; | |
991 | ||
2ca3310e AK |
992 | dm_table_get(t); |
993 | dm_table_event_callback(t, event_callback, md); | |
994 | ||
1da177e4 LT |
995 | write_lock(&md->map_lock); |
996 | md->map = t; | |
2ca3310e | 997 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
998 | write_unlock(&md->map_lock); |
999 | ||
1da177e4 LT |
1000 | return 0; |
1001 | } | |
1002 | ||
1003 | static void __unbind(struct mapped_device *md) | |
1004 | { | |
1005 | struct dm_table *map = md->map; | |
1006 | ||
1007 | if (!map) | |
1008 | return; | |
1009 | ||
1010 | dm_table_event_callback(map, NULL, NULL); | |
1011 | write_lock(&md->map_lock); | |
1012 | md->map = NULL; | |
1013 | write_unlock(&md->map_lock); | |
1014 | dm_table_put(map); | |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Constructor for a new device. | |
1019 | */ | |
2b06cfff | 1020 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1021 | { |
1022 | struct mapped_device *md; | |
1023 | ||
2b06cfff | 1024 | md = alloc_dev(minor); |
1da177e4 LT |
1025 | if (!md) |
1026 | return -ENXIO; | |
1027 | ||
1028 | *result = md; | |
1029 | return 0; | |
1030 | } | |
1031 | ||
637842cf | 1032 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1033 | { |
1034 | struct mapped_device *md; | |
1da177e4 LT |
1035 | unsigned minor = MINOR(dev); |
1036 | ||
1037 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1038 | return NULL; | |
1039 | ||
f32c10b0 | 1040 | spin_lock(&_minor_lock); |
1da177e4 LT |
1041 | |
1042 | md = idr_find(&_minor_idr, minor); | |
fba9f90e JM |
1043 | if (md && (md == MINOR_ALLOCED || |
1044 | (dm_disk(md)->first_minor != minor) || | |
17b2f66f | 1045 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1046 | md = NULL; |
fba9f90e JM |
1047 | goto out; |
1048 | } | |
1da177e4 | 1049 | |
fba9f90e | 1050 | out: |
f32c10b0 | 1051 | spin_unlock(&_minor_lock); |
1da177e4 | 1052 | |
637842cf DT |
1053 | return md; |
1054 | } | |
1055 | ||
d229a958 DT |
1056 | struct mapped_device *dm_get_md(dev_t dev) |
1057 | { | |
1058 | struct mapped_device *md = dm_find_md(dev); | |
1059 | ||
1060 | if (md) | |
1061 | dm_get(md); | |
1062 | ||
1063 | return md; | |
1064 | } | |
1065 | ||
9ade92a9 | 1066 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1067 | { |
9ade92a9 | 1068 | return md->interface_ptr; |
1da177e4 LT |
1069 | } |
1070 | ||
1071 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1072 | { | |
1073 | md->interface_ptr = ptr; | |
1074 | } | |
1075 | ||
1076 | void dm_get(struct mapped_device *md) | |
1077 | { | |
1078 | atomic_inc(&md->holders); | |
1079 | } | |
1080 | ||
1081 | void dm_put(struct mapped_device *md) | |
1082 | { | |
1134e5ae | 1083 | struct dm_table *map; |
1da177e4 | 1084 | |
fba9f90e JM |
1085 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1086 | ||
f32c10b0 | 1087 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1088 | map = dm_get_table(md); |
ba61fdd1 | 1089 | idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); |
fba9f90e | 1090 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1091 | spin_unlock(&_minor_lock); |
cf222b37 | 1092 | if (!dm_suspended(md)) { |
1da177e4 LT |
1093 | dm_table_presuspend_targets(map); |
1094 | dm_table_postsuspend_targets(map); | |
1095 | } | |
1096 | __unbind(md); | |
1134e5ae | 1097 | dm_table_put(map); |
1da177e4 LT |
1098 | free_dev(md); |
1099 | } | |
1da177e4 LT |
1100 | } |
1101 | ||
1102 | /* | |
1103 | * Process the deferred bios | |
1104 | */ | |
1105 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1106 | { | |
1107 | struct bio *n; | |
1108 | ||
1109 | while (c) { | |
1110 | n = c->bi_next; | |
1111 | c->bi_next = NULL; | |
1112 | __split_bio(md, c); | |
1113 | c = n; | |
1114 | } | |
1115 | } | |
1116 | ||
1117 | /* | |
1118 | * Swap in a new table (destroying old one). | |
1119 | */ | |
1120 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1121 | { | |
93c534ae | 1122 | int r = -EINVAL; |
1da177e4 | 1123 | |
2ca3310e | 1124 | down(&md->suspend_lock); |
1da177e4 LT |
1125 | |
1126 | /* device must be suspended */ | |
cf222b37 | 1127 | if (!dm_suspended(md)) |
93c534ae | 1128 | goto out; |
1da177e4 LT |
1129 | |
1130 | __unbind(md); | |
1131 | r = __bind(md, table); | |
1da177e4 | 1132 | |
93c534ae | 1133 | out: |
2ca3310e | 1134 | up(&md->suspend_lock); |
93c534ae | 1135 | return r; |
1da177e4 LT |
1136 | } |
1137 | ||
1138 | /* | |
1139 | * Functions to lock and unlock any filesystem running on the | |
1140 | * device. | |
1141 | */ | |
2ca3310e | 1142 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1143 | { |
e39e2e95 | 1144 | int r; |
1da177e4 LT |
1145 | |
1146 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1147 | |
e39e2e95 | 1148 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1149 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1150 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1151 | md->frozen_sb = NULL; |
1152 | return r; | |
dfbe03f6 AK |
1153 | } |
1154 | ||
aa8d7c2f AK |
1155 | set_bit(DMF_FROZEN, &md->flags); |
1156 | ||
1da177e4 | 1157 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1158 | * to go away while it is locked. |
1da177e4 LT |
1159 | */ |
1160 | return 0; | |
1161 | } | |
1162 | ||
2ca3310e | 1163 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1164 | { |
aa8d7c2f AK |
1165 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1166 | return; | |
1167 | ||
e39e2e95 | 1168 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1169 | md->frozen_sb = NULL; |
aa8d7c2f | 1170 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1171 | } |
1172 | ||
1173 | /* | |
1174 | * We need to be able to change a mapping table under a mounted | |
1175 | * filesystem. For example we might want to move some data in | |
1176 | * the background. Before the table can be swapped with | |
1177 | * dm_bind_table, dm_suspend must be called to flush any in | |
1178 | * flight bios and ensure that any further io gets deferred. | |
1179 | */ | |
aa8d7c2f | 1180 | int dm_suspend(struct mapped_device *md, int do_lockfs) |
1da177e4 | 1181 | { |
2ca3310e | 1182 | struct dm_table *map = NULL; |
1da177e4 | 1183 | DECLARE_WAITQUEUE(wait, current); |
1ecac7fd | 1184 | struct bio *def; |
cf222b37 | 1185 | int r = -EINVAL; |
1da177e4 | 1186 | |
2ca3310e AK |
1187 | down(&md->suspend_lock); |
1188 | ||
1189 | if (dm_suspended(md)) | |
1190 | goto out; | |
1da177e4 LT |
1191 | |
1192 | map = dm_get_table(md); | |
1da177e4 | 1193 | |
cf222b37 AK |
1194 | /* This does not get reverted if there's an error later. */ |
1195 | dm_table_presuspend_targets(map); | |
1196 | ||
e39e2e95 AK |
1197 | md->suspended_bdev = bdget_disk(md->disk, 0); |
1198 | if (!md->suspended_bdev) { | |
1199 | DMWARN("bdget failed in dm_suspend"); | |
1200 | r = -ENOMEM; | |
1201 | goto out; | |
1202 | } | |
1203 | ||
cf222b37 | 1204 | /* Flush I/O to the device. */ |
aa8d7c2f AK |
1205 | if (do_lockfs) { |
1206 | r = lock_fs(md); | |
1207 | if (r) | |
1208 | goto out; | |
1209 | } | |
1da177e4 LT |
1210 | |
1211 | /* | |
354e0071 | 1212 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1213 | */ |
2ca3310e AK |
1214 | down_write(&md->io_lock); |
1215 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1216 | |
1da177e4 | 1217 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1218 | up_write(&md->io_lock); |
1da177e4 LT |
1219 | |
1220 | /* unplug */ | |
2ca3310e | 1221 | if (map) |
1da177e4 | 1222 | dm_table_unplug_all(map); |
1da177e4 LT |
1223 | |
1224 | /* | |
1225 | * Then we wait for the already mapped ios to | |
1226 | * complete. | |
1227 | */ | |
1228 | while (1) { | |
1229 | set_current_state(TASK_INTERRUPTIBLE); | |
1230 | ||
1231 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1232 | break; | |
1233 | ||
1234 | io_schedule(); | |
1235 | } | |
1236 | set_current_state(TASK_RUNNING); | |
1237 | ||
2ca3310e | 1238 | down_write(&md->io_lock); |
1da177e4 LT |
1239 | remove_wait_queue(&md->wait, &wait); |
1240 | ||
1241 | /* were we interrupted ? */ | |
cf222b37 | 1242 | r = -EINTR; |
2ca3310e | 1243 | if (atomic_read(&md->pending)) { |
1ecac7fd JN |
1244 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1245 | def = bio_list_get(&md->deferred); | |
1246 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1247 | up_write(&md->io_lock); |
1248 | unlock_fs(md); | |
2ca3310e AK |
1249 | goto out; |
1250 | } | |
1251 | up_write(&md->io_lock); | |
1da177e4 | 1252 | |
cf222b37 | 1253 | dm_table_postsuspend_targets(map); |
1da177e4 | 1254 | |
2ca3310e | 1255 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1256 | |
2ca3310e | 1257 | r = 0; |
b84b0287 | 1258 | |
2ca3310e | 1259 | out: |
e39e2e95 AK |
1260 | if (r && md->suspended_bdev) { |
1261 | bdput(md->suspended_bdev); | |
1262 | md->suspended_bdev = NULL; | |
1263 | } | |
1264 | ||
2ca3310e AK |
1265 | dm_table_put(map); |
1266 | up(&md->suspend_lock); | |
cf222b37 | 1267 | return r; |
1da177e4 LT |
1268 | } |
1269 | ||
1270 | int dm_resume(struct mapped_device *md) | |
1271 | { | |
cf222b37 | 1272 | int r = -EINVAL; |
1da177e4 | 1273 | struct bio *def; |
cf222b37 | 1274 | struct dm_table *map = NULL; |
1da177e4 | 1275 | |
2ca3310e AK |
1276 | down(&md->suspend_lock); |
1277 | if (!dm_suspended(md)) | |
cf222b37 | 1278 | goto out; |
cf222b37 AK |
1279 | |
1280 | map = dm_get_table(md); | |
2ca3310e | 1281 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1282 | goto out; |
1da177e4 LT |
1283 | |
1284 | dm_table_resume_targets(map); | |
2ca3310e AK |
1285 | |
1286 | down_write(&md->io_lock); | |
1da177e4 LT |
1287 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1288 | ||
1289 | def = bio_list_get(&md->deferred); | |
1290 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1291 | up_write(&md->io_lock); |
1292 | ||
1293 | unlock_fs(md); | |
1294 | ||
e39e2e95 AK |
1295 | bdput(md->suspended_bdev); |
1296 | md->suspended_bdev = NULL; | |
1297 | ||
2ca3310e AK |
1298 | clear_bit(DMF_SUSPENDED, &md->flags); |
1299 | ||
1da177e4 | 1300 | dm_table_unplug_all(map); |
1da177e4 | 1301 | |
cf222b37 | 1302 | r = 0; |
2ca3310e | 1303 | |
cf222b37 AK |
1304 | out: |
1305 | dm_table_put(map); | |
2ca3310e AK |
1306 | up(&md->suspend_lock); |
1307 | ||
cf222b37 | 1308 | return r; |
1da177e4 LT |
1309 | } |
1310 | ||
1311 | /*----------------------------------------------------------------- | |
1312 | * Event notification. | |
1313 | *---------------------------------------------------------------*/ | |
1314 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1315 | { | |
1316 | return atomic_read(&md->event_nr); | |
1317 | } | |
1318 | ||
1319 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1320 | { | |
1321 | return wait_event_interruptible(md->eventq, | |
1322 | (event_nr != atomic_read(&md->event_nr))); | |
1323 | } | |
1324 | ||
1325 | /* | |
1326 | * The gendisk is only valid as long as you have a reference | |
1327 | * count on 'md'. | |
1328 | */ | |
1329 | struct gendisk *dm_disk(struct mapped_device *md) | |
1330 | { | |
1331 | return md->disk; | |
1332 | } | |
1333 | ||
1334 | int dm_suspended(struct mapped_device *md) | |
1335 | { | |
1336 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1337 | } | |
1338 | ||
1339 | static struct block_device_operations dm_blk_dops = { | |
1340 | .open = dm_blk_open, | |
1341 | .release = dm_blk_close, | |
3ac51e74 | 1342 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1343 | .owner = THIS_MODULE |
1344 | }; | |
1345 | ||
1346 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1347 | ||
1348 | /* | |
1349 | * module hooks | |
1350 | */ | |
1351 | module_init(dm_init); | |
1352 | module_exit(dm_exit); | |
1353 | ||
1354 | module_param(major, uint, 0); | |
1355 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1356 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1357 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1358 | MODULE_LICENSE("GPL"); |