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 | */ | |
028867ac | 48 | struct dm_target_io { |
1da177e4 LT |
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 | 56 | if (bio && bio->bi_private) |
028867ac | 57 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 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 |
2e93ccc1 | 71 | #define DMF_NOFLUSH_SUSPENDING 5 |
1da177e4 LT |
72 | |
73 | struct mapped_device { | |
2ca3310e AK |
74 | struct rw_semaphore io_lock; |
75 | struct semaphore suspend_lock; | |
2e93ccc1 | 76 | spinlock_t pushback_lock; |
1da177e4 LT |
77 | rwlock_t map_lock; |
78 | atomic_t holders; | |
5c6bd75d | 79 | atomic_t open_count; |
1da177e4 LT |
80 | |
81 | unsigned long flags; | |
82 | ||
83 | request_queue_t *queue; | |
84 | struct gendisk *disk; | |
7e51f257 | 85 | char name[16]; |
1da177e4 LT |
86 | |
87 | void *interface_ptr; | |
88 | ||
89 | /* | |
90 | * A list of ios that arrived while we were suspended. | |
91 | */ | |
92 | atomic_t pending; | |
93 | wait_queue_head_t wait; | |
74859364 | 94 | struct bio_list deferred; |
2e93ccc1 | 95 | struct bio_list pushback; |
1da177e4 LT |
96 | |
97 | /* | |
98 | * The current mapping. | |
99 | */ | |
100 | struct dm_table *map; | |
101 | ||
102 | /* | |
103 | * io objects are allocated from here. | |
104 | */ | |
105 | mempool_t *io_pool; | |
106 | mempool_t *tio_pool; | |
107 | ||
9faf400f SB |
108 | struct bio_set *bs; |
109 | ||
1da177e4 LT |
110 | /* |
111 | * Event handling. | |
112 | */ | |
113 | atomic_t event_nr; | |
114 | wait_queue_head_t eventq; | |
115 | ||
116 | /* | |
117 | * freeze/thaw support require holding onto a super block | |
118 | */ | |
119 | struct super_block *frozen_sb; | |
e39e2e95 | 120 | struct block_device *suspended_bdev; |
3ac51e74 DW |
121 | |
122 | /* forced geometry settings */ | |
123 | struct hd_geometry geometry; | |
1da177e4 LT |
124 | }; |
125 | ||
126 | #define MIN_IOS 256 | |
e18b890b CL |
127 | static struct kmem_cache *_io_cache; |
128 | static struct kmem_cache *_tio_cache; | |
1da177e4 | 129 | |
1da177e4 LT |
130 | static int __init local_init(void) |
131 | { | |
132 | int r; | |
133 | ||
1da177e4 | 134 | /* allocate a slab for the dm_ios */ |
028867ac | 135 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 LT |
136 | if (!_io_cache) |
137 | return -ENOMEM; | |
138 | ||
139 | /* allocate a slab for the target ios */ | |
028867ac | 140 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
1da177e4 LT |
141 | if (!_tio_cache) { |
142 | kmem_cache_destroy(_io_cache); | |
143 | return -ENOMEM; | |
144 | } | |
145 | ||
146 | _major = major; | |
147 | r = register_blkdev(_major, _name); | |
148 | if (r < 0) { | |
149 | kmem_cache_destroy(_tio_cache); | |
150 | kmem_cache_destroy(_io_cache); | |
151 | return r; | |
152 | } | |
153 | ||
154 | if (!_major) | |
155 | _major = r; | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static void local_exit(void) | |
161 | { | |
162 | kmem_cache_destroy(_tio_cache); | |
163 | kmem_cache_destroy(_io_cache); | |
164 | ||
1da177e4 | 165 | if (unregister_blkdev(_major, _name) < 0) |
890fbae2 | 166 | DMERR("unregister_blkdev failed"); |
1da177e4 LT |
167 | |
168 | _major = 0; | |
169 | ||
170 | DMINFO("cleaned up"); | |
171 | } | |
172 | ||
173 | int (*_inits[])(void) __initdata = { | |
174 | local_init, | |
175 | dm_target_init, | |
176 | dm_linear_init, | |
177 | dm_stripe_init, | |
178 | dm_interface_init, | |
179 | }; | |
180 | ||
181 | void (*_exits[])(void) = { | |
182 | local_exit, | |
183 | dm_target_exit, | |
184 | dm_linear_exit, | |
185 | dm_stripe_exit, | |
186 | dm_interface_exit, | |
187 | }; | |
188 | ||
189 | static int __init dm_init(void) | |
190 | { | |
191 | const int count = ARRAY_SIZE(_inits); | |
192 | ||
193 | int r, i; | |
194 | ||
195 | for (i = 0; i < count; i++) { | |
196 | r = _inits[i](); | |
197 | if (r) | |
198 | goto bad; | |
199 | } | |
200 | ||
201 | return 0; | |
202 | ||
203 | bad: | |
204 | while (i--) | |
205 | _exits[i](); | |
206 | ||
207 | return r; | |
208 | } | |
209 | ||
210 | static void __exit dm_exit(void) | |
211 | { | |
212 | int i = ARRAY_SIZE(_exits); | |
213 | ||
214 | while (i--) | |
215 | _exits[i](); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Block device functions | |
220 | */ | |
221 | static int dm_blk_open(struct inode *inode, struct file *file) | |
222 | { | |
223 | struct mapped_device *md; | |
224 | ||
fba9f90e JM |
225 | spin_lock(&_minor_lock); |
226 | ||
1da177e4 | 227 | md = inode->i_bdev->bd_disk->private_data; |
fba9f90e JM |
228 | if (!md) |
229 | goto out; | |
230 | ||
5c6bd75d AK |
231 | if (test_bit(DMF_FREEING, &md->flags) || |
232 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
233 | md = NULL; |
234 | goto out; | |
235 | } | |
236 | ||
1da177e4 | 237 | dm_get(md); |
5c6bd75d | 238 | atomic_inc(&md->open_count); |
fba9f90e JM |
239 | |
240 | out: | |
241 | spin_unlock(&_minor_lock); | |
242 | ||
243 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
244 | } |
245 | ||
246 | static int dm_blk_close(struct inode *inode, struct file *file) | |
247 | { | |
248 | struct mapped_device *md; | |
249 | ||
250 | md = inode->i_bdev->bd_disk->private_data; | |
5c6bd75d | 251 | atomic_dec(&md->open_count); |
1da177e4 LT |
252 | dm_put(md); |
253 | return 0; | |
254 | } | |
255 | ||
5c6bd75d AK |
256 | int dm_open_count(struct mapped_device *md) |
257 | { | |
258 | return atomic_read(&md->open_count); | |
259 | } | |
260 | ||
261 | /* | |
262 | * Guarantees nothing is using the device before it's deleted. | |
263 | */ | |
264 | int dm_lock_for_deletion(struct mapped_device *md) | |
265 | { | |
266 | int r = 0; | |
267 | ||
268 | spin_lock(&_minor_lock); | |
269 | ||
270 | if (dm_open_count(md)) | |
271 | r = -EBUSY; | |
272 | else | |
273 | set_bit(DMF_DELETING, &md->flags); | |
274 | ||
275 | spin_unlock(&_minor_lock); | |
276 | ||
277 | return r; | |
278 | } | |
279 | ||
3ac51e74 DW |
280 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
281 | { | |
282 | struct mapped_device *md = bdev->bd_disk->private_data; | |
283 | ||
284 | return dm_get_geometry(md, geo); | |
285 | } | |
286 | ||
aa129a22 MB |
287 | static int dm_blk_ioctl(struct inode *inode, struct file *file, |
288 | unsigned int cmd, unsigned long arg) | |
289 | { | |
290 | struct mapped_device *md; | |
291 | struct dm_table *map; | |
292 | struct dm_target *tgt; | |
293 | int r = -ENOTTY; | |
294 | ||
295 | /* We don't really need this lock, but we do need 'inode'. */ | |
296 | unlock_kernel(); | |
297 | ||
298 | md = inode->i_bdev->bd_disk->private_data; | |
299 | ||
300 | map = dm_get_table(md); | |
301 | ||
302 | if (!map || !dm_table_get_size(map)) | |
303 | goto out; | |
304 | ||
305 | /* We only support devices that have a single target */ | |
306 | if (dm_table_get_num_targets(map) != 1) | |
307 | goto out; | |
308 | ||
309 | tgt = dm_table_get_target(map, 0); | |
310 | ||
311 | if (dm_suspended(md)) { | |
312 | r = -EAGAIN; | |
313 | goto out; | |
314 | } | |
315 | ||
316 | if (tgt->type->ioctl) | |
317 | r = tgt->type->ioctl(tgt, inode, file, cmd, arg); | |
318 | ||
319 | out: | |
320 | dm_table_put(map); | |
321 | ||
322 | lock_kernel(); | |
323 | return r; | |
324 | } | |
325 | ||
028867ac | 326 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
327 | { |
328 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
329 | } | |
330 | ||
028867ac | 331 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
332 | { |
333 | mempool_free(io, md->io_pool); | |
334 | } | |
335 | ||
028867ac | 336 | static struct dm_target_io *alloc_tio(struct mapped_device *md) |
1da177e4 LT |
337 | { |
338 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
339 | } | |
340 | ||
028867ac | 341 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
342 | { |
343 | mempool_free(tio, md->tio_pool); | |
344 | } | |
345 | ||
3eaf840e JNN |
346 | static void start_io_acct(struct dm_io *io) |
347 | { | |
348 | struct mapped_device *md = io->md; | |
349 | ||
350 | io->start_time = jiffies; | |
351 | ||
352 | preempt_disable(); | |
353 | disk_round_stats(dm_disk(md)); | |
354 | preempt_enable(); | |
355 | dm_disk(md)->in_flight = atomic_inc_return(&md->pending); | |
356 | } | |
357 | ||
358 | static int end_io_acct(struct dm_io *io) | |
359 | { | |
360 | struct mapped_device *md = io->md; | |
361 | struct bio *bio = io->bio; | |
362 | unsigned long duration = jiffies - io->start_time; | |
363 | int pending; | |
364 | int rw = bio_data_dir(bio); | |
365 | ||
366 | preempt_disable(); | |
367 | disk_round_stats(dm_disk(md)); | |
368 | preempt_enable(); | |
369 | dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending); | |
370 | ||
371 | disk_stat_add(dm_disk(md), ticks[rw], duration); | |
372 | ||
373 | return !pending; | |
374 | } | |
375 | ||
1da177e4 LT |
376 | /* |
377 | * Add the bio to the list of deferred io. | |
378 | */ | |
379 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
380 | { | |
2ca3310e | 381 | down_write(&md->io_lock); |
1da177e4 LT |
382 | |
383 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 384 | up_write(&md->io_lock); |
1da177e4 LT |
385 | return 1; |
386 | } | |
387 | ||
388 | bio_list_add(&md->deferred, bio); | |
389 | ||
2ca3310e | 390 | up_write(&md->io_lock); |
1da177e4 LT |
391 | return 0; /* deferred successfully */ |
392 | } | |
393 | ||
394 | /* | |
395 | * Everyone (including functions in this file), should use this | |
396 | * function to access the md->map field, and make sure they call | |
397 | * dm_table_put() when finished. | |
398 | */ | |
399 | struct dm_table *dm_get_table(struct mapped_device *md) | |
400 | { | |
401 | struct dm_table *t; | |
402 | ||
403 | read_lock(&md->map_lock); | |
404 | t = md->map; | |
405 | if (t) | |
406 | dm_table_get(t); | |
407 | read_unlock(&md->map_lock); | |
408 | ||
409 | return t; | |
410 | } | |
411 | ||
3ac51e74 DW |
412 | /* |
413 | * Get the geometry associated with a dm device | |
414 | */ | |
415 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
416 | { | |
417 | *geo = md->geometry; | |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
422 | /* | |
423 | * Set the geometry of a device. | |
424 | */ | |
425 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
426 | { | |
427 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
428 | ||
429 | if (geo->start > sz) { | |
430 | DMWARN("Start sector is beyond the geometry limits."); | |
431 | return -EINVAL; | |
432 | } | |
433 | ||
434 | md->geometry = *geo; | |
435 | ||
436 | return 0; | |
437 | } | |
438 | ||
1da177e4 LT |
439 | /*----------------------------------------------------------------- |
440 | * CRUD START: | |
441 | * A more elegant soln is in the works that uses the queue | |
442 | * merge fn, unfortunately there are a couple of changes to | |
443 | * the block layer that I want to make for this. So in the | |
444 | * interests of getting something for people to use I give | |
445 | * you this clearly demarcated crap. | |
446 | *---------------------------------------------------------------*/ | |
447 | ||
2e93ccc1 KU |
448 | static int __noflush_suspending(struct mapped_device *md) |
449 | { | |
450 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
451 | } | |
452 | ||
1da177e4 LT |
453 | /* |
454 | * Decrements the number of outstanding ios that a bio has been | |
455 | * cloned into, completing the original io if necc. | |
456 | */ | |
858119e1 | 457 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 458 | { |
2e93ccc1 KU |
459 | unsigned long flags; |
460 | ||
461 | /* Push-back supersedes any I/O errors */ | |
462 | if (error && !(io->error > 0 && __noflush_suspending(io->md))) | |
1da177e4 LT |
463 | io->error = error; |
464 | ||
465 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
466 | if (io->error == DM_ENDIO_REQUEUE) { |
467 | /* | |
468 | * Target requested pushing back the I/O. | |
469 | * This must be handled before the sleeper on | |
470 | * suspend queue merges the pushback list. | |
471 | */ | |
472 | spin_lock_irqsave(&io->md->pushback_lock, flags); | |
473 | if (__noflush_suspending(io->md)) | |
474 | bio_list_add(&io->md->pushback, io->bio); | |
475 | else | |
476 | /* noflush suspend was interrupted. */ | |
477 | io->error = -EIO; | |
478 | spin_unlock_irqrestore(&io->md->pushback_lock, flags); | |
479 | } | |
480 | ||
3eaf840e | 481 | if (end_io_acct(io)) |
1da177e4 LT |
482 | /* nudge anyone waiting on suspend queue */ |
483 | wake_up(&io->md->wait); | |
484 | ||
2e93ccc1 KU |
485 | if (io->error != DM_ENDIO_REQUEUE) { |
486 | blk_add_trace_bio(io->md->queue, io->bio, | |
487 | BLK_TA_COMPLETE); | |
488 | ||
489 | bio_endio(io->bio, io->bio->bi_size, io->error); | |
490 | } | |
2056a782 | 491 | |
1da177e4 LT |
492 | free_io(io->md, io); |
493 | } | |
494 | } | |
495 | ||
496 | static int clone_endio(struct bio *bio, unsigned int done, int error) | |
497 | { | |
498 | int r = 0; | |
028867ac | 499 | struct dm_target_io *tio = bio->bi_private; |
9faf400f | 500 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
501 | dm_endio_fn endio = tio->ti->type->end_io; |
502 | ||
503 | if (bio->bi_size) | |
504 | return 1; | |
505 | ||
506 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) | |
507 | error = -EIO; | |
508 | ||
509 | if (endio) { | |
510 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
511 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
512 | /* | |
513 | * error and requeue request are handled | |
514 | * in dec_pending(). | |
515 | */ | |
1da177e4 | 516 | error = r; |
45cbcd79 KU |
517 | else if (r == DM_ENDIO_INCOMPLETE) |
518 | /* The target will handle the io */ | |
1da177e4 | 519 | return 1; |
45cbcd79 KU |
520 | else if (r) { |
521 | DMWARN("unimplemented target endio return value: %d", r); | |
522 | BUG(); | |
523 | } | |
1da177e4 LT |
524 | } |
525 | ||
9faf400f SB |
526 | dec_pending(tio->io, error); |
527 | ||
528 | /* | |
529 | * Store md for cleanup instead of tio which is about to get freed. | |
530 | */ | |
531 | bio->bi_private = md->bs; | |
532 | ||
1da177e4 | 533 | bio_put(bio); |
9faf400f | 534 | free_tio(md, tio); |
1da177e4 LT |
535 | return r; |
536 | } | |
537 | ||
538 | static sector_t max_io_len(struct mapped_device *md, | |
539 | sector_t sector, struct dm_target *ti) | |
540 | { | |
541 | sector_t offset = sector - ti->begin; | |
542 | sector_t len = ti->len - offset; | |
543 | ||
544 | /* | |
545 | * Does the target need to split even further ? | |
546 | */ | |
547 | if (ti->split_io) { | |
548 | sector_t boundary; | |
549 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
550 | - offset; | |
551 | if (len > boundary) | |
552 | len = boundary; | |
553 | } | |
554 | ||
555 | return len; | |
556 | } | |
557 | ||
558 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 559 | struct dm_target_io *tio) |
1da177e4 LT |
560 | { |
561 | int r; | |
2056a782 | 562 | sector_t sector; |
9faf400f | 563 | struct mapped_device *md; |
1da177e4 LT |
564 | |
565 | /* | |
566 | * Sanity checks. | |
567 | */ | |
568 | BUG_ON(!clone->bi_size); | |
569 | ||
570 | clone->bi_end_io = clone_endio; | |
571 | clone->bi_private = tio; | |
572 | ||
573 | /* | |
574 | * Map the clone. If r == 0 we don't need to do | |
575 | * anything, the target has assumed ownership of | |
576 | * this io. | |
577 | */ | |
578 | atomic_inc(&tio->io->io_count); | |
2056a782 | 579 | sector = clone->bi_sector; |
1da177e4 | 580 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 581 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 582 | /* the bio has been remapped so dispatch it */ |
2056a782 | 583 | |
17b2f66f AK |
584 | blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, |
585 | tio->io->bio->bi_bdev->bd_dev, sector, | |
2056a782 JA |
586 | clone->bi_sector); |
587 | ||
1da177e4 | 588 | generic_make_request(clone); |
2e93ccc1 KU |
589 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
590 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
591 | md = tio->io->md; |
592 | dec_pending(tio->io, r); | |
593 | /* | |
594 | * Store bio_set for cleanup. | |
595 | */ | |
596 | clone->bi_private = md->bs; | |
1da177e4 | 597 | bio_put(clone); |
9faf400f | 598 | free_tio(md, tio); |
45cbcd79 KU |
599 | } else if (r) { |
600 | DMWARN("unimplemented target map return value: %d", r); | |
601 | BUG(); | |
1da177e4 LT |
602 | } |
603 | } | |
604 | ||
605 | struct clone_info { | |
606 | struct mapped_device *md; | |
607 | struct dm_table *map; | |
608 | struct bio *bio; | |
609 | struct dm_io *io; | |
610 | sector_t sector; | |
611 | sector_t sector_count; | |
612 | unsigned short idx; | |
613 | }; | |
614 | ||
3676347a PO |
615 | static void dm_bio_destructor(struct bio *bio) |
616 | { | |
9faf400f SB |
617 | struct bio_set *bs = bio->bi_private; |
618 | ||
619 | bio_free(bio, bs); | |
3676347a PO |
620 | } |
621 | ||
1da177e4 LT |
622 | /* |
623 | * Creates a little bio that is just does part of a bvec. | |
624 | */ | |
625 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
626 | unsigned short idx, unsigned int offset, | |
9faf400f | 627 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
628 | { |
629 | struct bio *clone; | |
630 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
631 | ||
9faf400f | 632 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 633 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
634 | *clone->bi_io_vec = *bv; |
635 | ||
636 | clone->bi_sector = sector; | |
637 | clone->bi_bdev = bio->bi_bdev; | |
638 | clone->bi_rw = bio->bi_rw; | |
639 | clone->bi_vcnt = 1; | |
640 | clone->bi_size = to_bytes(len); | |
641 | clone->bi_io_vec->bv_offset = offset; | |
642 | clone->bi_io_vec->bv_len = clone->bi_size; | |
643 | ||
644 | return clone; | |
645 | } | |
646 | ||
647 | /* | |
648 | * Creates a bio that consists of range of complete bvecs. | |
649 | */ | |
650 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
651 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 652 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
653 | { |
654 | struct bio *clone; | |
655 | ||
9faf400f SB |
656 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
657 | __bio_clone(clone, bio); | |
658 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
659 | clone->bi_sector = sector; |
660 | clone->bi_idx = idx; | |
661 | clone->bi_vcnt = idx + bv_count; | |
662 | clone->bi_size = to_bytes(len); | |
663 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
664 | ||
665 | return clone; | |
666 | } | |
667 | ||
668 | static void __clone_and_map(struct clone_info *ci) | |
669 | { | |
670 | struct bio *clone, *bio = ci->bio; | |
671 | struct dm_target *ti = dm_table_find_target(ci->map, ci->sector); | |
672 | sector_t len = 0, max = max_io_len(ci->md, ci->sector, ti); | |
028867ac | 673 | struct dm_target_io *tio; |
1da177e4 LT |
674 | |
675 | /* | |
676 | * Allocate a target io object. | |
677 | */ | |
678 | tio = alloc_tio(ci->md); | |
679 | tio->io = ci->io; | |
680 | tio->ti = ti; | |
681 | memset(&tio->info, 0, sizeof(tio->info)); | |
682 | ||
683 | if (ci->sector_count <= max) { | |
684 | /* | |
685 | * Optimise for the simple case where we can do all of | |
686 | * the remaining io with a single clone. | |
687 | */ | |
688 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
689 | bio->bi_vcnt - ci->idx, ci->sector_count, |
690 | ci->md->bs); | |
1da177e4 LT |
691 | __map_bio(ti, clone, tio); |
692 | ci->sector_count = 0; | |
693 | ||
694 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
695 | /* | |
696 | * There are some bvecs that don't span targets. | |
697 | * Do as many of these as possible. | |
698 | */ | |
699 | int i; | |
700 | sector_t remaining = max; | |
701 | sector_t bv_len; | |
702 | ||
703 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
704 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
705 | ||
706 | if (bv_len > remaining) | |
707 | break; | |
708 | ||
709 | remaining -= bv_len; | |
710 | len += bv_len; | |
711 | } | |
712 | ||
9faf400f SB |
713 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
714 | ci->md->bs); | |
1da177e4 LT |
715 | __map_bio(ti, clone, tio); |
716 | ||
717 | ci->sector += len; | |
718 | ci->sector_count -= len; | |
719 | ci->idx = i; | |
720 | ||
721 | } else { | |
722 | /* | |
d2044a94 | 723 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
724 | */ |
725 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
726 | sector_t remaining = to_sector(bv->bv_len); |
727 | unsigned int offset = 0; | |
1da177e4 | 728 | |
d2044a94 AK |
729 | do { |
730 | if (offset) { | |
731 | ti = dm_table_find_target(ci->map, ci->sector); | |
732 | max = max_io_len(ci->md, ci->sector, ti); | |
1da177e4 | 733 | |
d2044a94 AK |
734 | tio = alloc_tio(ci->md); |
735 | tio->io = ci->io; | |
736 | tio->ti = ti; | |
737 | memset(&tio->info, 0, sizeof(tio->info)); | |
738 | } | |
739 | ||
740 | len = min(remaining, max); | |
741 | ||
742 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
743 | bv->bv_offset + offset, len, |
744 | ci->md->bs); | |
d2044a94 AK |
745 | |
746 | __map_bio(ti, clone, tio); | |
747 | ||
748 | ci->sector += len; | |
749 | ci->sector_count -= len; | |
750 | offset += to_bytes(len); | |
751 | } while (remaining -= len); | |
1da177e4 | 752 | |
1da177e4 LT |
753 | ci->idx++; |
754 | } | |
755 | } | |
756 | ||
757 | /* | |
758 | * Split the bio into several clones. | |
759 | */ | |
760 | static void __split_bio(struct mapped_device *md, struct bio *bio) | |
761 | { | |
762 | struct clone_info ci; | |
763 | ||
764 | ci.map = dm_get_table(md); | |
765 | if (!ci.map) { | |
766 | bio_io_error(bio, bio->bi_size); | |
767 | return; | |
768 | } | |
769 | ||
770 | ci.md = md; | |
771 | ci.bio = bio; | |
772 | ci.io = alloc_io(md); | |
773 | ci.io->error = 0; | |
774 | atomic_set(&ci.io->io_count, 1); | |
775 | ci.io->bio = bio; | |
776 | ci.io->md = md; | |
777 | ci.sector = bio->bi_sector; | |
778 | ci.sector_count = bio_sectors(bio); | |
779 | ci.idx = bio->bi_idx; | |
780 | ||
3eaf840e | 781 | start_io_acct(ci.io); |
1da177e4 LT |
782 | while (ci.sector_count) |
783 | __clone_and_map(&ci); | |
784 | ||
785 | /* drop the extra reference count */ | |
786 | dec_pending(ci.io, 0); | |
787 | dm_table_put(ci.map); | |
788 | } | |
789 | /*----------------------------------------------------------------- | |
790 | * CRUD END | |
791 | *---------------------------------------------------------------*/ | |
792 | ||
793 | /* | |
794 | * The request function that just remaps the bio built up by | |
795 | * dm_merge_bvec. | |
796 | */ | |
797 | static int dm_request(request_queue_t *q, struct bio *bio) | |
798 | { | |
799 | int r; | |
12f03a49 | 800 | int rw = bio_data_dir(bio); |
1da177e4 LT |
801 | struct mapped_device *md = q->queuedata; |
802 | ||
07a83c47 SB |
803 | /* |
804 | * There is no use in forwarding any barrier request since we can't | |
805 | * guarantee it is (or can be) handled by the targets correctly. | |
806 | */ | |
807 | if (unlikely(bio_barrier(bio))) { | |
808 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); | |
809 | return 0; | |
810 | } | |
811 | ||
2ca3310e | 812 | down_read(&md->io_lock); |
1da177e4 | 813 | |
12f03a49 KC |
814 | disk_stat_inc(dm_disk(md), ios[rw]); |
815 | disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio)); | |
816 | ||
1da177e4 LT |
817 | /* |
818 | * If we're suspended we have to queue | |
819 | * this io for later. | |
820 | */ | |
821 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 822 | up_read(&md->io_lock); |
1da177e4 LT |
823 | |
824 | if (bio_rw(bio) == READA) { | |
825 | bio_io_error(bio, bio->bi_size); | |
826 | return 0; | |
827 | } | |
828 | ||
829 | r = queue_io(md, bio); | |
830 | if (r < 0) { | |
831 | bio_io_error(bio, bio->bi_size); | |
832 | return 0; | |
833 | ||
834 | } else if (r == 0) | |
835 | return 0; /* deferred successfully */ | |
836 | ||
837 | /* | |
838 | * We're in a while loop, because someone could suspend | |
839 | * before we get to the following read lock. | |
840 | */ | |
2ca3310e | 841 | down_read(&md->io_lock); |
1da177e4 LT |
842 | } |
843 | ||
844 | __split_bio(md, bio); | |
2ca3310e | 845 | up_read(&md->io_lock); |
1da177e4 LT |
846 | return 0; |
847 | } | |
848 | ||
849 | static int dm_flush_all(request_queue_t *q, struct gendisk *disk, | |
850 | sector_t *error_sector) | |
851 | { | |
852 | struct mapped_device *md = q->queuedata; | |
853 | struct dm_table *map = dm_get_table(md); | |
854 | int ret = -ENXIO; | |
855 | ||
856 | if (map) { | |
cf222b37 | 857 | ret = dm_table_flush_all(map); |
1da177e4 LT |
858 | dm_table_put(map); |
859 | } | |
860 | ||
861 | return ret; | |
862 | } | |
863 | ||
864 | static void dm_unplug_all(request_queue_t *q) | |
865 | { | |
866 | struct mapped_device *md = q->queuedata; | |
867 | struct dm_table *map = dm_get_table(md); | |
868 | ||
869 | if (map) { | |
870 | dm_table_unplug_all(map); | |
871 | dm_table_put(map); | |
872 | } | |
873 | } | |
874 | ||
875 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
876 | { | |
877 | int r; | |
878 | struct mapped_device *md = (struct mapped_device *) congested_data; | |
879 | struct dm_table *map = dm_get_table(md); | |
880 | ||
881 | if (!map || test_bit(DMF_BLOCK_IO, &md->flags)) | |
882 | r = bdi_bits; | |
883 | else | |
884 | r = dm_table_any_congested(map, bdi_bits); | |
885 | ||
886 | dm_table_put(map); | |
887 | return r; | |
888 | } | |
889 | ||
890 | /*----------------------------------------------------------------- | |
891 | * An IDR is used to keep track of allocated minor numbers. | |
892 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
893 | static DEFINE_IDR(_minor_idr); |
894 | ||
2b06cfff | 895 | static void free_minor(int minor) |
1da177e4 | 896 | { |
f32c10b0 | 897 | spin_lock(&_minor_lock); |
1da177e4 | 898 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 899 | spin_unlock(&_minor_lock); |
1da177e4 LT |
900 | } |
901 | ||
902 | /* | |
903 | * See if the device with a specific minor # is free. | |
904 | */ | |
2b06cfff | 905 | static int specific_minor(struct mapped_device *md, int minor) |
1da177e4 LT |
906 | { |
907 | int r, m; | |
908 | ||
909 | if (minor >= (1 << MINORBITS)) | |
910 | return -EINVAL; | |
911 | ||
62f75c2f JM |
912 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
913 | if (!r) | |
914 | return -ENOMEM; | |
915 | ||
f32c10b0 | 916 | spin_lock(&_minor_lock); |
1da177e4 LT |
917 | |
918 | if (idr_find(&_minor_idr, minor)) { | |
919 | r = -EBUSY; | |
920 | goto out; | |
921 | } | |
922 | ||
ba61fdd1 | 923 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 924 | if (r) |
1da177e4 | 925 | goto out; |
1da177e4 LT |
926 | |
927 | if (m != minor) { | |
928 | idr_remove(&_minor_idr, m); | |
929 | r = -EBUSY; | |
930 | goto out; | |
931 | } | |
932 | ||
933 | out: | |
f32c10b0 | 934 | spin_unlock(&_minor_lock); |
1da177e4 LT |
935 | return r; |
936 | } | |
937 | ||
2b06cfff | 938 | static int next_free_minor(struct mapped_device *md, int *minor) |
1da177e4 | 939 | { |
2b06cfff | 940 | int r, m; |
1da177e4 | 941 | |
1da177e4 | 942 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
943 | if (!r) |
944 | return -ENOMEM; | |
945 | ||
f32c10b0 | 946 | spin_lock(&_minor_lock); |
1da177e4 | 947 | |
ba61fdd1 | 948 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
1da177e4 LT |
949 | if (r) { |
950 | goto out; | |
951 | } | |
952 | ||
953 | if (m >= (1 << MINORBITS)) { | |
954 | idr_remove(&_minor_idr, m); | |
955 | r = -ENOSPC; | |
956 | goto out; | |
957 | } | |
958 | ||
959 | *minor = m; | |
960 | ||
961 | out: | |
f32c10b0 | 962 | spin_unlock(&_minor_lock); |
1da177e4 LT |
963 | return r; |
964 | } | |
965 | ||
966 | static struct block_device_operations dm_blk_dops; | |
967 | ||
968 | /* | |
969 | * Allocate and initialise a blank device with a given minor. | |
970 | */ | |
2b06cfff | 971 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
972 | { |
973 | int r; | |
974 | struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); | |
ba61fdd1 | 975 | void *old_md; |
1da177e4 LT |
976 | |
977 | if (!md) { | |
978 | DMWARN("unable to allocate device, out of memory."); | |
979 | return NULL; | |
980 | } | |
981 | ||
10da4f79 JM |
982 | if (!try_module_get(THIS_MODULE)) |
983 | goto bad0; | |
984 | ||
1da177e4 | 985 | /* get a minor number for the dev */ |
2b06cfff AK |
986 | if (minor == DM_ANY_MINOR) |
987 | r = next_free_minor(md, &minor); | |
988 | else | |
989 | r = specific_minor(md, minor); | |
1da177e4 LT |
990 | if (r < 0) |
991 | goto bad1; | |
992 | ||
993 | memset(md, 0, sizeof(*md)); | |
2ca3310e AK |
994 | init_rwsem(&md->io_lock); |
995 | init_MUTEX(&md->suspend_lock); | |
2e93ccc1 | 996 | spin_lock_init(&md->pushback_lock); |
1da177e4 LT |
997 | rwlock_init(&md->map_lock); |
998 | atomic_set(&md->holders, 1); | |
5c6bd75d | 999 | atomic_set(&md->open_count, 0); |
1da177e4 LT |
1000 | atomic_set(&md->event_nr, 0); |
1001 | ||
1002 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
1003 | if (!md->queue) | |
e3f6ac61 | 1004 | goto bad1_free_minor; |
1da177e4 LT |
1005 | |
1006 | md->queue->queuedata = md; | |
1007 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1008 | md->queue->backing_dev_info.congested_data = md; | |
1009 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 1010 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 LT |
1011 | md->queue->unplug_fn = dm_unplug_all; |
1012 | md->queue->issue_flush_fn = dm_flush_all; | |
1013 | ||
93d2341c | 1014 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 KU |
1015 | if (!md->io_pool) |
1016 | goto bad2; | |
1da177e4 | 1017 | |
93d2341c | 1018 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 LT |
1019 | if (!md->tio_pool) |
1020 | goto bad3; | |
1021 | ||
5972511b | 1022 | md->bs = bioset_create(16, 16); |
9faf400f SB |
1023 | if (!md->bs) |
1024 | goto bad_no_bioset; | |
1025 | ||
1da177e4 LT |
1026 | md->disk = alloc_disk(1); |
1027 | if (!md->disk) | |
1028 | goto bad4; | |
1029 | ||
f0b04115 JM |
1030 | atomic_set(&md->pending, 0); |
1031 | init_waitqueue_head(&md->wait); | |
1032 | init_waitqueue_head(&md->eventq); | |
1033 | ||
1da177e4 LT |
1034 | md->disk->major = _major; |
1035 | md->disk->first_minor = minor; | |
1036 | md->disk->fops = &dm_blk_dops; | |
1037 | md->disk->queue = md->queue; | |
1038 | md->disk->private_data = md; | |
1039 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
1040 | add_disk(md->disk); | |
7e51f257 | 1041 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1042 | |
ba61fdd1 | 1043 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1044 | spin_lock(&_minor_lock); |
ba61fdd1 | 1045 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1046 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1047 | |
1048 | BUG_ON(old_md != MINOR_ALLOCED); | |
1049 | ||
1da177e4 LT |
1050 | return md; |
1051 | ||
1052 | bad4: | |
9faf400f SB |
1053 | bioset_free(md->bs); |
1054 | bad_no_bioset: | |
1da177e4 LT |
1055 | mempool_destroy(md->tio_pool); |
1056 | bad3: | |
1057 | mempool_destroy(md->io_pool); | |
1058 | bad2: | |
1312f40e | 1059 | blk_cleanup_queue(md->queue); |
e3f6ac61 | 1060 | bad1_free_minor: |
1da177e4 LT |
1061 | free_minor(minor); |
1062 | bad1: | |
10da4f79 JM |
1063 | module_put(THIS_MODULE); |
1064 | bad0: | |
1da177e4 LT |
1065 | kfree(md); |
1066 | return NULL; | |
1067 | } | |
1068 | ||
1069 | static void free_dev(struct mapped_device *md) | |
1070 | { | |
2b06cfff | 1071 | int minor = md->disk->first_minor; |
63d94e48 | 1072 | |
d9dde59b JN |
1073 | if (md->suspended_bdev) { |
1074 | thaw_bdev(md->suspended_bdev, NULL); | |
1075 | bdput(md->suspended_bdev); | |
1076 | } | |
1da177e4 LT |
1077 | mempool_destroy(md->tio_pool); |
1078 | mempool_destroy(md->io_pool); | |
9faf400f | 1079 | bioset_free(md->bs); |
1da177e4 | 1080 | del_gendisk(md->disk); |
63d94e48 | 1081 | free_minor(minor); |
fba9f90e JM |
1082 | |
1083 | spin_lock(&_minor_lock); | |
1084 | md->disk->private_data = NULL; | |
1085 | spin_unlock(&_minor_lock); | |
1086 | ||
1da177e4 | 1087 | put_disk(md->disk); |
1312f40e | 1088 | blk_cleanup_queue(md->queue); |
10da4f79 | 1089 | module_put(THIS_MODULE); |
1da177e4 LT |
1090 | kfree(md); |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * Bind a table to the device. | |
1095 | */ | |
1096 | static void event_callback(void *context) | |
1097 | { | |
1098 | struct mapped_device *md = (struct mapped_device *) context; | |
1099 | ||
1100 | atomic_inc(&md->event_nr); | |
1101 | wake_up(&md->eventq); | |
1102 | } | |
1103 | ||
4e90188b | 1104 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1105 | { |
4e90188b | 1106 | set_capacity(md->disk, size); |
1da177e4 | 1107 | |
1b1dcc1b | 1108 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1109 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1110 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1111 | } |
1112 | ||
1113 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1114 | { | |
1115 | request_queue_t *q = md->queue; | |
1116 | sector_t size; | |
1117 | ||
1118 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1119 | |
1120 | /* | |
1121 | * Wipe any geometry if the size of the table changed. | |
1122 | */ | |
1123 | if (size != get_capacity(md->disk)) | |
1124 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1125 | ||
bfa152fa JN |
1126 | if (md->suspended_bdev) |
1127 | __set_size(md, size); | |
1da177e4 LT |
1128 | if (size == 0) |
1129 | return 0; | |
1130 | ||
2ca3310e AK |
1131 | dm_table_get(t); |
1132 | dm_table_event_callback(t, event_callback, md); | |
1133 | ||
1da177e4 LT |
1134 | write_lock(&md->map_lock); |
1135 | md->map = t; | |
2ca3310e | 1136 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1137 | write_unlock(&md->map_lock); |
1138 | ||
1da177e4 LT |
1139 | return 0; |
1140 | } | |
1141 | ||
1142 | static void __unbind(struct mapped_device *md) | |
1143 | { | |
1144 | struct dm_table *map = md->map; | |
1145 | ||
1146 | if (!map) | |
1147 | return; | |
1148 | ||
1149 | dm_table_event_callback(map, NULL, NULL); | |
1150 | write_lock(&md->map_lock); | |
1151 | md->map = NULL; | |
1152 | write_unlock(&md->map_lock); | |
1153 | dm_table_put(map); | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * Constructor for a new device. | |
1158 | */ | |
2b06cfff | 1159 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1160 | { |
1161 | struct mapped_device *md; | |
1162 | ||
2b06cfff | 1163 | md = alloc_dev(minor); |
1da177e4 LT |
1164 | if (!md) |
1165 | return -ENXIO; | |
1166 | ||
1167 | *result = md; | |
1168 | return 0; | |
1169 | } | |
1170 | ||
637842cf | 1171 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1172 | { |
1173 | struct mapped_device *md; | |
1da177e4 LT |
1174 | unsigned minor = MINOR(dev); |
1175 | ||
1176 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1177 | return NULL; | |
1178 | ||
f32c10b0 | 1179 | spin_lock(&_minor_lock); |
1da177e4 LT |
1180 | |
1181 | md = idr_find(&_minor_idr, minor); | |
fba9f90e JM |
1182 | if (md && (md == MINOR_ALLOCED || |
1183 | (dm_disk(md)->first_minor != minor) || | |
17b2f66f | 1184 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1185 | md = NULL; |
fba9f90e JM |
1186 | goto out; |
1187 | } | |
1da177e4 | 1188 | |
fba9f90e | 1189 | out: |
f32c10b0 | 1190 | spin_unlock(&_minor_lock); |
1da177e4 | 1191 | |
637842cf DT |
1192 | return md; |
1193 | } | |
1194 | ||
d229a958 DT |
1195 | struct mapped_device *dm_get_md(dev_t dev) |
1196 | { | |
1197 | struct mapped_device *md = dm_find_md(dev); | |
1198 | ||
1199 | if (md) | |
1200 | dm_get(md); | |
1201 | ||
1202 | return md; | |
1203 | } | |
1204 | ||
9ade92a9 | 1205 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1206 | { |
9ade92a9 | 1207 | return md->interface_ptr; |
1da177e4 LT |
1208 | } |
1209 | ||
1210 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1211 | { | |
1212 | md->interface_ptr = ptr; | |
1213 | } | |
1214 | ||
1215 | void dm_get(struct mapped_device *md) | |
1216 | { | |
1217 | atomic_inc(&md->holders); | |
1218 | } | |
1219 | ||
72d94861 AK |
1220 | const char *dm_device_name(struct mapped_device *md) |
1221 | { | |
1222 | return md->name; | |
1223 | } | |
1224 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1225 | ||
1da177e4 LT |
1226 | void dm_put(struct mapped_device *md) |
1227 | { | |
1134e5ae | 1228 | struct dm_table *map; |
1da177e4 | 1229 | |
fba9f90e JM |
1230 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1231 | ||
f32c10b0 | 1232 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1233 | map = dm_get_table(md); |
ba61fdd1 | 1234 | idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); |
fba9f90e | 1235 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1236 | spin_unlock(&_minor_lock); |
cf222b37 | 1237 | if (!dm_suspended(md)) { |
1da177e4 LT |
1238 | dm_table_presuspend_targets(map); |
1239 | dm_table_postsuspend_targets(map); | |
1240 | } | |
1241 | __unbind(md); | |
1134e5ae | 1242 | dm_table_put(map); |
1da177e4 LT |
1243 | free_dev(md); |
1244 | } | |
1da177e4 | 1245 | } |
79eb885c | 1246 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 LT |
1247 | |
1248 | /* | |
1249 | * Process the deferred bios | |
1250 | */ | |
1251 | static void __flush_deferred_io(struct mapped_device *md, struct bio *c) | |
1252 | { | |
1253 | struct bio *n; | |
1254 | ||
1255 | while (c) { | |
1256 | n = c->bi_next; | |
1257 | c->bi_next = NULL; | |
1258 | __split_bio(md, c); | |
1259 | c = n; | |
1260 | } | |
1261 | } | |
1262 | ||
1263 | /* | |
1264 | * Swap in a new table (destroying old one). | |
1265 | */ | |
1266 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1267 | { | |
93c534ae | 1268 | int r = -EINVAL; |
1da177e4 | 1269 | |
2ca3310e | 1270 | down(&md->suspend_lock); |
1da177e4 LT |
1271 | |
1272 | /* device must be suspended */ | |
cf222b37 | 1273 | if (!dm_suspended(md)) |
93c534ae | 1274 | goto out; |
1da177e4 | 1275 | |
bfa152fa JN |
1276 | /* without bdev, the device size cannot be changed */ |
1277 | if (!md->suspended_bdev) | |
1278 | if (get_capacity(md->disk) != dm_table_get_size(table)) | |
1279 | goto out; | |
1280 | ||
1da177e4 LT |
1281 | __unbind(md); |
1282 | r = __bind(md, table); | |
1da177e4 | 1283 | |
93c534ae | 1284 | out: |
2ca3310e | 1285 | up(&md->suspend_lock); |
93c534ae | 1286 | return r; |
1da177e4 LT |
1287 | } |
1288 | ||
1289 | /* | |
1290 | * Functions to lock and unlock any filesystem running on the | |
1291 | * device. | |
1292 | */ | |
2ca3310e | 1293 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1294 | { |
e39e2e95 | 1295 | int r; |
1da177e4 LT |
1296 | |
1297 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1298 | |
e39e2e95 | 1299 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1300 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1301 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1302 | md->frozen_sb = NULL; |
1303 | return r; | |
dfbe03f6 AK |
1304 | } |
1305 | ||
aa8d7c2f AK |
1306 | set_bit(DMF_FROZEN, &md->flags); |
1307 | ||
1da177e4 | 1308 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1309 | * to go away while it is locked. |
1da177e4 LT |
1310 | */ |
1311 | return 0; | |
1312 | } | |
1313 | ||
2ca3310e | 1314 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1315 | { |
aa8d7c2f AK |
1316 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1317 | return; | |
1318 | ||
e39e2e95 | 1319 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1320 | md->frozen_sb = NULL; |
aa8d7c2f | 1321 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1322 | } |
1323 | ||
1324 | /* | |
1325 | * We need to be able to change a mapping table under a mounted | |
1326 | * filesystem. For example we might want to move some data in | |
1327 | * the background. Before the table can be swapped with | |
1328 | * dm_bind_table, dm_suspend must be called to flush any in | |
1329 | * flight bios and ensure that any further io gets deferred. | |
1330 | */ | |
a3d77d35 | 1331 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1332 | { |
2ca3310e | 1333 | struct dm_table *map = NULL; |
2e93ccc1 | 1334 | unsigned long flags; |
1da177e4 | 1335 | DECLARE_WAITQUEUE(wait, current); |
1ecac7fd | 1336 | struct bio *def; |
cf222b37 | 1337 | int r = -EINVAL; |
a3d77d35 | 1338 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 1339 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 1340 | |
2ca3310e AK |
1341 | down(&md->suspend_lock); |
1342 | ||
1343 | if (dm_suspended(md)) | |
d287483d | 1344 | goto out_unlock; |
1da177e4 LT |
1345 | |
1346 | map = dm_get_table(md); | |
1da177e4 | 1347 | |
2e93ccc1 KU |
1348 | /* |
1349 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
1350 | * This flag is cleared before dm_suspend returns. | |
1351 | */ | |
1352 | if (noflush) | |
1353 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1354 | ||
cf222b37 AK |
1355 | /* This does not get reverted if there's an error later. */ |
1356 | dm_table_presuspend_targets(map); | |
1357 | ||
bfa152fa JN |
1358 | /* bdget() can stall if the pending I/Os are not flushed */ |
1359 | if (!noflush) { | |
1360 | md->suspended_bdev = bdget_disk(md->disk, 0); | |
1361 | if (!md->suspended_bdev) { | |
1362 | DMWARN("bdget failed in dm_suspend"); | |
1363 | r = -ENOMEM; | |
1364 | goto flush_and_out; | |
1365 | } | |
e39e2e95 AK |
1366 | } |
1367 | ||
2e93ccc1 KU |
1368 | /* |
1369 | * Flush I/O to the device. | |
1370 | * noflush supersedes do_lockfs, because lock_fs() needs to flush I/Os. | |
1371 | */ | |
1372 | if (do_lockfs && !noflush) { | |
aa8d7c2f AK |
1373 | r = lock_fs(md); |
1374 | if (r) | |
1375 | goto out; | |
1376 | } | |
1da177e4 LT |
1377 | |
1378 | /* | |
354e0071 | 1379 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1380 | */ |
2ca3310e AK |
1381 | down_write(&md->io_lock); |
1382 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1383 | |
1da177e4 | 1384 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1385 | up_write(&md->io_lock); |
1da177e4 LT |
1386 | |
1387 | /* unplug */ | |
2ca3310e | 1388 | if (map) |
1da177e4 | 1389 | dm_table_unplug_all(map); |
1da177e4 LT |
1390 | |
1391 | /* | |
1392 | * Then we wait for the already mapped ios to | |
1393 | * complete. | |
1394 | */ | |
1395 | while (1) { | |
1396 | set_current_state(TASK_INTERRUPTIBLE); | |
1397 | ||
1398 | if (!atomic_read(&md->pending) || signal_pending(current)) | |
1399 | break; | |
1400 | ||
1401 | io_schedule(); | |
1402 | } | |
1403 | set_current_state(TASK_RUNNING); | |
1404 | ||
2ca3310e | 1405 | down_write(&md->io_lock); |
1da177e4 LT |
1406 | remove_wait_queue(&md->wait, &wait); |
1407 | ||
2e93ccc1 KU |
1408 | if (noflush) { |
1409 | spin_lock_irqsave(&md->pushback_lock, flags); | |
1410 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1411 | bio_list_merge_head(&md->deferred, &md->pushback); | |
1412 | bio_list_init(&md->pushback); | |
1413 | spin_unlock_irqrestore(&md->pushback_lock, flags); | |
1414 | } | |
1415 | ||
1da177e4 | 1416 | /* were we interrupted ? */ |
cf222b37 | 1417 | r = -EINTR; |
2ca3310e | 1418 | if (atomic_read(&md->pending)) { |
1ecac7fd JN |
1419 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1420 | def = bio_list_get(&md->deferred); | |
1421 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1422 | up_write(&md->io_lock); |
1423 | unlock_fs(md); | |
2e93ccc1 | 1424 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e AK |
1425 | } |
1426 | up_write(&md->io_lock); | |
1da177e4 | 1427 | |
cf222b37 | 1428 | dm_table_postsuspend_targets(map); |
1da177e4 | 1429 | |
2ca3310e | 1430 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1431 | |
2ca3310e | 1432 | r = 0; |
b84b0287 | 1433 | |
2e93ccc1 KU |
1434 | flush_and_out: |
1435 | if (r && noflush) { | |
1436 | /* | |
1437 | * Because there may be already I/Os in the pushback list, | |
1438 | * flush them before return. | |
1439 | */ | |
1440 | down_write(&md->io_lock); | |
1441 | ||
1442 | spin_lock_irqsave(&md->pushback_lock, flags); | |
1443 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1444 | bio_list_merge_head(&md->deferred, &md->pushback); | |
1445 | bio_list_init(&md->pushback); | |
1446 | spin_unlock_irqrestore(&md->pushback_lock, flags); | |
1447 | ||
1448 | def = bio_list_get(&md->deferred); | |
1449 | __flush_deferred_io(md, def); | |
1450 | up_write(&md->io_lock); | |
1451 | } | |
1452 | ||
2ca3310e | 1453 | out: |
e39e2e95 AK |
1454 | if (r && md->suspended_bdev) { |
1455 | bdput(md->suspended_bdev); | |
1456 | md->suspended_bdev = NULL; | |
1457 | } | |
1458 | ||
2ca3310e | 1459 | dm_table_put(map); |
d287483d AK |
1460 | |
1461 | out_unlock: | |
2ca3310e | 1462 | up(&md->suspend_lock); |
cf222b37 | 1463 | return r; |
1da177e4 LT |
1464 | } |
1465 | ||
1466 | int dm_resume(struct mapped_device *md) | |
1467 | { | |
cf222b37 | 1468 | int r = -EINVAL; |
1da177e4 | 1469 | struct bio *def; |
cf222b37 | 1470 | struct dm_table *map = NULL; |
1da177e4 | 1471 | |
2ca3310e AK |
1472 | down(&md->suspend_lock); |
1473 | if (!dm_suspended(md)) | |
cf222b37 | 1474 | goto out; |
cf222b37 AK |
1475 | |
1476 | map = dm_get_table(md); | |
2ca3310e | 1477 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1478 | goto out; |
1da177e4 | 1479 | |
8757b776 MB |
1480 | r = dm_table_resume_targets(map); |
1481 | if (r) | |
1482 | goto out; | |
2ca3310e AK |
1483 | |
1484 | down_write(&md->io_lock); | |
1da177e4 LT |
1485 | clear_bit(DMF_BLOCK_IO, &md->flags); |
1486 | ||
1487 | def = bio_list_get(&md->deferred); | |
1488 | __flush_deferred_io(md, def); | |
2ca3310e AK |
1489 | up_write(&md->io_lock); |
1490 | ||
1491 | unlock_fs(md); | |
1492 | ||
bfa152fa JN |
1493 | if (md->suspended_bdev) { |
1494 | bdput(md->suspended_bdev); | |
1495 | md->suspended_bdev = NULL; | |
1496 | } | |
e39e2e95 | 1497 | |
2ca3310e AK |
1498 | clear_bit(DMF_SUSPENDED, &md->flags); |
1499 | ||
1da177e4 | 1500 | dm_table_unplug_all(map); |
1da177e4 | 1501 | |
8560ed6f HR |
1502 | kobject_uevent(&md->disk->kobj, KOBJ_CHANGE); |
1503 | ||
cf222b37 | 1504 | r = 0; |
2ca3310e | 1505 | |
cf222b37 AK |
1506 | out: |
1507 | dm_table_put(map); | |
2ca3310e AK |
1508 | up(&md->suspend_lock); |
1509 | ||
cf222b37 | 1510 | return r; |
1da177e4 LT |
1511 | } |
1512 | ||
1513 | /*----------------------------------------------------------------- | |
1514 | * Event notification. | |
1515 | *---------------------------------------------------------------*/ | |
1516 | uint32_t dm_get_event_nr(struct mapped_device *md) | |
1517 | { | |
1518 | return atomic_read(&md->event_nr); | |
1519 | } | |
1520 | ||
1521 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1522 | { | |
1523 | return wait_event_interruptible(md->eventq, | |
1524 | (event_nr != atomic_read(&md->event_nr))); | |
1525 | } | |
1526 | ||
1527 | /* | |
1528 | * The gendisk is only valid as long as you have a reference | |
1529 | * count on 'md'. | |
1530 | */ | |
1531 | struct gendisk *dm_disk(struct mapped_device *md) | |
1532 | { | |
1533 | return md->disk; | |
1534 | } | |
1535 | ||
1536 | int dm_suspended(struct mapped_device *md) | |
1537 | { | |
1538 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1539 | } | |
1540 | ||
2e93ccc1 KU |
1541 | int dm_noflush_suspending(struct dm_target *ti) |
1542 | { | |
1543 | struct mapped_device *md = dm_table_get_md(ti->table); | |
1544 | int r = __noflush_suspending(md); | |
1545 | ||
1546 | dm_put(md); | |
1547 | ||
1548 | return r; | |
1549 | } | |
1550 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
1551 | ||
1da177e4 LT |
1552 | static struct block_device_operations dm_blk_dops = { |
1553 | .open = dm_blk_open, | |
1554 | .release = dm_blk_close, | |
aa129a22 | 1555 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1556 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1557 | .owner = THIS_MODULE |
1558 | }; | |
1559 | ||
1560 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1561 | ||
1562 | /* | |
1563 | * module hooks | |
1564 | */ | |
1565 | module_init(dm_init); | |
1566 | module_exit(dm_exit); | |
1567 | ||
1568 | module_param(major, uint, 0); | |
1569 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1570 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1571 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1572 | MODULE_LICENSE("GPL"); |