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