Commit | Line | Data |
---|---|---|
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 |
5c6bd75d | 67 | #define DMF_DELETING 4 |
1da177e4 LT |
68 | |
69 | struct mapped_device { | |
2ca3310e AK |
70 | struct rw_semaphore io_lock; |
71 | struct semaphore suspend_lock; | |
1da177e4 LT |
72 | rwlock_t map_lock; |
73 | atomic_t holders; | |
5c6bd75d | 74 | atomic_t open_count; |
1da177e4 LT |
75 | |
76 | unsigned long flags; | |
77 | ||
78 | request_queue_t *queue; | |
79 | struct gendisk *disk; | |
7e51f257 | 80 | char name[16]; |
1da177e4 LT |
81 | |
82 | void *interface_ptr; | |
83 | ||
84 | /* | |
85 | * A list of ios that arrived while we were suspended. | |
86 | */ | |
87 | atomic_t pending; | |
88 | wait_queue_head_t wait; | |
89 | struct bio_list deferred; | |
90 | ||
91 | /* | |
92 | * The current mapping. | |
93 | */ | |
94 | struct dm_table *map; | |
95 | ||
96 | /* | |
97 | * io objects are allocated from here. | |
98 | */ | |
99 | mempool_t *io_pool; | |
100 | mempool_t *tio_pool; | |
101 | ||
102 | /* | |
103 | * Event handling. | |
104 | */ | |
105 | atomic_t event_nr; | |
106 | wait_queue_head_t eventq; | |
107 | ||
108 | /* | |
109 | * freeze/thaw support require holding onto a super block | |
110 | */ | |
111 | struct super_block *frozen_sb; | |
e39e2e95 | 112 | struct block_device *suspended_bdev; |
3ac51e74 DW |
113 | |
114 | /* forced geometry settings */ | |
115 | struct hd_geometry geometry; | |
1da177e4 LT |
116 | }; |
117 | ||
118 | #define MIN_IOS 256 | |
119 | static kmem_cache_t *_io_cache; | |
120 | static kmem_cache_t *_tio_cache; | |
121 | ||
122 | static struct bio_set *dm_set; | |
123 | ||
124 | static int __init local_init(void) | |
125 | { | |
126 | int r; | |
127 | ||
128 | dm_set = bioset_create(16, 16, 4); | |
129 | if (!dm_set) | |
130 | return -ENOMEM; | |
131 | ||
132 | /* allocate a slab for the dm_ios */ | |
133 | _io_cache = kmem_cache_create("dm_io", | |
134 | sizeof(struct dm_io), 0, 0, NULL, NULL); | |
135 | if (!_io_cache) | |
136 | return -ENOMEM; | |
137 | ||
138 | /* allocate a slab for the target ios */ | |
139 | _tio_cache = kmem_cache_create("dm_tio", sizeof(struct target_io), | |
140 | 0, 0, NULL, NULL); | |
141 | if (!_tio_cache) { | |
142 | kmem_cache_destroy(_io_cache); | |
143 | return -ENOMEM; | |
144 | } | |
145 | ||
146 | _major = major; | |
147 | r = register_blkdev(_major, _name); | |
148 | if (r < 0) { | |
149 | kmem_cache_destroy(_tio_cache); | |
150 | kmem_cache_destroy(_io_cache); | |
151 | return r; | |
152 | } | |
153 | ||
154 | if (!_major) | |
155 | _major = r; | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static void local_exit(void) | |
161 | { | |
162 | kmem_cache_destroy(_tio_cache); | |
163 | kmem_cache_destroy(_io_cache); | |
164 | ||
165 | bioset_free(dm_set); | |
166 | ||
167 | if (unregister_blkdev(_major, _name) < 0) | |
168 | DMERR("devfs_unregister_blkdev failed"); | |
169 | ||
170 | _major = 0; | |
171 | ||
172 | DMINFO("cleaned up"); | |
173 | } | |
174 | ||
175 | int (*_inits[])(void) __initdata = { | |
176 | local_init, | |
177 | dm_target_init, | |
178 | dm_linear_init, | |
179 | dm_stripe_init, | |
180 | dm_interface_init, | |
181 | }; | |
182 | ||
183 | void (*_exits[])(void) = { | |
184 | local_exit, | |
185 | dm_target_exit, | |
186 | dm_linear_exit, | |
187 | dm_stripe_exit, | |
188 | dm_interface_exit, | |
189 | }; | |
190 | ||
191 | static int __init dm_init(void) | |
192 | { | |
193 | const int count = ARRAY_SIZE(_inits); | |
194 | ||
195 | int r, i; | |
196 | ||
197 | for (i = 0; i < count; i++) { | |
198 | r = _inits[i](); | |
199 | if (r) | |
200 | goto bad; | |
201 | } | |
202 | ||
203 | return 0; | |
204 | ||
205 | bad: | |
206 | while (i--) | |
207 | _exits[i](); | |
208 | ||
209 | return r; | |
210 | } | |
211 | ||
212 | static void __exit dm_exit(void) | |
213 | { | |
214 | int i = ARRAY_SIZE(_exits); | |
215 | ||
216 | while (i--) | |
217 | _exits[i](); | |
218 | } | |
219 | ||
220 | /* | |
221 | * Block device functions | |
222 | */ | |
223 | static int dm_blk_open(struct inode *inode, struct file *file) | |
224 | { | |
225 | struct mapped_device *md; | |
226 | ||
fba9f90e JM |
227 | spin_lock(&_minor_lock); |
228 | ||
1da177e4 | 229 | md = inode->i_bdev->bd_disk->private_data; |
fba9f90e JM |
230 | if (!md) |
231 | goto out; | |
232 | ||
5c6bd75d AK |
233 | if (test_bit(DMF_FREEING, &md->flags) || |
234 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
235 | md = NULL; |
236 | goto out; | |
237 | } | |
238 | ||
1da177e4 | 239 | dm_get(md); |
5c6bd75d | 240 | atomic_inc(&md->open_count); |
fba9f90e JM |
241 | |
242 | out: | |
243 | spin_unlock(&_minor_lock); | |
244 | ||
245 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
246 | } |
247 | ||
248 | static int dm_blk_close(struct inode *inode, struct file *file) | |
249 | { | |
250 | struct mapped_device *md; | |
251 | ||
252 | md = inode->i_bdev->bd_disk->private_data; | |
5c6bd75d | 253 | atomic_dec(&md->open_count); |
1da177e4 LT |
254 | dm_put(md); |
255 | return 0; | |
256 | } | |
257 | ||
5c6bd75d AK |
258 | int dm_open_count(struct mapped_device *md) |
259 | { | |
260 | return atomic_read(&md->open_count); | |
261 | } | |
262 | ||
263 | /* | |
264 | * Guarantees nothing is using the device before it's deleted. | |
265 | */ | |
266 | int dm_lock_for_deletion(struct mapped_device *md) | |
267 | { | |
268 | int r = 0; | |
269 | ||
270 | spin_lock(&_minor_lock); | |
271 | ||
272 | if (dm_open_count(md)) | |
273 | r = -EBUSY; | |
274 | else | |
275 | set_bit(DMF_DELETING, &md->flags); | |
276 | ||
277 | spin_unlock(&_minor_lock); | |
278 | ||
279 | return r; | |
280 | } | |
281 | ||
3ac51e74 DW |
282 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
283 | { | |
284 | struct mapped_device *md = bdev->bd_disk->private_data; | |
285 | ||
286 | return dm_get_geometry(md, geo); | |
287 | } | |
288 | ||
1da177e4 LT |
289 | static inline struct dm_io *alloc_io(struct mapped_device *md) |
290 | { | |
291 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
292 | } | |
293 | ||
294 | static inline void free_io(struct mapped_device *md, struct dm_io *io) | |
295 | { | |
296 | mempool_free(io, md->io_pool); | |
297 | } | |
298 | ||
299 | static inline struct target_io *alloc_tio(struct mapped_device *md) | |
300 | { | |
301 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
302 | } | |
303 | ||
304 | static inline void free_tio(struct mapped_device *md, struct target_io *tio) | |
305 | { | |
306 | mempool_free(tio, md->tio_pool); | |
307 | } | |
308 | ||
3eaf840e JNN |
309 | static void start_io_acct(struct dm_io *io) |
310 | { | |
311 | struct mapped_device *md = io->md; | |
312 | ||
313 | io->start_time = jiffies; | |
314 | ||
315 | preempt_disable(); | |
316 | disk_round_stats(dm_disk(md)); | |
317 | preempt_enable(); | |
318 | dm_disk(md)->in_flight = atomic_inc_return(&md->pending); | |
319 | } | |
320 | ||
321 | static int end_io_acct(struct dm_io *io) | |
322 | { | |
323 | struct mapped_device *md = io->md; | |
324 | struct bio *bio = io->bio; | |
325 | unsigned long duration = jiffies - io->start_time; | |
326 | int pending; | |
327 | int rw = bio_data_dir(bio); | |
328 | ||
329 | preempt_disable(); | |
330 | disk_round_stats(dm_disk(md)); | |
331 | preempt_enable(); | |
332 | dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending); | |
333 | ||
334 | disk_stat_add(dm_disk(md), ticks[rw], duration); | |
335 | ||
336 | return !pending; | |
337 | } | |
338 | ||
1da177e4 LT |
339 | /* |
340 | * Add the bio to the list of deferred io. | |
341 | */ | |
342 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
343 | { | |
2ca3310e | 344 | down_write(&md->io_lock); |
1da177e4 LT |
345 | |
346 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 347 | up_write(&md->io_lock); |
1da177e4 LT |
348 | return 1; |
349 | } | |
350 | ||
351 | bio_list_add(&md->deferred, bio); | |
352 | ||
2ca3310e | 353 | up_write(&md->io_lock); |
1da177e4 LT |
354 | return 0; /* deferred successfully */ |
355 | } | |
356 | ||
357 | /* | |
358 | * Everyone (including functions in this file), should use this | |
359 | * function to access the md->map field, and make sure they call | |
360 | * dm_table_put() when finished. | |
361 | */ | |
362 | struct dm_table *dm_get_table(struct mapped_device *md) | |
363 | { | |
364 | struct dm_table *t; | |
365 | ||
366 | read_lock(&md->map_lock); | |
367 | t = md->map; | |
368 | if (t) | |
369 | dm_table_get(t); | |
370 | read_unlock(&md->map_lock); | |
371 | ||
372 | return t; | |
373 | } | |
374 | ||
3ac51e74 DW |
375 | /* |
376 | * Get the geometry associated with a dm device | |
377 | */ | |
378 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
379 | { | |
380 | *geo = md->geometry; | |
381 | ||
382 | return 0; | |
383 | } | |
384 | ||
385 | /* | |
386 | * Set the geometry of a device. | |
387 | */ | |
388 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
389 | { | |
390 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
391 | ||
392 | if (geo->start > sz) { | |
393 | DMWARN("Start sector is beyond the geometry limits."); | |
394 | return -EINVAL; | |
395 | } | |
396 | ||
397 | md->geometry = *geo; | |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
1da177e4 LT |
402 | /*----------------------------------------------------------------- |
403 | * CRUD START: | |
404 | * A more elegant soln is in the works that uses the queue | |
405 | * merge fn, unfortunately there are a couple of changes to | |
406 | * the block layer that I want to make for this. So in the | |
407 | * interests of getting something for people to use I give | |
408 | * you this clearly demarcated crap. | |
409 | *---------------------------------------------------------------*/ | |
410 | ||
411 | /* | |
412 | * Decrements the number of outstanding ios that a bio has been | |
413 | * cloned into, completing the original io if necc. | |
414 | */ | |
858119e1 | 415 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 LT |
416 | { |
417 | if (error) | |
418 | io->error = error; | |
419 | ||
420 | if (atomic_dec_and_test(&io->io_count)) { | |
3eaf840e | 421 | if (end_io_acct(io)) |
1da177e4 LT |
422 | /* nudge anyone waiting on suspend queue */ |
423 | wake_up(&io->md->wait); | |
424 | ||
2056a782 JA |
425 | blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); |
426 | ||
1da177e4 LT |
427 | bio_endio(io->bio, io->bio->bi_size, io->error); |
428 | free_io(io->md, io); | |
429 | } | |
430 | } | |
431 | ||
432 | static int clone_endio(struct bio *bio, unsigned int done, int error) | |
433 | { | |
434 | int r = 0; | |
435 | struct target_io *tio = bio->bi_private; | |
436 | struct dm_io *io = tio->io; | |
437 | dm_endio_fn endio = tio->ti->type->end_io; | |
438 | ||
439 | if (bio->bi_size) | |
440 | return 1; | |
441 | ||
442 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) | |
443 | error = -EIO; | |
444 | ||
445 | if (endio) { | |
446 | r = endio(tio->ti, bio, error, &tio->info); | |
447 | if (r < 0) | |
448 | error = r; | |
449 | ||
450 | else if (r > 0) | |
451 | /* the target wants another shot at the io */ | |
452 | return 1; | |
453 | } | |
454 | ||
455 | free_tio(io->md, tio); | |
456 | dec_pending(io, error); | |
457 | bio_put(bio); | |
458 | return r; | |
459 | } | |
460 | ||
461 | static sector_t max_io_len(struct mapped_device *md, | |
462 | sector_t sector, struct dm_target *ti) | |
463 | { | |
464 | sector_t offset = sector - ti->begin; | |
465 | sector_t len = ti->len - offset; | |
466 | ||
467 | /* | |
468 | * Does the target need to split even further ? | |
469 | */ | |
470 | if (ti->split_io) { | |
471 | sector_t boundary; | |
472 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
473 | - offset; | |
474 | if (len > boundary) | |
475 | len = boundary; | |
476 | } | |
477 | ||
478 | return len; | |
479 | } | |
480 | ||
481 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
482 | struct target_io *tio) | |
483 | { | |
484 | int r; | |
2056a782 | 485 | sector_t sector; |
1da177e4 LT |
486 | |
487 | /* | |
488 | * Sanity checks. | |
489 | */ | |
490 | BUG_ON(!clone->bi_size); | |
491 | ||
492 | clone->bi_end_io = clone_endio; | |
493 | clone->bi_private = tio; | |
494 | ||
495 | /* | |
496 | * Map the clone. If r == 0 we don't need to do | |
497 | * anything, the target has assumed ownership of | |
498 | * this io. | |
499 | */ | |
500 | atomic_inc(&tio->io->io_count); | |
2056a782 | 501 | sector = clone->bi_sector; |
1da177e4 | 502 | r = ti->type->map(ti, clone, &tio->info); |
2056a782 | 503 | if (r > 0) { |
1da177e4 | 504 | /* the bio has been remapped so dispatch it */ |
2056a782 | 505 | |
17b2f66f AK |
506 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, |
507 | tio->io->bio->bi_bdev->bd_dev, sector, | |
2056a782 JA |
508 | clone->bi_sector); |
509 | ||
1da177e4 | 510 | generic_make_request(clone); |
2056a782 | 511 | } |
1da177e4 LT |
512 | |
513 | else if (r < 0) { | |
514 | /* error the io and bail out */ | |
515 | struct dm_io *io = tio->io; | |
516 | free_tio(tio->io->md, tio); | |
f6a80ea8 | 517 | dec_pending(io, r); |
1da177e4 LT |
518 | bio_put(clone); |
519 | } | |
520 | } | |
521 | ||
522 | struct clone_info { | |
523 | struct mapped_device *md; | |
524 | struct dm_table *map; | |
525 | struct bio *bio; | |
526 | struct dm_io *io; | |
527 | sector_t sector; | |
528 | sector_t sector_count; | |
529 | unsigned short idx; | |
530 | }; | |
531 | ||
3676347a PO |
532 | static void dm_bio_destructor(struct bio *bio) |
533 | { | |
534 | bio_free(bio, dm_set); | |
535 | } | |
536 | ||
1da177e4 LT |
537 | /* |
538 | * Creates a little bio that is just does part of a bvec. | |
539 | */ | |
540 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
541 | unsigned short idx, unsigned int offset, | |
542 | unsigned int len) | |
543 | { | |
544 | struct bio *clone; | |
545 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
546 | ||
547 | clone = bio_alloc_bioset(GFP_NOIO, 1, dm_set); | |
3676347a | 548 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
549 | *clone->bi_io_vec = *bv; |
550 | ||
551 | clone->bi_sector = sector; | |
552 | clone->bi_bdev = bio->bi_bdev; | |
553 | clone->bi_rw = bio->bi_rw; | |
554 | clone->bi_vcnt = 1; | |
555 | clone->bi_size = to_bytes(len); | |
556 | clone->bi_io_vec->bv_offset = offset; | |
557 | clone->bi_io_vec->bv_len = clone->bi_size; | |
558 | ||
559 | return clone; | |
560 | } | |
561 | ||
562 | /* | |
563 | * Creates a bio that consists of range of complete bvecs. | |
564 | */ | |
565 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
566 | unsigned short idx, unsigned short bv_count, | |
567 | unsigned int len) | |
568 | { | |
569 | struct bio *clone; | |
570 | ||
571 | clone = bio_clone(bio, GFP_NOIO); | |
572 | clone->bi_sector = sector; | |
573 | clone->bi_idx = idx; | |
574 | clone->bi_vcnt = idx + bv_count; | |
575 | clone->bi_size = to_bytes(len); | |
576 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
577 | ||
578 | return clone; | |
579 | } | |
580 | ||
581 | static void __clone_and_map(struct clone_info *ci) | |
582 | { | |
583 | struct bio *clone, *bio = ci->bio; | |
584 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
585 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
586 | struct target_io *tio; | |
587 | ||
588 | /* | |
589 | * Allocate a target io object. | |
590 | */ | |
591 | tio = alloc_tio(ci->md); | |
592 | tio->io = ci->io; | |
593 | tio->ti = ti; | |
594 | memset(&tio->info, 0, sizeof(tio->info)); | |
595 | ||
596 | if (ci->sector_count <= max) { | |
597 | /* | |
598 | * Optimise for the simple case where we can do all of | |
599 | * the remaining io with a single clone. | |
600 | */ | |
601 | clone = clone_bio(bio, ci->sector, ci->idx, | |
602 | bio->bi_vcnt - ci->idx, ci->sector_count); | |
603 | __map_bio(ti, clone, tio); | |
604 | ci->sector_count = 0; | |
605 | ||
606 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
607 | /* | |
608 | * There are some bvecs that don't span targets. | |
609 | * Do as many of these as possible. | |
610 | */ | |
611 | int i; | |
612 | sector_t remaining = max; | |
613 | sector_t bv_len; | |
614 | ||
615 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
616 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
617 | ||
618 | if (bv_len > remaining) | |
619 | break; | |
620 | ||
621 | remaining -= bv_len; | |
622 | len += bv_len; | |
623 | } | |
624 | ||
625 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len); | |
626 | __map_bio(ti, clone, tio); | |
627 | ||
628 | ci->sector += len; | |
629 | ci->sector_count -= len; | |
630 | ci->idx = i; | |
631 | ||
632 | } else { | |
633 | /* | |
d2044a94 | 634 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
635 | */ |
636 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
637 | sector_t remaining = to_sector(bv->bv_len); |
638 | unsigned int offset = 0; | |
1da177e4 | 639 | |
d2044a94 AK |
640 | do { |
641 | if (offset) { | |
642 | ti = dm_table_find_target(ci->map, ci->sector); | |
643 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 644 | |
d2044a94 AK |
645 | tio = alloc_tio(ci->md); |
646 | tio->io = ci->io; | |
647 | tio->ti = ti; | |
648 | memset(&tio->info, 0, sizeof(tio->info)); | |
649 | } | |
650 | ||
651 | len = min(remaining, max); | |
652 | ||
653 | clone = split_bvec(bio, ci->sector, ci->idx, | |
654 | bv->bv_offset + offset, len); | |
655 | ||
656 | __map_bio(ti, clone, tio); | |
657 | ||
658 | ci->sector += len; | |
659 | ci->sector_count -= len; | |
660 | offset += to_bytes(len); | |
661 | } while (remaining -= len); | |
1da177e4 | 662 | |
1da177e4 LT |
663 | ci->idx++; |
664 | } | |
665 | } | |
666 | ||
667 | /* | |
668 | * Split the bio into several clones. | |
669 | */ | |
670 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
671 | { | |
672 | struct clone_info ci; | |
673 | ||
674 | ci.map = dm_get_table(md); | |
675 | if (!ci.map) { | |
676 | bio_io_error(bio, bio->bi_size); | |
677 | return; | |
678 | } | |
679 | ||
680 | ci.md = md; | |
681 | ci.bio = bio; | |
682 | ci.io = alloc_io(md); | |
683 | ci.io->error = 0; | |
684 | atomic_set(&ci.io->io_count, 1); | |
685 | ci.io->bio = bio; | |
686 | ci.io->md = md; | |
687 | ci.sector = bio->bi_sector; | |
688 | ci.sector_count = bio_sectors(bio); | |
689 | ci.idx = bio->bi_idx; | |
690 | ||
3eaf840e | 691 | start_io_acct(ci.io); |
1da177e4 LT |
692 | while (ci.sector_count) |
693 | __clone_and_map(&ci); | |
694 | ||
695 | /* drop the extra reference count */ | |
696 | dec_pending(ci.io, 0); | |
697 | dm_table_put(ci.map); | |
698 | } | |
699 | /*----------------------------------------------------------------- | |
700 | * CRUD END | |
701 | *---------------------------------------------------------------*/ | |
702 | ||
703 | /* | |
704 | * The request function that just remaps the bio built up by | |
705 | * dm_merge_bvec. | |
706 | */ | |
707 | static int dm_request(request_queue_t *q, struct bio *bio) | |
708 | { | |
709 | int r; | |
12f03a49 | 710 | int rw = bio_data_dir(bio); |
1da177e4 LT |
711 | struct mapped_device *md = q->queuedata; |
712 | ||
2ca3310e | 713 | down_read(&md->io_lock); |
1da177e4 | 714 | |
12f03a49 KC |
715 | disk_stat_inc(dm_disk(md), ios[rw]); |
716 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
717 | ||
1da177e4 LT |
718 | /* |
719 | * If we're suspended we have to queue | |
720 | * this io for later. | |
721 | */ | |
722 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 723 | up_read(&md->io_lock); |
1da177e4 LT |
724 | |
725 | if (bio_rw(bio) == READA) { | |
726 | bio_io_error(bio, bio->bi_size); | |
727 | return 0; | |
728 | } | |
729 | ||
730 | r = queue_io(md, bio); | |
731 | if (r < 0) { | |
732 | bio_io_error(bio, bio->bi_size); | |
733 | return 0; | |
734 | ||
735 | } else if (r == 0) | |
736 | return 0; /* deferred successfully */ | |
737 | ||
738 | /* | |
739 | * We're in a while loop, because someone could suspend | |
740 | * before we get to the following read lock. | |
741 | */ | |
2ca3310e | 742 | down_read(&md->io_lock); |
1da177e4 LT |
743 | } |
744 | ||
745 | __split_bio(md, bio); | |
2ca3310e | 746 | up_read(&md->io_lock); |
1da177e4 LT |
747 | return 0; |
748 | } | |
749 | ||
750 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
751 | sector_t *error_sector) | |
752 | { | |
753 | struct mapped_device *md = q->queuedata; | |
754 | struct dm_table *map = dm_get_table(md); | |
755 | int ret = -ENXIO; | |
756 | ||
757 | if (map) { | |
cf222b37 | 758 | ret = dm_table_flush_all(map); |
1da177e4 LT |
759 | dm_table_put(map); |
760 | } | |
761 | ||
762 | return ret; | |
763 | } | |
764 | ||
765 | static void dm_unplug_all(request_queue_t *q) | |
766 | { | |
767 | struct mapped_device *md = q->queuedata; | |
768 | struct dm_table *map = dm_get_table(md); | |
769 | ||
770 | if (map) { | |
771 | dm_table_unplug_all(map); | |
772 | dm_table_put(map); | |
773 | } | |
774 | } | |
775 | ||
776 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
777 | { | |
778 | int r; | |
779 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
780 | struct dm_table *map = dm_get_table(md); | |
781 | ||
782 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
783 | r = bdi_bits; | |
784 | else | |
785 | r = dm_table_any_congested(map, bdi_bits); | |
786 | ||
787 | dm_table_put(map); | |
788 | return r; | |
789 | } | |
790 | ||
791 | /*----------------------------------------------------------------- | |
792 | * An IDR is used to keep track of allocated minor numbers. | |
793 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
794 | static DEFINE_IDR(_minor_idr); |
795 | ||
2b06cfff | 796 | static void free_minor(int minor) |
1da177e4 | 797 | { |
f32c10b0 | 798 | spin_lock(&_minor_lock); |
1da177e4 | 799 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 800 | spin_unlock(&_minor_lock); |
1da177e4 LT |
801 | } |
802 | ||
803 | /* | |
804 | * See if the device with a specific minor # is free. | |
805 | */ | |
2b06cfff | 806 | static int specific_minor(struct mapped_device *md, int minor) |
1da177e4 LT |
807 | { |
808 | int r, m; | |
809 | ||
810 | if (minor >= (1 << MINORBITS)) | |
811 | return -EINVAL; | |
812 | ||
62f75c2f JM |
813 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
814 | if (!r) | |
815 | return -ENOMEM; | |
816 | ||
f32c10b0 | 817 | spin_lock(&_minor_lock); |
1da177e4 LT |
818 | |
819 | if (idr_find(&_minor_idr, minor)) { | |
820 | r = -EBUSY; | |
821 | goto out; | |
822 | } | |
823 | ||
ba61fdd1 | 824 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 825 | if (r) |
1da177e4 | 826 | goto out; |
1da177e4 LT |
827 | |
828 | if (m != minor) { | |
829 | idr_remove(&_minor_idr, m); | |
830 | r = -EBUSY; | |
831 | goto out; | |
832 | } | |
833 | ||
834 | out: | |
f32c10b0 | 835 | spin_unlock(&_minor_lock); |
1da177e4 LT |
836 | return r; |
837 | } | |
838 | ||
2b06cfff | 839 | static int next_free_minor(struct mapped_device *md, int *minor) |
1da177e4 | 840 | { |
2b06cfff | 841 | int r, m; |
1da177e4 | 842 | |
1da177e4 | 843 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
844 | if (!r) |
845 | return -ENOMEM; | |
846 | ||
f32c10b0 | 847 | spin_lock(&_minor_lock); |
1da177e4 | 848 | |
ba61fdd1 | 849 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
1da177e4 LT |
850 | if (r) { |
851 | goto out; | |
852 | } | |
853 | ||
854 | if (m >= (1 << MINORBITS)) { | |
855 | idr_remove(&_minor_idr, m); | |
856 | r = -ENOSPC; | |
857 | goto out; | |
858 | } | |
859 | ||
860 | *minor = m; | |
861 | ||
862 | out: | |
f32c10b0 | 863 | spin_unlock(&_minor_lock); |
1da177e4 LT |
864 | return r; |
865 | } | |
866 | ||
867 | static struct block_device_operations dm_blk_dops; | |
868 | ||
869 | /* | |
870 | * Allocate and initialise a blank device with a given minor. | |
871 | */ | |
2b06cfff | 872 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
873 | { |
874 | int r; | |
875 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
ba61fdd1 | 876 | void *old_md; |
1da177e4 LT |
877 | |
878 | if (!md) { | |
879 | DMWARN("unable to allocate device, out of memory."); | |
880 | return NULL; | |
881 | } | |
882 | ||
10da4f79 JM |
883 | if (!try_module_get(THIS_MODULE)) |
884 | goto bad0; | |
885 | ||
1da177e4 | 886 | /* get a minor number for the dev */ |
2b06cfff AK |
887 | if (minor == DM_ANY_MINOR) |
888 | r = next_free_minor(md, &minor); | |
889 | else | |
890 | r = specific_minor(md, minor); | |
1da177e4 LT |
891 | if (r < 0) |
892 | goto bad1; | |
893 | ||
894 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
895 | init_rwsem(&md->io_lock); |
896 | init_MUTEX(&md->suspend_lock); | |
1da177e4 LT |
897 | rwlock_init(&md->map_lock); |
898 | atomic_set(&md->holders, 1); | |
5c6bd75d | 899 | atomic_set(&md->open_count, 0); |
1da177e4 LT |
900 | atomic_set(&md->event_nr, 0); |
901 | ||
902 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
903 | if (!md->queue) | |
904 | goto bad1; | |
905 | ||
906 | md->queue->queuedata = md; | |
907 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
908 | md->queue->backing_dev_info.congested_data = md; | |
909 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 910 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
911 | md->queue->unplug_fn = dm_unplug_all; |
912 | md->queue->issue_flush_fn = dm_flush_all; | |
913 | ||
93d2341c | 914 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
1da177e4 LT |
915 | if (!md->io_pool) |
916 | goto bad2; | |
917 | ||
93d2341c | 918 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
919 | if (!md->tio_pool) |
920 | goto bad3; | |
921 | ||
922 | md->disk = alloc_disk(1); | |
923 | if (!md->disk) | |
924 | goto bad4; | |
925 | ||
f0b04115 JM |
926 | atomic_set(&md->pending, 0); |
927 | init_waitqueue_head(&md->wait); | |
928 | init_waitqueue_head(&md->eventq); | |
929 | ||
1da177e4 LT |
930 | md->disk->major = _major; |
931 | md->disk->first_minor = minor; | |
932 | md->disk->fops = &dm_blk_dops; | |
933 | md->disk->queue = md->queue; | |
934 | md->disk->private_data = md; | |
935 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
936 | add_disk(md->disk); | |
7e51f257 | 937 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 938 | |
ba61fdd1 | 939 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 940 | spin_lock(&_minor_lock); |
ba61fdd1 | 941 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 942 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
943 | |
944 | BUG_ON(old_md != MINOR_ALLOCED); | |
945 | ||
1da177e4 LT |
946 | return md; |
947 | ||
948 | bad4: | |
949 | mempool_destroy(md->tio_pool); | |
950 | bad3: | |
951 | mempool_destroy(md->io_pool); | |
952 | bad2: | |
1312f40e | 953 | blk_cleanup_queue(md->queue); |
1da177e4 LT |
954 | free_minor(minor); |
955 | bad1: | |
10da4f79 JM |
956 | module_put(THIS_MODULE); |
957 | bad0: | |
1da177e4 LT |
958 | kfree(md); |
959 | return NULL; | |
960 | } | |
961 | ||
962 | static void free_dev(struct mapped_device *md) | |
963 | { | |
2b06cfff | 964 | int minor = md->disk->first_minor; |
63d94e48 | 965 | |
d9dde59b JN |
966 | if (md->suspended_bdev) { |
967 | thaw_bdev(md->suspended_bdev, NULL); | |
968 | bdput(md->suspended_bdev); | |
969 | } | |
1da177e4 LT |
970 | mempool_destroy(md->tio_pool); |
971 | mempool_destroy(md->io_pool); | |
972 | del_gendisk(md->disk); | |
63d94e48 | 973 | free_minor(minor); |
fba9f90e JM |
974 | |
975 | spin_lock(&_minor_lock); | |
976 | md->disk->private_data = NULL; | |
977 | spin_unlock(&_minor_lock); | |
978 | ||
1da177e4 | 979 | put_disk(md->disk); |
1312f40e | 980 | blk_cleanup_queue(md->queue); |
10da4f79 | 981 | module_put(THIS_MODULE); |
1da177e4 LT |
982 | kfree(md); |
983 | } | |
984 | ||
985 | /* | |
986 | * Bind a table to the device. | |
987 | */ | |
988 | static void event_callback(void *context) | |
989 | { | |
990 | struct mapped_device *md = (struct mapped_device *) context; | |
991 | ||
992 | atomic_inc(&md->event_nr); | |
993 | wake_up(&md->eventq); | |
994 | } | |
995 | ||
4e90188b | 996 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 997 | { |
4e90188b | 998 | set_capacity(md->disk, size); |
1da177e4 | 999 | |
1b1dcc1b | 1000 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1001 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1002 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1003 | } |
1004 | ||
1005 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1006 | { | |
1007 | request_queue_t *q = md->queue; | |
1008 | sector_t size; | |
1009 | ||
1010 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1011 | |
1012 | /* | |
1013 | * Wipe any geometry if the size of the table changed. | |
1014 | */ | |
1015 | if (size != get_capacity(md->disk)) | |
1016 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1017 | ||
4e90188b | 1018 | __set_size(md, size); |
1da177e4 LT |
1019 | if (size == 0) |
1020 | return 0; | |
1021 | ||
2ca3310e AK |
1022 | dm_table_get(t); |
1023 | dm_table_event_callback(t, event_callback, md); | |
1024 | ||
1da177e4 LT |
1025 | write_lock(&md->map_lock); |
1026 | md->map = t; | |
2ca3310e | 1027 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1028 | write_unlock(&md->map_lock); |
1029 | ||
1da177e4 LT |
1030 | return 0; |
1031 | } | |
1032 | ||
1033 | static void __unbind(struct mapped_device *md) | |
1034 | { | |
1035 | struct dm_table *map = md->map; | |
1036 | ||
1037 | if (!map) | |
1038 | return; | |
1039 | ||
1040 | dm_table_event_callback(map, NULL, NULL); | |
1041 | write_lock(&md->map_lock); | |
1042 | md->map = NULL; | |
1043 | write_unlock(&md->map_lock); | |
1044 | dm_table_put(map); | |
1045 | } | |
1046 | ||
1047 | /* | |
1048 | * Constructor for a new device. | |
1049 | */ | |
2b06cfff | 1050 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1051 | { |
1052 | struct mapped_device *md; | |
1053 | ||
2b06cfff | 1054 | md = alloc_dev(minor); |
1da177e4 LT |
1055 | if (!md) |
1056 | return -ENXIO; | |
1057 | ||
1058 | *result = md; | |
1059 | return 0; | |
1060 | } | |
1061 | ||
637842cf | 1062 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1063 | { |
1064 | struct mapped_device *md; | |
1da177e4 LT |
1065 | unsigned minor = MINOR(dev); |
1066 | ||
1067 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1068 | return NULL; | |
1069 | ||
f32c10b0 | 1070 | spin_lock(&_minor_lock); |
1da177e4 LT |
1071 | |
1072 | md = idr_find(&_minor_idr, minor); | |
fba9f90e JM |
1073 | if (md && (md == MINOR_ALLOCED || |
1074 | (dm_disk(md)->first_minor != minor) || | |
17b2f66f | 1075 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1076 | md = NULL; |
fba9f90e JM |
1077 | goto out; |
1078 | } | |
1da177e4 | 1079 | |
fba9f90e | 1080 | out: |
f32c10b0 | 1081 | spin_unlock(&_minor_lock); |
1da177e4 | 1082 | |
637842cf DT |
1083 | return md; |
1084 | } | |
1085 | ||
d229a958 DT |
1086 | struct mapped_device *dm_get_md(dev_t dev) |
1087 | { | |
1088 | struct mapped_device *md = dm_find_md(dev); | |
1089 | ||
1090 | if (md) | |
1091 | dm_get(md); | |
1092 | ||
1093 | return md; | |
1094 | } | |
1095 | ||
9ade92a9 | 1096 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1097 | { |
9ade92a9 | 1098 | return md->interface_ptr; |
1da177e4 LT |
1099 | } |
1100 | ||
1101 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1102 | { | |
1103 | md->interface_ptr = ptr; | |
1104 | } | |
1105 | ||
1106 | void dm_get(struct mapped_device *md) | |
1107 | { | |
1108 | atomic_inc(&md->holders); | |
1109 | } | |
1110 | ||
1111 | void dm_put(struct mapped_device *md) | |
1112 | { | |
1134e5ae | 1113 | struct dm_table *map; |
1da177e4 | 1114 | |
fba9f90e JM |
1115 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1116 | ||
f32c10b0 | 1117 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1118 | map = dm_get_table(md); |
ba61fdd1 | 1119 | idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); |
fba9f90e | 1120 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1121 | spin_unlock(&_minor_lock); |
cf222b37 | 1122 | if (!dm_suspended(md)) { |
1da177e4 LT |
1123 | dm_table_presuspend_targets(map); |
1124 | dm_table_postsuspend_targets(map); | |
1125 | } | |
1126 | __unbind(md); | |
1134e5ae | 1127 | dm_table_put(map); |
1da177e4 LT |
1128 | free_dev(md); |
1129 | } | |
1da177e4 LT |
1130 | } |
1131 | ||
1132 | /* | |
1133 | * Process the deferred bios | |
1134 | */ | |
1135 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1136 | { | |
1137 | struct bio *n; | |
1138 | ||
1139 | while (c) { | |
1140 | n = c->bi_next; | |
1141 | c->bi_next = NULL; | |
1142 | __split_bio(md, c); | |
1143 | c = n; | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * Swap in a new table (destroying old one). | |
1149 | */ | |
1150 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1151 | { | |
93c534ae | 1152 | int r = -EINVAL; |
1da177e4 | 1153 | |
2ca3310e | 1154 | down(&md->suspend_lock); |
1da177e4 LT |
1155 | |
1156 | /* device must be suspended */ | |
cf222b37 | 1157 | if (!dm_suspended(md)) |
93c534ae | 1158 | goto out; |
1da177e4 LT |
1159 | |
1160 | __unbind(md); | |
1161 | r = __bind(md, table); | |
1da177e4 | 1162 | |
93c534ae | 1163 | out: |
2ca3310e | 1164 | up(&md->suspend_lock); |
93c534ae | 1165 | return r; |
1da177e4 LT |
1166 | } |
1167 | ||
1168 | /* | |
1169 | * Functions to lock and unlock any filesystem running on the | |
1170 | * device. | |
1171 | */ | |
2ca3310e | 1172 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1173 | { |
e39e2e95 | 1174 | int r; |
1da177e4 LT |
1175 | |
1176 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1177 | |
e39e2e95 | 1178 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1179 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1180 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1181 | md->frozen_sb = NULL; |
1182 | return r; | |
dfbe03f6 AK |
1183 | } |
1184 | ||
aa8d7c2f AK |
1185 | set_bit(DMF_FROZEN, &md->flags); |
1186 | ||
1da177e4 | 1187 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1188 | * to go away while it is locked. |
1da177e4 LT |
1189 | */ |
1190 | return 0; | |
1191 | } | |
1192 | ||
2ca3310e | 1193 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1194 | { |
aa8d7c2f AK |
1195 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1196 | return; | |
1197 | ||
e39e2e95 | 1198 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1199 | md->frozen_sb = NULL; |
aa8d7c2f | 1200 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1201 | } |
1202 | ||
1203 | /* | |
1204 | * We need to be able to change a mapping table under a mounted | |
1205 | * filesystem. For example we might want to move some data in | |
1206 | * the background. Before the table can be swapped with | |
1207 | * dm_bind_table, dm_suspend must be called to flush any in | |
1208 | * flight bios and ensure that any further io gets deferred. | |
1209 | */ | |
aa8d7c2f | 1210 | int dm_suspend(struct mapped_device *md, int do_lockfs) |
1da177e4 | 1211 | { |
2ca3310e | 1212 | struct dm_table *map = NULL; |
1da177e4 | 1213 | DECLARE_WAITQUEUE(wait, current); |
1ecac7fd | 1214 | struct bio *def; |
cf222b37 | 1215 | int r = -EINVAL; |
1da177e4 | 1216 | |
2ca3310e AK |
1217 | down(&md->suspend_lock); |
1218 | ||
1219 | if (dm_suspended(md)) | |
1220 | goto out; | |
1da177e4 LT |
1221 | |
1222 | map = dm_get_table(md); | |
1da177e4 | 1223 | |
cf222b37 AK |
1224 | /* This does not get reverted if there's an error later. */ |
1225 | dm_table_presuspend_targets(map); | |
1226 | ||
e39e2e95 AK |
1227 | md->suspended_bdev = bdget_disk(md->disk, 0); |
1228 | if (!md->suspended_bdev) { | |
1229 | DMWARN("bdget failed in dm_suspend"); | |
1230 | r = -ENOMEM; | |
1231 | goto out; | |
1232 | } | |
1233 | ||
cf222b37 | 1234 | /* Flush I/O to the device. */ |
aa8d7c2f AK |
1235 | if (do_lockfs) { |
1236 | r = lock_fs(md); | |
1237 | if (r) | |
1238 | goto out; | |
1239 | } | |
1da177e4 LT |
1240 | |
1241 | /* | |
354e0071 | 1242 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1243 | */ |
2ca3310e AK |
1244 | down_write(&md->io_lock); |
1245 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1246 | |
1da177e4 | 1247 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1248 | up_write(&md->io_lock); |
1da177e4 LT |
1249 | |
1250 | /* unplug */ | |
2ca3310e | 1251 | if (map) |
1da177e4 | 1252 | dm_table_unplug_all(map); |
1da177e4 LT |
1253 | |
1254 | /* | |
1255 | * Then we wait for the already mapped ios to | |
1256 | * complete. | |
1257 | */ | |
1258 | while (1) { | |
1259 | set_current_state(TASK_INTERRUPTIBLE); | |
1260 | ||
1261 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1262 | break; | |
1263 | ||
1264 | io_schedule(); | |
1265 | } | |
1266 | set_current_state(TASK_RUNNING); | |
1267 | ||
2ca3310e | 1268 | down_write(&md->io_lock); |
1da177e4 LT |
1269 | remove_wait_queue(&md->wait, &wait); |
1270 | ||
1271 | /* were we interrupted ? */ | |
cf222b37 | 1272 | r = -EINTR; |
2ca3310e | 1273 | if (atomic_read(&md->pending)) { |
1ecac7fd JN |
1274 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1275 | def = bio_list_get(&md->deferred); | |
1276 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1277 | up_write(&md->io_lock); |
1278 | unlock_fs(md); | |
2ca3310e AK |
1279 | goto out; |
1280 | } | |
1281 | up_write(&md->io_lock); | |
1da177e4 | 1282 | |
cf222b37 | 1283 | dm_table_postsuspend_targets(map); |
1da177e4 | 1284 | |
2ca3310e | 1285 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1286 | |
2ca3310e | 1287 | r = 0; |
b84b0287 | 1288 | |
2ca3310e | 1289 | out: |
e39e2e95 AK |
1290 | if (r && md->suspended_bdev) { |
1291 | bdput(md->suspended_bdev); | |
1292 | md->suspended_bdev = NULL; | |
1293 | } | |
1294 | ||
2ca3310e AK |
1295 | dm_table_put(map); |
1296 | up(&md->suspend_lock); | |
cf222b37 | 1297 | return r; |
1da177e4 LT |
1298 | } |
1299 | ||
1300 | int dm_resume(struct mapped_device *md) | |
1301 | { | |
cf222b37 | 1302 | int r = -EINVAL; |
1da177e4 | 1303 | struct bio *def; |
cf222b37 | 1304 | struct dm_table *map = NULL; |
1da177e4 | 1305 | |
2ca3310e AK |
1306 | down(&md->suspend_lock); |
1307 | if (!dm_suspended(md)) | |
cf222b37 | 1308 | goto out; |
cf222b37 AK |
1309 | |
1310 | map = dm_get_table(md); | |
2ca3310e | 1311 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1312 | goto out; |
1da177e4 LT |
1313 | |
1314 | dm_table_resume_targets(map); | |
2ca3310e AK |
1315 | |
1316 | down_write(&md->io_lock); | |
1da177e4 LT |
1317 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1318 | ||
1319 | def = bio_list_get(&md->deferred); | |
1320 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1321 | up_write(&md->io_lock); |
1322 | ||
1323 | unlock_fs(md); | |
1324 | ||
e39e2e95 AK |
1325 | bdput(md->suspended_bdev); |
1326 | md->suspended_bdev = NULL; | |
1327 | ||
2ca3310e AK |
1328 | clear_bit(DMF_SUSPENDED, &md->flags); |
1329 | ||
1da177e4 | 1330 | dm_table_unplug_all(map); |
1da177e4 | 1331 | |
cf222b37 | 1332 | r = 0; |
2ca3310e | 1333 | |
cf222b37 AK |
1334 | out: |
1335 | dm_table_put(map); | |
2ca3310e AK |
1336 | up(&md->suspend_lock); |
1337 | ||
cf222b37 | 1338 | return r; |
1da177e4 LT |
1339 | } |
1340 | ||
1341 | /*----------------------------------------------------------------- | |
1342 | * Event notification. | |
1343 | *---------------------------------------------------------------*/ | |
1344 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1345 | { | |
1346 | return atomic_read(&md->event_nr); | |
1347 | } | |
1348 | ||
1349 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1350 | { | |
1351 | return wait_event_interruptible(md->eventq, | |
1352 | (event_nr != atomic_read(&md->event_nr))); | |
1353 | } | |
1354 | ||
1355 | /* | |
1356 | * The gendisk is only valid as long as you have a reference | |
1357 | * count on 'md'. | |
1358 | */ | |
1359 | struct gendisk *dm_disk(struct mapped_device *md) | |
1360 | { | |
1361 | return md->disk; | |
1362 | } | |
1363 | ||
1364 | int dm_suspended(struct mapped_device *md) | |
1365 | { | |
1366 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1367 | } | |
1368 | ||
1369 | static struct block_device_operations dm_blk_dops = { | |
1370 | .open = dm_blk_open, | |
1371 | .release = dm_blk_close, | |
3ac51e74 | 1372 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1373 | .owner = THIS_MODULE |
1374 | }; | |
1375 | ||
1376 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1377 | ||
1378 | /* | |
1379 | * module hooks | |
1380 | */ | |
1381 | module_init(dm_init); | |
1382 | module_exit(dm_exit); | |
1383 | ||
1384 | module_param(major, uint, 0); | |
1385 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1386 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1387 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1388 | MODULE_LICENSE("GPL"); |