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> |
aa129a22 | 23 | #include <linux/smp_lock.h> |
1da177e4 | 24 | |
72d94861 AK |
25 | #define DM_MSG_PREFIX "core" |
26 | ||
1da177e4 LT |
27 | static const char *_name = DM_NAME; |
28 | ||
29 | static unsigned int major = 0; | |
30 | static unsigned int _major = 0; | |
31 | ||
f32c10b0 | 32 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 LT |
33 | /* |
34 | * One of these is allocated per bio. | |
35 | */ | |
36 | struct dm_io { | |
37 | struct mapped_device *md; | |
38 | int error; | |
39 | struct bio *bio; | |
40 | atomic_t io_count; | |
3eaf840e | 41 | unsigned long start_time; |
1da177e4 LT |
42 | }; |
43 | ||
44 | /* | |
45 | * One of these is allocated per target within a bio. Hopefully | |
46 | * this will be simplified out one day. | |
47 | */ | |
48 | struct target_io { | |
49 | struct dm_io *io; | |
50 | struct dm_target *ti; | |
51 | union map_info info; | |
52 | }; | |
53 | ||
54 | union map_info *dm_get_mapinfo(struct bio *bio) | |
55 | { | |
17b2f66f AK |
56 | if (bio && bio->bi_private) |
57 | return &((struct target_io *)bio->bi_private)->info; | |
58 | return NULL; | |
1da177e4 LT |
59 | } |
60 | ||
ba61fdd1 JM |
61 | #define MINOR_ALLOCED ((void *)-1) |
62 | ||
1da177e4 LT |
63 | /* |
64 | * Bits for the md->flags field. | |
65 | */ | |
66 | #define DMF_BLOCK_IO 0 | |
67 | #define DMF_SUSPENDED 1 | |
aa8d7c2f | 68 | #define DMF_FROZEN 2 |
fba9f90e | 69 | #define DMF_FREEING 3 |
5c6bd75d | 70 | #define DMF_DELETING 4 |
1da177e4 LT |
71 | |
72 | struct mapped_device { | |
2ca3310e AK |
73 | struct rw_semaphore io_lock; |
74 | struct semaphore suspend_lock; | |
1da177e4 LT |
75 | rwlock_t map_lock; |
76 | atomic_t holders; | |
5c6bd75d | 77 | atomic_t open_count; |
1da177e4 LT |
78 | |
79 | unsigned long flags; | |
80 | ||
81 | request_queue_t *queue; | |
82 | struct gendisk *disk; | |
7e51f257 | 83 | char name[16]; |
1da177e4 LT |
84 | |
85 | void *interface_ptr; | |
86 | ||
87 | /* | |
88 | * A list of ios that arrived while we were suspended. | |
89 | */ | |
90 | atomic_t pending; | |
91 | wait_queue_head_t wait; | |
74859364 | 92 | struct bio_list deferred; |
1da177e4 LT |
93 | |
94 | /* | |
95 | * The current mapping. | |
96 | */ | |
97 | struct dm_table *map; | |
98 | ||
99 | /* | |
100 | * io objects are allocated from here. | |
101 | */ | |
102 | mempool_t *io_pool; | |
103 | mempool_t *tio_pool; | |
104 | ||
9faf400f SB |
105 | struct bio_set *bs; |
106 | ||
1da177e4 LT |
107 | /* |
108 | * Event handling. | |
109 | */ | |
110 | atomic_t event_nr; | |
111 | wait_queue_head_t eventq; | |
112 | ||
113 | /* | |
114 | * freeze/thaw support require holding onto a super block | |
115 | */ | |
116 | struct super_block *frozen_sb; | |
e39e2e95 | 117 | struct block_device *suspended_bdev; |
3ac51e74 DW |
118 | |
119 | /* forced geometry settings */ | |
120 | struct hd_geometry geometry; | |
1da177e4 LT |
121 | }; |
122 | ||
123 | #define MIN_IOS 256 | |
e18b890b CL |
124 | static struct kmem_cache *_io_cache; |
125 | static struct kmem_cache *_tio_cache; | |
1da177e4 | 126 | |
1da177e4 LT |
127 | static int __init local_init(void) |
128 | { | |
129 | int r; | |
130 | ||
1da177e4 LT |
131 | /* allocate a slab for the dm_ios */ |
132 | _io_cache = kmem_cache_create("dm_io", | |
133 | sizeof(struct dm_io), 0, 0, NULL, NULL); | |
134 | if (!_io_cache) | |
135 | return -ENOMEM; | |
136 | ||
137 | /* allocate a slab for the target ios */ | |
138 | _tio_cache = kmem_cache_create("dm_tio", sizeof(struct target_io), | |
139 | 0, 0, NULL, NULL); | |
140 | if (!_tio_cache) { | |
141 | kmem_cache_destroy(_io_cache); | |
142 | return -ENOMEM; | |
143 | } | |
144 | ||
145 | _major = major; | |
146 | r = register_blkdev(_major, _name); | |
147 | if (r < 0) { | |
148 | kmem_cache_destroy(_tio_cache); | |
149 | kmem_cache_destroy(_io_cache); | |
150 | return r; | |
151 | } | |
152 | ||
153 | if (!_major) | |
154 | _major = r; | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | static void local_exit(void) | |
160 | { | |
161 | kmem_cache_destroy(_tio_cache); | |
162 | kmem_cache_destroy(_io_cache); | |
163 | ||
1da177e4 | 164 | if (unregister_blkdev(_major, _name) < 0) |
890fbae2 | 165 | DMERR("unregister_blkdev failed"); |
1da177e4 LT |
166 | |
167 | _major = 0; | |
168 | ||
169 | DMINFO("cleaned up"); | |
170 | } | |
171 | ||
172 | int (*_inits[])(void) __initdata = { | |
173 | local_init, | |
174 | dm_target_init, | |
175 | dm_linear_init, | |
176 | dm_stripe_init, | |
177 | dm_interface_init, | |
178 | }; | |
179 | ||
180 | void (*_exits[])(void) = { | |
181 | local_exit, | |
182 | dm_target_exit, | |
183 | dm_linear_exit, | |
184 | dm_stripe_exit, | |
185 | dm_interface_exit, | |
186 | }; | |
187 | ||
188 | static int __init dm_init(void) | |
189 | { | |
190 | const int count = ARRAY_SIZE(_inits); | |
191 | ||
192 | int r, i; | |
193 | ||
194 | for (i = 0; i < count; i++) { | |
195 | r = _inits[i](); | |
196 | if (r) | |
197 | goto bad; | |
198 | } | |
199 | ||
200 | return 0; | |
201 | ||
202 | bad: | |
203 | while (i--) | |
204 | _exits[i](); | |
205 | ||
206 | return r; | |
207 | } | |
208 | ||
209 | static void __exit dm_exit(void) | |
210 | { | |
211 | int i = ARRAY_SIZE(_exits); | |
212 | ||
213 | while (i--) | |
214 | _exits[i](); | |
215 | } | |
216 | ||
217 | /* | |
218 | * Block device functions | |
219 | */ | |
220 | static int dm_blk_open(struct inode *inode, struct file *file) | |
221 | { | |
222 | struct mapped_device *md; | |
223 | ||
fba9f90e JM |
224 | spin_lock(&_minor_lock); |
225 | ||
1da177e4 | 226 | md = inode->i_bdev->bd_disk->private_data; |
fba9f90e JM |
227 | if (!md) |
228 | goto out; | |
229 | ||
5c6bd75d AK |
230 | if (test_bit(DMF_FREEING, &md->flags) || |
231 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
232 | md = NULL; |
233 | goto out; | |
234 | } | |
235 | ||
1da177e4 | 236 | dm_get(md); |
5c6bd75d | 237 | atomic_inc(&md->open_count); |
fba9f90e JM |
238 | |
239 | out: | |
240 | spin_unlock(&_minor_lock); | |
241 | ||
242 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
243 | } |
244 | ||
245 | static int dm_blk_close(struct inode *inode, struct file *file) | |
246 | { | |
247 | struct mapped_device *md; | |
248 | ||
249 | md = inode->i_bdev->bd_disk->private_data; | |
5c6bd75d | 250 | atomic_dec(&md->open_count); |
1da177e4 LT |
251 | dm_put(md); |
252 | return 0; | |
253 | } | |
254 | ||
5c6bd75d AK |
255 | int dm_open_count(struct mapped_device *md) |
256 | { | |
257 | return atomic_read(&md->open_count); | |
258 | } | |
259 | ||
260 | /* | |
261 | * Guarantees nothing is using the device before it's deleted. | |
262 | */ | |
263 | int dm_lock_for_deletion(struct mapped_device *md) | |
264 | { | |
265 | int r = 0; | |
266 | ||
267 | spin_lock(&_minor_lock); | |
268 | ||
269 | if (dm_open_count(md)) | |
270 | r = -EBUSY; | |
271 | else | |
272 | set_bit(DMF_DELETING, &md->flags); | |
273 | ||
274 | spin_unlock(&_minor_lock); | |
275 | ||
276 | return r; | |
277 | } | |
278 | ||
3ac51e74 DW |
279 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
280 | { | |
281 | struct mapped_device *md = bdev->bd_disk->private_data; | |
282 | ||
283 | return dm_get_geometry(md, geo); | |
284 | } | |
285 | ||
aa129a22 MB |
286 | static int dm_blk_ioctl(struct inode *inode, struct file *file, |
287 | unsigned int cmd, unsigned long arg) | |
288 | { | |
289 | struct mapped_device *md; | |
290 | struct dm_table *map; | |
291 | struct dm_target *tgt; | |
292 | int r = -ENOTTY; | |
293 | ||
294 | /* We don't really need this lock, but we do need 'inode'. */ | |
295 | unlock_kernel(); | |
296 | ||
297 | md = inode->i_bdev->bd_disk->private_data; | |
298 | ||
299 | map = dm_get_table(md); | |
300 | ||
301 | if (!map || !dm_table_get_size(map)) | |
302 | goto out; | |
303 | ||
304 | /* We only support devices that have a single target */ | |
305 | if (dm_table_get_num_targets(map) != 1) | |
306 | goto out; | |
307 | ||
308 | tgt = dm_table_get_target(map, 0); | |
309 | ||
310 | if (dm_suspended(md)) { | |
311 | r = -EAGAIN; | |
312 | goto out; | |
313 | } | |
314 | ||
315 | if (tgt->type->ioctl) | |
316 | r = tgt->type->ioctl(tgt, inode, file, cmd, arg); | |
317 | ||
318 | out: | |
319 | dm_table_put(map); | |
320 | ||
321 | lock_kernel(); | |
322 | return r; | |
323 | } | |
324 | ||
1da177e4 LT |
325 | static inline struct dm_io *alloc_io(struct mapped_device *md) |
326 | { | |
327 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
328 | } | |
329 | ||
330 | static inline void free_io(struct mapped_device *md, struct dm_io *io) | |
331 | { | |
332 | mempool_free(io, md->io_pool); | |
333 | } | |
334 | ||
335 | static inline struct target_io *alloc_tio(struct mapped_device *md) | |
336 | { | |
337 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
338 | } | |
339 | ||
340 | static inline void free_tio(struct mapped_device *md, struct target_io *tio) | |
341 | { | |
342 | mempool_free(tio, md->tio_pool); | |
343 | } | |
344 | ||
3eaf840e JNN |
345 | static void start_io_acct(struct dm_io *io) |
346 | { | |
347 | struct mapped_device *md = io->md; | |
348 | ||
349 | io->start_time = jiffies; | |
350 | ||
351 | preempt_disable(); | |
352 | disk_round_stats(dm_disk(md)); | |
353 | preempt_enable(); | |
354 | dm_disk(md)->in_flight = atomic_inc_return(&md->pending); | |
355 | } | |
356 | ||
357 | static int end_io_acct(struct dm_io *io) | |
358 | { | |
359 | struct mapped_device *md = io->md; | |
360 | struct bio *bio = io->bio; | |
361 | unsigned long duration = jiffies - io->start_time; | |
362 | int pending; | |
363 | int rw = bio_data_dir(bio); | |
364 | ||
365 | preempt_disable(); | |
366 | disk_round_stats(dm_disk(md)); | |
367 | preempt_enable(); | |
368 | dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending); | |
369 | ||
370 | disk_stat_add(dm_disk(md), ticks[rw], duration); | |
371 | ||
372 | return !pending; | |
373 | } | |
374 | ||
1da177e4 LT |
375 | /* |
376 | * Add the bio to the list of deferred io. | |
377 | */ | |
378 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
379 | { | |
2ca3310e | 380 | down_write(&md->io_lock); |
1da177e4 LT |
381 | |
382 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 383 | up_write(&md->io_lock); |
1da177e4 LT |
384 | return 1; |
385 | } | |
386 | ||
387 | bio_list_add(&md->deferred, bio); | |
388 | ||
2ca3310e | 389 | up_write(&md->io_lock); |
1da177e4 LT |
390 | return 0; /* deferred successfully */ |
391 | } | |
392 | ||
393 | /* | |
394 | * Everyone (including functions in this file), should use this | |
395 | * function to access the md->map field, and make sure they call | |
396 | * dm_table_put() when finished. | |
397 | */ | |
398 | struct dm_table *dm_get_table(struct mapped_device *md) | |
399 | { | |
400 | struct dm_table *t; | |
401 | ||
402 | read_lock(&md->map_lock); | |
403 | t = md->map; | |
404 | if (t) | |
405 | dm_table_get(t); | |
406 | read_unlock(&md->map_lock); | |
407 | ||
408 | return t; | |
409 | } | |
410 | ||
3ac51e74 DW |
411 | /* |
412 | * Get the geometry associated with a dm device | |
413 | */ | |
414 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
415 | { | |
416 | *geo = md->geometry; | |
417 | ||
418 | return 0; | |
419 | } | |
420 | ||
421 | /* | |
422 | * Set the geometry of a device. | |
423 | */ | |
424 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
425 | { | |
426 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
427 | ||
428 | if (geo->start > sz) { | |
429 | DMWARN("Start sector is beyond the geometry limits."); | |
430 | return -EINVAL; | |
431 | } | |
432 | ||
433 | md->geometry = *geo; | |
434 | ||
435 | return 0; | |
436 | } | |
437 | ||
1da177e4 LT |
438 | /*----------------------------------------------------------------- |
439 | * CRUD START: | |
440 | * A more elegant soln is in the works that uses the queue | |
441 | * merge fn, unfortunately there are a couple of changes to | |
442 | * the block layer that I want to make for this. So in the | |
443 | * interests of getting something for people to use I give | |
444 | * you this clearly demarcated crap. | |
445 | *---------------------------------------------------------------*/ | |
446 | ||
447 | /* | |
448 | * Decrements the number of outstanding ios that a bio has been | |
449 | * cloned into, completing the original io if necc. | |
450 | */ | |
858119e1 | 451 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 LT |
452 | { |
453 | if (error) | |
454 | io->error = error; | |
455 | ||
456 | if (atomic_dec_and_test(&io->io_count)) { | |
3eaf840e | 457 | if (end_io_acct(io)) |
1da177e4 LT |
458 | /* nudge anyone waiting on suspend queue */ |
459 | wake_up(&io->md->wait); | |
460 | ||
2056a782 JA |
461 | blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); |
462 | ||
1da177e4 LT |
463 | bio_endio(io->bio, io->bio->bi_size, io->error); |
464 | free_io(io->md, io); | |
465 | } | |
466 | } | |
467 | ||
468 | static int clone_endio(struct bio *bio, unsigned int done, int error) | |
469 | { | |
470 | int r = 0; | |
471 | struct target_io *tio = bio->bi_private; | |
9faf400f | 472 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
473 | dm_endio_fn endio = tio->ti->type->end_io; |
474 | ||
475 | if (bio->bi_size) | |
476 | return 1; | |
477 | ||
478 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) | |
479 | error = -EIO; | |
480 | ||
481 | if (endio) { | |
482 | r = endio(tio->ti, bio, error, &tio->info); | |
483 | if (r < 0) | |
484 | error = r; | |
1da177e4 LT |
485 | else if (r > 0) |
486 | /* the target wants another shot at the io */ | |
487 | return 1; | |
488 | } | |
489 | ||
9faf400f SB |
490 | dec_pending(tio->io, error); |
491 | ||
492 | /* | |
493 | * Store md for cleanup instead of tio which is about to get freed. | |
494 | */ | |
495 | bio->bi_private = md->bs; | |
496 | ||
1da177e4 | 497 | bio_put(bio); |
9faf400f | 498 | free_tio(md, tio); |
1da177e4 LT |
499 | return r; |
500 | } | |
501 | ||
502 | static sector_t max_io_len(struct mapped_device *md, | |
503 | sector_t sector, struct dm_target *ti) | |
504 | { | |
505 | sector_t offset = sector - ti->begin; | |
506 | sector_t len = ti->len - offset; | |
507 | ||
508 | /* | |
509 | * Does the target need to split even further ? | |
510 | */ | |
511 | if (ti->split_io) { | |
512 | sector_t boundary; | |
513 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
514 | - offset; | |
515 | if (len > boundary) | |
516 | len = boundary; | |
517 | } | |
518 | ||
519 | return len; | |
520 | } | |
521 | ||
522 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
523 | struct target_io *tio) | |
524 | { | |
525 | int r; | |
2056a782 | 526 | sector_t sector; |
9faf400f | 527 | struct mapped_device *md; |
1da177e4 LT |
528 | |
529 | /* | |
530 | * Sanity checks. | |
531 | */ | |
532 | BUG_ON(!clone->bi_size); | |
533 | ||
534 | clone->bi_end_io = clone_endio; | |
535 | clone->bi_private = tio; | |
536 | ||
537 | /* | |
538 | * Map the clone. If r == 0 we don't need to do | |
539 | * anything, the target has assumed ownership of | |
540 | * this io. | |
541 | */ | |
542 | atomic_inc(&tio->io->io_count); | |
2056a782 | 543 | sector = clone->bi_sector; |
1da177e4 | 544 | r = ti->type->map(ti, clone, &tio->info); |
2056a782 | 545 | if (r > 0) { |
1da177e4 | 546 | /* the bio has been remapped so dispatch it */ |
2056a782 | 547 | |
17b2f66f AK |
548 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, |
549 | tio->io->bio->bi_bdev->bd_dev, sector, | |
2056a782 JA |
550 | clone->bi_sector); |
551 | ||
1da177e4 | 552 | generic_make_request(clone); |
74859364 | 553 | } else if (r < 0) { |
1da177e4 | 554 | /* error the io and bail out */ |
9faf400f SB |
555 | md = tio->io->md; |
556 | dec_pending(tio->io, r); | |
557 | /* | |
558 | * Store bio_set for cleanup. | |
559 | */ | |
560 | clone->bi_private = md->bs; | |
1da177e4 | 561 | bio_put(clone); |
9faf400f | 562 | free_tio(md, tio); |
1da177e4 LT |
563 | } |
564 | } | |
565 | ||
566 | struct clone_info { | |
567 | struct mapped_device *md; | |
568 | struct dm_table *map; | |
569 | struct bio *bio; | |
570 | struct dm_io *io; | |
571 | sector_t sector; | |
572 | sector_t sector_count; | |
573 | unsigned short idx; | |
574 | }; | |
575 | ||
3676347a PO |
576 | static void dm_bio_destructor(struct bio *bio) |
577 | { | |
9faf400f SB |
578 | struct bio_set *bs = bio->bi_private; |
579 | ||
580 | bio_free(bio, bs); | |
3676347a PO |
581 | } |
582 | ||
1da177e4 LT |
583 | /* |
584 | * Creates a little bio that is just does part of a bvec. | |
585 | */ | |
586 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
587 | unsigned short idx, unsigned int offset, | |
9faf400f | 588 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
589 | { |
590 | struct bio *clone; | |
591 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
592 | ||
9faf400f | 593 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 594 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
595 | *clone->bi_io_vec = *bv; |
596 | ||
597 | clone->bi_sector = sector; | |
598 | clone->bi_bdev = bio->bi_bdev; | |
599 | clone->bi_rw = bio->bi_rw; | |
600 | clone->bi_vcnt = 1; | |
601 | clone->bi_size = to_bytes(len); | |
602 | clone->bi_io_vec->bv_offset = offset; | |
603 | clone->bi_io_vec->bv_len = clone->bi_size; | |
604 | ||
605 | return clone; | |
606 | } | |
607 | ||
608 | /* | |
609 | * Creates a bio that consists of range of complete bvecs. | |
610 | */ | |
611 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
612 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 613 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
614 | { |
615 | struct bio *clone; | |
616 | ||
9faf400f SB |
617 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
618 | __bio_clone(clone, bio); | |
619 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
620 | clone->bi_sector = sector; |
621 | clone->bi_idx = idx; | |
622 | clone->bi_vcnt = idx + bv_count; | |
623 | clone->bi_size = to_bytes(len); | |
624 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
625 | ||
626 | return clone; | |
627 | } | |
628 | ||
629 | static void __clone_and_map(struct clone_info *ci) | |
630 | { | |
631 | struct bio *clone, *bio = ci->bio; | |
632 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
633 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
634 | struct target_io *tio; | |
635 | ||
636 | /* | |
637 | * Allocate a target io object. | |
638 | */ | |
639 | tio = alloc_tio(ci->md); | |
640 | tio->io = ci->io; | |
641 | tio->ti = ti; | |
642 | memset(&tio->info, 0, sizeof(tio->info)); | |
643 | ||
644 | if (ci->sector_count <= max) { | |
645 | /* | |
646 | * Optimise for the simple case where we can do all of | |
647 | * the remaining io with a single clone. | |
648 | */ | |
649 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
650 | bio->bi_vcnt - ci->idx, ci->sector_count, |
651 | ci->md->bs); | |
1da177e4 LT |
652 | __map_bio(ti, clone, tio); |
653 | ci->sector_count = 0; | |
654 | ||
655 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
656 | /* | |
657 | * There are some bvecs that don't span targets. | |
658 | * Do as many of these as possible. | |
659 | */ | |
660 | int i; | |
661 | sector_t remaining = max; | |
662 | sector_t bv_len; | |
663 | ||
664 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
665 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
666 | ||
667 | if (bv_len > remaining) | |
668 | break; | |
669 | ||
670 | remaining -= bv_len; | |
671 | len += bv_len; | |
672 | } | |
673 | ||
9faf400f SB |
674 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
675 | ci->md->bs); | |
1da177e4 LT |
676 | __map_bio(ti, clone, tio); |
677 | ||
678 | ci->sector += len; | |
679 | ci->sector_count -= len; | |
680 | ci->idx = i; | |
681 | ||
682 | } else { | |
683 | /* | |
d2044a94 | 684 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
685 | */ |
686 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
687 | sector_t remaining = to_sector(bv->bv_len); |
688 | unsigned int offset = 0; | |
1da177e4 | 689 | |
d2044a94 AK |
690 | do { |
691 | if (offset) { | |
692 | ti = dm_table_find_target(ci->map, ci->sector); | |
693 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 694 | |
d2044a94 AK |
695 | tio = alloc_tio(ci->md); |
696 | tio->io = ci->io; | |
697 | tio->ti = ti; | |
698 | memset(&tio->info, 0, sizeof(tio->info)); | |
699 | } | |
700 | ||
701 | len = min(remaining, max); | |
702 | ||
703 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
704 | bv->bv_offset + offset, len, |
705 | ci->md->bs); | |
d2044a94 AK |
706 | |
707 | __map_bio(ti, clone, tio); | |
708 | ||
709 | ci->sector += len; | |
710 | ci->sector_count -= len; | |
711 | offset += to_bytes(len); | |
712 | } while (remaining -= len); | |
1da177e4 | 713 | |
1da177e4 LT |
714 | ci->idx++; |
715 | } | |
716 | } | |
717 | ||
718 | /* | |
719 | * Split the bio into several clones. | |
720 | */ | |
721 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
722 | { | |
723 | struct clone_info ci; | |
724 | ||
725 | ci.map = dm_get_table(md); | |
726 | if (!ci.map) { | |
727 | bio_io_error(bio, bio->bi_size); | |
728 | return; | |
729 | } | |
730 | ||
731 | ci.md = md; | |
732 | ci.bio = bio; | |
733 | ci.io = alloc_io(md); | |
734 | ci.io->error = 0; | |
735 | atomic_set(&ci.io->io_count, 1); | |
736 | ci.io->bio = bio; | |
737 | ci.io->md = md; | |
738 | ci.sector = bio->bi_sector; | |
739 | ci.sector_count = bio_sectors(bio); | |
740 | ci.idx = bio->bi_idx; | |
741 | ||
3eaf840e | 742 | start_io_acct(ci.io); |
1da177e4 LT |
743 | while (ci.sector_count) |
744 | __clone_and_map(&ci); | |
745 | ||
746 | /* drop the extra reference count */ | |
747 | dec_pending(ci.io, 0); | |
748 | dm_table_put(ci.map); | |
749 | } | |
750 | /*----------------------------------------------------------------- | |
751 | * CRUD END | |
752 | *---------------------------------------------------------------*/ | |
753 | ||
754 | /* | |
755 | * The request function that just remaps the bio built up by | |
756 | * dm_merge_bvec. | |
757 | */ | |
758 | static int dm_request(request_queue_t *q, struct bio *bio) | |
759 | { | |
760 | int r; | |
12f03a49 | 761 | int rw = bio_data_dir(bio); |
1da177e4 LT |
762 | struct mapped_device *md = q->queuedata; |
763 | ||
2ca3310e | 764 | down_read(&md->io_lock); |
1da177e4 | 765 | |
12f03a49 KC |
766 | disk_stat_inc(dm_disk(md), ios[rw]); |
767 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
768 | ||
1da177e4 LT |
769 | /* |
770 | * If we're suspended we have to queue | |
771 | * this io for later. | |
772 | */ | |
773 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 774 | up_read(&md->io_lock); |
1da177e4 LT |
775 | |
776 | if (bio_rw(bio) == READA) { | |
777 | bio_io_error(bio, bio->bi_size); | |
778 | return 0; | |
779 | } | |
780 | ||
781 | r = queue_io(md, bio); | |
782 | if (r < 0) { | |
783 | bio_io_error(bio, bio->bi_size); | |
784 | return 0; | |
785 | ||
786 | } else if (r == 0) | |
787 | return 0; /* deferred successfully */ | |
788 | ||
789 | /* | |
790 | * We're in a while loop, because someone could suspend | |
791 | * before we get to the following read lock. | |
792 | */ | |
2ca3310e | 793 | down_read(&md->io_lock); |
1da177e4 LT |
794 | } |
795 | ||
796 | __split_bio(md, bio); | |
2ca3310e | 797 | up_read(&md->io_lock); |
1da177e4 LT |
798 | return 0; |
799 | } | |
800 | ||
801 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
802 | sector_t *error_sector) | |
803 | { | |
804 | struct mapped_device *md = q->queuedata; | |
805 | struct dm_table *map = dm_get_table(md); | |
806 | int ret = -ENXIO; | |
807 | ||
808 | if (map) { | |
cf222b37 | 809 | ret = dm_table_flush_all(map); |
1da177e4 LT |
810 | dm_table_put(map); |
811 | } | |
812 | ||
813 | return ret; | |
814 | } | |
815 | ||
816 | static void dm_unplug_all(request_queue_t *q) | |
817 | { | |
818 | struct mapped_device *md = q->queuedata; | |
819 | struct dm_table *map = dm_get_table(md); | |
820 | ||
821 | if (map) { | |
822 | dm_table_unplug_all(map); | |
823 | dm_table_put(map); | |
824 | } | |
825 | } | |
826 | ||
827 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
828 | { | |
829 | int r; | |
830 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
831 | struct dm_table *map = dm_get_table(md); | |
832 | ||
833 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
834 | r = bdi_bits; | |
835 | else | |
836 | r = dm_table_any_congested(map, bdi_bits); | |
837 | ||
838 | dm_table_put(map); | |
839 | return r; | |
840 | } | |
841 | ||
842 | /*----------------------------------------------------------------- | |
843 | * An IDR is used to keep track of allocated minor numbers. | |
844 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
845 | static DEFINE_IDR(_minor_idr); |
846 | ||
2b06cfff | 847 | static void free_minor(int minor) |
1da177e4 | 848 | { |
f32c10b0 | 849 | spin_lock(&_minor_lock); |
1da177e4 | 850 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 851 | spin_unlock(&_minor_lock); |
1da177e4 LT |
852 | } |
853 | ||
854 | /* | |
855 | * See if the device with a specific minor # is free. | |
856 | */ | |
2b06cfff | 857 | static int specific_minor(struct mapped_device *md, int minor) |
1da177e4 LT |
858 | { |
859 | int r, m; | |
860 | ||
861 | if (minor >= (1 << MINORBITS)) | |
862 | return -EINVAL; | |
863 | ||
62f75c2f JM |
864 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
865 | if (!r) | |
866 | return -ENOMEM; | |
867 | ||
f32c10b0 | 868 | spin_lock(&_minor_lock); |
1da177e4 LT |
869 | |
870 | if (idr_find(&_minor_idr, minor)) { | |
871 | r = -EBUSY; | |
872 | goto out; | |
873 | } | |
874 | ||
ba61fdd1 | 875 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 876 | if (r) |
1da177e4 | 877 | goto out; |
1da177e4 LT |
878 | |
879 | if (m != minor) { | |
880 | idr_remove(&_minor_idr, m); | |
881 | r = -EBUSY; | |
882 | goto out; | |
883 | } | |
884 | ||
885 | out: | |
f32c10b0 | 886 | spin_unlock(&_minor_lock); |
1da177e4 LT |
887 | return r; |
888 | } | |
889 | ||
2b06cfff | 890 | static int next_free_minor(struct mapped_device *md, int *minor) |
1da177e4 | 891 | { |
2b06cfff | 892 | int r, m; |
1da177e4 | 893 | |
1da177e4 | 894 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
895 | if (!r) |
896 | return -ENOMEM; | |
897 | ||
f32c10b0 | 898 | spin_lock(&_minor_lock); |
1da177e4 | 899 | |
ba61fdd1 | 900 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
1da177e4 LT |
901 | if (r) { |
902 | goto out; | |
903 | } | |
904 | ||
905 | if (m >= (1 << MINORBITS)) { | |
906 | idr_remove(&_minor_idr, m); | |
907 | r = -ENOSPC; | |
908 | goto out; | |
909 | } | |
910 | ||
911 | *minor = m; | |
912 | ||
913 | out: | |
f32c10b0 | 914 | spin_unlock(&_minor_lock); |
1da177e4 LT |
915 | return r; |
916 | } | |
917 | ||
918 | static struct block_device_operations dm_blk_dops; | |
919 | ||
920 | /* | |
921 | * Allocate and initialise a blank device with a given minor. | |
922 | */ | |
2b06cfff | 923 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
924 | { |
925 | int r; | |
926 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
ba61fdd1 | 927 | void *old_md; |
1da177e4 LT |
928 | |
929 | if (!md) { | |
930 | DMWARN("unable to allocate device, out of memory."); | |
931 | return NULL; | |
932 | } | |
933 | ||
10da4f79 JM |
934 | if (!try_module_get(THIS_MODULE)) |
935 | goto bad0; | |
936 | ||
1da177e4 | 937 | /* get a minor number for the dev */ |
2b06cfff AK |
938 | if (minor == DM_ANY_MINOR) |
939 | r = next_free_minor(md, &minor); | |
940 | else | |
941 | r = specific_minor(md, minor); | |
1da177e4 LT |
942 | if (r < 0) |
943 | goto bad1; | |
944 | ||
945 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
946 | init_rwsem(&md->io_lock); |
947 | init_MUTEX(&md->suspend_lock); | |
1da177e4 LT |
948 | rwlock_init(&md->map_lock); |
949 | atomic_set(&md->holders, 1); | |
5c6bd75d | 950 | atomic_set(&md->open_count, 0); |
1da177e4 LT |
951 | atomic_set(&md->event_nr, 0); |
952 | ||
953 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
954 | if (!md->queue) | |
e3f6ac61 | 955 | goto bad1_free_minor; |
1da177e4 LT |
956 | |
957 | md->queue->queuedata = md; | |
958 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
959 | md->queue->backing_dev_info.congested_data = md; | |
960 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 961 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
962 | md->queue->unplug_fn = dm_unplug_all; |
963 | md->queue->issue_flush_fn = dm_flush_all; | |
964 | ||
93d2341c | 965 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 KU |
966 | if (!md->io_pool) |
967 | goto bad2; | |
1da177e4 | 968 | |
93d2341c | 969 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
970 | if (!md->tio_pool) |
971 | goto bad3; | |
972 | ||
9faf400f SB |
973 | md->bs = bioset_create(16, 16, 4); |
974 | if (!md->bs) | |
975 | goto bad_no_bioset; | |
976 | ||
1da177e4 LT |
977 | md->disk = alloc_disk(1); |
978 | if (!md->disk) | |
979 | goto bad4; | |
980 | ||
f0b04115 JM |
981 | atomic_set(&md->pending, 0); |
982 | init_waitqueue_head(&md->wait); | |
983 | init_waitqueue_head(&md->eventq); | |
984 | ||
1da177e4 LT |
985 | md->disk->major = _major; |
986 | md->disk->first_minor = minor; | |
987 | md->disk->fops = &dm_blk_dops; | |
988 | md->disk->queue = md->queue; | |
989 | md->disk->private_data = md; | |
990 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
991 | add_disk(md->disk); | |
7e51f257 | 992 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 993 | |
ba61fdd1 | 994 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 995 | spin_lock(&_minor_lock); |
ba61fdd1 | 996 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 997 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
998 | |
999 | BUG_ON(old_md != MINOR_ALLOCED); | |
1000 | ||
1da177e4 LT |
1001 | return md; |
1002 | ||
1003 | bad4: | |
9faf400f SB |
1004 | bioset_free(md->bs); |
1005 | bad_no_bioset: | |
1da177e4 LT |
1006 | mempool_destroy(md->tio_pool); |
1007 | bad3: | |
1008 | mempool_destroy(md->io_pool); | |
1009 | bad2: | |
1312f40e | 1010 | blk_cleanup_queue(md->queue); |
e3f6ac61 | 1011 | bad1_free_minor: |
1da177e4 LT |
1012 | free_minor(minor); |
1013 | bad1: | |
10da4f79 JM |
1014 | module_put(THIS_MODULE); |
1015 | bad0: | |
1da177e4 LT |
1016 | kfree(md); |
1017 | return NULL; | |
1018 | } | |
1019 | ||
1020 | static void free_dev(struct mapped_device *md) | |
1021 | { | |
2b06cfff | 1022 | int minor = md->disk->first_minor; |
63d94e48 | 1023 | |
d9dde59b JN |
1024 | if (md->suspended_bdev) { |
1025 | thaw_bdev(md->suspended_bdev, NULL); | |
1026 | bdput(md->suspended_bdev); | |
1027 | } | |
1da177e4 LT |
1028 | mempool_destroy(md->tio_pool); |
1029 | mempool_destroy(md->io_pool); | |
9faf400f | 1030 | bioset_free(md->bs); |
1da177e4 | 1031 | del_gendisk(md->disk); |
63d94e48 | 1032 | free_minor(minor); |
fba9f90e JM |
1033 | |
1034 | spin_lock(&_minor_lock); | |
1035 | md->disk->private_data = NULL; | |
1036 | spin_unlock(&_minor_lock); | |
1037 | ||
1da177e4 | 1038 | put_disk(md->disk); |
1312f40e | 1039 | blk_cleanup_queue(md->queue); |
10da4f79 | 1040 | module_put(THIS_MODULE); |
1da177e4 LT |
1041 | kfree(md); |
1042 | } | |
1043 | ||
1044 | /* | |
1045 | * Bind a table to the device. | |
1046 | */ | |
1047 | static void event_callback(void *context) | |
1048 | { | |
1049 | struct mapped_device *md = (struct mapped_device *) context; | |
1050 | ||
1051 | atomic_inc(&md->event_nr); | |
1052 | wake_up(&md->eventq); | |
1053 | } | |
1054 | ||
4e90188b | 1055 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1056 | { |
4e90188b | 1057 | set_capacity(md->disk, size); |
1da177e4 | 1058 | |
1b1dcc1b | 1059 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1060 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1061 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1062 | } |
1063 | ||
1064 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1065 | { | |
1066 | request_queue_t *q = md->queue; | |
1067 | sector_t size; | |
1068 | ||
1069 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1070 | |
1071 | /* | |
1072 | * Wipe any geometry if the size of the table changed. | |
1073 | */ | |
1074 | if (size != get_capacity(md->disk)) | |
1075 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1076 | ||
4e90188b | 1077 | __set_size(md, size); |
1da177e4 LT |
1078 | if (size == 0) |
1079 | return 0; | |
1080 | ||
2ca3310e AK |
1081 | dm_table_get(t); |
1082 | dm_table_event_callback(t, event_callback, md); | |
1083 | ||
1da177e4 LT |
1084 | write_lock(&md->map_lock); |
1085 | md->map = t; | |
2ca3310e | 1086 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1087 | write_unlock(&md->map_lock); |
1088 | ||
1da177e4 LT |
1089 | return 0; |
1090 | } | |
1091 | ||
1092 | static void __unbind(struct mapped_device *md) | |
1093 | { | |
1094 | struct dm_table *map = md->map; | |
1095 | ||
1096 | if (!map) | |
1097 | return; | |
1098 | ||
1099 | dm_table_event_callback(map, NULL, NULL); | |
1100 | write_lock(&md->map_lock); | |
1101 | md->map = NULL; | |
1102 | write_unlock(&md->map_lock); | |
1103 | dm_table_put(map); | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Constructor for a new device. | |
1108 | */ | |
2b06cfff | 1109 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1110 | { |
1111 | struct mapped_device *md; | |
1112 | ||
2b06cfff | 1113 | md = alloc_dev(minor); |
1da177e4 LT |
1114 | if (!md) |
1115 | return -ENXIO; | |
1116 | ||
1117 | *result = md; | |
1118 | return 0; | |
1119 | } | |
1120 | ||
637842cf | 1121 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1122 | { |
1123 | struct mapped_device *md; | |
1da177e4 LT |
1124 | unsigned minor = MINOR(dev); |
1125 | ||
1126 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1127 | return NULL; | |
1128 | ||
f32c10b0 | 1129 | spin_lock(&_minor_lock); |
1da177e4 LT |
1130 | |
1131 | md = idr_find(&_minor_idr, minor); | |
fba9f90e JM |
1132 | if (md && (md == MINOR_ALLOCED || |
1133 | (dm_disk(md)->first_minor != minor) || | |
17b2f66f | 1134 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1135 | md = NULL; |
fba9f90e JM |
1136 | goto out; |
1137 | } | |
1da177e4 | 1138 | |
fba9f90e | 1139 | out: |
f32c10b0 | 1140 | spin_unlock(&_minor_lock); |
1da177e4 | 1141 | |
637842cf DT |
1142 | return md; |
1143 | } | |
1144 | ||
d229a958 DT |
1145 | struct mapped_device *dm_get_md(dev_t dev) |
1146 | { | |
1147 | struct mapped_device *md = dm_find_md(dev); | |
1148 | ||
1149 | if (md) | |
1150 | dm_get(md); | |
1151 | ||
1152 | return md; | |
1153 | } | |
1154 | ||
9ade92a9 | 1155 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1156 | { |
9ade92a9 | 1157 | return md->interface_ptr; |
1da177e4 LT |
1158 | } |
1159 | ||
1160 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1161 | { | |
1162 | md->interface_ptr = ptr; | |
1163 | } | |
1164 | ||
1165 | void dm_get(struct mapped_device *md) | |
1166 | { | |
1167 | atomic_inc(&md->holders); | |
1168 | } | |
1169 | ||
72d94861 AK |
1170 | const char *dm_device_name(struct mapped_device *md) |
1171 | { | |
1172 | return md->name; | |
1173 | } | |
1174 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1175 | ||
1da177e4 LT |
1176 | void dm_put(struct mapped_device *md) |
1177 | { | |
1134e5ae | 1178 | struct dm_table *map; |
1da177e4 | 1179 | |
fba9f90e JM |
1180 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1181 | ||
f32c10b0 | 1182 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1183 | map = dm_get_table(md); |
ba61fdd1 | 1184 | idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); |
fba9f90e | 1185 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1186 | spin_unlock(&_minor_lock); |
cf222b37 | 1187 | if (!dm_suspended(md)) { |
1da177e4 LT |
1188 | dm_table_presuspend_targets(map); |
1189 | dm_table_postsuspend_targets(map); | |
1190 | } | |
1191 | __unbind(md); | |
1134e5ae | 1192 | dm_table_put(map); |
1da177e4 LT |
1193 | free_dev(md); |
1194 | } | |
1da177e4 LT |
1195 | } |
1196 | ||
1197 | /* | |
1198 | * Process the deferred bios | |
1199 | */ | |
1200 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1201 | { | |
1202 | struct bio *n; | |
1203 | ||
1204 | while (c) { | |
1205 | n = c->bi_next; | |
1206 | c->bi_next = NULL; | |
1207 | __split_bio(md, c); | |
1208 | c = n; | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | /* | |
1213 | * Swap in a new table (destroying old one). | |
1214 | */ | |
1215 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1216 | { | |
93c534ae | 1217 | int r = -EINVAL; |
1da177e4 | 1218 | |
2ca3310e | 1219 | down(&md->suspend_lock); |
1da177e4 LT |
1220 | |
1221 | /* device must be suspended */ | |
cf222b37 | 1222 | if (!dm_suspended(md)) |
93c534ae | 1223 | goto out; |
1da177e4 LT |
1224 | |
1225 | __unbind(md); | |
1226 | r = __bind(md, table); | |
1da177e4 | 1227 | |
93c534ae | 1228 | out: |
2ca3310e | 1229 | up(&md->suspend_lock); |
93c534ae | 1230 | return r; |
1da177e4 LT |
1231 | } |
1232 | ||
1233 | /* | |
1234 | * Functions to lock and unlock any filesystem running on the | |
1235 | * device. | |
1236 | */ | |
2ca3310e | 1237 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1238 | { |
e39e2e95 | 1239 | int r; |
1da177e4 LT |
1240 | |
1241 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1242 | |
e39e2e95 | 1243 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1244 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1245 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1246 | md->frozen_sb = NULL; |
1247 | return r; | |
dfbe03f6 AK |
1248 | } |
1249 | ||
aa8d7c2f AK |
1250 | set_bit(DMF_FROZEN, &md->flags); |
1251 | ||
1da177e4 | 1252 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1253 | * to go away while it is locked. |
1da177e4 LT |
1254 | */ |
1255 | return 0; | |
1256 | } | |
1257 | ||
2ca3310e | 1258 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1259 | { |
aa8d7c2f AK |
1260 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1261 | return; | |
1262 | ||
e39e2e95 | 1263 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1264 | md->frozen_sb = NULL; |
aa8d7c2f | 1265 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1266 | } |
1267 | ||
1268 | /* | |
1269 | * We need to be able to change a mapping table under a mounted | |
1270 | * filesystem. For example we might want to move some data in | |
1271 | * the background. Before the table can be swapped with | |
1272 | * dm_bind_table, dm_suspend must be called to flush any in | |
1273 | * flight bios and ensure that any further io gets deferred. | |
1274 | */ | |
a3d77d35 | 1275 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1276 | { |
2ca3310e | 1277 | struct dm_table *map = NULL; |
1da177e4 | 1278 | DECLARE_WAITQUEUE(wait, current); |
1ecac7fd | 1279 | struct bio *def; |
cf222b37 | 1280 | int r = -EINVAL; |
a3d77d35 | 1281 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
1da177e4 | 1282 | |
2ca3310e AK |
1283 | down(&md->suspend_lock); |
1284 | ||
1285 | if (dm_suspended(md)) | |
d287483d | 1286 | goto out_unlock; |
1da177e4 LT |
1287 | |
1288 | map = dm_get_table(md); | |
1da177e4 | 1289 | |
cf222b37 AK |
1290 | /* This does not get reverted if there's an error later. */ |
1291 | dm_table_presuspend_targets(map); | |
1292 | ||
e39e2e95 AK |
1293 | md->suspended_bdev = bdget_disk(md->disk, 0); |
1294 | if (!md->suspended_bdev) { | |
1295 | DMWARN("bdget failed in dm_suspend"); | |
1296 | r = -ENOMEM; | |
1297 | goto out; | |
1298 | } | |
1299 | ||
cf222b37 | 1300 | /* Flush I/O to the device. */ |
aa8d7c2f AK |
1301 | if (do_lockfs) { |
1302 | r = lock_fs(md); | |
1303 | if (r) | |
1304 | goto out; | |
1305 | } | |
1da177e4 LT |
1306 | |
1307 | /* | |
354e0071 | 1308 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1309 | */ |
2ca3310e AK |
1310 | down_write(&md->io_lock); |
1311 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1312 | |
1da177e4 | 1313 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1314 | up_write(&md->io_lock); |
1da177e4 LT |
1315 | |
1316 | /* unplug */ | |
2ca3310e | 1317 | if (map) |
1da177e4 | 1318 | dm_table_unplug_all(map); |
1da177e4 LT |
1319 | |
1320 | /* | |
1321 | * Then we wait for the already mapped ios to | |
1322 | * complete. | |
1323 | */ | |
1324 | while (1) { | |
1325 | set_current_state(TASK_INTERRUPTIBLE); | |
1326 | ||
1327 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1328 | break; | |
1329 | ||
1330 | io_schedule(); | |
1331 | } | |
1332 | set_current_state(TASK_RUNNING); | |
1333 | ||
2ca3310e | 1334 | down_write(&md->io_lock); |
1da177e4 LT |
1335 | remove_wait_queue(&md->wait, &wait); |
1336 | ||
1337 | /* were we interrupted ? */ | |
cf222b37 | 1338 | r = -EINTR; |
2ca3310e | 1339 | if (atomic_read(&md->pending)) { |
1ecac7fd JN |
1340 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1341 | def = bio_list_get(&md->deferred); | |
1342 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1343 | up_write(&md->io_lock); |
1344 | unlock_fs(md); | |
2ca3310e AK |
1345 | goto out; |
1346 | } | |
1347 | up_write(&md->io_lock); | |
1da177e4 | 1348 | |
cf222b37 | 1349 | dm_table_postsuspend_targets(map); |
1da177e4 | 1350 | |
2ca3310e | 1351 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1352 | |
2ca3310e | 1353 | r = 0; |
b84b0287 | 1354 | |
2ca3310e | 1355 | out: |
e39e2e95 AK |
1356 | if (r && md->suspended_bdev) { |
1357 | bdput(md->suspended_bdev); | |
1358 | md->suspended_bdev = NULL; | |
1359 | } | |
1360 | ||
2ca3310e | 1361 | dm_table_put(map); |
d287483d AK |
1362 | |
1363 | out_unlock: | |
2ca3310e | 1364 | up(&md->suspend_lock); |
cf222b37 | 1365 | return r; |
1da177e4 LT |
1366 | } |
1367 | ||
1368 | int dm_resume(struct mapped_device *md) | |
1369 | { | |
cf222b37 | 1370 | int r = -EINVAL; |
1da177e4 | 1371 | struct bio *def; |
cf222b37 | 1372 | struct dm_table *map = NULL; |
1da177e4 | 1373 | |
2ca3310e AK |
1374 | down(&md->suspend_lock); |
1375 | if (!dm_suspended(md)) | |
cf222b37 | 1376 | goto out; |
cf222b37 AK |
1377 | |
1378 | map = dm_get_table(md); | |
2ca3310e | 1379 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1380 | goto out; |
1da177e4 | 1381 | |
8757b776 MB |
1382 | r = dm_table_resume_targets(map); |
1383 | if (r) | |
1384 | goto out; | |
2ca3310e AK |
1385 | |
1386 | down_write(&md->io_lock); | |
1da177e4 LT |
1387 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1388 | ||
1389 | def = bio_list_get(&md->deferred); | |
1390 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1391 | up_write(&md->io_lock); |
1392 | ||
1393 | unlock_fs(md); | |
1394 | ||
e39e2e95 AK |
1395 | bdput(md->suspended_bdev); |
1396 | md->suspended_bdev = NULL; | |
1397 | ||
2ca3310e AK |
1398 | clear_bit(DMF_SUSPENDED, &md->flags); |
1399 | ||
1da177e4 | 1400 | dm_table_unplug_all(map); |
1da177e4 | 1401 | |
8560ed6f HR |
1402 | kobject_uevent(&md->disk->kobj, KOBJ_CHANGE); |
1403 | ||
cf222b37 | 1404 | r = 0; |
2ca3310e | 1405 | |
cf222b37 AK |
1406 | out: |
1407 | dm_table_put(map); | |
2ca3310e AK |
1408 | up(&md->suspend_lock); |
1409 | ||
cf222b37 | 1410 | return r; |
1da177e4 LT |
1411 | } |
1412 | ||
1413 | /*----------------------------------------------------------------- | |
1414 | * Event notification. | |
1415 | *---------------------------------------------------------------*/ | |
1416 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1417 | { | |
1418 | return atomic_read(&md->event_nr); | |
1419 | } | |
1420 | ||
1421 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1422 | { | |
1423 | return wait_event_interruptible(md->eventq, | |
1424 | (event_nr != atomic_read(&md->event_nr))); | |
1425 | } | |
1426 | ||
1427 | /* | |
1428 | * The gendisk is only valid as long as you have a reference | |
1429 | * count on 'md'. | |
1430 | */ | |
1431 | struct gendisk *dm_disk(struct mapped_device *md) | |
1432 | { | |
1433 | return md->disk; | |
1434 | } | |
1435 | ||
1436 | int dm_suspended(struct mapped_device *md) | |
1437 | { | |
1438 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1439 | } | |
1440 | ||
1441 | static struct block_device_operations dm_blk_dops = { | |
1442 | .open = dm_blk_open, | |
1443 | .release = dm_blk_close, | |
aa129a22 | 1444 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1445 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1446 | .owner = THIS_MODULE |
1447 | }; | |
1448 | ||
1449 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1450 | ||
1451 | /* | |
1452 | * module hooks | |
1453 | */ | |
1454 | module_init(dm_init); | |
1455 | module_exit(dm_exit); | |
1456 | ||
1457 | module_param(major, uint, 0); | |
1458 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1459 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1460 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1461 | MODULE_LICENSE("GPL"); |