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; | |
45cbcd79 KU |
485 | else if (r == DM_ENDIO_INCOMPLETE) |
486 | /* The target will handle the io */ | |
1da177e4 | 487 | return 1; |
45cbcd79 KU |
488 | else if (r) { |
489 | DMWARN("unimplemented target endio return value: %d", r); | |
490 | BUG(); | |
491 | } | |
1da177e4 LT |
492 | } |
493 | ||
9faf400f SB |
494 | dec_pending(tio->io, error); |
495 | ||
496 | /* | |
497 | * Store md for cleanup instead of tio which is about to get freed. | |
498 | */ | |
499 | bio->bi_private = md->bs; | |
500 | ||
1da177e4 | 501 | bio_put(bio); |
9faf400f | 502 | free_tio(md, tio); |
1da177e4 LT |
503 | return r; |
504 | } | |
505 | ||
506 | static sector_t max_io_len(struct mapped_device *md, | |
507 | sector_t sector, struct dm_target *ti) | |
508 | { | |
509 | sector_t offset = sector - ti->begin; | |
510 | sector_t len = ti->len - offset; | |
511 | ||
512 | /* | |
513 | * Does the target need to split even further ? | |
514 | */ | |
515 | if (ti->split_io) { | |
516 | sector_t boundary; | |
517 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
518 | - offset; | |
519 | if (len > boundary) | |
520 | len = boundary; | |
521 | } | |
522 | ||
523 | return len; | |
524 | } | |
525 | ||
526 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
527 | struct target_io *tio) | |
528 | { | |
529 | int r; | |
2056a782 | 530 | sector_t sector; |
9faf400f | 531 | struct mapped_device *md; |
1da177e4 LT |
532 | |
533 | /* | |
534 | * Sanity checks. | |
535 | */ | |
536 | BUG_ON(!clone->bi_size); | |
537 | ||
538 | clone->bi_end_io = clone_endio; | |
539 | clone->bi_private = tio; | |
540 | ||
541 | /* | |
542 | * Map the clone. If r == 0 we don't need to do | |
543 | * anything, the target has assumed ownership of | |
544 | * this io. | |
545 | */ | |
546 | atomic_inc(&tio->io->io_count); | |
2056a782 | 547 | sector = clone->bi_sector; |
1da177e4 | 548 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 549 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 550 | /* the bio has been remapped so dispatch it */ |
2056a782 | 551 | |
17b2f66f AK |
552 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, |
553 | tio->io->bio->bi_bdev->bd_dev, sector, | |
2056a782 JA |
554 | clone->bi_sector); |
555 | ||
1da177e4 | 556 | generic_make_request(clone); |
74859364 | 557 | } else if (r < 0) { |
1da177e4 | 558 | /* error the io and bail out */ |
9faf400f SB |
559 | md = tio->io->md; |
560 | dec_pending(tio->io, r); | |
561 | /* | |
562 | * Store bio_set for cleanup. | |
563 | */ | |
564 | clone->bi_private = md->bs; | |
1da177e4 | 565 | bio_put(clone); |
9faf400f | 566 | free_tio(md, tio); |
45cbcd79 KU |
567 | } else if (r) { |
568 | DMWARN("unimplemented target map return value: %d", r); | |
569 | BUG(); | |
1da177e4 LT |
570 | } |
571 | } | |
572 | ||
573 | struct clone_info { | |
574 | struct mapped_device *md; | |
575 | struct dm_table *map; | |
576 | struct bio *bio; | |
577 | struct dm_io *io; | |
578 | sector_t sector; | |
579 | sector_t sector_count; | |
580 | unsigned short idx; | |
581 | }; | |
582 | ||
3676347a PO |
583 | static void dm_bio_destructor(struct bio *bio) |
584 | { | |
9faf400f SB |
585 | struct bio_set *bs = bio->bi_private; |
586 | ||
587 | bio_free(bio, bs); | |
3676347a PO |
588 | } |
589 | ||
1da177e4 LT |
590 | /* |
591 | * Creates a little bio that is just does part of a bvec. | |
592 | */ | |
593 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
594 | unsigned short idx, unsigned int offset, | |
9faf400f | 595 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
596 | { |
597 | struct bio *clone; | |
598 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
599 | ||
9faf400f | 600 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 601 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
602 | *clone->bi_io_vec = *bv; |
603 | ||
604 | clone->bi_sector = sector; | |
605 | clone->bi_bdev = bio->bi_bdev; | |
606 | clone->bi_rw = bio->bi_rw; | |
607 | clone->bi_vcnt = 1; | |
608 | clone->bi_size = to_bytes(len); | |
609 | clone->bi_io_vec->bv_offset = offset; | |
610 | clone->bi_io_vec->bv_len = clone->bi_size; | |
611 | ||
612 | return clone; | |
613 | } | |
614 | ||
615 | /* | |
616 | * Creates a bio that consists of range of complete bvecs. | |
617 | */ | |
618 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
619 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 620 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
621 | { |
622 | struct bio *clone; | |
623 | ||
9faf400f SB |
624 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
625 | __bio_clone(clone, bio); | |
626 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
627 | clone->bi_sector = sector; |
628 | clone->bi_idx = idx; | |
629 | clone->bi_vcnt = idx + bv_count; | |
630 | clone->bi_size = to_bytes(len); | |
631 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
632 | ||
633 | return clone; | |
634 | } | |
635 | ||
636 | static void __clone_and_map(struct clone_info *ci) | |
637 | { | |
638 | struct bio *clone, *bio = ci->bio; | |
639 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
640 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
641 | struct target_io *tio; | |
642 | ||
643 | /* | |
644 | * Allocate a target io object. | |
645 | */ | |
646 | tio = alloc_tio(ci->md); | |
647 | tio->io = ci->io; | |
648 | tio->ti = ti; | |
649 | memset(&tio->info, 0, sizeof(tio->info)); | |
650 | ||
651 | if (ci->sector_count <= max) { | |
652 | /* | |
653 | * Optimise for the simple case where we can do all of | |
654 | * the remaining io with a single clone. | |
655 | */ | |
656 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
657 | bio->bi_vcnt - ci->idx, ci->sector_count, |
658 | ci->md->bs); | |
1da177e4 LT |
659 | __map_bio(ti, clone, tio); |
660 | ci->sector_count = 0; | |
661 | ||
662 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
663 | /* | |
664 | * There are some bvecs that don't span targets. | |
665 | * Do as many of these as possible. | |
666 | */ | |
667 | int i; | |
668 | sector_t remaining = max; | |
669 | sector_t bv_len; | |
670 | ||
671 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
672 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
673 | ||
674 | if (bv_len > remaining) | |
675 | break; | |
676 | ||
677 | remaining -= bv_len; | |
678 | len += bv_len; | |
679 | } | |
680 | ||
9faf400f SB |
681 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
682 | ci->md->bs); | |
1da177e4 LT |
683 | __map_bio(ti, clone, tio); |
684 | ||
685 | ci->sector += len; | |
686 | ci->sector_count -= len; | |
687 | ci->idx = i; | |
688 | ||
689 | } else { | |
690 | /* | |
d2044a94 | 691 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
692 | */ |
693 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
694 | sector_t remaining = to_sector(bv->bv_len); |
695 | unsigned int offset = 0; | |
1da177e4 | 696 | |
d2044a94 AK |
697 | do { |
698 | if (offset) { | |
699 | ti = dm_table_find_target(ci->map, ci->sector); | |
700 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 701 | |
d2044a94 AK |
702 | tio = alloc_tio(ci->md); |
703 | tio->io = ci->io; | |
704 | tio->ti = ti; | |
705 | memset(&tio->info, 0, sizeof(tio->info)); | |
706 | } | |
707 | ||
708 | len = min(remaining, max); | |
709 | ||
710 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
711 | bv->bv_offset + offset, len, |
712 | ci->md->bs); | |
d2044a94 AK |
713 | |
714 | __map_bio(ti, clone, tio); | |
715 | ||
716 | ci->sector += len; | |
717 | ci->sector_count -= len; | |
718 | offset += to_bytes(len); | |
719 | } while (remaining -= len); | |
1da177e4 | 720 | |
1da177e4 LT |
721 | ci->idx++; |
722 | } | |
723 | } | |
724 | ||
725 | /* | |
726 | * Split the bio into several clones. | |
727 | */ | |
728 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
729 | { | |
730 | struct clone_info ci; | |
731 | ||
732 | ci.map = dm_get_table(md); | |
733 | if (!ci.map) { | |
734 | bio_io_error(bio, bio->bi_size); | |
735 | return; | |
736 | } | |
737 | ||
738 | ci.md = md; | |
739 | ci.bio = bio; | |
740 | ci.io = alloc_io(md); | |
741 | ci.io->error = 0; | |
742 | atomic_set(&ci.io->io_count, 1); | |
743 | ci.io->bio = bio; | |
744 | ci.io->md = md; | |
745 | ci.sector = bio->bi_sector; | |
746 | ci.sector_count = bio_sectors(bio); | |
747 | ci.idx = bio->bi_idx; | |
748 | ||
3eaf840e | 749 | start_io_acct(ci.io); |
1da177e4 LT |
750 | while (ci.sector_count) |
751 | __clone_and_map(&ci); | |
752 | ||
753 | /* drop the extra reference count */ | |
754 | dec_pending(ci.io, 0); | |
755 | dm_table_put(ci.map); | |
756 | } | |
757 | /*----------------------------------------------------------------- | |
758 | * CRUD END | |
759 | *---------------------------------------------------------------*/ | |
760 | ||
761 | /* | |
762 | * The request function that just remaps the bio built up by | |
763 | * dm_merge_bvec. | |
764 | */ | |
765 | static int dm_request(request_queue_t *q, struct bio *bio) | |
766 | { | |
767 | int r; | |
12f03a49 | 768 | int rw = bio_data_dir(bio); |
1da177e4 LT |
769 | struct mapped_device *md = q->queuedata; |
770 | ||
2ca3310e | 771 | down_read(&md->io_lock); |
1da177e4 | 772 | |
12f03a49 KC |
773 | disk_stat_inc(dm_disk(md), ios[rw]); |
774 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
775 | ||
1da177e4 LT |
776 | /* |
777 | * If we're suspended we have to queue | |
778 | * this io for later. | |
779 | */ | |
780 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 781 | up_read(&md->io_lock); |
1da177e4 LT |
782 | |
783 | if (bio_rw(bio) == READA) { | |
784 | bio_io_error(bio, bio->bi_size); | |
785 | return 0; | |
786 | } | |
787 | ||
788 | r = queue_io(md, bio); | |
789 | if (r < 0) { | |
790 | bio_io_error(bio, bio->bi_size); | |
791 | return 0; | |
792 | ||
793 | } else if (r == 0) | |
794 | return 0; /* deferred successfully */ | |
795 | ||
796 | /* | |
797 | * We're in a while loop, because someone could suspend | |
798 | * before we get to the following read lock. | |
799 | */ | |
2ca3310e | 800 | down_read(&md->io_lock); |
1da177e4 LT |
801 | } |
802 | ||
803 | __split_bio(md, bio); | |
2ca3310e | 804 | up_read(&md->io_lock); |
1da177e4 LT |
805 | return 0; |
806 | } | |
807 | ||
808 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
809 | sector_t *error_sector) | |
810 | { | |
811 | struct mapped_device *md = q->queuedata; | |
812 | struct dm_table *map = dm_get_table(md); | |
813 | int ret = -ENXIO; | |
814 | ||
815 | if (map) { | |
cf222b37 | 816 | ret = dm_table_flush_all(map); |
1da177e4 LT |
817 | dm_table_put(map); |
818 | } | |
819 | ||
820 | return ret; | |
821 | } | |
822 | ||
823 | static void dm_unplug_all(request_queue_t *q) | |
824 | { | |
825 | struct mapped_device *md = q->queuedata; | |
826 | struct dm_table *map = dm_get_table(md); | |
827 | ||
828 | if (map) { | |
829 | dm_table_unplug_all(map); | |
830 | dm_table_put(map); | |
831 | } | |
832 | } | |
833 | ||
834 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
835 | { | |
836 | int r; | |
837 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
838 | struct dm_table *map = dm_get_table(md); | |
839 | ||
840 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
841 | r = bdi_bits; | |
842 | else | |
843 | r = dm_table_any_congested(map, bdi_bits); | |
844 | ||
845 | dm_table_put(map); | |
846 | return r; | |
847 | } | |
848 | ||
849 | /*----------------------------------------------------------------- | |
850 | * An IDR is used to keep track of allocated minor numbers. | |
851 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
852 | static DEFINE_IDR(_minor_idr); |
853 | ||
2b06cfff | 854 | static void free_minor(int minor) |
1da177e4 | 855 | { |
f32c10b0 | 856 | spin_lock(&_minor_lock); |
1da177e4 | 857 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 858 | spin_unlock(&_minor_lock); |
1da177e4 LT |
859 | } |
860 | ||
861 | /* | |
862 | * See if the device with a specific minor # is free. | |
863 | */ | |
2b06cfff | 864 | static int specific_minor(struct mapped_device *md, int minor) |
1da177e4 LT |
865 | { |
866 | int r, m; | |
867 | ||
868 | if (minor >= (1 << MINORBITS)) | |
869 | return -EINVAL; | |
870 | ||
62f75c2f JM |
871 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
872 | if (!r) | |
873 | return -ENOMEM; | |
874 | ||
f32c10b0 | 875 | spin_lock(&_minor_lock); |
1da177e4 LT |
876 | |
877 | if (idr_find(&_minor_idr, minor)) { | |
878 | r = -EBUSY; | |
879 | goto out; | |
880 | } | |
881 | ||
ba61fdd1 | 882 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 883 | if (r) |
1da177e4 | 884 | goto out; |
1da177e4 LT |
885 | |
886 | if (m != minor) { | |
887 | idr_remove(&_minor_idr, m); | |
888 | r = -EBUSY; | |
889 | goto out; | |
890 | } | |
891 | ||
892 | out: | |
f32c10b0 | 893 | spin_unlock(&_minor_lock); |
1da177e4 LT |
894 | return r; |
895 | } | |
896 | ||
2b06cfff | 897 | static int next_free_minor(struct mapped_device *md, int *minor) |
1da177e4 | 898 | { |
2b06cfff | 899 | int r, m; |
1da177e4 | 900 | |
1da177e4 | 901 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
902 | if (!r) |
903 | return -ENOMEM; | |
904 | ||
f32c10b0 | 905 | spin_lock(&_minor_lock); |
1da177e4 | 906 | |
ba61fdd1 | 907 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
1da177e4 LT |
908 | if (r) { |
909 | goto out; | |
910 | } | |
911 | ||
912 | if (m >= (1 << MINORBITS)) { | |
913 | idr_remove(&_minor_idr, m); | |
914 | r = -ENOSPC; | |
915 | goto out; | |
916 | } | |
917 | ||
918 | *minor = m; | |
919 | ||
920 | out: | |
f32c10b0 | 921 | spin_unlock(&_minor_lock); |
1da177e4 LT |
922 | return r; |
923 | } | |
924 | ||
925 | static struct block_device_operations dm_blk_dops; | |
926 | ||
927 | /* | |
928 | * Allocate and initialise a blank device with a given minor. | |
929 | */ | |
2b06cfff | 930 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
931 | { |
932 | int r; | |
933 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
ba61fdd1 | 934 | void *old_md; |
1da177e4 LT |
935 | |
936 | if (!md) { | |
937 | DMWARN("unable to allocate device, out of memory."); | |
938 | return NULL; | |
939 | } | |
940 | ||
10da4f79 JM |
941 | if (!try_module_get(THIS_MODULE)) |
942 | goto bad0; | |
943 | ||
1da177e4 | 944 | /* get a minor number for the dev */ |
2b06cfff AK |
945 | if (minor == DM_ANY_MINOR) |
946 | r = next_free_minor(md, &minor); | |
947 | else | |
948 | r = specific_minor(md, minor); | |
1da177e4 LT |
949 | if (r < 0) |
950 | goto bad1; | |
951 | ||
952 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
953 | init_rwsem(&md->io_lock); |
954 | init_MUTEX(&md->suspend_lock); | |
1da177e4 LT |
955 | rwlock_init(&md->map_lock); |
956 | atomic_set(&md->holders, 1); | |
5c6bd75d | 957 | atomic_set(&md->open_count, 0); |
1da177e4 LT |
958 | atomic_set(&md->event_nr, 0); |
959 | ||
960 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
961 | if (!md->queue) | |
e3f6ac61 | 962 | goto bad1_free_minor; |
1da177e4 LT |
963 | |
964 | md->queue->queuedata = md; | |
965 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
966 | md->queue->backing_dev_info.congested_data = md; | |
967 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 968 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
969 | md->queue->unplug_fn = dm_unplug_all; |
970 | md->queue->issue_flush_fn = dm_flush_all; | |
971 | ||
93d2341c | 972 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 KU |
973 | if (!md->io_pool) |
974 | goto bad2; | |
1da177e4 | 975 | |
93d2341c | 976 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
977 | if (!md->tio_pool) |
978 | goto bad3; | |
979 | ||
9faf400f SB |
980 | md->bs = bioset_create(16, 16, 4); |
981 | if (!md->bs) | |
982 | goto bad_no_bioset; | |
983 | ||
1da177e4 LT |
984 | md->disk = alloc_disk(1); |
985 | if (!md->disk) | |
986 | goto bad4; | |
987 | ||
f0b04115 JM |
988 | atomic_set(&md->pending, 0); |
989 | init_waitqueue_head(&md->wait); | |
990 | init_waitqueue_head(&md->eventq); | |
991 | ||
1da177e4 LT |
992 | md->disk->major = _major; |
993 | md->disk->first_minor = minor; | |
994 | md->disk->fops = &dm_blk_dops; | |
995 | md->disk->queue = md->queue; | |
996 | md->disk->private_data = md; | |
997 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
998 | add_disk(md->disk); | |
7e51f257 | 999 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1000 | |
ba61fdd1 | 1001 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1002 | spin_lock(&_minor_lock); |
ba61fdd1 | 1003 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1004 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1005 | |
1006 | BUG_ON(old_md != MINOR_ALLOCED); | |
1007 | ||
1da177e4 LT |
1008 | return md; |
1009 | ||
1010 | bad4: | |
9faf400f SB |
1011 | bioset_free(md->bs); |
1012 | bad_no_bioset: | |
1da177e4 LT |
1013 | mempool_destroy(md->tio_pool); |
1014 | bad3: | |
1015 | mempool_destroy(md->io_pool); | |
1016 | bad2: | |
1312f40e | 1017 | blk_cleanup_queue(md->queue); |
e3f6ac61 | 1018 | bad1_free_minor: |
1da177e4 LT |
1019 | free_minor(minor); |
1020 | bad1: | |
10da4f79 JM |
1021 | module_put(THIS_MODULE); |
1022 | bad0: | |
1da177e4 LT |
1023 | kfree(md); |
1024 | return NULL; | |
1025 | } | |
1026 | ||
1027 | static void free_dev(struct mapped_device *md) | |
1028 | { | |
2b06cfff | 1029 | int minor = md->disk->first_minor; |
63d94e48 | 1030 | |
d9dde59b JN |
1031 | if (md->suspended_bdev) { |
1032 | thaw_bdev(md->suspended_bdev, NULL); | |
1033 | bdput(md->suspended_bdev); | |
1034 | } | |
1da177e4 LT |
1035 | mempool_destroy(md->tio_pool); |
1036 | mempool_destroy(md->io_pool); | |
9faf400f | 1037 | bioset_free(md->bs); |
1da177e4 | 1038 | del_gendisk(md->disk); |
63d94e48 | 1039 | free_minor(minor); |
fba9f90e JM |
1040 | |
1041 | spin_lock(&_minor_lock); | |
1042 | md->disk->private_data = NULL; | |
1043 | spin_unlock(&_minor_lock); | |
1044 | ||
1da177e4 | 1045 | put_disk(md->disk); |
1312f40e | 1046 | blk_cleanup_queue(md->queue); |
10da4f79 | 1047 | module_put(THIS_MODULE); |
1da177e4 LT |
1048 | kfree(md); |
1049 | } | |
1050 | ||
1051 | /* | |
1052 | * Bind a table to the device. | |
1053 | */ | |
1054 | static void event_callback(void *context) | |
1055 | { | |
1056 | struct mapped_device *md = (struct mapped_device *) context; | |
1057 | ||
1058 | atomic_inc(&md->event_nr); | |
1059 | wake_up(&md->eventq); | |
1060 | } | |
1061 | ||
4e90188b | 1062 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1063 | { |
4e90188b | 1064 | set_capacity(md->disk, size); |
1da177e4 | 1065 | |
1b1dcc1b | 1066 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1067 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1068 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1069 | } |
1070 | ||
1071 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1072 | { | |
1073 | request_queue_t *q = md->queue; | |
1074 | sector_t size; | |
1075 | ||
1076 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1077 | |
1078 | /* | |
1079 | * Wipe any geometry if the size of the table changed. | |
1080 | */ | |
1081 | if (size != get_capacity(md->disk)) | |
1082 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1083 | ||
4e90188b | 1084 | __set_size(md, size); |
1da177e4 LT |
1085 | if (size == 0) |
1086 | return 0; | |
1087 | ||
2ca3310e AK |
1088 | dm_table_get(t); |
1089 | dm_table_event_callback(t, event_callback, md); | |
1090 | ||
1da177e4 LT |
1091 | write_lock(&md->map_lock); |
1092 | md->map = t; | |
2ca3310e | 1093 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1094 | write_unlock(&md->map_lock); |
1095 | ||
1da177e4 LT |
1096 | return 0; |
1097 | } | |
1098 | ||
1099 | static void __unbind(struct mapped_device *md) | |
1100 | { | |
1101 | struct dm_table *map = md->map; | |
1102 | ||
1103 | if (!map) | |
1104 | return; | |
1105 | ||
1106 | dm_table_event_callback(map, NULL, NULL); | |
1107 | write_lock(&md->map_lock); | |
1108 | md->map = NULL; | |
1109 | write_unlock(&md->map_lock); | |
1110 | dm_table_put(map); | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * Constructor for a new device. | |
1115 | */ | |
2b06cfff | 1116 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1117 | { |
1118 | struct mapped_device *md; | |
1119 | ||
2b06cfff | 1120 | md = alloc_dev(minor); |
1da177e4 LT |
1121 | if (!md) |
1122 | return -ENXIO; | |
1123 | ||
1124 | *result = md; | |
1125 | return 0; | |
1126 | } | |
1127 | ||
637842cf | 1128 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1129 | { |
1130 | struct mapped_device *md; | |
1da177e4 LT |
1131 | unsigned minor = MINOR(dev); |
1132 | ||
1133 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1134 | return NULL; | |
1135 | ||
f32c10b0 | 1136 | spin_lock(&_minor_lock); |
1da177e4 LT |
1137 | |
1138 | md = idr_find(&_minor_idr, minor); | |
fba9f90e JM |
1139 | if (md && (md == MINOR_ALLOCED || |
1140 | (dm_disk(md)->first_minor != minor) || | |
17b2f66f | 1141 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1142 | md = NULL; |
fba9f90e JM |
1143 | goto out; |
1144 | } | |
1da177e4 | 1145 | |
fba9f90e | 1146 | out: |
f32c10b0 | 1147 | spin_unlock(&_minor_lock); |
1da177e4 | 1148 | |
637842cf DT |
1149 | return md; |
1150 | } | |
1151 | ||
d229a958 DT |
1152 | struct mapped_device *dm_get_md(dev_t dev) |
1153 | { | |
1154 | struct mapped_device *md = dm_find_md(dev); | |
1155 | ||
1156 | if (md) | |
1157 | dm_get(md); | |
1158 | ||
1159 | return md; | |
1160 | } | |
1161 | ||
9ade92a9 | 1162 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1163 | { |
9ade92a9 | 1164 | return md->interface_ptr; |
1da177e4 LT |
1165 | } |
1166 | ||
1167 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1168 | { | |
1169 | md->interface_ptr = ptr; | |
1170 | } | |
1171 | ||
1172 | void dm_get(struct mapped_device *md) | |
1173 | { | |
1174 | atomic_inc(&md->holders); | |
1175 | } | |
1176 | ||
72d94861 AK |
1177 | const char *dm_device_name(struct mapped_device *md) |
1178 | { | |
1179 | return md->name; | |
1180 | } | |
1181 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1182 | ||
1da177e4 LT |
1183 | void dm_put(struct mapped_device *md) |
1184 | { | |
1134e5ae | 1185 | struct dm_table *map; |
1da177e4 | 1186 | |
fba9f90e JM |
1187 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1188 | ||
f32c10b0 | 1189 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1190 | map = dm_get_table(md); |
ba61fdd1 | 1191 | idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); |
fba9f90e | 1192 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1193 | spin_unlock(&_minor_lock); |
cf222b37 | 1194 | if (!dm_suspended(md)) { |
1da177e4 LT |
1195 | dm_table_presuspend_targets(map); |
1196 | dm_table_postsuspend_targets(map); | |
1197 | } | |
1198 | __unbind(md); | |
1134e5ae | 1199 | dm_table_put(map); |
1da177e4 LT |
1200 | free_dev(md); |
1201 | } | |
1da177e4 LT |
1202 | } |
1203 | ||
1204 | /* | |
1205 | * Process the deferred bios | |
1206 | */ | |
1207 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1208 | { | |
1209 | struct bio *n; | |
1210 | ||
1211 | while (c) { | |
1212 | n = c->bi_next; | |
1213 | c->bi_next = NULL; | |
1214 | __split_bio(md, c); | |
1215 | c = n; | |
1216 | } | |
1217 | } | |
1218 | ||
1219 | /* | |
1220 | * Swap in a new table (destroying old one). | |
1221 | */ | |
1222 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1223 | { | |
93c534ae | 1224 | int r = -EINVAL; |
1da177e4 | 1225 | |
2ca3310e | 1226 | down(&md->suspend_lock); |
1da177e4 LT |
1227 | |
1228 | /* device must be suspended */ | |
cf222b37 | 1229 | if (!dm_suspended(md)) |
93c534ae | 1230 | goto out; |
1da177e4 LT |
1231 | |
1232 | __unbind(md); | |
1233 | r = __bind(md, table); | |
1da177e4 | 1234 | |
93c534ae | 1235 | out: |
2ca3310e | 1236 | up(&md->suspend_lock); |
93c534ae | 1237 | return r; |
1da177e4 LT |
1238 | } |
1239 | ||
1240 | /* | |
1241 | * Functions to lock and unlock any filesystem running on the | |
1242 | * device. | |
1243 | */ | |
2ca3310e | 1244 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1245 | { |
e39e2e95 | 1246 | int r; |
1da177e4 LT |
1247 | |
1248 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1249 | |
e39e2e95 | 1250 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1251 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1252 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1253 | md->frozen_sb = NULL; |
1254 | return r; | |
dfbe03f6 AK |
1255 | } |
1256 | ||
aa8d7c2f AK |
1257 | set_bit(DMF_FROZEN, &md->flags); |
1258 | ||
1da177e4 | 1259 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1260 | * to go away while it is locked. |
1da177e4 LT |
1261 | */ |
1262 | return 0; | |
1263 | } | |
1264 | ||
2ca3310e | 1265 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1266 | { |
aa8d7c2f AK |
1267 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1268 | return; | |
1269 | ||
e39e2e95 | 1270 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1271 | md->frozen_sb = NULL; |
aa8d7c2f | 1272 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1273 | } |
1274 | ||
1275 | /* | |
1276 | * We need to be able to change a mapping table under a mounted | |
1277 | * filesystem. For example we might want to move some data in | |
1278 | * the background. Before the table can be swapped with | |
1279 | * dm_bind_table, dm_suspend must be called to flush any in | |
1280 | * flight bios and ensure that any further io gets deferred. | |
1281 | */ | |
a3d77d35 | 1282 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1283 | { |
2ca3310e | 1284 | struct dm_table *map = NULL; |
1da177e4 | 1285 | DECLARE_WAITQUEUE(wait, current); |
1ecac7fd | 1286 | struct bio *def; |
cf222b37 | 1287 | int r = -EINVAL; |
a3d77d35 | 1288 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
1da177e4 | 1289 | |
2ca3310e AK |
1290 | down(&md->suspend_lock); |
1291 | ||
1292 | if (dm_suspended(md)) | |
d287483d | 1293 | goto out_unlock; |
1da177e4 LT |
1294 | |
1295 | map = dm_get_table(md); | |
1da177e4 | 1296 | |
cf222b37 AK |
1297 | /* This does not get reverted if there's an error later. */ |
1298 | dm_table_presuspend_targets(map); | |
1299 | ||
e39e2e95 AK |
1300 | md->suspended_bdev = bdget_disk(md->disk, 0); |
1301 | if (!md->suspended_bdev) { | |
1302 | DMWARN("bdget failed in dm_suspend"); | |
1303 | r = -ENOMEM; | |
1304 | goto out; | |
1305 | } | |
1306 | ||
cf222b37 | 1307 | /* Flush I/O to the device. */ |
aa8d7c2f AK |
1308 | if (do_lockfs) { |
1309 | r = lock_fs(md); | |
1310 | if (r) | |
1311 | goto out; | |
1312 | } | |
1da177e4 LT |
1313 | |
1314 | /* | |
354e0071 | 1315 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1316 | */ |
2ca3310e AK |
1317 | down_write(&md->io_lock); |
1318 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1319 | |
1da177e4 | 1320 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1321 | up_write(&md->io_lock); |
1da177e4 LT |
1322 | |
1323 | /* unplug */ | |
2ca3310e | 1324 | if (map) |
1da177e4 | 1325 | dm_table_unplug_all(map); |
1da177e4 LT |
1326 | |
1327 | /* | |
1328 | * Then we wait for the already mapped ios to | |
1329 | * complete. | |
1330 | */ | |
1331 | while (1) { | |
1332 | set_current_state(TASK_INTERRUPTIBLE); | |
1333 | ||
1334 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1335 | break; | |
1336 | ||
1337 | io_schedule(); | |
1338 | } | |
1339 | set_current_state(TASK_RUNNING); | |
1340 | ||
2ca3310e | 1341 | down_write(&md->io_lock); |
1da177e4 LT |
1342 | remove_wait_queue(&md->wait, &wait); |
1343 | ||
1344 | /* were we interrupted ? */ | |
cf222b37 | 1345 | r = -EINTR; |
2ca3310e | 1346 | if (atomic_read(&md->pending)) { |
1ecac7fd JN |
1347 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1348 | def = bio_list_get(&md->deferred); | |
1349 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1350 | up_write(&md->io_lock); |
1351 | unlock_fs(md); | |
2ca3310e AK |
1352 | goto out; |
1353 | } | |
1354 | up_write(&md->io_lock); | |
1da177e4 | 1355 | |
cf222b37 | 1356 | dm_table_postsuspend_targets(map); |
1da177e4 | 1357 | |
2ca3310e | 1358 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1359 | |
2ca3310e | 1360 | r = 0; |
b84b0287 | 1361 | |
2ca3310e | 1362 | out: |
e39e2e95 AK |
1363 | if (r && md->suspended_bdev) { |
1364 | bdput(md->suspended_bdev); | |
1365 | md->suspended_bdev = NULL; | |
1366 | } | |
1367 | ||
2ca3310e | 1368 | dm_table_put(map); |
d287483d AK |
1369 | |
1370 | out_unlock: | |
2ca3310e | 1371 | up(&md->suspend_lock); |
cf222b37 | 1372 | return r; |
1da177e4 LT |
1373 | } |
1374 | ||
1375 | int dm_resume(struct mapped_device *md) | |
1376 | { | |
cf222b37 | 1377 | int r = -EINVAL; |
1da177e4 | 1378 | struct bio *def; |
cf222b37 | 1379 | struct dm_table *map = NULL; |
1da177e4 | 1380 | |
2ca3310e AK |
1381 | down(&md->suspend_lock); |
1382 | if (!dm_suspended(md)) | |
cf222b37 | 1383 | goto out; |
cf222b37 AK |
1384 | |
1385 | map = dm_get_table(md); | |
2ca3310e | 1386 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1387 | goto out; |
1da177e4 | 1388 | |
8757b776 MB |
1389 | r = dm_table_resume_targets(map); |
1390 | if (r) | |
1391 | goto out; | |
2ca3310e AK |
1392 | |
1393 | down_write(&md->io_lock); | |
1da177e4 LT |
1394 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1395 | ||
1396 | def = bio_list_get(&md->deferred); | |
1397 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1398 | up_write(&md->io_lock); |
1399 | ||
1400 | unlock_fs(md); | |
1401 | ||
e39e2e95 AK |
1402 | bdput(md->suspended_bdev); |
1403 | md->suspended_bdev = NULL; | |
1404 | ||
2ca3310e AK |
1405 | clear_bit(DMF_SUSPENDED, &md->flags); |
1406 | ||
1da177e4 | 1407 | dm_table_unplug_all(map); |
1da177e4 | 1408 | |
8560ed6f HR |
1409 | kobject_uevent(&md->disk->kobj, KOBJ_CHANGE); |
1410 | ||
cf222b37 | 1411 | r = 0; |
2ca3310e | 1412 | |
cf222b37 AK |
1413 | out: |
1414 | dm_table_put(map); | |
2ca3310e AK |
1415 | up(&md->suspend_lock); |
1416 | ||
cf222b37 | 1417 | return r; |
1da177e4 LT |
1418 | } |
1419 | ||
1420 | /*----------------------------------------------------------------- | |
1421 | * Event notification. | |
1422 | *---------------------------------------------------------------*/ | |
1423 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1424 | { | |
1425 | return atomic_read(&md->event_nr); | |
1426 | } | |
1427 | ||
1428 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1429 | { | |
1430 | return wait_event_interruptible(md->eventq, | |
1431 | (event_nr != atomic_read(&md->event_nr))); | |
1432 | } | |
1433 | ||
1434 | /* | |
1435 | * The gendisk is only valid as long as you have a reference | |
1436 | * count on 'md'. | |
1437 | */ | |
1438 | struct gendisk *dm_disk(struct mapped_device *md) | |
1439 | { | |
1440 | return md->disk; | |
1441 | } | |
1442 | ||
1443 | int dm_suspended(struct mapped_device *md) | |
1444 | { | |
1445 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1446 | } | |
1447 | ||
1448 | static struct block_device_operations dm_blk_dops = { | |
1449 | .open = dm_blk_open, | |
1450 | .release = dm_blk_close, | |
aa129a22 | 1451 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1452 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1453 | .owner = THIS_MODULE |
1454 | }; | |
1455 | ||
1456 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1457 | ||
1458 | /* | |
1459 | * module hooks | |
1460 | */ | |
1461 | module_init(dm_init); | |
1462 | module_exit(dm_exit); | |
1463 | ||
1464 | module_param(major, uint, 0); | |
1465 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1466 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1467 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1468 | MODULE_LICENSE("GPL"); |