Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. | |
784aae73 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
4 | * |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include "dm.h" | |
51e5b2bd | 9 | #include "dm-uevent.h" |
1da177e4 LT |
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> |
5f3ea37c | 23 | #include <trace/block.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 | 33 | /* |
8fbf26ad | 34 | * For bio-based dm. |
1da177e4 LT |
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 | /* | |
8fbf26ad | 46 | * For bio-based dm. |
1da177e4 LT |
47 | * One of these is allocated per target within a bio. Hopefully |
48 | * this will be simplified out one day. | |
49 | */ | |
028867ac | 50 | struct dm_target_io { |
1da177e4 LT |
51 | struct dm_io *io; |
52 | struct dm_target *ti; | |
53 | union map_info info; | |
54 | }; | |
55 | ||
0bfc2455 IM |
56 | DEFINE_TRACE(block_bio_complete); |
57 | ||
8fbf26ad KU |
58 | /* |
59 | * For request-based dm. | |
60 | * One of these is allocated per request. | |
61 | */ | |
62 | struct dm_rq_target_io { | |
63 | struct mapped_device *md; | |
64 | struct dm_target *ti; | |
65 | struct request *orig, clone; | |
66 | int error; | |
67 | union map_info info; | |
68 | }; | |
69 | ||
70 | /* | |
71 | * For request-based dm. | |
72 | * One of these is allocated per bio. | |
73 | */ | |
74 | struct dm_rq_clone_bio_info { | |
75 | struct bio *orig; | |
76 | struct request *rq; | |
77 | }; | |
78 | ||
1da177e4 LT |
79 | union map_info *dm_get_mapinfo(struct bio *bio) |
80 | { | |
17b2f66f | 81 | if (bio && bio->bi_private) |
028867ac | 82 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 83 | return NULL; |
1da177e4 LT |
84 | } |
85 | ||
ba61fdd1 JM |
86 | #define MINOR_ALLOCED ((void *)-1) |
87 | ||
1da177e4 LT |
88 | /* |
89 | * Bits for the md->flags field. | |
90 | */ | |
1eb787ec | 91 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
1da177e4 | 92 | #define DMF_SUSPENDED 1 |
aa8d7c2f | 93 | #define DMF_FROZEN 2 |
fba9f90e | 94 | #define DMF_FREEING 3 |
5c6bd75d | 95 | #define DMF_DELETING 4 |
2e93ccc1 | 96 | #define DMF_NOFLUSH_SUSPENDING 5 |
1eb787ec | 97 | #define DMF_QUEUE_IO_TO_THREAD 6 |
1da177e4 | 98 | |
304f3f6a MB |
99 | /* |
100 | * Work processed by per-device workqueue. | |
101 | */ | |
1da177e4 | 102 | struct mapped_device { |
2ca3310e | 103 | struct rw_semaphore io_lock; |
e61290a4 | 104 | struct mutex suspend_lock; |
1da177e4 LT |
105 | rwlock_t map_lock; |
106 | atomic_t holders; | |
5c6bd75d | 107 | atomic_t open_count; |
1da177e4 LT |
108 | |
109 | unsigned long flags; | |
110 | ||
165125e1 | 111 | struct request_queue *queue; |
1da177e4 | 112 | struct gendisk *disk; |
7e51f257 | 113 | char name[16]; |
1da177e4 LT |
114 | |
115 | void *interface_ptr; | |
116 | ||
117 | /* | |
118 | * A list of ios that arrived while we were suspended. | |
119 | */ | |
120 | atomic_t pending; | |
121 | wait_queue_head_t wait; | |
53d5914f | 122 | struct work_struct work; |
74859364 | 123 | struct bio_list deferred; |
022c2611 | 124 | spinlock_t deferred_lock; |
1da177e4 | 125 | |
af7e466a MP |
126 | /* |
127 | * An error from the barrier request currently being processed. | |
128 | */ | |
129 | int barrier_error; | |
130 | ||
304f3f6a MB |
131 | /* |
132 | * Processing queue (flush/barriers) | |
133 | */ | |
134 | struct workqueue_struct *wq; | |
135 | ||
1da177e4 LT |
136 | /* |
137 | * The current mapping. | |
138 | */ | |
139 | struct dm_table *map; | |
140 | ||
141 | /* | |
142 | * io objects are allocated from here. | |
143 | */ | |
144 | mempool_t *io_pool; | |
145 | mempool_t *tio_pool; | |
146 | ||
9faf400f SB |
147 | struct bio_set *bs; |
148 | ||
1da177e4 LT |
149 | /* |
150 | * Event handling. | |
151 | */ | |
152 | atomic_t event_nr; | |
153 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
154 | atomic_t uevent_seq; |
155 | struct list_head uevent_list; | |
156 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
157 | |
158 | /* | |
159 | * freeze/thaw support require holding onto a super block | |
160 | */ | |
161 | struct super_block *frozen_sb; | |
e39e2e95 | 162 | struct block_device *suspended_bdev; |
3ac51e74 DW |
163 | |
164 | /* forced geometry settings */ | |
165 | struct hd_geometry geometry; | |
784aae73 MB |
166 | |
167 | /* sysfs handle */ | |
168 | struct kobject kobj; | |
1da177e4 LT |
169 | }; |
170 | ||
171 | #define MIN_IOS 256 | |
e18b890b CL |
172 | static struct kmem_cache *_io_cache; |
173 | static struct kmem_cache *_tio_cache; | |
8fbf26ad KU |
174 | static struct kmem_cache *_rq_tio_cache; |
175 | static struct kmem_cache *_rq_bio_info_cache; | |
1da177e4 | 176 | |
1da177e4 LT |
177 | static int __init local_init(void) |
178 | { | |
51157b4a | 179 | int r = -ENOMEM; |
1da177e4 | 180 | |
1da177e4 | 181 | /* allocate a slab for the dm_ios */ |
028867ac | 182 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 183 | if (!_io_cache) |
51157b4a | 184 | return r; |
1da177e4 LT |
185 | |
186 | /* allocate a slab for the target ios */ | |
028867ac | 187 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
51157b4a KU |
188 | if (!_tio_cache) |
189 | goto out_free_io_cache; | |
1da177e4 | 190 | |
8fbf26ad KU |
191 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
192 | if (!_rq_tio_cache) | |
193 | goto out_free_tio_cache; | |
194 | ||
195 | _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0); | |
196 | if (!_rq_bio_info_cache) | |
197 | goto out_free_rq_tio_cache; | |
198 | ||
51e5b2bd | 199 | r = dm_uevent_init(); |
51157b4a | 200 | if (r) |
8fbf26ad | 201 | goto out_free_rq_bio_info_cache; |
51e5b2bd | 202 | |
1da177e4 LT |
203 | _major = major; |
204 | r = register_blkdev(_major, _name); | |
51157b4a KU |
205 | if (r < 0) |
206 | goto out_uevent_exit; | |
1da177e4 LT |
207 | |
208 | if (!_major) | |
209 | _major = r; | |
210 | ||
211 | return 0; | |
51157b4a KU |
212 | |
213 | out_uevent_exit: | |
214 | dm_uevent_exit(); | |
8fbf26ad KU |
215 | out_free_rq_bio_info_cache: |
216 | kmem_cache_destroy(_rq_bio_info_cache); | |
217 | out_free_rq_tio_cache: | |
218 | kmem_cache_destroy(_rq_tio_cache); | |
51157b4a KU |
219 | out_free_tio_cache: |
220 | kmem_cache_destroy(_tio_cache); | |
221 | out_free_io_cache: | |
222 | kmem_cache_destroy(_io_cache); | |
223 | ||
224 | return r; | |
1da177e4 LT |
225 | } |
226 | ||
227 | static void local_exit(void) | |
228 | { | |
8fbf26ad KU |
229 | kmem_cache_destroy(_rq_bio_info_cache); |
230 | kmem_cache_destroy(_rq_tio_cache); | |
1da177e4 LT |
231 | kmem_cache_destroy(_tio_cache); |
232 | kmem_cache_destroy(_io_cache); | |
00d59405 | 233 | unregister_blkdev(_major, _name); |
51e5b2bd | 234 | dm_uevent_exit(); |
1da177e4 LT |
235 | |
236 | _major = 0; | |
237 | ||
238 | DMINFO("cleaned up"); | |
239 | } | |
240 | ||
b9249e55 | 241 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
242 | local_init, |
243 | dm_target_init, | |
244 | dm_linear_init, | |
245 | dm_stripe_init, | |
945fa4d2 | 246 | dm_kcopyd_init, |
1da177e4 LT |
247 | dm_interface_init, |
248 | }; | |
249 | ||
b9249e55 | 250 | static void (*_exits[])(void) = { |
1da177e4 LT |
251 | local_exit, |
252 | dm_target_exit, | |
253 | dm_linear_exit, | |
254 | dm_stripe_exit, | |
945fa4d2 | 255 | dm_kcopyd_exit, |
1da177e4 LT |
256 | dm_interface_exit, |
257 | }; | |
258 | ||
259 | static int __init dm_init(void) | |
260 | { | |
261 | const int count = ARRAY_SIZE(_inits); | |
262 | ||
263 | int r, i; | |
264 | ||
265 | for (i = 0; i < count; i++) { | |
266 | r = _inits[i](); | |
267 | if (r) | |
268 | goto bad; | |
269 | } | |
270 | ||
271 | return 0; | |
272 | ||
273 | bad: | |
274 | while (i--) | |
275 | _exits[i](); | |
276 | ||
277 | return r; | |
278 | } | |
279 | ||
280 | static void __exit dm_exit(void) | |
281 | { | |
282 | int i = ARRAY_SIZE(_exits); | |
283 | ||
284 | while (i--) | |
285 | _exits[i](); | |
286 | } | |
287 | ||
288 | /* | |
289 | * Block device functions | |
290 | */ | |
fe5f9f2c | 291 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
292 | { |
293 | struct mapped_device *md; | |
294 | ||
fba9f90e JM |
295 | spin_lock(&_minor_lock); |
296 | ||
fe5f9f2c | 297 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
298 | if (!md) |
299 | goto out; | |
300 | ||
5c6bd75d AK |
301 | if (test_bit(DMF_FREEING, &md->flags) || |
302 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
303 | md = NULL; |
304 | goto out; | |
305 | } | |
306 | ||
1da177e4 | 307 | dm_get(md); |
5c6bd75d | 308 | atomic_inc(&md->open_count); |
fba9f90e JM |
309 | |
310 | out: | |
311 | spin_unlock(&_minor_lock); | |
312 | ||
313 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
314 | } |
315 | ||
fe5f9f2c | 316 | static int dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 317 | { |
fe5f9f2c | 318 | struct mapped_device *md = disk->private_data; |
5c6bd75d | 319 | atomic_dec(&md->open_count); |
1da177e4 LT |
320 | dm_put(md); |
321 | return 0; | |
322 | } | |
323 | ||
5c6bd75d AK |
324 | int dm_open_count(struct mapped_device *md) |
325 | { | |
326 | return atomic_read(&md->open_count); | |
327 | } | |
328 | ||
329 | /* | |
330 | * Guarantees nothing is using the device before it's deleted. | |
331 | */ | |
332 | int dm_lock_for_deletion(struct mapped_device *md) | |
333 | { | |
334 | int r = 0; | |
335 | ||
336 | spin_lock(&_minor_lock); | |
337 | ||
338 | if (dm_open_count(md)) | |
339 | r = -EBUSY; | |
340 | else | |
341 | set_bit(DMF_DELETING, &md->flags); | |
342 | ||
343 | spin_unlock(&_minor_lock); | |
344 | ||
345 | return r; | |
346 | } | |
347 | ||
3ac51e74 DW |
348 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
349 | { | |
350 | struct mapped_device *md = bdev->bd_disk->private_data; | |
351 | ||
352 | return dm_get_geometry(md, geo); | |
353 | } | |
354 | ||
fe5f9f2c | 355 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
356 | unsigned int cmd, unsigned long arg) |
357 | { | |
fe5f9f2c AV |
358 | struct mapped_device *md = bdev->bd_disk->private_data; |
359 | struct dm_table *map = dm_get_table(md); | |
aa129a22 MB |
360 | struct dm_target *tgt; |
361 | int r = -ENOTTY; | |
362 | ||
aa129a22 MB |
363 | if (!map || !dm_table_get_size(map)) |
364 | goto out; | |
365 | ||
366 | /* We only support devices that have a single target */ | |
367 | if (dm_table_get_num_targets(map) != 1) | |
368 | goto out; | |
369 | ||
370 | tgt = dm_table_get_target(map, 0); | |
371 | ||
372 | if (dm_suspended(md)) { | |
373 | r = -EAGAIN; | |
374 | goto out; | |
375 | } | |
376 | ||
377 | if (tgt->type->ioctl) | |
647b3d00 | 378 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
379 | |
380 | out: | |
381 | dm_table_put(map); | |
382 | ||
aa129a22 MB |
383 | return r; |
384 | } | |
385 | ||
028867ac | 386 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
387 | { |
388 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
389 | } | |
390 | ||
028867ac | 391 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
392 | { |
393 | mempool_free(io, md->io_pool); | |
394 | } | |
395 | ||
028867ac | 396 | static struct dm_target_io *alloc_tio(struct mapped_device *md) |
1da177e4 LT |
397 | { |
398 | return mempool_alloc(md->tio_pool, GFP_NOIO); | |
399 | } | |
400 | ||
028867ac | 401 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
402 | { |
403 | mempool_free(tio, md->tio_pool); | |
404 | } | |
405 | ||
3eaf840e JNN |
406 | static void start_io_acct(struct dm_io *io) |
407 | { | |
408 | struct mapped_device *md = io->md; | |
c9959059 | 409 | int cpu; |
3eaf840e JNN |
410 | |
411 | io->start_time = jiffies; | |
412 | ||
074a7aca TH |
413 | cpu = part_stat_lock(); |
414 | part_round_stats(cpu, &dm_disk(md)->part0); | |
415 | part_stat_unlock(); | |
416 | dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending); | |
3eaf840e JNN |
417 | } |
418 | ||
d221d2e7 | 419 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
420 | { |
421 | struct mapped_device *md = io->md; | |
422 | struct bio *bio = io->bio; | |
423 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 424 | int pending, cpu; |
3eaf840e JNN |
425 | int rw = bio_data_dir(bio); |
426 | ||
074a7aca TH |
427 | cpu = part_stat_lock(); |
428 | part_round_stats(cpu, &dm_disk(md)->part0); | |
429 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
430 | part_stat_unlock(); | |
3eaf840e | 431 | |
af7e466a MP |
432 | /* |
433 | * After this is decremented the bio must not be touched if it is | |
434 | * a barrier. | |
435 | */ | |
074a7aca TH |
436 | dm_disk(md)->part0.in_flight = pending = |
437 | atomic_dec_return(&md->pending); | |
3eaf840e | 438 | |
d221d2e7 MP |
439 | /* nudge anyone waiting on suspend queue */ |
440 | if (!pending) | |
441 | wake_up(&md->wait); | |
3eaf840e JNN |
442 | } |
443 | ||
1da177e4 LT |
444 | /* |
445 | * Add the bio to the list of deferred io. | |
446 | */ | |
92c63902 | 447 | static void queue_io(struct mapped_device *md, struct bio *bio) |
1da177e4 | 448 | { |
2ca3310e | 449 | down_write(&md->io_lock); |
1da177e4 | 450 | |
022c2611 | 451 | spin_lock_irq(&md->deferred_lock); |
1da177e4 | 452 | bio_list_add(&md->deferred, bio); |
022c2611 | 453 | spin_unlock_irq(&md->deferred_lock); |
1da177e4 | 454 | |
92c63902 MP |
455 | if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) |
456 | queue_work(md->wq, &md->work); | |
457 | ||
2ca3310e | 458 | up_write(&md->io_lock); |
1da177e4 LT |
459 | } |
460 | ||
461 | /* | |
462 | * Everyone (including functions in this file), should use this | |
463 | * function to access the md->map field, and make sure they call | |
464 | * dm_table_put() when finished. | |
465 | */ | |
466 | struct dm_table *dm_get_table(struct mapped_device *md) | |
467 | { | |
468 | struct dm_table *t; | |
469 | ||
470 | read_lock(&md->map_lock); | |
471 | t = md->map; | |
472 | if (t) | |
473 | dm_table_get(t); | |
474 | read_unlock(&md->map_lock); | |
475 | ||
476 | return t; | |
477 | } | |
478 | ||
3ac51e74 DW |
479 | /* |
480 | * Get the geometry associated with a dm device | |
481 | */ | |
482 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
483 | { | |
484 | *geo = md->geometry; | |
485 | ||
486 | return 0; | |
487 | } | |
488 | ||
489 | /* | |
490 | * Set the geometry of a device. | |
491 | */ | |
492 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
493 | { | |
494 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
495 | ||
496 | if (geo->start > sz) { | |
497 | DMWARN("Start sector is beyond the geometry limits."); | |
498 | return -EINVAL; | |
499 | } | |
500 | ||
501 | md->geometry = *geo; | |
502 | ||
503 | return 0; | |
504 | } | |
505 | ||
1da177e4 LT |
506 | /*----------------------------------------------------------------- |
507 | * CRUD START: | |
508 | * A more elegant soln is in the works that uses the queue | |
509 | * merge fn, unfortunately there are a couple of changes to | |
510 | * the block layer that I want to make for this. So in the | |
511 | * interests of getting something for people to use I give | |
512 | * you this clearly demarcated crap. | |
513 | *---------------------------------------------------------------*/ | |
514 | ||
2e93ccc1 KU |
515 | static int __noflush_suspending(struct mapped_device *md) |
516 | { | |
517 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
518 | } | |
519 | ||
1da177e4 LT |
520 | /* |
521 | * Decrements the number of outstanding ios that a bio has been | |
522 | * cloned into, completing the original io if necc. | |
523 | */ | |
858119e1 | 524 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 525 | { |
2e93ccc1 | 526 | unsigned long flags; |
b35f8caa MB |
527 | int io_error; |
528 | struct bio *bio; | |
529 | struct mapped_device *md = io->md; | |
2e93ccc1 KU |
530 | |
531 | /* Push-back supersedes any I/O errors */ | |
b35f8caa | 532 | if (error && !(io->error > 0 && __noflush_suspending(md))) |
1da177e4 LT |
533 | io->error = error; |
534 | ||
535 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
536 | if (io->error == DM_ENDIO_REQUEUE) { |
537 | /* | |
538 | * Target requested pushing back the I/O. | |
2e93ccc1 | 539 | */ |
022c2611 | 540 | spin_lock_irqsave(&md->deferred_lock, flags); |
b35f8caa | 541 | if (__noflush_suspending(md)) |
af7e466a | 542 | bio_list_add_head(&md->deferred, io->bio); |
2e93ccc1 KU |
543 | else |
544 | /* noflush suspend was interrupted. */ | |
545 | io->error = -EIO; | |
022c2611 | 546 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
2e93ccc1 KU |
547 | } |
548 | ||
b35f8caa MB |
549 | io_error = io->error; |
550 | bio = io->bio; | |
2e93ccc1 | 551 | |
af7e466a MP |
552 | if (bio_barrier(bio)) { |
553 | /* | |
554 | * There can be just one barrier request so we use | |
555 | * a per-device variable for error reporting. | |
556 | * Note that you can't touch the bio after end_io_acct | |
557 | */ | |
558 | md->barrier_error = io_error; | |
559 | end_io_acct(io); | |
560 | } else { | |
561 | end_io_acct(io); | |
b35f8caa | 562 | |
af7e466a MP |
563 | if (io_error != DM_ENDIO_REQUEUE) { |
564 | trace_block_bio_complete(md->queue, bio); | |
2056a782 | 565 | |
af7e466a MP |
566 | bio_endio(bio, io_error); |
567 | } | |
b35f8caa | 568 | } |
af7e466a MP |
569 | |
570 | free_io(md, io); | |
1da177e4 LT |
571 | } |
572 | } | |
573 | ||
6712ecf8 | 574 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
575 | { |
576 | int r = 0; | |
028867ac | 577 | struct dm_target_io *tio = bio->bi_private; |
b35f8caa | 578 | struct dm_io *io = tio->io; |
9faf400f | 579 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
580 | dm_endio_fn endio = tio->ti->type->end_io; |
581 | ||
1da177e4 LT |
582 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
583 | error = -EIO; | |
584 | ||
585 | if (endio) { | |
586 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
587 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
588 | /* | |
589 | * error and requeue request are handled | |
590 | * in dec_pending(). | |
591 | */ | |
1da177e4 | 592 | error = r; |
45cbcd79 KU |
593 | else if (r == DM_ENDIO_INCOMPLETE) |
594 | /* The target will handle the io */ | |
6712ecf8 | 595 | return; |
45cbcd79 KU |
596 | else if (r) { |
597 | DMWARN("unimplemented target endio return value: %d", r); | |
598 | BUG(); | |
599 | } | |
1da177e4 LT |
600 | } |
601 | ||
9faf400f SB |
602 | /* |
603 | * Store md for cleanup instead of tio which is about to get freed. | |
604 | */ | |
605 | bio->bi_private = md->bs; | |
606 | ||
9faf400f | 607 | free_tio(md, tio); |
b35f8caa MB |
608 | bio_put(bio); |
609 | dec_pending(io, error); | |
1da177e4 LT |
610 | } |
611 | ||
612 | static sector_t max_io_len(struct mapped_device *md, | |
613 | sector_t sector, struct dm_target *ti) | |
614 | { | |
615 | sector_t offset = sector - ti->begin; | |
616 | sector_t len = ti->len - offset; | |
617 | ||
618 | /* | |
619 | * Does the target need to split even further ? | |
620 | */ | |
621 | if (ti->split_io) { | |
622 | sector_t boundary; | |
623 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
624 | - offset; | |
625 | if (len > boundary) | |
626 | len = boundary; | |
627 | } | |
628 | ||
629 | return len; | |
630 | } | |
631 | ||
632 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 633 | struct dm_target_io *tio) |
1da177e4 LT |
634 | { |
635 | int r; | |
2056a782 | 636 | sector_t sector; |
9faf400f | 637 | struct mapped_device *md; |
1da177e4 LT |
638 | |
639 | /* | |
640 | * Sanity checks. | |
641 | */ | |
642 | BUG_ON(!clone->bi_size); | |
643 | ||
644 | clone->bi_end_io = clone_endio; | |
645 | clone->bi_private = tio; | |
646 | ||
647 | /* | |
648 | * Map the clone. If r == 0 we don't need to do | |
649 | * anything, the target has assumed ownership of | |
650 | * this io. | |
651 | */ | |
652 | atomic_inc(&tio->io->io_count); | |
2056a782 | 653 | sector = clone->bi_sector; |
1da177e4 | 654 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 655 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 656 | /* the bio has been remapped so dispatch it */ |
2056a782 | 657 | |
5f3ea37c | 658 | trace_block_remap(bdev_get_queue(clone->bi_bdev), clone, |
c7149d6b AB |
659 | tio->io->bio->bi_bdev->bd_dev, |
660 | clone->bi_sector, sector); | |
2056a782 | 661 | |
1da177e4 | 662 | generic_make_request(clone); |
2e93ccc1 KU |
663 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
664 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
665 | md = tio->io->md; |
666 | dec_pending(tio->io, r); | |
667 | /* | |
668 | * Store bio_set for cleanup. | |
669 | */ | |
670 | clone->bi_private = md->bs; | |
1da177e4 | 671 | bio_put(clone); |
9faf400f | 672 | free_tio(md, tio); |
45cbcd79 KU |
673 | } else if (r) { |
674 | DMWARN("unimplemented target map return value: %d", r); | |
675 | BUG(); | |
1da177e4 LT |
676 | } |
677 | } | |
678 | ||
679 | struct clone_info { | |
680 | struct mapped_device *md; | |
681 | struct dm_table *map; | |
682 | struct bio *bio; | |
683 | struct dm_io *io; | |
684 | sector_t sector; | |
685 | sector_t sector_count; | |
686 | unsigned short idx; | |
687 | }; | |
688 | ||
3676347a PO |
689 | static void dm_bio_destructor(struct bio *bio) |
690 | { | |
9faf400f SB |
691 | struct bio_set *bs = bio->bi_private; |
692 | ||
693 | bio_free(bio, bs); | |
3676347a PO |
694 | } |
695 | ||
1da177e4 LT |
696 | /* |
697 | * Creates a little bio that is just does part of a bvec. | |
698 | */ | |
699 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
700 | unsigned short idx, unsigned int offset, | |
9faf400f | 701 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
702 | { |
703 | struct bio *clone; | |
704 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
705 | ||
9faf400f | 706 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 707 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
708 | *clone->bi_io_vec = *bv; |
709 | ||
710 | clone->bi_sector = sector; | |
711 | clone->bi_bdev = bio->bi_bdev; | |
af7e466a | 712 | clone->bi_rw = bio->bi_rw & ~(1 << BIO_RW_BARRIER); |
1da177e4 LT |
713 | clone->bi_vcnt = 1; |
714 | clone->bi_size = to_bytes(len); | |
715 | clone->bi_io_vec->bv_offset = offset; | |
716 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 717 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 | 718 | |
9c47008d MP |
719 | if (bio_integrity(bio)) { |
720 | bio_integrity_clone(clone, bio, GFP_NOIO); | |
721 | bio_integrity_trim(clone, | |
722 | bio_sector_offset(bio, idx, offset), len); | |
723 | } | |
724 | ||
1da177e4 LT |
725 | return clone; |
726 | } | |
727 | ||
728 | /* | |
729 | * Creates a bio that consists of range of complete bvecs. | |
730 | */ | |
731 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
732 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 733 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
734 | { |
735 | struct bio *clone; | |
736 | ||
9faf400f SB |
737 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
738 | __bio_clone(clone, bio); | |
af7e466a | 739 | clone->bi_rw &= ~(1 << BIO_RW_BARRIER); |
9faf400f | 740 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
741 | clone->bi_sector = sector; |
742 | clone->bi_idx = idx; | |
743 | clone->bi_vcnt = idx + bv_count; | |
744 | clone->bi_size = to_bytes(len); | |
745 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
746 | ||
9c47008d MP |
747 | if (bio_integrity(bio)) { |
748 | bio_integrity_clone(clone, bio, GFP_NOIO); | |
749 | ||
750 | if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) | |
751 | bio_integrity_trim(clone, | |
752 | bio_sector_offset(bio, idx, 0), len); | |
753 | } | |
754 | ||
1da177e4 LT |
755 | return clone; |
756 | } | |
757 | ||
512875bd | 758 | static int __clone_and_map(struct clone_info *ci) |
1da177e4 LT |
759 | { |
760 | struct bio *clone, *bio = ci->bio; | |
512875bd JN |
761 | struct dm_target *ti; |
762 | sector_t len = 0, max; | |
028867ac | 763 | struct dm_target_io *tio; |
1da177e4 | 764 | |
512875bd JN |
765 | ti = dm_table_find_target(ci->map, ci->sector); |
766 | if (!dm_target_is_valid(ti)) | |
767 | return -EIO; | |
768 | ||
769 | max = max_io_len(ci->md, ci->sector, ti); | |
770 | ||
1da177e4 LT |
771 | /* |
772 | * Allocate a target io object. | |
773 | */ | |
774 | tio = alloc_tio(ci->md); | |
775 | tio->io = ci->io; | |
776 | tio->ti = ti; | |
777 | memset(&tio->info, 0, sizeof(tio->info)); | |
778 | ||
779 | if (ci->sector_count <= max) { | |
780 | /* | |
781 | * Optimise for the simple case where we can do all of | |
782 | * the remaining io with a single clone. | |
783 | */ | |
784 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
785 | bio->bi_vcnt - ci->idx, ci->sector_count, |
786 | ci->md->bs); | |
1da177e4 LT |
787 | __map_bio(ti, clone, tio); |
788 | ci->sector_count = 0; | |
789 | ||
790 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
791 | /* | |
792 | * There are some bvecs that don't span targets. | |
793 | * Do as many of these as possible. | |
794 | */ | |
795 | int i; | |
796 | sector_t remaining = max; | |
797 | sector_t bv_len; | |
798 | ||
799 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
800 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
801 | ||
802 | if (bv_len > remaining) | |
803 | break; | |
804 | ||
805 | remaining -= bv_len; | |
806 | len += bv_len; | |
807 | } | |
808 | ||
9faf400f SB |
809 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
810 | ci->md->bs); | |
1da177e4 LT |
811 | __map_bio(ti, clone, tio); |
812 | ||
813 | ci->sector += len; | |
814 | ci->sector_count -= len; | |
815 | ci->idx = i; | |
816 | ||
817 | } else { | |
818 | /* | |
d2044a94 | 819 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
820 | */ |
821 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
822 | sector_t remaining = to_sector(bv->bv_len); |
823 | unsigned int offset = 0; | |
1da177e4 | 824 | |
d2044a94 AK |
825 | do { |
826 | if (offset) { | |
827 | ti = dm_table_find_target(ci->map, ci->sector); | |
512875bd JN |
828 | if (!dm_target_is_valid(ti)) |
829 | return -EIO; | |
830 | ||
d2044a94 | 831 | max = max_io_len(ci->md, ci->sector, ti); |
1da177e4 | 832 | |
d2044a94 AK |
833 | tio = alloc_tio(ci->md); |
834 | tio->io = ci->io; | |
835 | tio->ti = ti; | |
836 | memset(&tio->info, 0, sizeof(tio->info)); | |
837 | } | |
838 | ||
839 | len = min(remaining, max); | |
840 | ||
841 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
842 | bv->bv_offset + offset, len, |
843 | ci->md->bs); | |
d2044a94 AK |
844 | |
845 | __map_bio(ti, clone, tio); | |
846 | ||
847 | ci->sector += len; | |
848 | ci->sector_count -= len; | |
849 | offset += to_bytes(len); | |
850 | } while (remaining -= len); | |
1da177e4 | 851 | |
1da177e4 LT |
852 | ci->idx++; |
853 | } | |
512875bd JN |
854 | |
855 | return 0; | |
1da177e4 LT |
856 | } |
857 | ||
858 | /* | |
8a53c28d | 859 | * Split the bio into several clones and submit it to targets. |
1da177e4 | 860 | */ |
f0b9a450 | 861 | static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) |
1da177e4 LT |
862 | { |
863 | struct clone_info ci; | |
512875bd | 864 | int error = 0; |
1da177e4 LT |
865 | |
866 | ci.map = dm_get_table(md); | |
f0b9a450 | 867 | if (unlikely(!ci.map)) { |
af7e466a MP |
868 | if (!bio_barrier(bio)) |
869 | bio_io_error(bio); | |
870 | else | |
871 | md->barrier_error = -EIO; | |
f0b9a450 MP |
872 | return; |
873 | } | |
692d0eb9 | 874 | |
1da177e4 LT |
875 | ci.md = md; |
876 | ci.bio = bio; | |
877 | ci.io = alloc_io(md); | |
878 | ci.io->error = 0; | |
879 | atomic_set(&ci.io->io_count, 1); | |
880 | ci.io->bio = bio; | |
881 | ci.io->md = md; | |
882 | ci.sector = bio->bi_sector; | |
883 | ci.sector_count = bio_sectors(bio); | |
884 | ci.idx = bio->bi_idx; | |
885 | ||
3eaf840e | 886 | start_io_acct(ci.io); |
512875bd JN |
887 | while (ci.sector_count && !error) |
888 | error = __clone_and_map(&ci); | |
1da177e4 LT |
889 | |
890 | /* drop the extra reference count */ | |
512875bd | 891 | dec_pending(ci.io, error); |
1da177e4 LT |
892 | dm_table_put(ci.map); |
893 | } | |
894 | /*----------------------------------------------------------------- | |
895 | * CRUD END | |
896 | *---------------------------------------------------------------*/ | |
897 | ||
f6fccb12 MB |
898 | static int dm_merge_bvec(struct request_queue *q, |
899 | struct bvec_merge_data *bvm, | |
900 | struct bio_vec *biovec) | |
901 | { | |
902 | struct mapped_device *md = q->queuedata; | |
903 | struct dm_table *map = dm_get_table(md); | |
904 | struct dm_target *ti; | |
905 | sector_t max_sectors; | |
5037108a | 906 | int max_size = 0; |
f6fccb12 MB |
907 | |
908 | if (unlikely(!map)) | |
5037108a | 909 | goto out; |
f6fccb12 MB |
910 | |
911 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac MP |
912 | if (!dm_target_is_valid(ti)) |
913 | goto out_table; | |
f6fccb12 MB |
914 | |
915 | /* | |
916 | * Find maximum amount of I/O that won't need splitting | |
917 | */ | |
918 | max_sectors = min(max_io_len(md, bvm->bi_sector, ti), | |
919 | (sector_t) BIO_MAX_SECTORS); | |
920 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
921 | if (max_size < 0) | |
922 | max_size = 0; | |
923 | ||
924 | /* | |
925 | * merge_bvec_fn() returns number of bytes | |
926 | * it can accept at this offset | |
927 | * max is precomputed maximal io size | |
928 | */ | |
929 | if (max_size && ti->type->merge) | |
930 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
931 | ||
b01cd5ac | 932 | out_table: |
5037108a MP |
933 | dm_table_put(map); |
934 | ||
935 | out: | |
f6fccb12 MB |
936 | /* |
937 | * Always allow an entire first page | |
938 | */ | |
939 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
940 | max_size = biovec->bv_len; | |
941 | ||
f6fccb12 MB |
942 | return max_size; |
943 | } | |
944 | ||
1da177e4 LT |
945 | /* |
946 | * The request function that just remaps the bio built up by | |
947 | * dm_merge_bvec. | |
948 | */ | |
165125e1 | 949 | static int dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 950 | { |
12f03a49 | 951 | int rw = bio_data_dir(bio); |
1da177e4 | 952 | struct mapped_device *md = q->queuedata; |
c9959059 | 953 | int cpu; |
1da177e4 | 954 | |
2ca3310e | 955 | down_read(&md->io_lock); |
1da177e4 | 956 | |
074a7aca TH |
957 | cpu = part_stat_lock(); |
958 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
959 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
960 | part_stat_unlock(); | |
12f03a49 | 961 | |
1da177e4 | 962 | /* |
1eb787ec AK |
963 | * If we're suspended or the thread is processing barriers |
964 | * we have to queue this io for later. | |
1da177e4 | 965 | */ |
af7e466a MP |
966 | if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) || |
967 | unlikely(bio_barrier(bio))) { | |
2ca3310e | 968 | up_read(&md->io_lock); |
1da177e4 | 969 | |
54d9a1b4 AK |
970 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && |
971 | bio_rw(bio) == READA) { | |
972 | bio_io_error(bio); | |
973 | return 0; | |
974 | } | |
1da177e4 | 975 | |
92c63902 | 976 | queue_io(md, bio); |
1da177e4 | 977 | |
92c63902 | 978 | return 0; |
1da177e4 LT |
979 | } |
980 | ||
f0b9a450 | 981 | __split_and_process_bio(md, bio); |
2ca3310e | 982 | up_read(&md->io_lock); |
f0b9a450 | 983 | return 0; |
1da177e4 LT |
984 | } |
985 | ||
165125e1 | 986 | static void dm_unplug_all(struct request_queue *q) |
1da177e4 LT |
987 | { |
988 | struct mapped_device *md = q->queuedata; | |
989 | struct dm_table *map = dm_get_table(md); | |
990 | ||
991 | if (map) { | |
992 | dm_table_unplug_all(map); | |
993 | dm_table_put(map); | |
994 | } | |
995 | } | |
996 | ||
997 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
998 | { | |
8a57dfc6 CS |
999 | int r = bdi_bits; |
1000 | struct mapped_device *md = congested_data; | |
1001 | struct dm_table *map; | |
1da177e4 | 1002 | |
1eb787ec | 1003 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
8a57dfc6 CS |
1004 | map = dm_get_table(md); |
1005 | if (map) { | |
1006 | r = dm_table_any_congested(map, bdi_bits); | |
1007 | dm_table_put(map); | |
1008 | } | |
1009 | } | |
1010 | ||
1da177e4 LT |
1011 | return r; |
1012 | } | |
1013 | ||
1014 | /*----------------------------------------------------------------- | |
1015 | * An IDR is used to keep track of allocated minor numbers. | |
1016 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
1017 | static DEFINE_IDR(_minor_idr); |
1018 | ||
2b06cfff | 1019 | static void free_minor(int minor) |
1da177e4 | 1020 | { |
f32c10b0 | 1021 | spin_lock(&_minor_lock); |
1da177e4 | 1022 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 1023 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1024 | } |
1025 | ||
1026 | /* | |
1027 | * See if the device with a specific minor # is free. | |
1028 | */ | |
cf13ab8e | 1029 | static int specific_minor(int minor) |
1da177e4 LT |
1030 | { |
1031 | int r, m; | |
1032 | ||
1033 | if (minor >= (1 << MINORBITS)) | |
1034 | return -EINVAL; | |
1035 | ||
62f75c2f JM |
1036 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
1037 | if (!r) | |
1038 | return -ENOMEM; | |
1039 | ||
f32c10b0 | 1040 | spin_lock(&_minor_lock); |
1da177e4 LT |
1041 | |
1042 | if (idr_find(&_minor_idr, minor)) { | |
1043 | r = -EBUSY; | |
1044 | goto out; | |
1045 | } | |
1046 | ||
ba61fdd1 | 1047 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 1048 | if (r) |
1da177e4 | 1049 | goto out; |
1da177e4 LT |
1050 | |
1051 | if (m != minor) { | |
1052 | idr_remove(&_minor_idr, m); | |
1053 | r = -EBUSY; | |
1054 | goto out; | |
1055 | } | |
1056 | ||
1057 | out: | |
f32c10b0 | 1058 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1059 | return r; |
1060 | } | |
1061 | ||
cf13ab8e | 1062 | static int next_free_minor(int *minor) |
1da177e4 | 1063 | { |
2b06cfff | 1064 | int r, m; |
1da177e4 | 1065 | |
1da177e4 | 1066 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
1067 | if (!r) |
1068 | return -ENOMEM; | |
1069 | ||
f32c10b0 | 1070 | spin_lock(&_minor_lock); |
1da177e4 | 1071 | |
ba61fdd1 | 1072 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
cf13ab8e | 1073 | if (r) |
1da177e4 | 1074 | goto out; |
1da177e4 LT |
1075 | |
1076 | if (m >= (1 << MINORBITS)) { | |
1077 | idr_remove(&_minor_idr, m); | |
1078 | r = -ENOSPC; | |
1079 | goto out; | |
1080 | } | |
1081 | ||
1082 | *minor = m; | |
1083 | ||
1084 | out: | |
f32c10b0 | 1085 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1086 | return r; |
1087 | } | |
1088 | ||
1089 | static struct block_device_operations dm_blk_dops; | |
1090 | ||
53d5914f MP |
1091 | static void dm_wq_work(struct work_struct *work); |
1092 | ||
1da177e4 LT |
1093 | /* |
1094 | * Allocate and initialise a blank device with a given minor. | |
1095 | */ | |
2b06cfff | 1096 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1097 | { |
1098 | int r; | |
cf13ab8e | 1099 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1100 | void *old_md; |
1da177e4 LT |
1101 | |
1102 | if (!md) { | |
1103 | DMWARN("unable to allocate device, out of memory."); | |
1104 | return NULL; | |
1105 | } | |
1106 | ||
10da4f79 | 1107 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 1108 | goto bad_module_get; |
10da4f79 | 1109 | |
1da177e4 | 1110 | /* get a minor number for the dev */ |
2b06cfff | 1111 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 1112 | r = next_free_minor(&minor); |
2b06cfff | 1113 | else |
cf13ab8e | 1114 | r = specific_minor(minor); |
1da177e4 | 1115 | if (r < 0) |
6ed7ade8 | 1116 | goto bad_minor; |
1da177e4 | 1117 | |
2ca3310e | 1118 | init_rwsem(&md->io_lock); |
e61290a4 | 1119 | mutex_init(&md->suspend_lock); |
022c2611 | 1120 | spin_lock_init(&md->deferred_lock); |
1da177e4 LT |
1121 | rwlock_init(&md->map_lock); |
1122 | atomic_set(&md->holders, 1); | |
5c6bd75d | 1123 | atomic_set(&md->open_count, 0); |
1da177e4 | 1124 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
1125 | atomic_set(&md->uevent_seq, 0); |
1126 | INIT_LIST_HEAD(&md->uevent_list); | |
1127 | spin_lock_init(&md->uevent_lock); | |
1da177e4 LT |
1128 | |
1129 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
1130 | if (!md->queue) | |
6ed7ade8 | 1131 | goto bad_queue; |
1da177e4 LT |
1132 | |
1133 | md->queue->queuedata = md; | |
1134 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1135 | md->queue->backing_dev_info.congested_data = md; | |
1136 | blk_queue_make_request(md->queue, dm_request); | |
99360b4c | 1137 | blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN, NULL); |
daef265f | 1138 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 | 1139 | md->queue->unplug_fn = dm_unplug_all; |
f6fccb12 | 1140 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
1da177e4 | 1141 | |
93d2341c | 1142 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 | 1143 | if (!md->io_pool) |
6ed7ade8 | 1144 | goto bad_io_pool; |
1da177e4 | 1145 | |
93d2341c | 1146 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 | 1147 | if (!md->tio_pool) |
6ed7ade8 | 1148 | goto bad_tio_pool; |
1da177e4 | 1149 | |
bb799ca0 | 1150 | md->bs = bioset_create(16, 0); |
9faf400f SB |
1151 | if (!md->bs) |
1152 | goto bad_no_bioset; | |
1153 | ||
1da177e4 LT |
1154 | md->disk = alloc_disk(1); |
1155 | if (!md->disk) | |
6ed7ade8 | 1156 | goto bad_disk; |
1da177e4 | 1157 | |
f0b04115 JM |
1158 | atomic_set(&md->pending, 0); |
1159 | init_waitqueue_head(&md->wait); | |
53d5914f | 1160 | INIT_WORK(&md->work, dm_wq_work); |
f0b04115 JM |
1161 | init_waitqueue_head(&md->eventq); |
1162 | ||
1da177e4 LT |
1163 | md->disk->major = _major; |
1164 | md->disk->first_minor = minor; | |
1165 | md->disk->fops = &dm_blk_dops; | |
1166 | md->disk->queue = md->queue; | |
1167 | md->disk->private_data = md; | |
1168 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
1169 | add_disk(md->disk); | |
7e51f257 | 1170 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1171 | |
304f3f6a MB |
1172 | md->wq = create_singlethread_workqueue("kdmflush"); |
1173 | if (!md->wq) | |
1174 | goto bad_thread; | |
1175 | ||
ba61fdd1 | 1176 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1177 | spin_lock(&_minor_lock); |
ba61fdd1 | 1178 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1179 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1180 | |
1181 | BUG_ON(old_md != MINOR_ALLOCED); | |
1182 | ||
1da177e4 LT |
1183 | return md; |
1184 | ||
304f3f6a MB |
1185 | bad_thread: |
1186 | put_disk(md->disk); | |
6ed7ade8 | 1187 | bad_disk: |
9faf400f | 1188 | bioset_free(md->bs); |
6ed7ade8 | 1189 | bad_no_bioset: |
1da177e4 | 1190 | mempool_destroy(md->tio_pool); |
6ed7ade8 | 1191 | bad_tio_pool: |
1da177e4 | 1192 | mempool_destroy(md->io_pool); |
6ed7ade8 | 1193 | bad_io_pool: |
1312f40e | 1194 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 1195 | bad_queue: |
1da177e4 | 1196 | free_minor(minor); |
6ed7ade8 | 1197 | bad_minor: |
10da4f79 | 1198 | module_put(THIS_MODULE); |
6ed7ade8 | 1199 | bad_module_get: |
1da177e4 LT |
1200 | kfree(md); |
1201 | return NULL; | |
1202 | } | |
1203 | ||
ae9da83f JN |
1204 | static void unlock_fs(struct mapped_device *md); |
1205 | ||
1da177e4 LT |
1206 | static void free_dev(struct mapped_device *md) |
1207 | { | |
f331c029 | 1208 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 1209 | |
d9dde59b | 1210 | if (md->suspended_bdev) { |
ae9da83f | 1211 | unlock_fs(md); |
d9dde59b JN |
1212 | bdput(md->suspended_bdev); |
1213 | } | |
304f3f6a | 1214 | destroy_workqueue(md->wq); |
1da177e4 LT |
1215 | mempool_destroy(md->tio_pool); |
1216 | mempool_destroy(md->io_pool); | |
9faf400f | 1217 | bioset_free(md->bs); |
9c47008d | 1218 | blk_integrity_unregister(md->disk); |
1da177e4 | 1219 | del_gendisk(md->disk); |
63d94e48 | 1220 | free_minor(minor); |
fba9f90e JM |
1221 | |
1222 | spin_lock(&_minor_lock); | |
1223 | md->disk->private_data = NULL; | |
1224 | spin_unlock(&_minor_lock); | |
1225 | ||
1da177e4 | 1226 | put_disk(md->disk); |
1312f40e | 1227 | blk_cleanup_queue(md->queue); |
10da4f79 | 1228 | module_put(THIS_MODULE); |
1da177e4 LT |
1229 | kfree(md); |
1230 | } | |
1231 | ||
1232 | /* | |
1233 | * Bind a table to the device. | |
1234 | */ | |
1235 | static void event_callback(void *context) | |
1236 | { | |
7a8c3d3b MA |
1237 | unsigned long flags; |
1238 | LIST_HEAD(uevents); | |
1da177e4 LT |
1239 | struct mapped_device *md = (struct mapped_device *) context; |
1240 | ||
7a8c3d3b MA |
1241 | spin_lock_irqsave(&md->uevent_lock, flags); |
1242 | list_splice_init(&md->uevent_list, &uevents); | |
1243 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1244 | ||
ed9e1982 | 1245 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 1246 | |
1da177e4 LT |
1247 | atomic_inc(&md->event_nr); |
1248 | wake_up(&md->eventq); | |
1249 | } | |
1250 | ||
4e90188b | 1251 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1252 | { |
4e90188b | 1253 | set_capacity(md->disk, size); |
1da177e4 | 1254 | |
1b1dcc1b | 1255 | mutex_lock(&md->suspended_bdev->bd_inode->i_mutex); |
e39e2e95 | 1256 | i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1b1dcc1b | 1257 | mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex); |
1da177e4 LT |
1258 | } |
1259 | ||
1260 | static int __bind(struct mapped_device *md, struct dm_table *t) | |
1261 | { | |
165125e1 | 1262 | struct request_queue *q = md->queue; |
1da177e4 LT |
1263 | sector_t size; |
1264 | ||
1265 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1266 | |
1267 | /* | |
1268 | * Wipe any geometry if the size of the table changed. | |
1269 | */ | |
1270 | if (size != get_capacity(md->disk)) | |
1271 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1272 | ||
bfa152fa JN |
1273 | if (md->suspended_bdev) |
1274 | __set_size(md, size); | |
d5816876 MP |
1275 | |
1276 | if (!size) { | |
1277 | dm_table_destroy(t); | |
1da177e4 | 1278 | return 0; |
d5816876 | 1279 | } |
1da177e4 | 1280 | |
2ca3310e AK |
1281 | dm_table_event_callback(t, event_callback, md); |
1282 | ||
1da177e4 LT |
1283 | write_lock(&md->map_lock); |
1284 | md->map = t; | |
2ca3310e | 1285 | dm_table_set_restrictions(t, q); |
1da177e4 LT |
1286 | write_unlock(&md->map_lock); |
1287 | ||
1da177e4 LT |
1288 | return 0; |
1289 | } | |
1290 | ||
1291 | static void __unbind(struct mapped_device *md) | |
1292 | { | |
1293 | struct dm_table *map = md->map; | |
1294 | ||
1295 | if (!map) | |
1296 | return; | |
1297 | ||
1298 | dm_table_event_callback(map, NULL, NULL); | |
1299 | write_lock(&md->map_lock); | |
1300 | md->map = NULL; | |
1301 | write_unlock(&md->map_lock); | |
d5816876 | 1302 | dm_table_destroy(map); |
1da177e4 LT |
1303 | } |
1304 | ||
1305 | /* | |
1306 | * Constructor for a new device. | |
1307 | */ | |
2b06cfff | 1308 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1309 | { |
1310 | struct mapped_device *md; | |
1311 | ||
2b06cfff | 1312 | md = alloc_dev(minor); |
1da177e4 LT |
1313 | if (!md) |
1314 | return -ENXIO; | |
1315 | ||
784aae73 MB |
1316 | dm_sysfs_init(md); |
1317 | ||
1da177e4 LT |
1318 | *result = md; |
1319 | return 0; | |
1320 | } | |
1321 | ||
637842cf | 1322 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1323 | { |
1324 | struct mapped_device *md; | |
1da177e4 LT |
1325 | unsigned minor = MINOR(dev); |
1326 | ||
1327 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1328 | return NULL; | |
1329 | ||
f32c10b0 | 1330 | spin_lock(&_minor_lock); |
1da177e4 LT |
1331 | |
1332 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 1333 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 1334 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
17b2f66f | 1335 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1336 | md = NULL; |
fba9f90e JM |
1337 | goto out; |
1338 | } | |
1da177e4 | 1339 | |
fba9f90e | 1340 | out: |
f32c10b0 | 1341 | spin_unlock(&_minor_lock); |
1da177e4 | 1342 | |
637842cf DT |
1343 | return md; |
1344 | } | |
1345 | ||
d229a958 DT |
1346 | struct mapped_device *dm_get_md(dev_t dev) |
1347 | { | |
1348 | struct mapped_device *md = dm_find_md(dev); | |
1349 | ||
1350 | if (md) | |
1351 | dm_get(md); | |
1352 | ||
1353 | return md; | |
1354 | } | |
1355 | ||
9ade92a9 | 1356 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1357 | { |
9ade92a9 | 1358 | return md->interface_ptr; |
1da177e4 LT |
1359 | } |
1360 | ||
1361 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1362 | { | |
1363 | md->interface_ptr = ptr; | |
1364 | } | |
1365 | ||
1366 | void dm_get(struct mapped_device *md) | |
1367 | { | |
1368 | atomic_inc(&md->holders); | |
1369 | } | |
1370 | ||
72d94861 AK |
1371 | const char *dm_device_name(struct mapped_device *md) |
1372 | { | |
1373 | return md->name; | |
1374 | } | |
1375 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1376 | ||
1da177e4 LT |
1377 | void dm_put(struct mapped_device *md) |
1378 | { | |
1134e5ae | 1379 | struct dm_table *map; |
1da177e4 | 1380 | |
fba9f90e JM |
1381 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1382 | ||
f32c10b0 | 1383 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1384 | map = dm_get_table(md); |
f331c029 TH |
1385 | idr_replace(&_minor_idr, MINOR_ALLOCED, |
1386 | MINOR(disk_devt(dm_disk(md)))); | |
fba9f90e | 1387 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1388 | spin_unlock(&_minor_lock); |
cf222b37 | 1389 | if (!dm_suspended(md)) { |
1da177e4 LT |
1390 | dm_table_presuspend_targets(map); |
1391 | dm_table_postsuspend_targets(map); | |
1392 | } | |
784aae73 | 1393 | dm_sysfs_exit(md); |
1134e5ae | 1394 | dm_table_put(map); |
a1b51e98 | 1395 | __unbind(md); |
1da177e4 LT |
1396 | free_dev(md); |
1397 | } | |
1da177e4 | 1398 | } |
79eb885c | 1399 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 1400 | |
401600df | 1401 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
46125c1c MB |
1402 | { |
1403 | int r = 0; | |
b44ebeb0 MP |
1404 | DECLARE_WAITQUEUE(wait, current); |
1405 | ||
1406 | dm_unplug_all(md->queue); | |
1407 | ||
1408 | add_wait_queue(&md->wait, &wait); | |
46125c1c MB |
1409 | |
1410 | while (1) { | |
401600df | 1411 | set_current_state(interruptible); |
46125c1c MB |
1412 | |
1413 | smp_mb(); | |
1414 | if (!atomic_read(&md->pending)) | |
1415 | break; | |
1416 | ||
401600df MP |
1417 | if (interruptible == TASK_INTERRUPTIBLE && |
1418 | signal_pending(current)) { | |
46125c1c MB |
1419 | r = -EINTR; |
1420 | break; | |
1421 | } | |
1422 | ||
1423 | io_schedule(); | |
1424 | } | |
1425 | set_current_state(TASK_RUNNING); | |
1426 | ||
b44ebeb0 MP |
1427 | remove_wait_queue(&md->wait, &wait); |
1428 | ||
46125c1c MB |
1429 | return r; |
1430 | } | |
1431 | ||
af7e466a MP |
1432 | static int dm_flush(struct mapped_device *md) |
1433 | { | |
1434 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); | |
1435 | return 0; | |
1436 | } | |
1437 | ||
1438 | static void process_barrier(struct mapped_device *md, struct bio *bio) | |
1439 | { | |
1440 | int error = dm_flush(md); | |
1441 | ||
1442 | if (unlikely(error)) { | |
1443 | bio_endio(bio, error); | |
1444 | return; | |
1445 | } | |
1446 | if (bio_empty_barrier(bio)) { | |
1447 | bio_endio(bio, 0); | |
1448 | return; | |
1449 | } | |
1450 | ||
1451 | __split_and_process_bio(md, bio); | |
1452 | ||
1453 | error = dm_flush(md); | |
1454 | ||
1455 | if (!error && md->barrier_error) | |
1456 | error = md->barrier_error; | |
1457 | ||
1458 | if (md->barrier_error != DM_ENDIO_REQUEUE) | |
1459 | bio_endio(bio, error); | |
1460 | } | |
1461 | ||
1da177e4 LT |
1462 | /* |
1463 | * Process the deferred bios | |
1464 | */ | |
ef208587 | 1465 | static void dm_wq_work(struct work_struct *work) |
1da177e4 | 1466 | { |
ef208587 MP |
1467 | struct mapped_device *md = container_of(work, struct mapped_device, |
1468 | work); | |
6d6f10df | 1469 | struct bio *c; |
1da177e4 | 1470 | |
ef208587 MP |
1471 | down_write(&md->io_lock); |
1472 | ||
3b00b203 | 1473 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
df12ee99 AK |
1474 | spin_lock_irq(&md->deferred_lock); |
1475 | c = bio_list_pop(&md->deferred); | |
1476 | spin_unlock_irq(&md->deferred_lock); | |
1477 | ||
1478 | if (!c) { | |
1eb787ec | 1479 | clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); |
df12ee99 AK |
1480 | break; |
1481 | } | |
022c2611 | 1482 | |
3b00b203 MP |
1483 | up_write(&md->io_lock); |
1484 | ||
af7e466a MP |
1485 | if (bio_barrier(c)) |
1486 | process_barrier(md, c); | |
1487 | else | |
1488 | __split_and_process_bio(md, c); | |
3b00b203 MP |
1489 | |
1490 | down_write(&md->io_lock); | |
022c2611 | 1491 | } |
73d410c0 | 1492 | |
ef208587 | 1493 | up_write(&md->io_lock); |
1da177e4 LT |
1494 | } |
1495 | ||
9a1fb464 | 1496 | static void dm_queue_flush(struct mapped_device *md) |
304f3f6a | 1497 | { |
3b00b203 MP |
1498 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
1499 | smp_mb__after_clear_bit(); | |
53d5914f | 1500 | queue_work(md->wq, &md->work); |
304f3f6a MB |
1501 | } |
1502 | ||
1da177e4 LT |
1503 | /* |
1504 | * Swap in a new table (destroying old one). | |
1505 | */ | |
1506 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1507 | { | |
93c534ae | 1508 | int r = -EINVAL; |
1da177e4 | 1509 | |
e61290a4 | 1510 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
1511 | |
1512 | /* device must be suspended */ | |
cf222b37 | 1513 | if (!dm_suspended(md)) |
93c534ae | 1514 | goto out; |
1da177e4 | 1515 | |
bfa152fa JN |
1516 | /* without bdev, the device size cannot be changed */ |
1517 | if (!md->suspended_bdev) | |
1518 | if (get_capacity(md->disk) != dm_table_get_size(table)) | |
1519 | goto out; | |
1520 | ||
1da177e4 LT |
1521 | __unbind(md); |
1522 | r = __bind(md, table); | |
1da177e4 | 1523 | |
93c534ae | 1524 | out: |
e61290a4 | 1525 | mutex_unlock(&md->suspend_lock); |
93c534ae | 1526 | return r; |
1da177e4 LT |
1527 | } |
1528 | ||
1529 | /* | |
1530 | * Functions to lock and unlock any filesystem running on the | |
1531 | * device. | |
1532 | */ | |
2ca3310e | 1533 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1534 | { |
e39e2e95 | 1535 | int r; |
1da177e4 LT |
1536 | |
1537 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1538 | |
e39e2e95 | 1539 | md->frozen_sb = freeze_bdev(md->suspended_bdev); |
dfbe03f6 | 1540 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1541 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1542 | md->frozen_sb = NULL; |
1543 | return r; | |
dfbe03f6 AK |
1544 | } |
1545 | ||
aa8d7c2f AK |
1546 | set_bit(DMF_FROZEN, &md->flags); |
1547 | ||
1da177e4 | 1548 | /* don't bdput right now, we don't want the bdev |
e39e2e95 | 1549 | * to go away while it is locked. |
1da177e4 LT |
1550 | */ |
1551 | return 0; | |
1552 | } | |
1553 | ||
2ca3310e | 1554 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1555 | { |
aa8d7c2f AK |
1556 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1557 | return; | |
1558 | ||
e39e2e95 | 1559 | thaw_bdev(md->suspended_bdev, md->frozen_sb); |
1da177e4 | 1560 | md->frozen_sb = NULL; |
aa8d7c2f | 1561 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1562 | } |
1563 | ||
1564 | /* | |
1565 | * We need to be able to change a mapping table under a mounted | |
1566 | * filesystem. For example we might want to move some data in | |
1567 | * the background. Before the table can be swapped with | |
1568 | * dm_bind_table, dm_suspend must be called to flush any in | |
1569 | * flight bios and ensure that any further io gets deferred. | |
1570 | */ | |
a3d77d35 | 1571 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1572 | { |
2ca3310e | 1573 | struct dm_table *map = NULL; |
46125c1c | 1574 | int r = 0; |
a3d77d35 | 1575 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 1576 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 1577 | |
e61290a4 | 1578 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1579 | |
73d410c0 MB |
1580 | if (dm_suspended(md)) { |
1581 | r = -EINVAL; | |
d287483d | 1582 | goto out_unlock; |
73d410c0 | 1583 | } |
1da177e4 LT |
1584 | |
1585 | map = dm_get_table(md); | |
1da177e4 | 1586 | |
2e93ccc1 KU |
1587 | /* |
1588 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
1589 | * This flag is cleared before dm_suspend returns. | |
1590 | */ | |
1591 | if (noflush) | |
1592 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1593 | ||
cf222b37 AK |
1594 | /* This does not get reverted if there's an error later. */ |
1595 | dm_table_presuspend_targets(map); | |
1596 | ||
bfa152fa JN |
1597 | /* bdget() can stall if the pending I/Os are not flushed */ |
1598 | if (!noflush) { | |
1599 | md->suspended_bdev = bdget_disk(md->disk, 0); | |
1600 | if (!md->suspended_bdev) { | |
1601 | DMWARN("bdget failed in dm_suspend"); | |
1602 | r = -ENOMEM; | |
f431d966 | 1603 | goto out; |
bfa152fa | 1604 | } |
e39e2e95 | 1605 | |
6d6f10df MB |
1606 | /* |
1607 | * Flush I/O to the device. noflush supersedes do_lockfs, | |
1608 | * because lock_fs() needs to flush I/Os. | |
1609 | */ | |
1610 | if (do_lockfs) { | |
1611 | r = lock_fs(md); | |
1612 | if (r) | |
1613 | goto out; | |
1614 | } | |
aa8d7c2f | 1615 | } |
1da177e4 LT |
1616 | |
1617 | /* | |
3b00b203 MP |
1618 | * Here we must make sure that no processes are submitting requests |
1619 | * to target drivers i.e. no one may be executing | |
1620 | * __split_and_process_bio. This is called from dm_request and | |
1621 | * dm_wq_work. | |
1622 | * | |
1623 | * To get all processes out of __split_and_process_bio in dm_request, | |
1624 | * we take the write lock. To prevent any process from reentering | |
1625 | * __split_and_process_bio from dm_request, we set | |
1626 | * DMF_QUEUE_IO_TO_THREAD. | |
1627 | * | |
1628 | * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND | |
1629 | * and call flush_workqueue(md->wq). flush_workqueue will wait until | |
1630 | * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any | |
1631 | * further calls to __split_and_process_bio from dm_wq_work. | |
1da177e4 | 1632 | */ |
2ca3310e | 1633 | down_write(&md->io_lock); |
1eb787ec AK |
1634 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
1635 | set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); | |
2ca3310e | 1636 | up_write(&md->io_lock); |
1da177e4 | 1637 | |
3b00b203 MP |
1638 | flush_workqueue(md->wq); |
1639 | ||
1da177e4 | 1640 | /* |
3b00b203 MP |
1641 | * At this point no more requests are entering target request routines. |
1642 | * We call dm_wait_for_completion to wait for all existing requests | |
1643 | * to finish. | |
1da177e4 | 1644 | */ |
401600df | 1645 | r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE); |
1da177e4 | 1646 | |
2ca3310e | 1647 | down_write(&md->io_lock); |
6d6f10df | 1648 | if (noflush) |
022c2611 | 1649 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
94d6351e | 1650 | up_write(&md->io_lock); |
2e93ccc1 | 1651 | |
1da177e4 | 1652 | /* were we interrupted ? */ |
46125c1c | 1653 | if (r < 0) { |
9a1fb464 | 1654 | dm_queue_flush(md); |
73d410c0 | 1655 | |
2ca3310e | 1656 | unlock_fs(md); |
2e93ccc1 | 1657 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 1658 | } |
1da177e4 | 1659 | |
3b00b203 MP |
1660 | /* |
1661 | * If dm_wait_for_completion returned 0, the device is completely | |
1662 | * quiescent now. There is no request-processing activity. All new | |
1663 | * requests are being added to md->deferred list. | |
1664 | */ | |
1665 | ||
cf222b37 | 1666 | dm_table_postsuspend_targets(map); |
1da177e4 | 1667 | |
2ca3310e | 1668 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1669 | |
2ca3310e | 1670 | out: |
e39e2e95 AK |
1671 | if (r && md->suspended_bdev) { |
1672 | bdput(md->suspended_bdev); | |
1673 | md->suspended_bdev = NULL; | |
1674 | } | |
1675 | ||
2ca3310e | 1676 | dm_table_put(map); |
d287483d AK |
1677 | |
1678 | out_unlock: | |
e61290a4 | 1679 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 1680 | return r; |
1da177e4 LT |
1681 | } |
1682 | ||
1683 | int dm_resume(struct mapped_device *md) | |
1684 | { | |
cf222b37 | 1685 | int r = -EINVAL; |
cf222b37 | 1686 | struct dm_table *map = NULL; |
1da177e4 | 1687 | |
e61290a4 | 1688 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1689 | if (!dm_suspended(md)) |
cf222b37 | 1690 | goto out; |
cf222b37 AK |
1691 | |
1692 | map = dm_get_table(md); | |
2ca3310e | 1693 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1694 | goto out; |
1da177e4 | 1695 | |
8757b776 MB |
1696 | r = dm_table_resume_targets(map); |
1697 | if (r) | |
1698 | goto out; | |
2ca3310e | 1699 | |
9a1fb464 | 1700 | dm_queue_flush(md); |
2ca3310e AK |
1701 | |
1702 | unlock_fs(md); | |
1703 | ||
bfa152fa JN |
1704 | if (md->suspended_bdev) { |
1705 | bdput(md->suspended_bdev); | |
1706 | md->suspended_bdev = NULL; | |
1707 | } | |
e39e2e95 | 1708 | |
2ca3310e AK |
1709 | clear_bit(DMF_SUSPENDED, &md->flags); |
1710 | ||
1da177e4 | 1711 | dm_table_unplug_all(map); |
1da177e4 | 1712 | |
69267a30 | 1713 | dm_kobject_uevent(md); |
8560ed6f | 1714 | |
cf222b37 | 1715 | r = 0; |
2ca3310e | 1716 | |
cf222b37 AK |
1717 | out: |
1718 | dm_table_put(map); | |
e61290a4 | 1719 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 1720 | |
cf222b37 | 1721 | return r; |
1da177e4 LT |
1722 | } |
1723 | ||
1724 | /*----------------------------------------------------------------- | |
1725 | * Event notification. | |
1726 | *---------------------------------------------------------------*/ | |
69267a30 AK |
1727 | void dm_kobject_uevent(struct mapped_device *md) |
1728 | { | |
ed9e1982 | 1729 | kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE); |
69267a30 AK |
1730 | } |
1731 | ||
7a8c3d3b MA |
1732 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
1733 | { | |
1734 | return atomic_add_return(1, &md->uevent_seq); | |
1735 | } | |
1736 | ||
1da177e4 LT |
1737 | uint32_t dm_get_event_nr(struct mapped_device *md) |
1738 | { | |
1739 | return atomic_read(&md->event_nr); | |
1740 | } | |
1741 | ||
1742 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1743 | { | |
1744 | return wait_event_interruptible(md->eventq, | |
1745 | (event_nr != atomic_read(&md->event_nr))); | |
1746 | } | |
1747 | ||
7a8c3d3b MA |
1748 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
1749 | { | |
1750 | unsigned long flags; | |
1751 | ||
1752 | spin_lock_irqsave(&md->uevent_lock, flags); | |
1753 | list_add(elist, &md->uevent_list); | |
1754 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1755 | } | |
1756 | ||
1da177e4 LT |
1757 | /* |
1758 | * The gendisk is only valid as long as you have a reference | |
1759 | * count on 'md'. | |
1760 | */ | |
1761 | struct gendisk *dm_disk(struct mapped_device *md) | |
1762 | { | |
1763 | return md->disk; | |
1764 | } | |
1765 | ||
784aae73 MB |
1766 | struct kobject *dm_kobject(struct mapped_device *md) |
1767 | { | |
1768 | return &md->kobj; | |
1769 | } | |
1770 | ||
1771 | /* | |
1772 | * struct mapped_device should not be exported outside of dm.c | |
1773 | * so use this check to verify that kobj is part of md structure | |
1774 | */ | |
1775 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) | |
1776 | { | |
1777 | struct mapped_device *md; | |
1778 | ||
1779 | md = container_of(kobj, struct mapped_device, kobj); | |
1780 | if (&md->kobj != kobj) | |
1781 | return NULL; | |
1782 | ||
1783 | dm_get(md); | |
1784 | return md; | |
1785 | } | |
1786 | ||
1da177e4 LT |
1787 | int dm_suspended(struct mapped_device *md) |
1788 | { | |
1789 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1790 | } | |
1791 | ||
2e93ccc1 KU |
1792 | int dm_noflush_suspending(struct dm_target *ti) |
1793 | { | |
1794 | struct mapped_device *md = dm_table_get_md(ti->table); | |
1795 | int r = __noflush_suspending(md); | |
1796 | ||
1797 | dm_put(md); | |
1798 | ||
1799 | return r; | |
1800 | } | |
1801 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
1802 | ||
1da177e4 LT |
1803 | static struct block_device_operations dm_blk_dops = { |
1804 | .open = dm_blk_open, | |
1805 | .release = dm_blk_close, | |
aa129a22 | 1806 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1807 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1808 | .owner = THIS_MODULE |
1809 | }; | |
1810 | ||
1811 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1812 | ||
1813 | /* | |
1814 | * module hooks | |
1815 | */ | |
1816 | module_init(dm_init); | |
1817 | module_exit(dm_exit); | |
1818 | ||
1819 | module_param(major, uint, 0); | |
1820 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1821 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1822 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1823 | MODULE_LICENSE("GPL"); |