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Commit | Line | Data |
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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" | |
51e5b2bd | 10 | #include "dm-uevent.h" |
1da177e4 LT |
11 | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
48c9c27b | 14 | #include <linux/mutex.h> |
1da177e4 LT |
15 | #include <linux/moduleparam.h> |
16 | #include <linux/blkpg.h> | |
17 | #include <linux/bio.h> | |
18 | #include <linux/buffer_head.h> | |
19 | #include <linux/mempool.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/idr.h> | |
3ac51e74 | 22 | #include <linux/hdreg.h> |
2056a782 | 23 | #include <linux/blktrace_api.h> |
5f3ea37c | 24 | #include <trace/block.h> |
1da177e4 | 25 | |
72d94861 AK |
26 | #define DM_MSG_PREFIX "core" |
27 | ||
1da177e4 LT |
28 | static const char *_name = DM_NAME; |
29 | ||
30 | static unsigned int major = 0; | |
31 | static unsigned int _major = 0; | |
32 | ||
f32c10b0 | 33 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 LT |
34 | /* |
35 | * One of these is allocated per bio. | |
36 | */ | |
37 | struct dm_io { | |
38 | struct mapped_device *md; | |
39 | int error; | |
1da177e4 | 40 | atomic_t io_count; |
6ae2fa67 | 41 | struct bio *bio; |
3eaf840e | 42 | unsigned long start_time; |
1da177e4 LT |
43 | }; |
44 | ||
45 | /* | |
46 | * One of these is allocated per target within a bio. Hopefully | |
47 | * this will be simplified out one day. | |
48 | */ | |
028867ac | 49 | struct dm_target_io { |
1da177e4 LT |
50 | struct dm_io *io; |
51 | struct dm_target *ti; | |
52 | union map_info info; | |
53 | }; | |
54 | ||
55 | union map_info *dm_get_mapinfo(struct bio *bio) | |
56 | { | |
17b2f66f | 57 | if (bio && bio->bi_private) |
028867ac | 58 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 59 | return NULL; |
1da177e4 LT |
60 | } |
61 | ||
ba61fdd1 JM |
62 | #define MINOR_ALLOCED ((void *)-1) |
63 | ||
1da177e4 LT |
64 | /* |
65 | * Bits for the md->flags field. | |
66 | */ | |
67 | #define DMF_BLOCK_IO 0 | |
68 | #define DMF_SUSPENDED 1 | |
aa8d7c2f | 69 | #define DMF_FROZEN 2 |
fba9f90e | 70 | #define DMF_FREEING 3 |
5c6bd75d | 71 | #define DMF_DELETING 4 |
2e93ccc1 | 72 | #define DMF_NOFLUSH_SUSPENDING 5 |
1da177e4 | 73 | |
304f3f6a MB |
74 | /* |
75 | * Work processed by per-device workqueue. | |
76 | */ | |
77 | struct dm_wq_req { | |
78 | enum { | |
304f3f6a MB |
79 | DM_WQ_FLUSH_DEFERRED, |
80 | } type; | |
81 | struct work_struct work; | |
82 | struct mapped_device *md; | |
83 | void *context; | |
84 | }; | |
85 | ||
1da177e4 | 86 | struct mapped_device { |
2ca3310e | 87 | struct rw_semaphore io_lock; |
e61290a4 | 88 | struct mutex suspend_lock; |
2e93ccc1 | 89 | spinlock_t pushback_lock; |
1da177e4 LT |
90 | rwlock_t map_lock; |
91 | atomic_t holders; | |
5c6bd75d | 92 | atomic_t open_count; |
1da177e4 LT |
93 | |
94 | unsigned long flags; | |
95 | ||
165125e1 | 96 | struct request_queue *queue; |
1da177e4 | 97 | struct gendisk *disk; |
7e51f257 | 98 | char name[16]; |
1da177e4 LT |
99 | |
100 | void *interface_ptr; | |
101 | ||
102 | /* | |
103 | * A list of ios that arrived while we were suspended. | |
104 | */ | |
105 | atomic_t pending; | |
106 | wait_queue_head_t wait; | |
74859364 | 107 | struct bio_list deferred; |
2e93ccc1 | 108 | struct bio_list pushback; |
1da177e4 | 109 | |
304f3f6a MB |
110 | /* |
111 | * Processing queue (flush/barriers) | |
112 | */ | |
113 | struct workqueue_struct *wq; | |
114 | ||
1da177e4 LT |
115 | /* |
116 | * The current mapping. | |
117 | */ | |
118 | struct dm_table *map; | |
119 | ||
120 | /* | |
121 | * io objects are allocated from here. | |
122 | */ | |
123 | mempool_t *io_pool; | |
124 | mempool_t *tio_pool; | |
125 | ||
9faf400f SB |
126 | struct bio_set *bs; |
127 | ||
1da177e4 LT |
128 | /* |
129 | * Event handling. | |
130 | */ | |
131 | atomic_t event_nr; | |
132 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
133 | atomic_t uevent_seq; |
134 | struct list_head uevent_list; | |
135 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
136 | |
137 | /* | |
138 | * freeze/thaw support require holding onto a super block | |
139 | */ | |
140 | struct super_block *frozen_sb; | |
e39e2e95 | 141 | struct block_device *suspended_bdev; |
3ac51e74 DW |
142 | |
143 | /* forced geometry settings */ | |
144 | struct hd_geometry geometry; | |
1da177e4 LT |
145 | }; |
146 | ||
147 | #define MIN_IOS 256 | |
e18b890b CL |
148 | static struct kmem_cache *_io_cache; |
149 | static struct kmem_cache *_tio_cache; | |
1da177e4 | 150 | |
1da177e4 LT |
151 | static int __init local_init(void) |
152 | { | |
51157b4a | 153 | int r = -ENOMEM; |
1da177e4 | 154 | |
1da177e4 | 155 | /* allocate a slab for the dm_ios */ |
028867ac | 156 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 157 | if (!_io_cache) |
51157b4a | 158 | return r; |
1da177e4 LT |
159 | |
160 | /* allocate a slab for the target ios */ | |
028867ac | 161 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
51157b4a KU |
162 | if (!_tio_cache) |
163 | goto out_free_io_cache; | |
1da177e4 | 164 | |
51e5b2bd | 165 | r = dm_uevent_init(); |
51157b4a KU |
166 | if (r) |
167 | goto out_free_tio_cache; | |
51e5b2bd | 168 | |
1da177e4 LT |
169 | _major = major; |
170 | r = register_blkdev(_major, _name); | |
51157b4a KU |
171 | if (r < 0) |
172 | goto out_uevent_exit; | |
1da177e4 LT |
173 | |
174 | if (!_major) | |
175 | _major = r; | |
176 | ||
177 | return 0; | |
51157b4a KU |
178 | |
179 | out_uevent_exit: | |
180 | dm_uevent_exit(); | |
181 | out_free_tio_cache: | |
182 | kmem_cache_destroy(_tio_cache); | |
183 | out_free_io_cache: | |
184 | kmem_cache_destroy(_io_cache); | |
185 | ||
186 | return r; | |
1da177e4 LT |
187 | } |
188 | ||
189 | static void local_exit(void) | |
190 | { | |
191 | kmem_cache_destroy(_tio_cache); | |
192 | kmem_cache_destroy(_io_cache); | |
00d59405 | 193 | unregister_blkdev(_major, _name); |
51e5b2bd | 194 | dm_uevent_exit(); |
1da177e4 LT |
195 | |
196 | _major = 0; | |
197 | ||
198 | DMINFO("cleaned up"); | |
199 | } | |
200 | ||
b9249e55 | 201 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
202 | local_init, |
203 | dm_target_init, | |
204 | dm_linear_init, | |
205 | dm_stripe_init, | |
945fa4d2 | 206 | dm_kcopyd_init, |
1da177e4 LT |
207 | dm_interface_init, |
208 | }; | |
209 | ||
b9249e55 | 210 | static void (*_exits[])(void) = { |
1da177e4 LT |
211 | local_exit, |
212 | dm_target_exit, | |
213 | dm_linear_exit, | |
214 | dm_stripe_exit, | |
945fa4d2 | 215 | dm_kcopyd_exit, |
1da177e4 LT |
216 | dm_interface_exit, |
217 | }; | |
218 | ||
219 | static int __init dm_init(void) | |
220 | { | |
221 | const int count = ARRAY_SIZE(_inits); | |
222 | ||
223 | int r, i; | |
224 | ||
225 | for (i = 0; i < count; i++) { | |
226 | r = _inits[i](); | |
227 | if (r) | |
228 | goto bad; | |
229 | } | |
230 | ||
231 | return 0; | |
232 | ||
233 | bad: | |
234 | while (i--) | |
235 | _exits[i](); | |
236 | ||
237 | return r; | |
238 | } | |
239 | ||
240 | static void __exit dm_exit(void) | |
241 | { | |
242 | int i = ARRAY_SIZE(_exits); | |
243 | ||
244 | while (i--) | |
245 | _exits[i](); | |
246 | } | |
247 | ||
248 | /* | |
249 | * Block device functions | |
250 | */ | |
fe5f9f2c | 251 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
252 | { |
253 | struct mapped_device *md; | |
254 | ||
fba9f90e JM |
255 | spin_lock(&_minor_lock); |
256 | ||
fe5f9f2c | 257 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
258 | if (!md) |
259 | goto out; | |
260 | ||
5c6bd75d AK |
261 | if (test_bit(DMF_FREEING, &md->flags) || |
262 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
263 | md = NULL; |
264 | goto out; | |
265 | } | |
266 | ||
1da177e4 | 267 | dm_get(md); |
5c6bd75d | 268 | atomic_inc(&md->open_count); |
fba9f90e JM |
269 | |
270 | out: | |
271 | spin_unlock(&_minor_lock); | |
272 | ||
273 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
274 | } |
275 | ||
fe5f9f2c | 276 | static int dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 277 | { |
fe5f9f2c | 278 | struct mapped_device *md = disk->private_data; |
5c6bd75d | 279 | atomic_dec(&md->open_count); |
1da177e4 LT |
280 | dm_put(md); |
281 | return 0; | |
282 | } | |
283 | ||
5c6bd75d AK |
284 | int dm_open_count(struct mapped_device *md) |
285 | { | |
286 | return atomic_read(&md->open_count); | |
287 | } | |
288 | ||
289 | /* | |
290 | * Guarantees nothing is using the device before it's deleted. | |
291 | */ | |
292 | int dm_lock_for_deletion(struct mapped_device *md) | |
293 | { | |
294 | int r = 0; | |
295 | ||
296 | spin_lock(&_minor_lock); | |
297 | ||
298 | if (dm_open_count(md)) | |
299 | r = -EBUSY; | |
300 | else | |
301 | set_bit(DMF_DELETING, &md->flags); | |
302 | ||
303 | spin_unlock(&_minor_lock); | |
304 | ||
305 | return r; | |
306 | } | |
307 | ||
3ac51e74 DW |
308 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
309 | { | |
310 | struct mapped_device *md = bdev->bd_disk->private_data; | |
311 | ||
312 | return dm_get_geometry(md, geo); | |
313 | } | |
314 | ||
fe5f9f2c | 315 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
316 | unsigned int cmd, unsigned long arg) |
317 | { | |
fe5f9f2c AV |
318 | struct mapped_device *md = bdev->bd_disk->private_data; |
319 | struct dm_table *map = dm_get_table(md); | |
aa129a22 MB |
320 | struct dm_target *tgt; |
321 | int r = -ENOTTY; | |
322 | ||
aa129a22 MB |
323 | if (!map || !dm_table_get_size(map)) |
324 | goto out; | |
325 | ||
326 | /* We only support devices that have a single target */ | |
327 | if (dm_table_get_num_targets(map) != 1) | |
328 | goto out; | |
329 | ||
330 | tgt = dm_table_get_target(map, 0); | |
331 | ||
332 | if (dm_suspended(md)) { | |
333 | r = -EAGAIN; | |
334 | goto out; | |
335 | } | |
336 | ||
337 | if (tgt->type->ioctl) | |
647b3d00 | 338 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
339 | |
340 | out: | |
341 | dm_table_put(map); | |
342 | ||
aa129a22 MB |
343 | return r; |
344 | } | |
345 | ||
028867ac | 346 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
347 | { |
348 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
349 | } | |
350 | ||
028867ac | 351 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
352 | { |
353 | mempool_free(io, md->io_pool); | |
354 | } | |
355 | ||
028867ac | 356 | static struct dm_target_io *alloc_tio(struct mapped_device *md) |
1da177e4 LT |
357 | { |
358 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
359 | } | |
360 | ||
028867ac | 361 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
362 | { |
363 | mempool_free(tio, md->tio_pool); | |
364 | } | |
365 | ||
3eaf840e JNN |
366 | static void start_io_acct(struct dm_io *io) |
367 | { | |
368 | struct mapped_device *md = io->md; | |
c9959059 | 369 | int cpu; |
3eaf840e JNN |
370 | |
371 | io->start_time = jiffies; | |
372 | ||
074a7aca TH |
373 | cpu = part_stat_lock(); |
374 | part_round_stats(cpu, &dm_disk(md)->part0); | |
375 | part_stat_unlock(); | |
376 | dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending); | |
3eaf840e JNN |
377 | } |
378 | ||
d221d2e7 | 379 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
380 | { |
381 | struct mapped_device *md = io->md; | |
382 | struct bio *bio = io->bio; | |
383 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 384 | int pending, cpu; |
3eaf840e JNN |
385 | int rw = bio_data_dir(bio); |
386 | ||
074a7aca TH |
387 | cpu = part_stat_lock(); |
388 | part_round_stats(cpu, &dm_disk(md)->part0); | |
389 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
390 | part_stat_unlock(); | |
3eaf840e | 391 | |
074a7aca TH |
392 | dm_disk(md)->part0.in_flight = pending = |
393 | atomic_dec_return(&md->pending); | |
3eaf840e | 394 | |
d221d2e7 MP |
395 | /* nudge anyone waiting on suspend queue */ |
396 | if (!pending) | |
397 | wake_up(&md->wait); | |
3eaf840e JNN |
398 | } |
399 | ||
1da177e4 LT |
400 | /* |
401 | * Add the bio to the list of deferred io. | |
402 | */ | |
403 | static int queue_io(struct mapped_device *md, struct bio *bio) | |
404 | { | |
2ca3310e | 405 | down_write(&md->io_lock); |
1da177e4 LT |
406 | |
407 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 408 | up_write(&md->io_lock); |
1da177e4 LT |
409 | return 1; |
410 | } | |
411 | ||
412 | bio_list_add(&md->deferred, bio); | |
413 | ||
2ca3310e | 414 | up_write(&md->io_lock); |
1da177e4 LT |
415 | return 0; /* deferred successfully */ |
416 | } | |
417 | ||
418 | /* | |
419 | * Everyone (including functions in this file), should use this | |
420 | * function to access the md->map field, and make sure they call | |
421 | * dm_table_put() when finished. | |
422 | */ | |
423 | struct dm_table *dm_get_table(struct mapped_device *md) | |
424 | { | |
425 | struct dm_table *t; | |
426 | ||
427 | read_lock(&md->map_lock); | |
428 | t = md->map; | |
429 | if (t) | |
430 | dm_table_get(t); | |
431 | read_unlock(&md->map_lock); | |
432 | ||
433 | return t; | |
434 | } | |
435 | ||
3ac51e74 DW |
436 | /* |
437 | * Get the geometry associated with a dm device | |
438 | */ | |
439 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
440 | { | |
441 | *geo = md->geometry; | |
442 | ||
443 | return 0; | |
444 | } | |
445 | ||
446 | /* | |
447 | * Set the geometry of a device. | |
448 | */ | |
449 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
450 | { | |
451 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
452 | ||
453 | if (geo->start > sz) { | |
454 | DMWARN("Start sector is beyond the geometry limits."); | |
455 | return -EINVAL; | |
456 | } | |
457 | ||
458 | md->geometry = *geo; | |
459 | ||
460 | return 0; | |
461 | } | |
462 | ||
1da177e4 LT |
463 | /*----------------------------------------------------------------- |
464 | * CRUD START: | |
465 | * A more elegant soln is in the works that uses the queue | |
466 | * merge fn, unfortunately there are a couple of changes to | |
467 | * the block layer that I want to make for this. So in the | |
468 | * interests of getting something for people to use I give | |
469 | * you this clearly demarcated crap. | |
470 | *---------------------------------------------------------------*/ | |
471 | ||
2e93ccc1 KU |
472 | static int __noflush_suspending(struct mapped_device *md) |
473 | { | |
474 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
475 | } | |
476 | ||
1da177e4 LT |
477 | /* |
478 | * Decrements the number of outstanding ios that a bio has been | |
479 | * cloned into, completing the original io if necc. | |
480 | */ | |
858119e1 | 481 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 482 | { |
2e93ccc1 KU |
483 | unsigned long flags; |
484 | ||
485 | /* Push-back supersedes any I/O errors */ | |
486 | if (error && !(io->error > 0 && __noflush_suspending(io->md))) | |
1da177e4 LT |
487 | io->error = error; |
488 | ||
489 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
490 | if (io->error == DM_ENDIO_REQUEUE) { |
491 | /* | |
492 | * Target requested pushing back the I/O. | |
493 | * This must be handled before the sleeper on | |
494 | * suspend queue merges the pushback list. | |
495 | */ | |
496 | spin_lock_irqsave(&io->md->pushback_lock, flags); | |
497 | if (__noflush_suspending(io->md)) | |
498 | bio_list_add(&io->md->pushback, io->bio); | |
499 | else | |
500 | /* noflush suspend was interrupted. */ | |
501 | io->error = -EIO; | |
502 | spin_unlock_irqrestore(&io->md->pushback_lock, flags); | |
503 | } | |
504 | ||
d221d2e7 | 505 | end_io_acct(io); |
1da177e4 | 506 | |
2e93ccc1 | 507 | if (io->error != DM_ENDIO_REQUEUE) { |
5f3ea37c | 508 | trace_block_bio_complete(io->md->queue, io->bio); |
2e93ccc1 | 509 | |
6712ecf8 | 510 | bio_endio(io->bio, io->error); |
2e93ccc1 | 511 | } |
2056a782 | 512 | |
1da177e4 LT |
513 | free_io(io->md, io); |
514 | } | |
515 | } | |
516 | ||
6712ecf8 | 517 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
518 | { |
519 | int r = 0; | |
028867ac | 520 | struct dm_target_io *tio = bio->bi_private; |
9faf400f | 521 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
522 | dm_endio_fn endio = tio->ti->type->end_io; |
523 | ||
1da177e4 LT |
524 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
525 | error = -EIO; | |
526 | ||
527 | if (endio) { | |
528 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
529 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
530 | /* | |
531 | * error and requeue request are handled | |
532 | * in dec_pending(). | |
533 | */ | |
1da177e4 | 534 | error = r; |
45cbcd79 KU |
535 | else if (r == DM_ENDIO_INCOMPLETE) |
536 | /* The target will handle the io */ | |
6712ecf8 | 537 | return; |
45cbcd79 KU |
538 | else if (r) { |
539 | DMWARN("unimplemented target endio return value: %d", r); | |
540 | BUG(); | |
541 | } | |
1da177e4 LT |
542 | } |
543 | ||
9faf400f SB |
544 | dec_pending(tio->io, error); |
545 | ||
546 | /* | |
547 | * Store md for cleanup instead of tio which is about to get freed. | |
548 | */ | |
549 | bio->bi_private = md->bs; | |
550 | ||
1da177e4 | 551 | bio_put(bio); |
9faf400f | 552 | free_tio(md, tio); |
1da177e4 LT |
553 | } |
554 | ||
555 | static sector_t max_io_len(struct mapped_device *md, | |
556 | sector_t sector, struct dm_target *ti) | |
557 | { | |
558 | sector_t offset = sector - ti->begin; | |
559 | sector_t len = ti->len - offset; | |
560 | ||
561 | /* | |
562 | * Does the target need to split even further ? | |
563 | */ | |
564 | if (ti->split_io) { | |
565 | sector_t boundary; | |
566 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
567 | - offset; | |
568 | if (len > boundary) | |
569 | len = boundary; | |
570 | } | |
571 | ||
572 | return len; | |
573 | } | |
574 | ||
575 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 576 | struct dm_target_io *tio) |
1da177e4 LT |
577 | { |
578 | int r; | |
2056a782 | 579 | sector_t sector; |
9faf400f | 580 | struct mapped_device *md; |
1da177e4 LT |
581 | |
582 | /* | |
583 | * Sanity checks. | |
584 | */ | |
585 | BUG_ON(!clone->bi_size); | |
586 | ||
587 | clone->bi_end_io = clone_endio; | |
588 | clone->bi_private = tio; | |
589 | ||
590 | /* | |
591 | * Map the clone. If r == 0 we don't need to do | |
592 | * anything, the target has assumed ownership of | |
593 | * this io. | |
594 | */ | |
595 | atomic_inc(&tio->io->io_count); | |
2056a782 | 596 | sector = clone->bi_sector; |
1da177e4 | 597 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 598 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 599 | /* the bio has been remapped so dispatch it */ |
2056a782 | 600 | |
5f3ea37c | 601 | trace_block_remap(bdev_get_queue(clone->bi_bdev), clone, |
c7149d6b AB |
602 | tio->io->bio->bi_bdev->bd_dev, |
603 | clone->bi_sector, sector); | |
2056a782 | 604 | |
1da177e4 | 605 | generic_make_request(clone); |
2e93ccc1 KU |
606 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
607 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
608 | md = tio->io->md; |
609 | dec_pending(tio->io, r); | |
610 | /* | |
611 | * Store bio_set for cleanup. | |
612 | */ | |
613 | clone->bi_private = md->bs; | |
1da177e4 | 614 | bio_put(clone); |
9faf400f | 615 | free_tio(md, tio); |
45cbcd79 KU |
616 | } else if (r) { |
617 | DMWARN("unimplemented target map return value: %d", r); | |
618 | BUG(); | |
1da177e4 LT |
619 | } |
620 | } | |
621 | ||
622 | struct clone_info { | |
623 | struct mapped_device *md; | |
624 | struct dm_table *map; | |
625 | struct bio *bio; | |
626 | struct dm_io *io; | |
627 | sector_t sector; | |
628 | sector_t sector_count; | |
629 | unsigned short idx; | |
630 | }; | |
631 | ||
3676347a PO |
632 | static void dm_bio_destructor(struct bio *bio) |
633 | { | |
9faf400f SB |
634 | struct bio_set *bs = bio->bi_private; |
635 | ||
636 | bio_free(bio, bs); | |
3676347a PO |
637 | } |
638 | ||
1da177e4 LT |
639 | /* |
640 | * Creates a little bio that is just does part of a bvec. | |
641 | */ | |
642 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
643 | unsigned short idx, unsigned int offset, | |
9faf400f | 644 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
645 | { |
646 | struct bio *clone; | |
647 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
648 | ||
9faf400f | 649 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 650 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
651 | *clone->bi_io_vec = *bv; |
652 | ||
653 | clone->bi_sector = sector; | |
654 | clone->bi_bdev = bio->bi_bdev; | |
655 | clone->bi_rw = bio->bi_rw; | |
656 | clone->bi_vcnt = 1; | |
657 | clone->bi_size = to_bytes(len); | |
658 | clone->bi_io_vec->bv_offset = offset; | |
659 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 660 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 LT |
661 | |
662 | return clone; | |
663 | } | |
664 | ||
665 | /* | |
666 | * Creates a bio that consists of range of complete bvecs. | |
667 | */ | |
668 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
669 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 670 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
671 | { |
672 | struct bio *clone; | |
673 | ||
9faf400f SB |
674 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
675 | __bio_clone(clone, bio); | |
676 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
677 | clone->bi_sector = sector; |
678 | clone->bi_idx = idx; | |
679 | clone->bi_vcnt = idx + bv_count; | |
680 | clone->bi_size = to_bytes(len); | |
681 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
682 | ||
683 | return clone; | |
684 | } | |
685 | ||
512875bd | 686 | static int __clone_and_map(struct clone_info *ci) |
1da177e4 LT |
687 | { |
688 | struct bio *clone, *bio = ci->bio; | |
512875bd JN |
689 | struct dm_target *ti; |
690 | sector_t len = 0, max; | |
028867ac | 691 | struct dm_target_io *tio; |
1da177e4 | 692 | |
512875bd JN |
693 | ti = dm_table_find_target(ci->map, ci->sector); |
694 | if (!dm_target_is_valid(ti)) | |
695 | return -EIO; | |
696 | ||
697 | max = max_io_len(ci->md, ci->sector, ti); | |
698 | ||
1da177e4 LT |
699 | /* |
700 | * Allocate a target io object. | |
701 | */ | |
702 | tio = alloc_tio(ci->md); | |
703 | tio->io = ci->io; | |
704 | tio->ti = ti; | |
705 | memset(&tio->info, 0, sizeof(tio->info)); | |
706 | ||
707 | if (ci->sector_count <= max) { | |
708 | /* | |
709 | * Optimise for the simple case where we can do all of | |
710 | * the remaining io with a single clone. | |
711 | */ | |
712 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
713 | bio->bi_vcnt - ci->idx, ci->sector_count, |
714 | ci->md->bs); | |
1da177e4 LT |
715 | __map_bio(ti, clone, tio); |
716 | ci->sector_count = 0; | |
717 | ||
718 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
719 | /* | |
720 | * There are some bvecs that don't span targets. | |
721 | * Do as many of these as possible. | |
722 | */ | |
723 | int i; | |
724 | sector_t remaining = max; | |
725 | sector_t bv_len; | |
726 | ||
727 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
728 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
729 | ||
730 | if (bv_len > remaining) | |
731 | break; | |
732 | ||
733 | remaining -= bv_len; | |
734 | len += bv_len; | |
735 | } | |
736 | ||
9faf400f SB |
737 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
738 | ci->md->bs); | |
1da177e4 LT |
739 | __map_bio(ti, clone, tio); |
740 | ||
741 | ci->sector += len; | |
742 | ci->sector_count -= len; | |
743 | ci->idx = i; | |
744 | ||
745 | } else { | |
746 | /* | |
d2044a94 | 747 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
748 | */ |
749 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
750 | sector_t remaining = to_sector(bv->bv_len); |
751 | unsigned int offset = 0; | |
1da177e4 | 752 | |
d2044a94 AK |
753 | do { |
754 | if (offset) { | |
755 | ti = dm_table_find_target(ci->map, ci->sector); | |
512875bd JN |
756 | if (!dm_target_is_valid(ti)) |
757 | return -EIO; | |
758 | ||
d2044a94 | 759 | max = max_io_len(ci->md, ci->sector, ti); |
1da177e4 | 760 | |
d2044a94 AK |
761 | tio = alloc_tio(ci->md); |
762 | tio->io = ci->io; | |
763 | tio->ti = ti; | |
764 | memset(&tio->info, 0, sizeof(tio->info)); | |
765 | } | |
766 | ||
767 | len = min(remaining, max); | |
768 | ||
769 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
770 | bv->bv_offset + offset, len, |
771 | ci->md->bs); | |
d2044a94 AK |
772 | |
773 | __map_bio(ti, clone, tio); | |
774 | ||
775 | ci->sector += len; | |
776 | ci->sector_count -= len; | |
777 | offset += to_bytes(len); | |
778 | } while (remaining -= len); | |
1da177e4 | 779 | |
1da177e4 LT |
780 | ci->idx++; |
781 | } | |
512875bd JN |
782 | |
783 | return 0; | |
1da177e4 LT |
784 | } |
785 | ||
786 | /* | |
787 | * Split the bio into several clones. | |
788 | */ | |
9e4e5f87 | 789 | static int __split_bio(struct mapped_device *md, struct bio *bio) |
1da177e4 LT |
790 | { |
791 | struct clone_info ci; | |
512875bd | 792 | int error = 0; |
1da177e4 LT |
793 | |
794 | ci.map = dm_get_table(md); | |
9e4e5f87 MB |
795 | if (unlikely(!ci.map)) |
796 | return -EIO; | |
1da177e4 LT |
797 | |
798 | ci.md = md; | |
799 | ci.bio = bio; | |
800 | ci.io = alloc_io(md); | |
801 | ci.io->error = 0; | |
802 | atomic_set(&ci.io->io_count, 1); | |
803 | ci.io->bio = bio; | |
804 | ci.io->md = md; | |
805 | ci.sector = bio->bi_sector; | |
806 | ci.sector_count = bio_sectors(bio); | |
807 | ci.idx = bio->bi_idx; | |
808 | ||
3eaf840e | 809 | start_io_acct(ci.io); |
512875bd JN |
810 | while (ci.sector_count && !error) |
811 | error = __clone_and_map(&ci); | |
1da177e4 LT |
812 | |
813 | /* drop the extra reference count */ | |
512875bd | 814 | dec_pending(ci.io, error); |
1da177e4 | 815 | dm_table_put(ci.map); |
9e4e5f87 MB |
816 | |
817 | return 0; | |
1da177e4 LT |
818 | } |
819 | /*----------------------------------------------------------------- | |
820 | * CRUD END | |
821 | *---------------------------------------------------------------*/ | |
822 | ||
f6fccb12 MB |
823 | static int dm_merge_bvec(struct request_queue *q, |
824 | struct bvec_merge_data *bvm, | |
825 | struct bio_vec *biovec) | |
826 | { | |
827 | struct mapped_device *md = q->queuedata; | |
828 | struct dm_table *map = dm_get_table(md); | |
829 | struct dm_target *ti; | |
830 | sector_t max_sectors; | |
5037108a | 831 | int max_size = 0; |
f6fccb12 MB |
832 | |
833 | if (unlikely(!map)) | |
5037108a | 834 | goto out; |
f6fccb12 MB |
835 | |
836 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac MP |
837 | if (!dm_target_is_valid(ti)) |
838 | goto out_table; | |
f6fccb12 MB |
839 | |
840 | /* | |
841 | * Find maximum amount of I/O that won't need splitting | |
842 | */ | |
843 | max_sectors = min(max_io_len(md, bvm->bi_sector, ti), | |
844 | (sector_t) BIO_MAX_SECTORS); | |
845 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
846 | if (max_size < 0) | |
847 | max_size = 0; | |
848 | ||
849 | /* | |
850 | * merge_bvec_fn() returns number of bytes | |
851 | * it can accept at this offset | |
852 | * max is precomputed maximal io size | |
853 | */ | |
854 | if (max_size && ti->type->merge) | |
855 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
856 | ||
b01cd5ac | 857 | out_table: |
5037108a MP |
858 | dm_table_put(map); |
859 | ||
860 | out: | |
f6fccb12 MB |
861 | /* |
862 | * Always allow an entire first page | |
863 | */ | |
864 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
865 | max_size = biovec->bv_len; | |
866 | ||
f6fccb12 MB |
867 | return max_size; |
868 | } | |
869 | ||
1da177e4 LT |
870 | /* |
871 | * The request function that just remaps the bio built up by | |
872 | * dm_merge_bvec. | |
873 | */ | |
165125e1 | 874 | static int dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 875 | { |
9e4e5f87 | 876 | int r = -EIO; |
12f03a49 | 877 | int rw = bio_data_dir(bio); |
1da177e4 | 878 | struct mapped_device *md = q->queuedata; |
c9959059 | 879 | int cpu; |
1da177e4 | 880 | |
07a83c47 SB |
881 | /* |
882 | * There is no use in forwarding any barrier request since we can't | |
883 | * guarantee it is (or can be) handled by the targets correctly. | |
884 | */ | |
885 | if (unlikely(bio_barrier(bio))) { | |
6712ecf8 | 886 | bio_endio(bio, -EOPNOTSUPP); |
07a83c47 SB |
887 | return 0; |
888 | } | |
889 | ||
2ca3310e | 890 | down_read(&md->io_lock); |
1da177e4 | 891 | |
074a7aca TH |
892 | cpu = part_stat_lock(); |
893 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
894 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
895 | part_stat_unlock(); | |
12f03a49 | 896 | |
1da177e4 LT |
897 | /* |
898 | * If we're suspended we have to queue | |
899 | * this io for later. | |
900 | */ | |
901 | while (test_bit(DMF_BLOCK_IO, &md->flags)) { | |
2ca3310e | 902 | up_read(&md->io_lock); |
1da177e4 | 903 | |
9e4e5f87 MB |
904 | if (bio_rw(bio) != READA) |
905 | r = queue_io(md, bio); | |
1da177e4 | 906 | |
9e4e5f87 MB |
907 | if (r <= 0) |
908 | goto out_req; | |
1da177e4 LT |
909 | |
910 | /* | |
911 | * We're in a while loop, because someone could suspend | |
912 | * before we get to the following read lock. | |
913 | */ | |
2ca3310e | 914 | down_read(&md->io_lock); |
1da177e4 LT |
915 | } |
916 | ||
9e4e5f87 | 917 | r = __split_bio(md, bio); |
2ca3310e | 918 | up_read(&md->io_lock); |
9e4e5f87 MB |
919 | |
920 | out_req: | |
921 | if (r < 0) | |
922 | bio_io_error(bio); | |
923 | ||
1da177e4 LT |
924 | return 0; |
925 | } | |
926 | ||
165125e1 | 927 | static void dm_unplug_all(struct request_queue *q) |
1da177e4 LT |
928 | { |
929 | struct mapped_device *md = q->queuedata; | |
930 | struct dm_table *map = dm_get_table(md); | |
931 | ||
932 | if (map) { | |
933 | dm_table_unplug_all(map); | |
934 | dm_table_put(map); | |
935 | } | |
936 | } | |
937 | ||
938 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
939 | { | |
8a57dfc6 CS |
940 | int r = bdi_bits; |
941 | struct mapped_device *md = congested_data; | |
942 | struct dm_table *map; | |
1da177e4 | 943 | |
8a57dfc6 CS |
944 | atomic_inc(&md->pending); |
945 | ||
946 | if (!test_bit(DMF_BLOCK_IO, &md->flags)) { | |
947 | map = dm_get_table(md); | |
948 | if (map) { | |
949 | r = dm_table_any_congested(map, bdi_bits); | |
950 | dm_table_put(map); | |
951 | } | |
952 | } | |
953 | ||
954 | if (!atomic_dec_return(&md->pending)) | |
955 | /* nudge anyone waiting on suspend queue */ | |
956 | wake_up(&md->wait); | |
1da177e4 | 957 | |
1da177e4 LT |
958 | return r; |
959 | } | |
960 | ||
961 | /*----------------------------------------------------------------- | |
962 | * An IDR is used to keep track of allocated minor numbers. | |
963 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
964 | static DEFINE_IDR(_minor_idr); |
965 | ||
2b06cfff | 966 | static void free_minor(int minor) |
1da177e4 | 967 | { |
f32c10b0 | 968 | spin_lock(&_minor_lock); |
1da177e4 | 969 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 970 | spin_unlock(&_minor_lock); |
1da177e4 LT |
971 | } |
972 | ||
973 | /* | |
974 | * See if the device with a specific minor # is free. | |
975 | */ | |
cf13ab8e | 976 | static int specific_minor(int minor) |
1da177e4 LT |
977 | { |
978 | int r, m; | |
979 | ||
980 | if (minor >= (1 << MINORBITS)) | |
981 | return -EINVAL; | |
982 | ||
62f75c2f JM |
983 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
984 | if (!r) | |
985 | return -ENOMEM; | |
986 | ||
f32c10b0 | 987 | spin_lock(&_minor_lock); |
1da177e4 LT |
988 | |
989 | if (idr_find(&_minor_idr, minor)) { | |
990 | r = -EBUSY; | |
991 | goto out; | |
992 | } | |
993 | ||
ba61fdd1 | 994 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 995 | if (r) |
1da177e4 | 996 | goto out; |
1da177e4 LT |
997 | |
998 | if (m != minor) { | |
999 | idr_remove(&_minor_idr, m); | |
1000 | r = -EBUSY; | |
1001 | goto out; | |
1002 | } | |
1003 | ||
1004 | out: | |
f32c10b0 | 1005 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1006 | return r; |
1007 | } | |
1008 | ||
cf13ab8e | 1009 | static int next_free_minor(int *minor) |
1da177e4 | 1010 | { |
2b06cfff | 1011 | int r, m; |
1da177e4 | 1012 | |
1da177e4 | 1013 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
1014 | if (!r) |
1015 | return -ENOMEM; | |
1016 | ||
f32c10b0 | 1017 | spin_lock(&_minor_lock); |
1da177e4 | 1018 | |
ba61fdd1 | 1019 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
cf13ab8e | 1020 | if (r) |
1da177e4 | 1021 | goto out; |
1da177e4 LT |
1022 | |
1023 | if (m >= (1 << MINORBITS)) { | |
1024 | idr_remove(&_minor_idr, m); | |
1025 | r = -ENOSPC; | |
1026 | goto out; | |
1027 | } | |
1028 | ||
1029 | *minor = m; | |
1030 | ||
1031 | out: | |
f32c10b0 | 1032 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1033 | return r; |
1034 | } | |
1035 | ||
1036 | static struct block_device_operations dm_blk_dops; | |
1037 | ||
1038 | /* | |
1039 | * Allocate and initialise a blank device with a given minor. | |
1040 | */ | |
2b06cfff | 1041 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1042 | { |
1043 | int r; | |
cf13ab8e | 1044 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1045 | void *old_md; |
1da177e4 LT |
1046 | |
1047 | if (!md) { | |
1048 | DMWARN("unable to allocate device, out of memory."); | |
1049 | return NULL; | |
1050 | } | |
1051 | ||
10da4f79 | 1052 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 1053 | goto bad_module_get; |
10da4f79 | 1054 | |
1da177e4 | 1055 | /* get a minor number for the dev */ |
2b06cfff | 1056 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 1057 | r = next_free_minor(&minor); |
2b06cfff | 1058 | else |
cf13ab8e | 1059 | r = specific_minor(minor); |
1da177e4 | 1060 | if (r < 0) |
6ed7ade8 | 1061 | goto bad_minor; |
1da177e4 | 1062 | |
2ca3310e | 1063 | init_rwsem(&md->io_lock); |
e61290a4 | 1064 | mutex_init(&md->suspend_lock); |
2e93ccc1 | 1065 | spin_lock_init(&md->pushback_lock); |
1da177e4 LT |
1066 | rwlock_init(&md->map_lock); |
1067 | atomic_set(&md->holders, 1); | |
5c6bd75d | 1068 | atomic_set(&md->open_count, 0); |
1da177e4 | 1069 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
1070 | atomic_set(&md->uevent_seq, 0); |
1071 | INIT_LIST_HEAD(&md->uevent_list); | |
1072 | spin_lock_init(&md->uevent_lock); | |
1da177e4 LT |
1073 | |
1074 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
1075 | if (!md->queue) | |
6ed7ade8 | 1076 | goto bad_queue; |
1da177e4 LT |
1077 | |
1078 | md->queue->queuedata = md; | |
1079 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1080 | md->queue->backing_dev_info.congested_data = md; | |
1081 | blk_queue_make_request(md->queue, dm_request); | |
daef265f | 1082 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 | 1083 | md->queue->unplug_fn = dm_unplug_all; |
f6fccb12 | 1084 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
1da177e4 | 1085 | |
93d2341c | 1086 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 | 1087 | if (!md->io_pool) |
6ed7ade8 | 1088 | goto bad_io_pool; |
1da177e4 | 1089 | |
93d2341c | 1090 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 | 1091 | if (!md->tio_pool) |
6ed7ade8 | 1092 | goto bad_tio_pool; |
1da177e4 | 1093 | |
5972511b | 1094 | md->bs = bioset_create(16, 16); |
9faf400f SB |
1095 | if (!md->bs) |
1096 | goto bad_no_bioset; | |
1097 | ||
1da177e4 LT |
1098 | md->disk = alloc_disk(1); |
1099 | if (!md->disk) | |
6ed7ade8 | 1100 | goto bad_disk; |
1da177e4 | 1101 | |
f0b04115 JM |
1102 | atomic_set(&md->pending, 0); |
1103 | init_waitqueue_head(&md->wait); | |
1104 | init_waitqueue_head(&md->eventq); | |
1105 | ||
1da177e4 LT |
1106 | md->disk->major = _major; |
1107 | md->disk->first_minor = minor; | |
1108 | md->disk->fops = &dm_blk_dops; | |
1109 | md->disk->queue = md->queue; | |
1110 | md->disk->private_data = md; | |
1111 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
1112 | add_disk(md->disk); | |
7e51f257 | 1113 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1114 | |
304f3f6a MB |
1115 | md->wq = create_singlethread_workqueue("kdmflush"); |
1116 | if (!md->wq) | |
1117 | goto bad_thread; | |
1118 | ||
ba61fdd1 | 1119 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1120 | spin_lock(&_minor_lock); |
ba61fdd1 | 1121 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1122 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1123 | |
1124 | BUG_ON(old_md != MINOR_ALLOCED); | |
1125 | ||
1da177e4 LT |
1126 | return md; |
1127 | ||
304f3f6a MB |
1128 | bad_thread: |
1129 | put_disk(md->disk); | |
6ed7ade8 | 1130 | bad_disk: |
9faf400f | 1131 | bioset_free(md->bs); |
6ed7ade8 | 1132 | bad_no_bioset: |
1da177e4 | 1133 | mempool_destroy(md->tio_pool); |
6ed7ade8 | 1134 | bad_tio_pool: |
1da177e4 | 1135 | mempool_destroy(md->io_pool); |
6ed7ade8 | 1136 | bad_io_pool: |
1312f40e | 1137 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 1138 | bad_queue: |
1da177e4 | 1139 | free_minor(minor); |
6ed7ade8 | 1140 | bad_minor: |
10da4f79 | 1141 | module_put(THIS_MODULE); |
6ed7ade8 | 1142 | bad_module_get: |
1da177e4 LT |
1143 | kfree(md); |
1144 | return NULL; | |
1145 | } | |
1146 | ||
ae9da83f JN |
1147 | static void unlock_fs(struct mapped_device *md); |
1148 | ||
1da177e4 LT |
1149 | static void free_dev(struct mapped_device *md) |
1150 | { | |
f331c029 | 1151 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 1152 | |
d9dde59b | 1153 | if (md->suspended_bdev) { |
ae9da83f | 1154 | unlock_fs(md); |
d9dde59b JN |
1155 | bdput(md->suspended_bdev); |
1156 | } | |
304f3f6a | 1157 | destroy_workqueue(md->wq); |
1da177e4 LT |
1158 | mempool_destroy(md->tio_pool); |
1159 | mempool_destroy(md->io_pool); | |
9faf400f | 1160 | bioset_free(md->bs); |
1da177e4 | 1161 | del_gendisk(md->disk); |
63d94e48 | 1162 | free_minor(minor); |
fba9f90e JM |
1163 | |
1164 | spin_lock(&_minor_lock); | |
1165 | md->disk->private_data = NULL; | |
1166 | spin_unlock(&_minor_lock); | |
1167 | ||
1da177e4 | 1168 | put_disk(md->disk); |
1312f40e | 1169 | blk_cleanup_queue(md->queue); |
10da4f79 | 1170 | module_put(THIS_MODULE); |
1da177e4 LT |
1171 | kfree(md); |
1172 | } | |
1173 | ||
1174 | /* | |
1175 | * Bind a table to the device. | |
1176 | */ | |
1177 | static void event_callback(void *context) | |
1178 | { | |
7a8c3d3b MA |
1179 | unsigned long flags; |
1180 | LIST_HEAD(uevents); | |
1da177e4 LT |
1181 | struct mapped_device *md = (struct mapped_device *) context; |
1182 | ||
7a8c3d3b MA |
1183 | spin_lock_irqsave(&md->uevent_lock, flags); |
1184 | list_splice_init(&md->uevent_list, &uevents); | |
1185 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1186 | ||
ed9e1982 | 1187 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 1188 | |
1da177e4 LT |
1189 | atomic_inc(&md->event_nr); |
1190 | wake_up(&md->eventq); | |
1191 | } | |
1192 | ||
4e90188b | 1193 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1194 | { |
4e90188b | 1195 | set_capacity(md->disk, size); |
1da177e4 | 1196 | |
1b1dcc1b | 1197 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1198 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1199 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1200 | } |
1201 | ||
1202 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1203 | { | |
165125e1 | 1204 | struct request_queue *q = md->queue; |
1da177e4 LT |
1205 | sector_t size; |
1206 | ||
1207 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1208 | |
1209 | /* | |
1210 | * Wipe any geometry if the size of the table changed. | |
1211 | */ | |
1212 | if (size != get_capacity(md->disk)) | |
1213 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1214 | ||
bfa152fa JN |
1215 | if (md->suspended_bdev) |
1216 | __set_size(md, size); | |
1da177e4 LT |
1217 | if (size == 0) |
1218 | return 0; | |
1219 | ||
2ca3310e AK |
1220 | dm_table_get(t); |
1221 | dm_table_event_callback(t, event_callback, md); | |
1222 | ||
1da177e4 LT |
1223 | write_lock(&md->map_lock); |
1224 | md->map = t; | |
2ca3310e | 1225 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1226 | write_unlock(&md->map_lock); |
1227 | ||
1da177e4 LT |
1228 | return 0; |
1229 | } | |
1230 | ||
1231 | static void __unbind(struct mapped_device *md) | |
1232 | { | |
1233 | struct dm_table *map = md->map; | |
1234 | ||
1235 | if (!map) | |
1236 | return; | |
1237 | ||
1238 | dm_table_event_callback(map, NULL, NULL); | |
1239 | write_lock(&md->map_lock); | |
1240 | md->map = NULL; | |
1241 | write_unlock(&md->map_lock); | |
1242 | dm_table_put(map); | |
1243 | } | |
1244 | ||
1245 | /* | |
1246 | * Constructor for a new device. | |
1247 | */ | |
2b06cfff | 1248 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1249 | { |
1250 | struct mapped_device *md; | |
1251 | ||
2b06cfff | 1252 | md = alloc_dev(minor); |
1da177e4 LT |
1253 | if (!md) |
1254 | return -ENXIO; | |
1255 | ||
1256 | *result = md; | |
1257 | return 0; | |
1258 | } | |
1259 | ||
637842cf | 1260 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1261 | { |
1262 | struct mapped_device *md; | |
1da177e4 LT |
1263 | unsigned minor = MINOR(dev); |
1264 | ||
1265 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1266 | return NULL; | |
1267 | ||
f32c10b0 | 1268 | spin_lock(&_minor_lock); |
1da177e4 LT |
1269 | |
1270 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 1271 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 1272 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
17b2f66f | 1273 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1274 | md = NULL; |
fba9f90e JM |
1275 | goto out; |
1276 | } | |
1da177e4 | 1277 | |
fba9f90e | 1278 | out: |
f32c10b0 | 1279 | spin_unlock(&_minor_lock); |
1da177e4 | 1280 | |
637842cf DT |
1281 | return md; |
1282 | } | |
1283 | ||
d229a958 DT |
1284 | struct mapped_device *dm_get_md(dev_t dev) |
1285 | { | |
1286 | struct mapped_device *md = dm_find_md(dev); | |
1287 | ||
1288 | if (md) | |
1289 | dm_get(md); | |
1290 | ||
1291 | return md; | |
1292 | } | |
1293 | ||
9ade92a9 | 1294 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1295 | { |
9ade92a9 | 1296 | return md->interface_ptr; |
1da177e4 LT |
1297 | } |
1298 | ||
1299 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1300 | { | |
1301 | md->interface_ptr = ptr; | |
1302 | } | |
1303 | ||
1304 | void dm_get(struct mapped_device *md) | |
1305 | { | |
1306 | atomic_inc(&md->holders); | |
1307 | } | |
1308 | ||
72d94861 AK |
1309 | const char *dm_device_name(struct mapped_device *md) |
1310 | { | |
1311 | return md->name; | |
1312 | } | |
1313 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1314 | ||
1da177e4 LT |
1315 | void dm_put(struct mapped_device *md) |
1316 | { | |
1134e5ae | 1317 | struct dm_table *map; |
1da177e4 | 1318 | |
fba9f90e JM |
1319 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1320 | ||
f32c10b0 | 1321 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1322 | map = dm_get_table(md); |
f331c029 TH |
1323 | idr_replace(&_minor_idr, MINOR_ALLOCED, |
1324 | MINOR(disk_devt(dm_disk(md)))); | |
fba9f90e | 1325 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1326 | spin_unlock(&_minor_lock); |
cf222b37 | 1327 | if (!dm_suspended(md)) { |
1da177e4 LT |
1328 | dm_table_presuspend_targets(map); |
1329 | dm_table_postsuspend_targets(map); | |
1330 | } | |
1331 | __unbind(md); | |
1134e5ae | 1332 | dm_table_put(map); |
1da177e4 LT |
1333 | free_dev(md); |
1334 | } | |
1da177e4 | 1335 | } |
79eb885c | 1336 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 1337 | |
46125c1c MB |
1338 | static int dm_wait_for_completion(struct mapped_device *md) |
1339 | { | |
1340 | int r = 0; | |
1341 | ||
1342 | while (1) { | |
1343 | set_current_state(TASK_INTERRUPTIBLE); | |
1344 | ||
1345 | smp_mb(); | |
1346 | if (!atomic_read(&md->pending)) | |
1347 | break; | |
1348 | ||
1349 | if (signal_pending(current)) { | |
1350 | r = -EINTR; | |
1351 | break; | |
1352 | } | |
1353 | ||
1354 | io_schedule(); | |
1355 | } | |
1356 | set_current_state(TASK_RUNNING); | |
1357 | ||
1358 | return r; | |
1359 | } | |
1360 | ||
1da177e4 LT |
1361 | /* |
1362 | * Process the deferred bios | |
1363 | */ | |
6d6f10df | 1364 | static void __flush_deferred_io(struct mapped_device *md) |
1da177e4 | 1365 | { |
6d6f10df | 1366 | struct bio *c; |
1da177e4 | 1367 | |
6d6f10df | 1368 | while ((c = bio_list_pop(&md->deferred))) { |
9e4e5f87 MB |
1369 | if (__split_bio(md, c)) |
1370 | bio_io_error(c); | |
1da177e4 | 1371 | } |
73d410c0 MB |
1372 | |
1373 | clear_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 LT |
1374 | } |
1375 | ||
6d6f10df MB |
1376 | static void __merge_pushback_list(struct mapped_device *md) |
1377 | { | |
1378 | unsigned long flags; | |
1379 | ||
1380 | spin_lock_irqsave(&md->pushback_lock, flags); | |
1381 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1382 | bio_list_merge_head(&md->deferred, &md->pushback); | |
1383 | bio_list_init(&md->pushback); | |
1384 | spin_unlock_irqrestore(&md->pushback_lock, flags); | |
1385 | } | |
1386 | ||
304f3f6a MB |
1387 | static void dm_wq_work(struct work_struct *work) |
1388 | { | |
1389 | struct dm_wq_req *req = container_of(work, struct dm_wq_req, work); | |
1390 | struct mapped_device *md = req->md; | |
1391 | ||
1392 | down_write(&md->io_lock); | |
1393 | switch (req->type) { | |
304f3f6a MB |
1394 | case DM_WQ_FLUSH_DEFERRED: |
1395 | __flush_deferred_io(md); | |
1396 | break; | |
1397 | default: | |
1398 | DMERR("dm_wq_work: unrecognised work type %d", req->type); | |
1399 | BUG(); | |
1400 | } | |
1401 | up_write(&md->io_lock); | |
1402 | } | |
1403 | ||
1404 | static void dm_wq_queue(struct mapped_device *md, int type, void *context, | |
1405 | struct dm_wq_req *req) | |
1406 | { | |
1407 | req->type = type; | |
1408 | req->md = md; | |
1409 | req->context = context; | |
1410 | INIT_WORK(&req->work, dm_wq_work); | |
1411 | queue_work(md->wq, &req->work); | |
1412 | } | |
1413 | ||
1414 | static void dm_queue_flush(struct mapped_device *md, int type, void *context) | |
1415 | { | |
1416 | struct dm_wq_req req; | |
1417 | ||
1418 | dm_wq_queue(md, type, context, &req); | |
1419 | flush_workqueue(md->wq); | |
1420 | } | |
1421 | ||
1da177e4 LT |
1422 | /* |
1423 | * Swap in a new table (destroying old one). | |
1424 | */ | |
1425 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1426 | { | |
93c534ae | 1427 | int r = -EINVAL; |
1da177e4 | 1428 | |
e61290a4 | 1429 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
1430 | |
1431 | /* device must be suspended */ | |
cf222b37 | 1432 | if (!dm_suspended(md)) |
93c534ae | 1433 | goto out; |
1da177e4 | 1434 | |
bfa152fa JN |
1435 | /* without bdev, the device size cannot be changed */ |
1436 | if (!md->suspended_bdev) | |
1437 | if (get_capacity(md->disk) != dm_table_get_size(table)) | |
1438 | goto out; | |
1439 | ||
1da177e4 LT |
1440 | __unbind(md); |
1441 | r = __bind(md, table); | |
1da177e4 | 1442 | |
93c534ae | 1443 | out: |
e61290a4 | 1444 | mutex_unlock(&md->suspend_lock); |
93c534ae | 1445 | return r; |
1da177e4 LT |
1446 | } |
1447 | ||
1448 | /* | |
1449 | * Functions to lock and unlock any filesystem running on the | |
1450 | * device. | |
1451 | */ | |
2ca3310e | 1452 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1453 | { |
e39e2e95 | 1454 | int r; |
1da177e4 LT |
1455 | |
1456 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1457 | |
e39e2e95 | 1458 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1459 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1460 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1461 | md->frozen_sb = NULL; |
1462 | return r; | |
dfbe03f6 AK |
1463 | } |
1464 | ||
aa8d7c2f AK |
1465 | set_bit(DMF_FROZEN, &md->flags); |
1466 | ||
1da177e4 | 1467 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1468 | * to go away while it is locked. |
1da177e4 LT |
1469 | */ |
1470 | return 0; | |
1471 | } | |
1472 | ||
2ca3310e | 1473 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1474 | { |
aa8d7c2f AK |
1475 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1476 | return; | |
1477 | ||
e39e2e95 | 1478 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1479 | md->frozen_sb = NULL; |
aa8d7c2f | 1480 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1481 | } |
1482 | ||
1483 | /* | |
1484 | * We need to be able to change a mapping table under a mounted | |
1485 | * filesystem. For example we might want to move some data in | |
1486 | * the background. Before the table can be swapped with | |
1487 | * dm_bind_table, dm_suspend must be called to flush any in | |
1488 | * flight bios and ensure that any further io gets deferred. | |
1489 | */ | |
a3d77d35 | 1490 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1491 | { |
2ca3310e | 1492 | struct dm_table *map = NULL; |
1da177e4 | 1493 | DECLARE_WAITQUEUE(wait, current); |
46125c1c | 1494 | int r = 0; |
a3d77d35 | 1495 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 1496 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 1497 | |
e61290a4 | 1498 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1499 | |
73d410c0 MB |
1500 | if (dm_suspended(md)) { |
1501 | r = -EINVAL; | |
d287483d | 1502 | goto out_unlock; |
73d410c0 | 1503 | } |
1da177e4 LT |
1504 | |
1505 | map = dm_get_table(md); | |
1da177e4 | 1506 | |
2e93ccc1 KU |
1507 | /* |
1508 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
1509 | * This flag is cleared before dm_suspend returns. | |
1510 | */ | |
1511 | if (noflush) | |
1512 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1513 | ||
cf222b37 AK |
1514 | /* This does not get reverted if there's an error later. */ |
1515 | dm_table_presuspend_targets(map); | |
1516 | ||
bfa152fa JN |
1517 | /* bdget() can stall if the pending I/Os are not flushed */ |
1518 | if (!noflush) { | |
1519 | md->suspended_bdev = bdget_disk(md->disk, 0); | |
1520 | if (!md->suspended_bdev) { | |
1521 | DMWARN("bdget failed in dm_suspend"); | |
1522 | r = -ENOMEM; | |
f431d966 | 1523 | goto out; |
bfa152fa | 1524 | } |
e39e2e95 | 1525 | |
6d6f10df MB |
1526 | /* |
1527 | * Flush I/O to the device. noflush supersedes do_lockfs, | |
1528 | * because lock_fs() needs to flush I/Os. | |
1529 | */ | |
1530 | if (do_lockfs) { | |
1531 | r = lock_fs(md); | |
1532 | if (r) | |
1533 | goto out; | |
1534 | } | |
aa8d7c2f | 1535 | } |
1da177e4 LT |
1536 | |
1537 | /* | |
354e0071 | 1538 | * First we set the BLOCK_IO flag so no more ios will be mapped. |
1da177e4 | 1539 | */ |
2ca3310e AK |
1540 | down_write(&md->io_lock); |
1541 | set_bit(DMF_BLOCK_IO, &md->flags); | |
1da177e4 | 1542 | |
1da177e4 | 1543 | add_wait_queue(&md->wait, &wait); |
2ca3310e | 1544 | up_write(&md->io_lock); |
1da177e4 LT |
1545 | |
1546 | /* unplug */ | |
2ca3310e | 1547 | if (map) |
1da177e4 | 1548 | dm_table_unplug_all(map); |
1da177e4 LT |
1549 | |
1550 | /* | |
46125c1c | 1551 | * Wait for the already-mapped ios to complete. |
1da177e4 | 1552 | */ |
46125c1c | 1553 | r = dm_wait_for_completion(md); |
1da177e4 | 1554 | |
2ca3310e | 1555 | down_write(&md->io_lock); |
1da177e4 LT |
1556 | remove_wait_queue(&md->wait, &wait); |
1557 | ||
6d6f10df MB |
1558 | if (noflush) |
1559 | __merge_pushback_list(md); | |
94d6351e | 1560 | up_write(&md->io_lock); |
2e93ccc1 | 1561 | |
1da177e4 | 1562 | /* were we interrupted ? */ |
46125c1c | 1563 | if (r < 0) { |
304f3f6a | 1564 | dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL); |
73d410c0 | 1565 | |
2ca3310e | 1566 | unlock_fs(md); |
2e93ccc1 | 1567 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 1568 | } |
1da177e4 | 1569 | |
cf222b37 | 1570 | dm_table_postsuspend_targets(map); |
1da177e4 | 1571 | |
2ca3310e | 1572 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1573 | |
2ca3310e | 1574 | out: |
e39e2e95 AK |
1575 | if (r && md->suspended_bdev) { |
1576 | bdput(md->suspended_bdev); | |
1577 | md->suspended_bdev = NULL; | |
1578 | } | |
1579 | ||
2ca3310e | 1580 | dm_table_put(map); |
d287483d AK |
1581 | |
1582 | out_unlock: | |
e61290a4 | 1583 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 1584 | return r; |
1da177e4 LT |
1585 | } |
1586 | ||
1587 | int dm_resume(struct mapped_device *md) | |
1588 | { | |
cf222b37 | 1589 | int r = -EINVAL; |
cf222b37 | 1590 | struct dm_table *map = NULL; |
1da177e4 | 1591 | |
e61290a4 | 1592 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1593 | if (!dm_suspended(md)) |
cf222b37 | 1594 | goto out; |
cf222b37 AK |
1595 | |
1596 | map = dm_get_table(md); | |
2ca3310e | 1597 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1598 | goto out; |
1da177e4 | 1599 | |
8757b776 MB |
1600 | r = dm_table_resume_targets(map); |
1601 | if (r) | |
1602 | goto out; | |
2ca3310e | 1603 | |
304f3f6a | 1604 | dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL); |
2ca3310e AK |
1605 | |
1606 | unlock_fs(md); | |
1607 | ||
bfa152fa JN |
1608 | if (md->suspended_bdev) { |
1609 | bdput(md->suspended_bdev); | |
1610 | md->suspended_bdev = NULL; | |
1611 | } | |
e39e2e95 | 1612 | |
2ca3310e AK |
1613 | clear_bit(DMF_SUSPENDED, &md->flags); |
1614 | ||
1da177e4 | 1615 | dm_table_unplug_all(map); |
1da177e4 | 1616 | |
69267a30 | 1617 | dm_kobject_uevent(md); |
8560ed6f | 1618 | |
cf222b37 | 1619 | r = 0; |
2ca3310e | 1620 | |
cf222b37 AK |
1621 | out: |
1622 | dm_table_put(map); | |
e61290a4 | 1623 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 1624 | |
cf222b37 | 1625 | return r; |
1da177e4 LT |
1626 | } |
1627 | ||
1628 | /*----------------------------------------------------------------- | |
1629 | * Event notification. | |
1630 | *---------------------------------------------------------------*/ | |
69267a30 AK |
1631 | void dm_kobject_uevent(struct mapped_device *md) |
1632 | { | |
ed9e1982 | 1633 | kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE); |
69267a30 AK |
1634 | } |
1635 | ||
7a8c3d3b MA |
1636 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
1637 | { | |
1638 | return atomic_add_return(1, &md->uevent_seq); | |
1639 | } | |
1640 | ||
1da177e4 LT |
1641 | uint32_t dm_get_event_nr(struct mapped_device *md) |
1642 | { | |
1643 | return atomic_read(&md->event_nr); | |
1644 | } | |
1645 | ||
1646 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1647 | { | |
1648 | return wait_event_interruptible(md->eventq, | |
1649 | (event_nr != atomic_read(&md->event_nr))); | |
1650 | } | |
1651 | ||
7a8c3d3b MA |
1652 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
1653 | { | |
1654 | unsigned long flags; | |
1655 | ||
1656 | spin_lock_irqsave(&md->uevent_lock, flags); | |
1657 | list_add(elist, &md->uevent_list); | |
1658 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1659 | } | |
1660 | ||
1da177e4 LT |
1661 | /* |
1662 | * The gendisk is only valid as long as you have a reference | |
1663 | * count on 'md'. | |
1664 | */ | |
1665 | struct gendisk *dm_disk(struct mapped_device *md) | |
1666 | { | |
1667 | return md->disk; | |
1668 | } | |
1669 | ||
1670 | int dm_suspended(struct mapped_device *md) | |
1671 | { | |
1672 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1673 | } | |
1674 | ||
2e93ccc1 KU |
1675 | int dm_noflush_suspending(struct dm_target *ti) |
1676 | { | |
1677 | struct mapped_device *md = dm_table_get_md(ti->table); | |
1678 | int r = __noflush_suspending(md); | |
1679 | ||
1680 | dm_put(md); | |
1681 | ||
1682 | return r; | |
1683 | } | |
1684 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
1685 | ||
1da177e4 LT |
1686 | static struct block_device_operations dm_blk_dops = { |
1687 | .open = dm_blk_open, | |
1688 | .release = dm_blk_close, | |
aa129a22 | 1689 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1690 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1691 | .owner = THIS_MODULE |
1692 | }; | |
1693 | ||
1694 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1695 | ||
1696 | /* | |
1697 | * module hooks | |
1698 | */ | |
1699 | module_init(dm_init); | |
1700 | module_exit(dm_exit); | |
1701 | ||
1702 | module_param(major, uint, 0); | |
1703 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1704 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1705 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1706 | MODULE_LICENSE("GPL"); |