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> |
3f77316d | 22 | #include <linux/delay.h> |
55782138 LZ |
23 | |
24 | #include <trace/events/block.h> | |
1da177e4 | 25 | |
72d94861 AK |
26 | #define DM_MSG_PREFIX "core" |
27 | ||
60935eb2 MB |
28 | /* |
29 | * Cookies are numeric values sent with CHANGE and REMOVE | |
30 | * uevents while resuming, removing or renaming the device. | |
31 | */ | |
32 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" | |
33 | #define DM_COOKIE_LENGTH 24 | |
34 | ||
1da177e4 LT |
35 | static const char *_name = DM_NAME; |
36 | ||
37 | static unsigned int major = 0; | |
38 | static unsigned int _major = 0; | |
39 | ||
f32c10b0 | 40 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 | 41 | /* |
8fbf26ad | 42 | * For bio-based dm. |
1da177e4 LT |
43 | * One of these is allocated per bio. |
44 | */ | |
45 | struct dm_io { | |
46 | struct mapped_device *md; | |
47 | int error; | |
1da177e4 | 48 | atomic_t io_count; |
6ae2fa67 | 49 | struct bio *bio; |
3eaf840e | 50 | unsigned long start_time; |
f88fb981 | 51 | spinlock_t endio_lock; |
1da177e4 LT |
52 | }; |
53 | ||
54 | /* | |
8fbf26ad | 55 | * For bio-based dm. |
1da177e4 LT |
56 | * One of these is allocated per target within a bio. Hopefully |
57 | * this will be simplified out one day. | |
58 | */ | |
028867ac | 59 | struct dm_target_io { |
1da177e4 LT |
60 | struct dm_io *io; |
61 | struct dm_target *ti; | |
62 | union map_info info; | |
63 | }; | |
64 | ||
8fbf26ad KU |
65 | /* |
66 | * For request-based dm. | |
67 | * One of these is allocated per request. | |
68 | */ | |
69 | struct dm_rq_target_io { | |
70 | struct mapped_device *md; | |
71 | struct dm_target *ti; | |
72 | struct request *orig, clone; | |
73 | int error; | |
74 | union map_info info; | |
75 | }; | |
76 | ||
77 | /* | |
78 | * For request-based dm. | |
79 | * One of these is allocated per bio. | |
80 | */ | |
81 | struct dm_rq_clone_bio_info { | |
82 | struct bio *orig; | |
cec47e3d | 83 | struct dm_rq_target_io *tio; |
8fbf26ad KU |
84 | }; |
85 | ||
1da177e4 LT |
86 | union map_info *dm_get_mapinfo(struct bio *bio) |
87 | { | |
17b2f66f | 88 | if (bio && bio->bi_private) |
028867ac | 89 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 90 | return NULL; |
1da177e4 LT |
91 | } |
92 | ||
cec47e3d KU |
93 | union map_info *dm_get_rq_mapinfo(struct request *rq) |
94 | { | |
95 | if (rq && rq->end_io_data) | |
96 | return &((struct dm_rq_target_io *)rq->end_io_data)->info; | |
97 | return NULL; | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); | |
100 | ||
ba61fdd1 JM |
101 | #define MINOR_ALLOCED ((void *)-1) |
102 | ||
1da177e4 LT |
103 | /* |
104 | * Bits for the md->flags field. | |
105 | */ | |
1eb787ec | 106 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
1da177e4 | 107 | #define DMF_SUSPENDED 1 |
aa8d7c2f | 108 | #define DMF_FROZEN 2 |
fba9f90e | 109 | #define DMF_FREEING 3 |
5c6bd75d | 110 | #define DMF_DELETING 4 |
2e93ccc1 | 111 | #define DMF_NOFLUSH_SUSPENDING 5 |
1da177e4 | 112 | |
304f3f6a MB |
113 | /* |
114 | * Work processed by per-device workqueue. | |
115 | */ | |
1da177e4 | 116 | struct mapped_device { |
2ca3310e | 117 | struct rw_semaphore io_lock; |
e61290a4 | 118 | struct mutex suspend_lock; |
1da177e4 LT |
119 | rwlock_t map_lock; |
120 | atomic_t holders; | |
5c6bd75d | 121 | atomic_t open_count; |
1da177e4 LT |
122 | |
123 | unsigned long flags; | |
124 | ||
165125e1 | 125 | struct request_queue *queue; |
a5664dad | 126 | unsigned type; |
4a0b4ddf | 127 | /* Protect queue and type against concurrent access. */ |
a5664dad MS |
128 | struct mutex type_lock; |
129 | ||
1da177e4 | 130 | struct gendisk *disk; |
7e51f257 | 131 | char name[16]; |
1da177e4 LT |
132 | |
133 | void *interface_ptr; | |
134 | ||
135 | /* | |
136 | * A list of ios that arrived while we were suspended. | |
137 | */ | |
316d315b | 138 | atomic_t pending[2]; |
1da177e4 | 139 | wait_queue_head_t wait; |
53d5914f | 140 | struct work_struct work; |
74859364 | 141 | struct bio_list deferred; |
022c2611 | 142 | spinlock_t deferred_lock; |
1da177e4 | 143 | |
af7e466a | 144 | /* |
29e4013d | 145 | * Processing queue (flush) |
304f3f6a MB |
146 | */ |
147 | struct workqueue_struct *wq; | |
148 | ||
1da177e4 LT |
149 | /* |
150 | * The current mapping. | |
151 | */ | |
152 | struct dm_table *map; | |
153 | ||
154 | /* | |
155 | * io objects are allocated from here. | |
156 | */ | |
157 | mempool_t *io_pool; | |
158 | mempool_t *tio_pool; | |
159 | ||
9faf400f SB |
160 | struct bio_set *bs; |
161 | ||
1da177e4 LT |
162 | /* |
163 | * Event handling. | |
164 | */ | |
165 | atomic_t event_nr; | |
166 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
167 | atomic_t uevent_seq; |
168 | struct list_head uevent_list; | |
169 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
170 | |
171 | /* | |
172 | * freeze/thaw support require holding onto a super block | |
173 | */ | |
174 | struct super_block *frozen_sb; | |
db8fef4f | 175 | struct block_device *bdev; |
3ac51e74 DW |
176 | |
177 | /* forced geometry settings */ | |
178 | struct hd_geometry geometry; | |
784aae73 | 179 | |
cec47e3d KU |
180 | /* For saving the address of __make_request for request based dm */ |
181 | make_request_fn *saved_make_request_fn; | |
182 | ||
784aae73 MB |
183 | /* sysfs handle */ |
184 | struct kobject kobj; | |
52b1fd5a | 185 | |
d87f4c14 TH |
186 | /* zero-length flush that will be cloned and submitted to targets */ |
187 | struct bio flush_bio; | |
1da177e4 LT |
188 | }; |
189 | ||
e6ee8c0b KU |
190 | /* |
191 | * For mempools pre-allocation at the table loading time. | |
192 | */ | |
193 | struct dm_md_mempools { | |
194 | mempool_t *io_pool; | |
195 | mempool_t *tio_pool; | |
196 | struct bio_set *bs; | |
197 | }; | |
198 | ||
1da177e4 | 199 | #define MIN_IOS 256 |
e18b890b CL |
200 | static struct kmem_cache *_io_cache; |
201 | static struct kmem_cache *_tio_cache; | |
8fbf26ad KU |
202 | static struct kmem_cache *_rq_tio_cache; |
203 | static struct kmem_cache *_rq_bio_info_cache; | |
1da177e4 | 204 | |
1da177e4 LT |
205 | static int __init local_init(void) |
206 | { | |
51157b4a | 207 | int r = -ENOMEM; |
1da177e4 | 208 | |
1da177e4 | 209 | /* allocate a slab for the dm_ios */ |
028867ac | 210 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 211 | if (!_io_cache) |
51157b4a | 212 | return r; |
1da177e4 LT |
213 | |
214 | /* allocate a slab for the target ios */ | |
028867ac | 215 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
51157b4a KU |
216 | if (!_tio_cache) |
217 | goto out_free_io_cache; | |
1da177e4 | 218 | |
8fbf26ad KU |
219 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
220 | if (!_rq_tio_cache) | |
221 | goto out_free_tio_cache; | |
222 | ||
223 | _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0); | |
224 | if (!_rq_bio_info_cache) | |
225 | goto out_free_rq_tio_cache; | |
226 | ||
51e5b2bd | 227 | r = dm_uevent_init(); |
51157b4a | 228 | if (r) |
8fbf26ad | 229 | goto out_free_rq_bio_info_cache; |
51e5b2bd | 230 | |
1da177e4 LT |
231 | _major = major; |
232 | r = register_blkdev(_major, _name); | |
51157b4a KU |
233 | if (r < 0) |
234 | goto out_uevent_exit; | |
1da177e4 LT |
235 | |
236 | if (!_major) | |
237 | _major = r; | |
238 | ||
239 | return 0; | |
51157b4a KU |
240 | |
241 | out_uevent_exit: | |
242 | dm_uevent_exit(); | |
8fbf26ad KU |
243 | out_free_rq_bio_info_cache: |
244 | kmem_cache_destroy(_rq_bio_info_cache); | |
245 | out_free_rq_tio_cache: | |
246 | kmem_cache_destroy(_rq_tio_cache); | |
51157b4a KU |
247 | out_free_tio_cache: |
248 | kmem_cache_destroy(_tio_cache); | |
249 | out_free_io_cache: | |
250 | kmem_cache_destroy(_io_cache); | |
251 | ||
252 | return r; | |
1da177e4 LT |
253 | } |
254 | ||
255 | static void local_exit(void) | |
256 | { | |
8fbf26ad KU |
257 | kmem_cache_destroy(_rq_bio_info_cache); |
258 | kmem_cache_destroy(_rq_tio_cache); | |
1da177e4 LT |
259 | kmem_cache_destroy(_tio_cache); |
260 | kmem_cache_destroy(_io_cache); | |
00d59405 | 261 | unregister_blkdev(_major, _name); |
51e5b2bd | 262 | dm_uevent_exit(); |
1da177e4 LT |
263 | |
264 | _major = 0; | |
265 | ||
266 | DMINFO("cleaned up"); | |
267 | } | |
268 | ||
b9249e55 | 269 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
270 | local_init, |
271 | dm_target_init, | |
272 | dm_linear_init, | |
273 | dm_stripe_init, | |
952b3557 | 274 | dm_io_init, |
945fa4d2 | 275 | dm_kcopyd_init, |
1da177e4 LT |
276 | dm_interface_init, |
277 | }; | |
278 | ||
b9249e55 | 279 | static void (*_exits[])(void) = { |
1da177e4 LT |
280 | local_exit, |
281 | dm_target_exit, | |
282 | dm_linear_exit, | |
283 | dm_stripe_exit, | |
952b3557 | 284 | dm_io_exit, |
945fa4d2 | 285 | dm_kcopyd_exit, |
1da177e4 LT |
286 | dm_interface_exit, |
287 | }; | |
288 | ||
289 | static int __init dm_init(void) | |
290 | { | |
291 | const int count = ARRAY_SIZE(_inits); | |
292 | ||
293 | int r, i; | |
294 | ||
295 | for (i = 0; i < count; i++) { | |
296 | r = _inits[i](); | |
297 | if (r) | |
298 | goto bad; | |
299 | } | |
300 | ||
301 | return 0; | |
302 | ||
303 | bad: | |
304 | while (i--) | |
305 | _exits[i](); | |
306 | ||
307 | return r; | |
308 | } | |
309 | ||
310 | static void __exit dm_exit(void) | |
311 | { | |
312 | int i = ARRAY_SIZE(_exits); | |
313 | ||
314 | while (i--) | |
315 | _exits[i](); | |
316 | } | |
317 | ||
318 | /* | |
319 | * Block device functions | |
320 | */ | |
432a212c MA |
321 | int dm_deleting_md(struct mapped_device *md) |
322 | { | |
323 | return test_bit(DMF_DELETING, &md->flags); | |
324 | } | |
325 | ||
fe5f9f2c | 326 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
327 | { |
328 | struct mapped_device *md; | |
329 | ||
fba9f90e JM |
330 | spin_lock(&_minor_lock); |
331 | ||
fe5f9f2c | 332 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
333 | if (!md) |
334 | goto out; | |
335 | ||
5c6bd75d | 336 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 337 | dm_deleting_md(md)) { |
fba9f90e JM |
338 | md = NULL; |
339 | goto out; | |
340 | } | |
341 | ||
1da177e4 | 342 | dm_get(md); |
5c6bd75d | 343 | atomic_inc(&md->open_count); |
fba9f90e JM |
344 | |
345 | out: | |
346 | spin_unlock(&_minor_lock); | |
347 | ||
348 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
349 | } |
350 | ||
fe5f9f2c | 351 | static int dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 352 | { |
fe5f9f2c | 353 | struct mapped_device *md = disk->private_data; |
6e9624b8 | 354 | |
4a1aeb98 MB |
355 | spin_lock(&_minor_lock); |
356 | ||
5c6bd75d | 357 | atomic_dec(&md->open_count); |
1da177e4 | 358 | dm_put(md); |
4a1aeb98 MB |
359 | |
360 | spin_unlock(&_minor_lock); | |
6e9624b8 | 361 | |
1da177e4 LT |
362 | return 0; |
363 | } | |
364 | ||
5c6bd75d AK |
365 | int dm_open_count(struct mapped_device *md) |
366 | { | |
367 | return atomic_read(&md->open_count); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Guarantees nothing is using the device before it's deleted. | |
372 | */ | |
373 | int dm_lock_for_deletion(struct mapped_device *md) | |
374 | { | |
375 | int r = 0; | |
376 | ||
377 | spin_lock(&_minor_lock); | |
378 | ||
379 | if (dm_open_count(md)) | |
380 | r = -EBUSY; | |
381 | else | |
382 | set_bit(DMF_DELETING, &md->flags); | |
383 | ||
384 | spin_unlock(&_minor_lock); | |
385 | ||
386 | return r; | |
387 | } | |
388 | ||
3ac51e74 DW |
389 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
390 | { | |
391 | struct mapped_device *md = bdev->bd_disk->private_data; | |
392 | ||
393 | return dm_get_geometry(md, geo); | |
394 | } | |
395 | ||
fe5f9f2c | 396 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
397 | unsigned int cmd, unsigned long arg) |
398 | { | |
fe5f9f2c | 399 | struct mapped_device *md = bdev->bd_disk->private_data; |
7c666411 | 400 | struct dm_table *map = dm_get_live_table(md); |
aa129a22 MB |
401 | struct dm_target *tgt; |
402 | int r = -ENOTTY; | |
403 | ||
aa129a22 MB |
404 | if (!map || !dm_table_get_size(map)) |
405 | goto out; | |
406 | ||
407 | /* We only support devices that have a single target */ | |
408 | if (dm_table_get_num_targets(map) != 1) | |
409 | goto out; | |
410 | ||
411 | tgt = dm_table_get_target(map, 0); | |
412 | ||
4f186f8b | 413 | if (dm_suspended_md(md)) { |
aa129a22 MB |
414 | r = -EAGAIN; |
415 | goto out; | |
416 | } | |
417 | ||
418 | if (tgt->type->ioctl) | |
647b3d00 | 419 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
420 | |
421 | out: | |
422 | dm_table_put(map); | |
423 | ||
aa129a22 MB |
424 | return r; |
425 | } | |
426 | ||
028867ac | 427 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
428 | { |
429 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
430 | } | |
431 | ||
028867ac | 432 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
433 | { |
434 | mempool_free(io, md->io_pool); | |
435 | } | |
436 | ||
028867ac | 437 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
438 | { |
439 | mempool_free(tio, md->tio_pool); | |
440 | } | |
441 | ||
08885643 KU |
442 | static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md, |
443 | gfp_t gfp_mask) | |
cec47e3d | 444 | { |
08885643 | 445 | return mempool_alloc(md->tio_pool, gfp_mask); |
cec47e3d KU |
446 | } |
447 | ||
448 | static void free_rq_tio(struct dm_rq_target_io *tio) | |
449 | { | |
450 | mempool_free(tio, tio->md->tio_pool); | |
451 | } | |
452 | ||
453 | static struct dm_rq_clone_bio_info *alloc_bio_info(struct mapped_device *md) | |
454 | { | |
455 | return mempool_alloc(md->io_pool, GFP_ATOMIC); | |
456 | } | |
457 | ||
458 | static void free_bio_info(struct dm_rq_clone_bio_info *info) | |
459 | { | |
460 | mempool_free(info, info->tio->md->io_pool); | |
461 | } | |
462 | ||
90abb8c4 KU |
463 | static int md_in_flight(struct mapped_device *md) |
464 | { | |
465 | return atomic_read(&md->pending[READ]) + | |
466 | atomic_read(&md->pending[WRITE]); | |
467 | } | |
468 | ||
3eaf840e JNN |
469 | static void start_io_acct(struct dm_io *io) |
470 | { | |
471 | struct mapped_device *md = io->md; | |
c9959059 | 472 | int cpu; |
316d315b | 473 | int rw = bio_data_dir(io->bio); |
3eaf840e JNN |
474 | |
475 | io->start_time = jiffies; | |
476 | ||
074a7aca TH |
477 | cpu = part_stat_lock(); |
478 | part_round_stats(cpu, &dm_disk(md)->part0); | |
479 | part_stat_unlock(); | |
316d315b | 480 | dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]); |
3eaf840e JNN |
481 | } |
482 | ||
d221d2e7 | 483 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
484 | { |
485 | struct mapped_device *md = io->md; | |
486 | struct bio *bio = io->bio; | |
487 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 488 | int pending, cpu; |
3eaf840e JNN |
489 | int rw = bio_data_dir(bio); |
490 | ||
074a7aca TH |
491 | cpu = part_stat_lock(); |
492 | part_round_stats(cpu, &dm_disk(md)->part0); | |
493 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
494 | part_stat_unlock(); | |
3eaf840e | 495 | |
af7e466a MP |
496 | /* |
497 | * After this is decremented the bio must not be touched if it is | |
d87f4c14 | 498 | * a flush. |
af7e466a | 499 | */ |
316d315b NK |
500 | dm_disk(md)->part0.in_flight[rw] = pending = |
501 | atomic_dec_return(&md->pending[rw]); | |
502 | pending += atomic_read(&md->pending[rw^0x1]); | |
3eaf840e | 503 | |
d221d2e7 MP |
504 | /* nudge anyone waiting on suspend queue */ |
505 | if (!pending) | |
506 | wake_up(&md->wait); | |
3eaf840e JNN |
507 | } |
508 | ||
1da177e4 LT |
509 | /* |
510 | * Add the bio to the list of deferred io. | |
511 | */ | |
92c63902 | 512 | static void queue_io(struct mapped_device *md, struct bio *bio) |
1da177e4 | 513 | { |
05447420 | 514 | unsigned long flags; |
1da177e4 | 515 | |
05447420 | 516 | spin_lock_irqsave(&md->deferred_lock, flags); |
1da177e4 | 517 | bio_list_add(&md->deferred, bio); |
05447420 | 518 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
6a8736d1 | 519 | queue_work(md->wq, &md->work); |
1da177e4 LT |
520 | } |
521 | ||
522 | /* | |
523 | * Everyone (including functions in this file), should use this | |
524 | * function to access the md->map field, and make sure they call | |
525 | * dm_table_put() when finished. | |
526 | */ | |
7c666411 | 527 | struct dm_table *dm_get_live_table(struct mapped_device *md) |
1da177e4 LT |
528 | { |
529 | struct dm_table *t; | |
523d9297 | 530 | unsigned long flags; |
1da177e4 | 531 | |
523d9297 | 532 | read_lock_irqsave(&md->map_lock, flags); |
1da177e4 LT |
533 | t = md->map; |
534 | if (t) | |
535 | dm_table_get(t); | |
523d9297 | 536 | read_unlock_irqrestore(&md->map_lock, flags); |
1da177e4 LT |
537 | |
538 | return t; | |
539 | } | |
540 | ||
3ac51e74 DW |
541 | /* |
542 | * Get the geometry associated with a dm device | |
543 | */ | |
544 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
545 | { | |
546 | *geo = md->geometry; | |
547 | ||
548 | return 0; | |
549 | } | |
550 | ||
551 | /* | |
552 | * Set the geometry of a device. | |
553 | */ | |
554 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
555 | { | |
556 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
557 | ||
558 | if (geo->start > sz) { | |
559 | DMWARN("Start sector is beyond the geometry limits."); | |
560 | return -EINVAL; | |
561 | } | |
562 | ||
563 | md->geometry = *geo; | |
564 | ||
565 | return 0; | |
566 | } | |
567 | ||
1da177e4 LT |
568 | /*----------------------------------------------------------------- |
569 | * CRUD START: | |
570 | * A more elegant soln is in the works that uses the queue | |
571 | * merge fn, unfortunately there are a couple of changes to | |
572 | * the block layer that I want to make for this. So in the | |
573 | * interests of getting something for people to use I give | |
574 | * you this clearly demarcated crap. | |
575 | *---------------------------------------------------------------*/ | |
576 | ||
2e93ccc1 KU |
577 | static int __noflush_suspending(struct mapped_device *md) |
578 | { | |
579 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
580 | } | |
581 | ||
1da177e4 LT |
582 | /* |
583 | * Decrements the number of outstanding ios that a bio has been | |
584 | * cloned into, completing the original io if necc. | |
585 | */ | |
858119e1 | 586 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 587 | { |
2e93ccc1 | 588 | unsigned long flags; |
b35f8caa MB |
589 | int io_error; |
590 | struct bio *bio; | |
591 | struct mapped_device *md = io->md; | |
2e93ccc1 KU |
592 | |
593 | /* Push-back supersedes any I/O errors */ | |
f88fb981 KU |
594 | if (unlikely(error)) { |
595 | spin_lock_irqsave(&io->endio_lock, flags); | |
596 | if (!(io->error > 0 && __noflush_suspending(md))) | |
597 | io->error = error; | |
598 | spin_unlock_irqrestore(&io->endio_lock, flags); | |
599 | } | |
1da177e4 LT |
600 | |
601 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
602 | if (io->error == DM_ENDIO_REQUEUE) { |
603 | /* | |
604 | * Target requested pushing back the I/O. | |
2e93ccc1 | 605 | */ |
022c2611 | 606 | spin_lock_irqsave(&md->deferred_lock, flags); |
6a8736d1 TH |
607 | if (__noflush_suspending(md)) |
608 | bio_list_add_head(&md->deferred, io->bio); | |
609 | else | |
2e93ccc1 KU |
610 | /* noflush suspend was interrupted. */ |
611 | io->error = -EIO; | |
022c2611 | 612 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
2e93ccc1 KU |
613 | } |
614 | ||
b35f8caa MB |
615 | io_error = io->error; |
616 | bio = io->bio; | |
6a8736d1 TH |
617 | end_io_acct(io); |
618 | free_io(md, io); | |
619 | ||
620 | if (io_error == DM_ENDIO_REQUEUE) | |
621 | return; | |
2e93ccc1 | 622 | |
b372d360 | 623 | if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) { |
af7e466a | 624 | /* |
6a8736d1 TH |
625 | * Preflush done for flush with data, reissue |
626 | * without REQ_FLUSH. | |
af7e466a | 627 | */ |
6a8736d1 TH |
628 | bio->bi_rw &= ~REQ_FLUSH; |
629 | queue_io(md, bio); | |
af7e466a | 630 | } else { |
b372d360 | 631 | /* done with normal IO or empty flush */ |
b7908c10 | 632 | trace_block_bio_complete(md->queue, bio, io_error); |
b372d360 | 633 | bio_endio(bio, io_error); |
b35f8caa | 634 | } |
1da177e4 LT |
635 | } |
636 | } | |
637 | ||
6712ecf8 | 638 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
639 | { |
640 | int r = 0; | |
028867ac | 641 | struct dm_target_io *tio = bio->bi_private; |
b35f8caa | 642 | struct dm_io *io = tio->io; |
9faf400f | 643 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
644 | dm_endio_fn endio = tio->ti->type->end_io; |
645 | ||
1da177e4 LT |
646 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
647 | error = -EIO; | |
648 | ||
649 | if (endio) { | |
650 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
651 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
652 | /* | |
653 | * error and requeue request are handled | |
654 | * in dec_pending(). | |
655 | */ | |
1da177e4 | 656 | error = r; |
45cbcd79 KU |
657 | else if (r == DM_ENDIO_INCOMPLETE) |
658 | /* The target will handle the io */ | |
6712ecf8 | 659 | return; |
45cbcd79 KU |
660 | else if (r) { |
661 | DMWARN("unimplemented target endio return value: %d", r); | |
662 | BUG(); | |
663 | } | |
1da177e4 LT |
664 | } |
665 | ||
9faf400f SB |
666 | /* |
667 | * Store md for cleanup instead of tio which is about to get freed. | |
668 | */ | |
669 | bio->bi_private = md->bs; | |
670 | ||
9faf400f | 671 | free_tio(md, tio); |
b35f8caa MB |
672 | bio_put(bio); |
673 | dec_pending(io, error); | |
1da177e4 LT |
674 | } |
675 | ||
cec47e3d KU |
676 | /* |
677 | * Partial completion handling for request-based dm | |
678 | */ | |
679 | static void end_clone_bio(struct bio *clone, int error) | |
680 | { | |
681 | struct dm_rq_clone_bio_info *info = clone->bi_private; | |
682 | struct dm_rq_target_io *tio = info->tio; | |
683 | struct bio *bio = info->orig; | |
684 | unsigned int nr_bytes = info->orig->bi_size; | |
685 | ||
686 | bio_put(clone); | |
687 | ||
688 | if (tio->error) | |
689 | /* | |
690 | * An error has already been detected on the request. | |
691 | * Once error occurred, just let clone->end_io() handle | |
692 | * the remainder. | |
693 | */ | |
694 | return; | |
695 | else if (error) { | |
696 | /* | |
697 | * Don't notice the error to the upper layer yet. | |
698 | * The error handling decision is made by the target driver, | |
699 | * when the request is completed. | |
700 | */ | |
701 | tio->error = error; | |
702 | return; | |
703 | } | |
704 | ||
705 | /* | |
706 | * I/O for the bio successfully completed. | |
707 | * Notice the data completion to the upper layer. | |
708 | */ | |
709 | ||
710 | /* | |
711 | * bios are processed from the head of the list. | |
712 | * So the completing bio should always be rq->bio. | |
713 | * If it's not, something wrong is happening. | |
714 | */ | |
715 | if (tio->orig->bio != bio) | |
716 | DMERR("bio completion is going in the middle of the request"); | |
717 | ||
718 | /* | |
719 | * Update the original request. | |
720 | * Do not use blk_end_request() here, because it may complete | |
721 | * the original request before the clone, and break the ordering. | |
722 | */ | |
723 | blk_update_request(tio->orig, 0, nr_bytes); | |
724 | } | |
725 | ||
726 | /* | |
727 | * Don't touch any member of the md after calling this function because | |
728 | * the md may be freed in dm_put() at the end of this function. | |
729 | * Or do dm_get() before calling this function and dm_put() later. | |
730 | */ | |
b4324fee | 731 | static void rq_completed(struct mapped_device *md, int rw, int run_queue) |
cec47e3d | 732 | { |
b4324fee | 733 | atomic_dec(&md->pending[rw]); |
cec47e3d KU |
734 | |
735 | /* nudge anyone waiting on suspend queue */ | |
b4324fee | 736 | if (!md_in_flight(md)) |
cec47e3d KU |
737 | wake_up(&md->wait); |
738 | ||
739 | if (run_queue) | |
b4324fee | 740 | blk_run_queue(md->queue); |
cec47e3d KU |
741 | |
742 | /* | |
743 | * dm_put() must be at the end of this function. See the comment above | |
744 | */ | |
745 | dm_put(md); | |
746 | } | |
747 | ||
a77e28c7 KU |
748 | static void free_rq_clone(struct request *clone) |
749 | { | |
750 | struct dm_rq_target_io *tio = clone->end_io_data; | |
751 | ||
752 | blk_rq_unprep_clone(clone); | |
753 | free_rq_tio(tio); | |
754 | } | |
755 | ||
980691e5 KU |
756 | /* |
757 | * Complete the clone and the original request. | |
758 | * Must be called without queue lock. | |
759 | */ | |
760 | static void dm_end_request(struct request *clone, int error) | |
761 | { | |
762 | int rw = rq_data_dir(clone); | |
763 | struct dm_rq_target_io *tio = clone->end_io_data; | |
764 | struct mapped_device *md = tio->md; | |
765 | struct request *rq = tio->orig; | |
766 | ||
29e4013d | 767 | if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { |
980691e5 KU |
768 | rq->errors = clone->errors; |
769 | rq->resid_len = clone->resid_len; | |
770 | ||
771 | if (rq->sense) | |
772 | /* | |
773 | * We are using the sense buffer of the original | |
774 | * request. | |
775 | * So setting the length of the sense data is enough. | |
776 | */ | |
777 | rq->sense_len = clone->sense_len; | |
778 | } | |
779 | ||
780 | free_rq_clone(clone); | |
29e4013d TH |
781 | blk_end_request_all(rq, error); |
782 | rq_completed(md, rw, true); | |
980691e5 KU |
783 | } |
784 | ||
cec47e3d KU |
785 | static void dm_unprep_request(struct request *rq) |
786 | { | |
787 | struct request *clone = rq->special; | |
cec47e3d KU |
788 | |
789 | rq->special = NULL; | |
790 | rq->cmd_flags &= ~REQ_DONTPREP; | |
791 | ||
a77e28c7 | 792 | free_rq_clone(clone); |
cec47e3d KU |
793 | } |
794 | ||
795 | /* | |
796 | * Requeue the original request of a clone. | |
797 | */ | |
798 | void dm_requeue_unmapped_request(struct request *clone) | |
799 | { | |
b4324fee | 800 | int rw = rq_data_dir(clone); |
cec47e3d KU |
801 | struct dm_rq_target_io *tio = clone->end_io_data; |
802 | struct mapped_device *md = tio->md; | |
803 | struct request *rq = tio->orig; | |
804 | struct request_queue *q = rq->q; | |
805 | unsigned long flags; | |
806 | ||
807 | dm_unprep_request(rq); | |
808 | ||
809 | spin_lock_irqsave(q->queue_lock, flags); | |
cec47e3d KU |
810 | blk_requeue_request(q, rq); |
811 | spin_unlock_irqrestore(q->queue_lock, flags); | |
812 | ||
b4324fee | 813 | rq_completed(md, rw, 0); |
cec47e3d KU |
814 | } |
815 | EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request); | |
816 | ||
817 | static void __stop_queue(struct request_queue *q) | |
818 | { | |
819 | blk_stop_queue(q); | |
820 | } | |
821 | ||
822 | static void stop_queue(struct request_queue *q) | |
823 | { | |
824 | unsigned long flags; | |
825 | ||
826 | spin_lock_irqsave(q->queue_lock, flags); | |
827 | __stop_queue(q); | |
828 | spin_unlock_irqrestore(q->queue_lock, flags); | |
829 | } | |
830 | ||
831 | static void __start_queue(struct request_queue *q) | |
832 | { | |
833 | if (blk_queue_stopped(q)) | |
834 | blk_start_queue(q); | |
835 | } | |
836 | ||
837 | static void start_queue(struct request_queue *q) | |
838 | { | |
839 | unsigned long flags; | |
840 | ||
841 | spin_lock_irqsave(q->queue_lock, flags); | |
842 | __start_queue(q); | |
843 | spin_unlock_irqrestore(q->queue_lock, flags); | |
844 | } | |
845 | ||
11a68244 | 846 | static void dm_done(struct request *clone, int error, bool mapped) |
cec47e3d | 847 | { |
11a68244 | 848 | int r = error; |
cec47e3d KU |
849 | struct dm_rq_target_io *tio = clone->end_io_data; |
850 | dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io; | |
cec47e3d | 851 | |
11a68244 KU |
852 | if (mapped && rq_end_io) |
853 | r = rq_end_io(tio->ti, clone, error, &tio->info); | |
cec47e3d | 854 | |
11a68244 | 855 | if (r <= 0) |
cec47e3d | 856 | /* The target wants to complete the I/O */ |
11a68244 KU |
857 | dm_end_request(clone, r); |
858 | else if (r == DM_ENDIO_INCOMPLETE) | |
cec47e3d KU |
859 | /* The target will handle the I/O */ |
860 | return; | |
11a68244 | 861 | else if (r == DM_ENDIO_REQUEUE) |
cec47e3d KU |
862 | /* The target wants to requeue the I/O */ |
863 | dm_requeue_unmapped_request(clone); | |
864 | else { | |
11a68244 | 865 | DMWARN("unimplemented target endio return value: %d", r); |
cec47e3d KU |
866 | BUG(); |
867 | } | |
868 | } | |
869 | ||
11a68244 KU |
870 | /* |
871 | * Request completion handler for request-based dm | |
872 | */ | |
873 | static void dm_softirq_done(struct request *rq) | |
874 | { | |
875 | bool mapped = true; | |
876 | struct request *clone = rq->completion_data; | |
877 | struct dm_rq_target_io *tio = clone->end_io_data; | |
878 | ||
879 | if (rq->cmd_flags & REQ_FAILED) | |
880 | mapped = false; | |
881 | ||
882 | dm_done(clone, tio->error, mapped); | |
883 | } | |
884 | ||
cec47e3d KU |
885 | /* |
886 | * Complete the clone and the original request with the error status | |
887 | * through softirq context. | |
888 | */ | |
889 | static void dm_complete_request(struct request *clone, int error) | |
890 | { | |
891 | struct dm_rq_target_io *tio = clone->end_io_data; | |
892 | struct request *rq = tio->orig; | |
893 | ||
894 | tio->error = error; | |
895 | rq->completion_data = clone; | |
896 | blk_complete_request(rq); | |
897 | } | |
898 | ||
899 | /* | |
900 | * Complete the not-mapped clone and the original request with the error status | |
901 | * through softirq context. | |
902 | * Target's rq_end_io() function isn't called. | |
903 | * This may be used when the target's map_rq() function fails. | |
904 | */ | |
905 | void dm_kill_unmapped_request(struct request *clone, int error) | |
906 | { | |
907 | struct dm_rq_target_io *tio = clone->end_io_data; | |
908 | struct request *rq = tio->orig; | |
909 | ||
910 | rq->cmd_flags |= REQ_FAILED; | |
911 | dm_complete_request(clone, error); | |
912 | } | |
913 | EXPORT_SYMBOL_GPL(dm_kill_unmapped_request); | |
914 | ||
915 | /* | |
916 | * Called with the queue lock held | |
917 | */ | |
918 | static void end_clone_request(struct request *clone, int error) | |
919 | { | |
920 | /* | |
921 | * For just cleaning up the information of the queue in which | |
922 | * the clone was dispatched. | |
923 | * The clone is *NOT* freed actually here because it is alloced from | |
924 | * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags. | |
925 | */ | |
926 | __blk_put_request(clone->q, clone); | |
927 | ||
928 | /* | |
929 | * Actual request completion is done in a softirq context which doesn't | |
930 | * hold the queue lock. Otherwise, deadlock could occur because: | |
931 | * - another request may be submitted by the upper level driver | |
932 | * of the stacking during the completion | |
933 | * - the submission which requires queue lock may be done | |
934 | * against this queue | |
935 | */ | |
936 | dm_complete_request(clone, error); | |
937 | } | |
938 | ||
56a67df7 MS |
939 | /* |
940 | * Return maximum size of I/O possible at the supplied sector up to the current | |
941 | * target boundary. | |
942 | */ | |
943 | static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti) | |
944 | { | |
945 | sector_t target_offset = dm_target_offset(ti, sector); | |
946 | ||
947 | return ti->len - target_offset; | |
948 | } | |
949 | ||
950 | static sector_t max_io_len(sector_t sector, struct dm_target *ti) | |
1da177e4 | 951 | { |
56a67df7 | 952 | sector_t len = max_io_len_target_boundary(sector, ti); |
1da177e4 LT |
953 | |
954 | /* | |
955 | * Does the target need to split even further ? | |
956 | */ | |
957 | if (ti->split_io) { | |
958 | sector_t boundary; | |
56a67df7 | 959 | sector_t offset = dm_target_offset(ti, sector); |
1da177e4 LT |
960 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) |
961 | - offset; | |
962 | if (len > boundary) | |
963 | len = boundary; | |
964 | } | |
965 | ||
966 | return len; | |
967 | } | |
968 | ||
969 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 970 | struct dm_target_io *tio) |
1da177e4 LT |
971 | { |
972 | int r; | |
2056a782 | 973 | sector_t sector; |
9faf400f | 974 | struct mapped_device *md; |
1da177e4 | 975 | |
1da177e4 LT |
976 | clone->bi_end_io = clone_endio; |
977 | clone->bi_private = tio; | |
978 | ||
979 | /* | |
980 | * Map the clone. If r == 0 we don't need to do | |
981 | * anything, the target has assumed ownership of | |
982 | * this io. | |
983 | */ | |
984 | atomic_inc(&tio->io->io_count); | |
2056a782 | 985 | sector = clone->bi_sector; |
1da177e4 | 986 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 987 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 988 | /* the bio has been remapped so dispatch it */ |
2056a782 | 989 | |
d07335e5 MS |
990 | trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone, |
991 | tio->io->bio->bi_bdev->bd_dev, sector); | |
2056a782 | 992 | |
1da177e4 | 993 | generic_make_request(clone); |
2e93ccc1 KU |
994 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
995 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
996 | md = tio->io->md; |
997 | dec_pending(tio->io, r); | |
998 | /* | |
999 | * Store bio_set for cleanup. | |
1000 | */ | |
1001 | clone->bi_private = md->bs; | |
1da177e4 | 1002 | bio_put(clone); |
9faf400f | 1003 | free_tio(md, tio); |
45cbcd79 KU |
1004 | } else if (r) { |
1005 | DMWARN("unimplemented target map return value: %d", r); | |
1006 | BUG(); | |
1da177e4 LT |
1007 | } |
1008 | } | |
1009 | ||
1010 | struct clone_info { | |
1011 | struct mapped_device *md; | |
1012 | struct dm_table *map; | |
1013 | struct bio *bio; | |
1014 | struct dm_io *io; | |
1015 | sector_t sector; | |
1016 | sector_t sector_count; | |
1017 | unsigned short idx; | |
1018 | }; | |
1019 | ||
3676347a PO |
1020 | static void dm_bio_destructor(struct bio *bio) |
1021 | { | |
9faf400f SB |
1022 | struct bio_set *bs = bio->bi_private; |
1023 | ||
1024 | bio_free(bio, bs); | |
3676347a PO |
1025 | } |
1026 | ||
1da177e4 | 1027 | /* |
d87f4c14 | 1028 | * Creates a little bio that just does part of a bvec. |
1da177e4 LT |
1029 | */ |
1030 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
1031 | unsigned short idx, unsigned int offset, | |
9faf400f | 1032 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
1033 | { |
1034 | struct bio *clone; | |
1035 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
1036 | ||
9faf400f | 1037 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 1038 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
1039 | *clone->bi_io_vec = *bv; |
1040 | ||
1041 | clone->bi_sector = sector; | |
1042 | clone->bi_bdev = bio->bi_bdev; | |
d87f4c14 | 1043 | clone->bi_rw = bio->bi_rw; |
1da177e4 LT |
1044 | clone->bi_vcnt = 1; |
1045 | clone->bi_size = to_bytes(len); | |
1046 | clone->bi_io_vec->bv_offset = offset; | |
1047 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 1048 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 | 1049 | |
9c47008d | 1050 | if (bio_integrity(bio)) { |
7878cba9 | 1051 | bio_integrity_clone(clone, bio, GFP_NOIO, bs); |
9c47008d MP |
1052 | bio_integrity_trim(clone, |
1053 | bio_sector_offset(bio, idx, offset), len); | |
1054 | } | |
1055 | ||
1da177e4 LT |
1056 | return clone; |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * Creates a bio that consists of range of complete bvecs. | |
1061 | */ | |
1062 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
1063 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 1064 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
1065 | { |
1066 | struct bio *clone; | |
1067 | ||
9faf400f SB |
1068 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
1069 | __bio_clone(clone, bio); | |
1070 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
1071 | clone->bi_sector = sector; |
1072 | clone->bi_idx = idx; | |
1073 | clone->bi_vcnt = idx + bv_count; | |
1074 | clone->bi_size = to_bytes(len); | |
1075 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
1076 | ||
9c47008d | 1077 | if (bio_integrity(bio)) { |
7878cba9 | 1078 | bio_integrity_clone(clone, bio, GFP_NOIO, bs); |
9c47008d MP |
1079 | |
1080 | if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) | |
1081 | bio_integrity_trim(clone, | |
1082 | bio_sector_offset(bio, idx, 0), len); | |
1083 | } | |
1084 | ||
1da177e4 LT |
1085 | return clone; |
1086 | } | |
1087 | ||
9015df24 AK |
1088 | static struct dm_target_io *alloc_tio(struct clone_info *ci, |
1089 | struct dm_target *ti) | |
f9ab94ce | 1090 | { |
9015df24 | 1091 | struct dm_target_io *tio = mempool_alloc(ci->md->tio_pool, GFP_NOIO); |
f9ab94ce MP |
1092 | |
1093 | tio->io = ci->io; | |
1094 | tio->ti = ti; | |
f9ab94ce | 1095 | memset(&tio->info, 0, sizeof(tio->info)); |
9015df24 AK |
1096 | |
1097 | return tio; | |
1098 | } | |
1099 | ||
06a426ce | 1100 | static void __issue_target_request(struct clone_info *ci, struct dm_target *ti, |
a79245b3 | 1101 | unsigned request_nr, sector_t len) |
9015df24 AK |
1102 | { |
1103 | struct dm_target_io *tio = alloc_tio(ci, ti); | |
1104 | struct bio *clone; | |
1105 | ||
57cba5d3 | 1106 | tio->info.target_request_nr = request_nr; |
f9ab94ce | 1107 | |
06a426ce MS |
1108 | /* |
1109 | * Discard requests require the bio's inline iovecs be initialized. | |
1110 | * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush | |
1111 | * and discard, so no need for concern about wasted bvec allocations. | |
1112 | */ | |
1113 | clone = bio_alloc_bioset(GFP_NOIO, ci->bio->bi_max_vecs, ci->md->bs); | |
f9ab94ce MP |
1114 | __bio_clone(clone, ci->bio); |
1115 | clone->bi_destructor = dm_bio_destructor; | |
a79245b3 MS |
1116 | if (len) { |
1117 | clone->bi_sector = ci->sector; | |
1118 | clone->bi_size = to_bytes(len); | |
1119 | } | |
f9ab94ce MP |
1120 | |
1121 | __map_bio(ti, clone, tio); | |
1122 | } | |
1123 | ||
06a426ce | 1124 | static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, |
a79245b3 | 1125 | unsigned num_requests, sector_t len) |
06a426ce MS |
1126 | { |
1127 | unsigned request_nr; | |
1128 | ||
1129 | for (request_nr = 0; request_nr < num_requests; request_nr++) | |
a79245b3 | 1130 | __issue_target_request(ci, ti, request_nr, len); |
06a426ce MS |
1131 | } |
1132 | ||
b372d360 | 1133 | static int __clone_and_map_empty_flush(struct clone_info *ci) |
f9ab94ce | 1134 | { |
06a426ce | 1135 | unsigned target_nr = 0; |
f9ab94ce MP |
1136 | struct dm_target *ti; |
1137 | ||
b372d360 | 1138 | BUG_ON(bio_has_data(ci->bio)); |
f9ab94ce | 1139 | while ((ti = dm_table_get_target(ci->map, target_nr++))) |
a79245b3 | 1140 | __issue_target_requests(ci, ti, ti->num_flush_requests, 0); |
f9ab94ce | 1141 | |
f9ab94ce MP |
1142 | return 0; |
1143 | } | |
1144 | ||
5ae89a87 MS |
1145 | /* |
1146 | * Perform all io with a single clone. | |
1147 | */ | |
1148 | static void __clone_and_map_simple(struct clone_info *ci, struct dm_target *ti) | |
1149 | { | |
1150 | struct bio *clone, *bio = ci->bio; | |
1151 | struct dm_target_io *tio; | |
1152 | ||
1153 | tio = alloc_tio(ci, ti); | |
1154 | clone = clone_bio(bio, ci->sector, ci->idx, | |
1155 | bio->bi_vcnt - ci->idx, ci->sector_count, | |
1156 | ci->md->bs); | |
1157 | __map_bio(ti, clone, tio); | |
1158 | ci->sector_count = 0; | |
1159 | } | |
1160 | ||
1161 | static int __clone_and_map_discard(struct clone_info *ci) | |
1162 | { | |
1163 | struct dm_target *ti; | |
a79245b3 | 1164 | sector_t len; |
5ae89a87 | 1165 | |
a79245b3 MS |
1166 | do { |
1167 | ti = dm_table_find_target(ci->map, ci->sector); | |
1168 | if (!dm_target_is_valid(ti)) | |
1169 | return -EIO; | |
5ae89a87 | 1170 | |
5ae89a87 | 1171 | /* |
a79245b3 MS |
1172 | * Even though the device advertised discard support, |
1173 | * reconfiguration might have changed that since the | |
1174 | * check was performed. | |
5ae89a87 | 1175 | */ |
a79245b3 MS |
1176 | if (!ti->num_discard_requests) |
1177 | return -EOPNOTSUPP; | |
5ae89a87 | 1178 | |
a79245b3 | 1179 | len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti)); |
06a426ce | 1180 | |
a79245b3 MS |
1181 | __issue_target_requests(ci, ti, ti->num_discard_requests, len); |
1182 | ||
1183 | ci->sector += len; | |
1184 | } while (ci->sector_count -= len); | |
5ae89a87 MS |
1185 | |
1186 | return 0; | |
1187 | } | |
1188 | ||
512875bd | 1189 | static int __clone_and_map(struct clone_info *ci) |
1da177e4 LT |
1190 | { |
1191 | struct bio *clone, *bio = ci->bio; | |
512875bd JN |
1192 | struct dm_target *ti; |
1193 | sector_t len = 0, max; | |
028867ac | 1194 | struct dm_target_io *tio; |
1da177e4 | 1195 | |
5ae89a87 MS |
1196 | if (unlikely(bio->bi_rw & REQ_DISCARD)) |
1197 | return __clone_and_map_discard(ci); | |
1198 | ||
512875bd JN |
1199 | ti = dm_table_find_target(ci->map, ci->sector); |
1200 | if (!dm_target_is_valid(ti)) | |
1201 | return -EIO; | |
1202 | ||
56a67df7 | 1203 | max = max_io_len(ci->sector, ti); |
512875bd | 1204 | |
1da177e4 LT |
1205 | if (ci->sector_count <= max) { |
1206 | /* | |
1207 | * Optimise for the simple case where we can do all of | |
1208 | * the remaining io with a single clone. | |
1209 | */ | |
5ae89a87 | 1210 | __clone_and_map_simple(ci, ti); |
1da177e4 LT |
1211 | |
1212 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
1213 | /* | |
1214 | * There are some bvecs that don't span targets. | |
1215 | * Do as many of these as possible. | |
1216 | */ | |
1217 | int i; | |
1218 | sector_t remaining = max; | |
1219 | sector_t bv_len; | |
1220 | ||
1221 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
1222 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
1223 | ||
1224 | if (bv_len > remaining) | |
1225 | break; | |
1226 | ||
1227 | remaining -= bv_len; | |
1228 | len += bv_len; | |
1229 | } | |
1230 | ||
5ae89a87 | 1231 | tio = alloc_tio(ci, ti); |
9faf400f SB |
1232 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
1233 | ci->md->bs); | |
1da177e4 LT |
1234 | __map_bio(ti, clone, tio); |
1235 | ||
1236 | ci->sector += len; | |
1237 | ci->sector_count -= len; | |
1238 | ci->idx = i; | |
1239 | ||
1240 | } else { | |
1241 | /* | |
d2044a94 | 1242 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
1243 | */ |
1244 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
1245 | sector_t remaining = to_sector(bv->bv_len); |
1246 | unsigned int offset = 0; | |
1da177e4 | 1247 | |
d2044a94 AK |
1248 | do { |
1249 | if (offset) { | |
1250 | ti = dm_table_find_target(ci->map, ci->sector); | |
512875bd JN |
1251 | if (!dm_target_is_valid(ti)) |
1252 | return -EIO; | |
1253 | ||
56a67df7 | 1254 | max = max_io_len(ci->sector, ti); |
d2044a94 AK |
1255 | } |
1256 | ||
1257 | len = min(remaining, max); | |
1258 | ||
5ae89a87 | 1259 | tio = alloc_tio(ci, ti); |
d2044a94 | 1260 | clone = split_bvec(bio, ci->sector, ci->idx, |
9faf400f SB |
1261 | bv->bv_offset + offset, len, |
1262 | ci->md->bs); | |
d2044a94 AK |
1263 | |
1264 | __map_bio(ti, clone, tio); | |
1265 | ||
1266 | ci->sector += len; | |
1267 | ci->sector_count -= len; | |
1268 | offset += to_bytes(len); | |
1269 | } while (remaining -= len); | |
1da177e4 | 1270 | |
1da177e4 LT |
1271 | ci->idx++; |
1272 | } | |
512875bd JN |
1273 | |
1274 | return 0; | |
1da177e4 LT |
1275 | } |
1276 | ||
1277 | /* | |
8a53c28d | 1278 | * Split the bio into several clones and submit it to targets. |
1da177e4 | 1279 | */ |
f0b9a450 | 1280 | static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) |
1da177e4 LT |
1281 | { |
1282 | struct clone_info ci; | |
512875bd | 1283 | int error = 0; |
1da177e4 | 1284 | |
7c666411 | 1285 | ci.map = dm_get_live_table(md); |
f0b9a450 | 1286 | if (unlikely(!ci.map)) { |
6a8736d1 | 1287 | bio_io_error(bio); |
f0b9a450 MP |
1288 | return; |
1289 | } | |
692d0eb9 | 1290 | |
1da177e4 | 1291 | ci.md = md; |
1da177e4 LT |
1292 | ci.io = alloc_io(md); |
1293 | ci.io->error = 0; | |
1294 | atomic_set(&ci.io->io_count, 1); | |
1295 | ci.io->bio = bio; | |
1296 | ci.io->md = md; | |
f88fb981 | 1297 | spin_lock_init(&ci.io->endio_lock); |
1da177e4 | 1298 | ci.sector = bio->bi_sector; |
1da177e4 LT |
1299 | ci.idx = bio->bi_idx; |
1300 | ||
3eaf840e | 1301 | start_io_acct(ci.io); |
b372d360 MS |
1302 | if (bio->bi_rw & REQ_FLUSH) { |
1303 | ci.bio = &ci.md->flush_bio; | |
1304 | ci.sector_count = 0; | |
1305 | error = __clone_and_map_empty_flush(&ci); | |
1306 | /* dec_pending submits any data associated with flush */ | |
1307 | } else { | |
6a8736d1 | 1308 | ci.bio = bio; |
d87f4c14 | 1309 | ci.sector_count = bio_sectors(bio); |
b372d360 | 1310 | while (ci.sector_count && !error) |
d87f4c14 | 1311 | error = __clone_and_map(&ci); |
d87f4c14 | 1312 | } |
1da177e4 LT |
1313 | |
1314 | /* drop the extra reference count */ | |
512875bd | 1315 | dec_pending(ci.io, error); |
1da177e4 LT |
1316 | dm_table_put(ci.map); |
1317 | } | |
1318 | /*----------------------------------------------------------------- | |
1319 | * CRUD END | |
1320 | *---------------------------------------------------------------*/ | |
1321 | ||
f6fccb12 MB |
1322 | static int dm_merge_bvec(struct request_queue *q, |
1323 | struct bvec_merge_data *bvm, | |
1324 | struct bio_vec *biovec) | |
1325 | { | |
1326 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1327 | struct dm_table *map = dm_get_live_table(md); |
f6fccb12 MB |
1328 | struct dm_target *ti; |
1329 | sector_t max_sectors; | |
5037108a | 1330 | int max_size = 0; |
f6fccb12 MB |
1331 | |
1332 | if (unlikely(!map)) | |
5037108a | 1333 | goto out; |
f6fccb12 MB |
1334 | |
1335 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac MP |
1336 | if (!dm_target_is_valid(ti)) |
1337 | goto out_table; | |
f6fccb12 MB |
1338 | |
1339 | /* | |
1340 | * Find maximum amount of I/O that won't need splitting | |
1341 | */ | |
56a67df7 | 1342 | max_sectors = min(max_io_len(bvm->bi_sector, ti), |
f6fccb12 MB |
1343 | (sector_t) BIO_MAX_SECTORS); |
1344 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
1345 | if (max_size < 0) | |
1346 | max_size = 0; | |
1347 | ||
1348 | /* | |
1349 | * merge_bvec_fn() returns number of bytes | |
1350 | * it can accept at this offset | |
1351 | * max is precomputed maximal io size | |
1352 | */ | |
1353 | if (max_size && ti->type->merge) | |
1354 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
8cbeb67a MP |
1355 | /* |
1356 | * If the target doesn't support merge method and some of the devices | |
1357 | * provided their merge_bvec method (we know this by looking at | |
1358 | * queue_max_hw_sectors), then we can't allow bios with multiple vector | |
1359 | * entries. So always set max_size to 0, and the code below allows | |
1360 | * just one page. | |
1361 | */ | |
1362 | else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) | |
1363 | ||
1364 | max_size = 0; | |
f6fccb12 | 1365 | |
b01cd5ac | 1366 | out_table: |
5037108a MP |
1367 | dm_table_put(map); |
1368 | ||
1369 | out: | |
f6fccb12 MB |
1370 | /* |
1371 | * Always allow an entire first page | |
1372 | */ | |
1373 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
1374 | max_size = biovec->bv_len; | |
1375 | ||
f6fccb12 MB |
1376 | return max_size; |
1377 | } | |
1378 | ||
1da177e4 LT |
1379 | /* |
1380 | * The request function that just remaps the bio built up by | |
1381 | * dm_merge_bvec. | |
1382 | */ | |
cec47e3d | 1383 | static int _dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 1384 | { |
12f03a49 | 1385 | int rw = bio_data_dir(bio); |
1da177e4 | 1386 | struct mapped_device *md = q->queuedata; |
c9959059 | 1387 | int cpu; |
1da177e4 | 1388 | |
2ca3310e | 1389 | down_read(&md->io_lock); |
1da177e4 | 1390 | |
074a7aca TH |
1391 | cpu = part_stat_lock(); |
1392 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
1393 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
1394 | part_stat_unlock(); | |
12f03a49 | 1395 | |
6a8736d1 TH |
1396 | /* if we're suspended, we have to queue this io for later */ |
1397 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { | |
2ca3310e | 1398 | up_read(&md->io_lock); |
1da177e4 | 1399 | |
6a8736d1 TH |
1400 | if (bio_rw(bio) != READA) |
1401 | queue_io(md, bio); | |
1402 | else | |
54d9a1b4 | 1403 | bio_io_error(bio); |
92c63902 | 1404 | return 0; |
1da177e4 LT |
1405 | } |
1406 | ||
f0b9a450 | 1407 | __split_and_process_bio(md, bio); |
2ca3310e | 1408 | up_read(&md->io_lock); |
f0b9a450 | 1409 | return 0; |
1da177e4 LT |
1410 | } |
1411 | ||
cec47e3d KU |
1412 | static int dm_make_request(struct request_queue *q, struct bio *bio) |
1413 | { | |
1414 | struct mapped_device *md = q->queuedata; | |
1415 | ||
cec47e3d KU |
1416 | return md->saved_make_request_fn(q, bio); /* call __make_request() */ |
1417 | } | |
1418 | ||
1419 | static int dm_request_based(struct mapped_device *md) | |
1420 | { | |
1421 | return blk_queue_stackable(md->queue); | |
1422 | } | |
1423 | ||
1424 | static int dm_request(struct request_queue *q, struct bio *bio) | |
1425 | { | |
1426 | struct mapped_device *md = q->queuedata; | |
1427 | ||
1428 | if (dm_request_based(md)) | |
1429 | return dm_make_request(q, bio); | |
1430 | ||
1431 | return _dm_request(q, bio); | |
1432 | } | |
1433 | ||
1434 | void dm_dispatch_request(struct request *rq) | |
1435 | { | |
1436 | int r; | |
1437 | ||
1438 | if (blk_queue_io_stat(rq->q)) | |
1439 | rq->cmd_flags |= REQ_IO_STAT; | |
1440 | ||
1441 | rq->start_time = jiffies; | |
1442 | r = blk_insert_cloned_request(rq->q, rq); | |
1443 | if (r) | |
1444 | dm_complete_request(rq, r); | |
1445 | } | |
1446 | EXPORT_SYMBOL_GPL(dm_dispatch_request); | |
1447 | ||
1448 | static void dm_rq_bio_destructor(struct bio *bio) | |
1449 | { | |
1450 | struct dm_rq_clone_bio_info *info = bio->bi_private; | |
1451 | struct mapped_device *md = info->tio->md; | |
1452 | ||
1453 | free_bio_info(info); | |
1454 | bio_free(bio, md->bs); | |
1455 | } | |
1456 | ||
1457 | static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, | |
1458 | void *data) | |
1459 | { | |
1460 | struct dm_rq_target_io *tio = data; | |
1461 | struct mapped_device *md = tio->md; | |
1462 | struct dm_rq_clone_bio_info *info = alloc_bio_info(md); | |
1463 | ||
1464 | if (!info) | |
1465 | return -ENOMEM; | |
1466 | ||
1467 | info->orig = bio_orig; | |
1468 | info->tio = tio; | |
1469 | bio->bi_end_io = end_clone_bio; | |
1470 | bio->bi_private = info; | |
1471 | bio->bi_destructor = dm_rq_bio_destructor; | |
1472 | ||
1473 | return 0; | |
1474 | } | |
1475 | ||
1476 | static int setup_clone(struct request *clone, struct request *rq, | |
1477 | struct dm_rq_target_io *tio) | |
1478 | { | |
d0bcb878 | 1479 | int r; |
cec47e3d | 1480 | |
29e4013d TH |
1481 | r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC, |
1482 | dm_rq_bio_constructor, tio); | |
1483 | if (r) | |
1484 | return r; | |
cec47e3d | 1485 | |
29e4013d TH |
1486 | clone->cmd = rq->cmd; |
1487 | clone->cmd_len = rq->cmd_len; | |
1488 | clone->sense = rq->sense; | |
1489 | clone->buffer = rq->buffer; | |
cec47e3d KU |
1490 | clone->end_io = end_clone_request; |
1491 | clone->end_io_data = tio; | |
1492 | ||
1493 | return 0; | |
1494 | } | |
1495 | ||
6facdaff KU |
1496 | static struct request *clone_rq(struct request *rq, struct mapped_device *md, |
1497 | gfp_t gfp_mask) | |
1498 | { | |
1499 | struct request *clone; | |
1500 | struct dm_rq_target_io *tio; | |
1501 | ||
1502 | tio = alloc_rq_tio(md, gfp_mask); | |
1503 | if (!tio) | |
1504 | return NULL; | |
1505 | ||
1506 | tio->md = md; | |
1507 | tio->ti = NULL; | |
1508 | tio->orig = rq; | |
1509 | tio->error = 0; | |
1510 | memset(&tio->info, 0, sizeof(tio->info)); | |
1511 | ||
1512 | clone = &tio->clone; | |
1513 | if (setup_clone(clone, rq, tio)) { | |
1514 | /* -ENOMEM */ | |
1515 | free_rq_tio(tio); | |
1516 | return NULL; | |
1517 | } | |
1518 | ||
1519 | return clone; | |
1520 | } | |
1521 | ||
cec47e3d KU |
1522 | /* |
1523 | * Called with the queue lock held. | |
1524 | */ | |
1525 | static int dm_prep_fn(struct request_queue *q, struct request *rq) | |
1526 | { | |
1527 | struct mapped_device *md = q->queuedata; | |
cec47e3d KU |
1528 | struct request *clone; |
1529 | ||
cec47e3d KU |
1530 | if (unlikely(rq->special)) { |
1531 | DMWARN("Already has something in rq->special."); | |
1532 | return BLKPREP_KILL; | |
1533 | } | |
1534 | ||
6facdaff KU |
1535 | clone = clone_rq(rq, md, GFP_ATOMIC); |
1536 | if (!clone) | |
cec47e3d | 1537 | return BLKPREP_DEFER; |
cec47e3d KU |
1538 | |
1539 | rq->special = clone; | |
1540 | rq->cmd_flags |= REQ_DONTPREP; | |
1541 | ||
1542 | return BLKPREP_OK; | |
1543 | } | |
1544 | ||
9eef87da KU |
1545 | /* |
1546 | * Returns: | |
1547 | * 0 : the request has been processed (not requeued) | |
1548 | * !0 : the request has been requeued | |
1549 | */ | |
1550 | static int map_request(struct dm_target *ti, struct request *clone, | |
1551 | struct mapped_device *md) | |
cec47e3d | 1552 | { |
9eef87da | 1553 | int r, requeued = 0; |
cec47e3d KU |
1554 | struct dm_rq_target_io *tio = clone->end_io_data; |
1555 | ||
1556 | /* | |
1557 | * Hold the md reference here for the in-flight I/O. | |
1558 | * We can't rely on the reference count by device opener, | |
1559 | * because the device may be closed during the request completion | |
1560 | * when all bios are completed. | |
1561 | * See the comment in rq_completed() too. | |
1562 | */ | |
1563 | dm_get(md); | |
1564 | ||
1565 | tio->ti = ti; | |
1566 | r = ti->type->map_rq(ti, clone, &tio->info); | |
1567 | switch (r) { | |
1568 | case DM_MAPIO_SUBMITTED: | |
1569 | /* The target has taken the I/O to submit by itself later */ | |
1570 | break; | |
1571 | case DM_MAPIO_REMAPPED: | |
1572 | /* The target has remapped the I/O so dispatch it */ | |
6db4ccd6 JN |
1573 | trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)), |
1574 | blk_rq_pos(tio->orig)); | |
cec47e3d KU |
1575 | dm_dispatch_request(clone); |
1576 | break; | |
1577 | case DM_MAPIO_REQUEUE: | |
1578 | /* The target wants to requeue the I/O */ | |
1579 | dm_requeue_unmapped_request(clone); | |
9eef87da | 1580 | requeued = 1; |
cec47e3d KU |
1581 | break; |
1582 | default: | |
1583 | if (r > 0) { | |
1584 | DMWARN("unimplemented target map return value: %d", r); | |
1585 | BUG(); | |
1586 | } | |
1587 | ||
1588 | /* The target wants to complete the I/O */ | |
1589 | dm_kill_unmapped_request(clone, r); | |
1590 | break; | |
1591 | } | |
9eef87da KU |
1592 | |
1593 | return requeued; | |
cec47e3d KU |
1594 | } |
1595 | ||
1596 | /* | |
1597 | * q->request_fn for request-based dm. | |
1598 | * Called with the queue lock held. | |
1599 | */ | |
1600 | static void dm_request_fn(struct request_queue *q) | |
1601 | { | |
1602 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1603 | struct dm_table *map = dm_get_live_table(md); |
cec47e3d | 1604 | struct dm_target *ti; |
b4324fee | 1605 | struct request *rq, *clone; |
29e4013d | 1606 | sector_t pos; |
cec47e3d KU |
1607 | |
1608 | /* | |
b4324fee KU |
1609 | * For suspend, check blk_queue_stopped() and increment |
1610 | * ->pending within a single queue_lock not to increment the | |
1611 | * number of in-flight I/Os after the queue is stopped in | |
1612 | * dm_suspend(). | |
cec47e3d | 1613 | */ |
7eaceacc | 1614 | while (!blk_queue_stopped(q)) { |
cec47e3d KU |
1615 | rq = blk_peek_request(q); |
1616 | if (!rq) | |
7eaceacc | 1617 | goto delay_and_out; |
cec47e3d | 1618 | |
29e4013d TH |
1619 | /* always use block 0 to find the target for flushes for now */ |
1620 | pos = 0; | |
1621 | if (!(rq->cmd_flags & REQ_FLUSH)) | |
1622 | pos = blk_rq_pos(rq); | |
1623 | ||
1624 | ti = dm_table_find_target(map, pos); | |
1625 | BUG_ON(!dm_target_is_valid(ti)); | |
d0bcb878 | 1626 | |
cec47e3d | 1627 | if (ti->type->busy && ti->type->busy(ti)) |
7eaceacc | 1628 | goto delay_and_out; |
cec47e3d KU |
1629 | |
1630 | blk_start_request(rq); | |
b4324fee KU |
1631 | clone = rq->special; |
1632 | atomic_inc(&md->pending[rq_data_dir(clone)]); | |
1633 | ||
cec47e3d | 1634 | spin_unlock(q->queue_lock); |
9eef87da KU |
1635 | if (map_request(ti, clone, md)) |
1636 | goto requeued; | |
1637 | ||
052189a2 KU |
1638 | BUG_ON(!irqs_disabled()); |
1639 | spin_lock(q->queue_lock); | |
cec47e3d KU |
1640 | } |
1641 | ||
1642 | goto out; | |
1643 | ||
9eef87da | 1644 | requeued: |
052189a2 KU |
1645 | BUG_ON(!irqs_disabled()); |
1646 | spin_lock(q->queue_lock); | |
9eef87da | 1647 | |
7eaceacc JA |
1648 | delay_and_out: |
1649 | blk_delay_queue(q, HZ / 10); | |
cec47e3d KU |
1650 | out: |
1651 | dm_table_put(map); | |
1652 | ||
1653 | return; | |
1654 | } | |
1655 | ||
1656 | int dm_underlying_device_busy(struct request_queue *q) | |
1657 | { | |
1658 | return blk_lld_busy(q); | |
1659 | } | |
1660 | EXPORT_SYMBOL_GPL(dm_underlying_device_busy); | |
1661 | ||
1662 | static int dm_lld_busy(struct request_queue *q) | |
1663 | { | |
1664 | int r; | |
1665 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1666 | struct dm_table *map = dm_get_live_table(md); |
cec47e3d KU |
1667 | |
1668 | if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) | |
1669 | r = 1; | |
1670 | else | |
1671 | r = dm_table_any_busy_target(map); | |
1672 | ||
1673 | dm_table_put(map); | |
1674 | ||
1675 | return r; | |
1676 | } | |
1677 | ||
1da177e4 LT |
1678 | static int dm_any_congested(void *congested_data, int bdi_bits) |
1679 | { | |
8a57dfc6 CS |
1680 | int r = bdi_bits; |
1681 | struct mapped_device *md = congested_data; | |
1682 | struct dm_table *map; | |
1da177e4 | 1683 | |
1eb787ec | 1684 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
7c666411 | 1685 | map = dm_get_live_table(md); |
8a57dfc6 | 1686 | if (map) { |
cec47e3d KU |
1687 | /* |
1688 | * Request-based dm cares about only own queue for | |
1689 | * the query about congestion status of request_queue | |
1690 | */ | |
1691 | if (dm_request_based(md)) | |
1692 | r = md->queue->backing_dev_info.state & | |
1693 | bdi_bits; | |
1694 | else | |
1695 | r = dm_table_any_congested(map, bdi_bits); | |
1696 | ||
8a57dfc6 CS |
1697 | dm_table_put(map); |
1698 | } | |
1699 | } | |
1700 | ||
1da177e4 LT |
1701 | return r; |
1702 | } | |
1703 | ||
1704 | /*----------------------------------------------------------------- | |
1705 | * An IDR is used to keep track of allocated minor numbers. | |
1706 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
1707 | static DEFINE_IDR(_minor_idr); |
1708 | ||
2b06cfff | 1709 | static void free_minor(int minor) |
1da177e4 | 1710 | { |
f32c10b0 | 1711 | spin_lock(&_minor_lock); |
1da177e4 | 1712 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 1713 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1714 | } |
1715 | ||
1716 | /* | |
1717 | * See if the device with a specific minor # is free. | |
1718 | */ | |
cf13ab8e | 1719 | static int specific_minor(int minor) |
1da177e4 LT |
1720 | { |
1721 | int r, m; | |
1722 | ||
1723 | if (minor >= (1 << MINORBITS)) | |
1724 | return -EINVAL; | |
1725 | ||
62f75c2f JM |
1726 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
1727 | if (!r) | |
1728 | return -ENOMEM; | |
1729 | ||
f32c10b0 | 1730 | spin_lock(&_minor_lock); |
1da177e4 LT |
1731 | |
1732 | if (idr_find(&_minor_idr, minor)) { | |
1733 | r = -EBUSY; | |
1734 | goto out; | |
1735 | } | |
1736 | ||
ba61fdd1 | 1737 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 1738 | if (r) |
1da177e4 | 1739 | goto out; |
1da177e4 LT |
1740 | |
1741 | if (m != minor) { | |
1742 | idr_remove(&_minor_idr, m); | |
1743 | r = -EBUSY; | |
1744 | goto out; | |
1745 | } | |
1746 | ||
1747 | out: | |
f32c10b0 | 1748 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1749 | return r; |
1750 | } | |
1751 | ||
cf13ab8e | 1752 | static int next_free_minor(int *minor) |
1da177e4 | 1753 | { |
2b06cfff | 1754 | int r, m; |
1da177e4 | 1755 | |
1da177e4 | 1756 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
1757 | if (!r) |
1758 | return -ENOMEM; | |
1759 | ||
f32c10b0 | 1760 | spin_lock(&_minor_lock); |
1da177e4 | 1761 | |
ba61fdd1 | 1762 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
cf13ab8e | 1763 | if (r) |
1da177e4 | 1764 | goto out; |
1da177e4 LT |
1765 | |
1766 | if (m >= (1 << MINORBITS)) { | |
1767 | idr_remove(&_minor_idr, m); | |
1768 | r = -ENOSPC; | |
1769 | goto out; | |
1770 | } | |
1771 | ||
1772 | *minor = m; | |
1773 | ||
1774 | out: | |
f32c10b0 | 1775 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1776 | return r; |
1777 | } | |
1778 | ||
83d5cde4 | 1779 | static const struct block_device_operations dm_blk_dops; |
1da177e4 | 1780 | |
53d5914f MP |
1781 | static void dm_wq_work(struct work_struct *work); |
1782 | ||
4a0b4ddf MS |
1783 | static void dm_init_md_queue(struct mapped_device *md) |
1784 | { | |
1785 | /* | |
1786 | * Request-based dm devices cannot be stacked on top of bio-based dm | |
1787 | * devices. The type of this dm device has not been decided yet. | |
1788 | * The type is decided at the first table loading time. | |
1789 | * To prevent problematic device stacking, clear the queue flag | |
1790 | * for request stacking support until then. | |
1791 | * | |
1792 | * This queue is new, so no concurrency on the queue_flags. | |
1793 | */ | |
1794 | queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); | |
1795 | ||
1796 | md->queue->queuedata = md; | |
1797 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1798 | md->queue->backing_dev_info.congested_data = md; | |
1799 | blk_queue_make_request(md->queue, dm_request); | |
1800 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); | |
4a0b4ddf | 1801 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
d87f4c14 | 1802 | blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA); |
4a0b4ddf MS |
1803 | } |
1804 | ||
1da177e4 LT |
1805 | /* |
1806 | * Allocate and initialise a blank device with a given minor. | |
1807 | */ | |
2b06cfff | 1808 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1809 | { |
1810 | int r; | |
cf13ab8e | 1811 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1812 | void *old_md; |
1da177e4 LT |
1813 | |
1814 | if (!md) { | |
1815 | DMWARN("unable to allocate device, out of memory."); | |
1816 | return NULL; | |
1817 | } | |
1818 | ||
10da4f79 | 1819 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 1820 | goto bad_module_get; |
10da4f79 | 1821 | |
1da177e4 | 1822 | /* get a minor number for the dev */ |
2b06cfff | 1823 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 1824 | r = next_free_minor(&minor); |
2b06cfff | 1825 | else |
cf13ab8e | 1826 | r = specific_minor(minor); |
1da177e4 | 1827 | if (r < 0) |
6ed7ade8 | 1828 | goto bad_minor; |
1da177e4 | 1829 | |
a5664dad | 1830 | md->type = DM_TYPE_NONE; |
2ca3310e | 1831 | init_rwsem(&md->io_lock); |
e61290a4 | 1832 | mutex_init(&md->suspend_lock); |
a5664dad | 1833 | mutex_init(&md->type_lock); |
022c2611 | 1834 | spin_lock_init(&md->deferred_lock); |
1da177e4 LT |
1835 | rwlock_init(&md->map_lock); |
1836 | atomic_set(&md->holders, 1); | |
5c6bd75d | 1837 | atomic_set(&md->open_count, 0); |
1da177e4 | 1838 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
1839 | atomic_set(&md->uevent_seq, 0); |
1840 | INIT_LIST_HEAD(&md->uevent_list); | |
1841 | spin_lock_init(&md->uevent_lock); | |
1da177e4 | 1842 | |
4a0b4ddf | 1843 | md->queue = blk_alloc_queue(GFP_KERNEL); |
1da177e4 | 1844 | if (!md->queue) |
6ed7ade8 | 1845 | goto bad_queue; |
1da177e4 | 1846 | |
4a0b4ddf | 1847 | dm_init_md_queue(md); |
9faf400f | 1848 | |
1da177e4 LT |
1849 | md->disk = alloc_disk(1); |
1850 | if (!md->disk) | |
6ed7ade8 | 1851 | goto bad_disk; |
1da177e4 | 1852 | |
316d315b NK |
1853 | atomic_set(&md->pending[0], 0); |
1854 | atomic_set(&md->pending[1], 0); | |
f0b04115 | 1855 | init_waitqueue_head(&md->wait); |
53d5914f | 1856 | INIT_WORK(&md->work, dm_wq_work); |
f0b04115 JM |
1857 | init_waitqueue_head(&md->eventq); |
1858 | ||
1da177e4 LT |
1859 | md->disk->major = _major; |
1860 | md->disk->first_minor = minor; | |
1861 | md->disk->fops = &dm_blk_dops; | |
1862 | md->disk->queue = md->queue; | |
1863 | md->disk->private_data = md; | |
1864 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
1865 | add_disk(md->disk); | |
7e51f257 | 1866 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1867 | |
9c4376de TH |
1868 | md->wq = alloc_workqueue("kdmflush", |
1869 | WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0); | |
304f3f6a MB |
1870 | if (!md->wq) |
1871 | goto bad_thread; | |
1872 | ||
32a926da MP |
1873 | md->bdev = bdget_disk(md->disk, 0); |
1874 | if (!md->bdev) | |
1875 | goto bad_bdev; | |
1876 | ||
6a8736d1 TH |
1877 | bio_init(&md->flush_bio); |
1878 | md->flush_bio.bi_bdev = md->bdev; | |
1879 | md->flush_bio.bi_rw = WRITE_FLUSH; | |
1880 | ||
ba61fdd1 | 1881 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1882 | spin_lock(&_minor_lock); |
ba61fdd1 | 1883 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1884 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1885 | |
1886 | BUG_ON(old_md != MINOR_ALLOCED); | |
1887 | ||
1da177e4 LT |
1888 | return md; |
1889 | ||
32a926da MP |
1890 | bad_bdev: |
1891 | destroy_workqueue(md->wq); | |
304f3f6a | 1892 | bad_thread: |
03022c54 | 1893 | del_gendisk(md->disk); |
304f3f6a | 1894 | put_disk(md->disk); |
6ed7ade8 | 1895 | bad_disk: |
1312f40e | 1896 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 1897 | bad_queue: |
1da177e4 | 1898 | free_minor(minor); |
6ed7ade8 | 1899 | bad_minor: |
10da4f79 | 1900 | module_put(THIS_MODULE); |
6ed7ade8 | 1901 | bad_module_get: |
1da177e4 LT |
1902 | kfree(md); |
1903 | return NULL; | |
1904 | } | |
1905 | ||
ae9da83f JN |
1906 | static void unlock_fs(struct mapped_device *md); |
1907 | ||
1da177e4 LT |
1908 | static void free_dev(struct mapped_device *md) |
1909 | { | |
f331c029 | 1910 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 1911 | |
32a926da MP |
1912 | unlock_fs(md); |
1913 | bdput(md->bdev); | |
304f3f6a | 1914 | destroy_workqueue(md->wq); |
e6ee8c0b KU |
1915 | if (md->tio_pool) |
1916 | mempool_destroy(md->tio_pool); | |
1917 | if (md->io_pool) | |
1918 | mempool_destroy(md->io_pool); | |
1919 | if (md->bs) | |
1920 | bioset_free(md->bs); | |
9c47008d | 1921 | blk_integrity_unregister(md->disk); |
1da177e4 | 1922 | del_gendisk(md->disk); |
63d94e48 | 1923 | free_minor(minor); |
fba9f90e JM |
1924 | |
1925 | spin_lock(&_minor_lock); | |
1926 | md->disk->private_data = NULL; | |
1927 | spin_unlock(&_minor_lock); | |
1928 | ||
1da177e4 | 1929 | put_disk(md->disk); |
1312f40e | 1930 | blk_cleanup_queue(md->queue); |
10da4f79 | 1931 | module_put(THIS_MODULE); |
1da177e4 LT |
1932 | kfree(md); |
1933 | } | |
1934 | ||
e6ee8c0b KU |
1935 | static void __bind_mempools(struct mapped_device *md, struct dm_table *t) |
1936 | { | |
1937 | struct dm_md_mempools *p; | |
1938 | ||
1939 | if (md->io_pool && md->tio_pool && md->bs) | |
1940 | /* the md already has necessary mempools */ | |
1941 | goto out; | |
1942 | ||
1943 | p = dm_table_get_md_mempools(t); | |
1944 | BUG_ON(!p || md->io_pool || md->tio_pool || md->bs); | |
1945 | ||
1946 | md->io_pool = p->io_pool; | |
1947 | p->io_pool = NULL; | |
1948 | md->tio_pool = p->tio_pool; | |
1949 | p->tio_pool = NULL; | |
1950 | md->bs = p->bs; | |
1951 | p->bs = NULL; | |
1952 | ||
1953 | out: | |
1954 | /* mempool bind completed, now no need any mempools in the table */ | |
1955 | dm_table_free_md_mempools(t); | |
1956 | } | |
1957 | ||
1da177e4 LT |
1958 | /* |
1959 | * Bind a table to the device. | |
1960 | */ | |
1961 | static void event_callback(void *context) | |
1962 | { | |
7a8c3d3b MA |
1963 | unsigned long flags; |
1964 | LIST_HEAD(uevents); | |
1da177e4 LT |
1965 | struct mapped_device *md = (struct mapped_device *) context; |
1966 | ||
7a8c3d3b MA |
1967 | spin_lock_irqsave(&md->uevent_lock, flags); |
1968 | list_splice_init(&md->uevent_list, &uevents); | |
1969 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1970 | ||
ed9e1982 | 1971 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 1972 | |
1da177e4 LT |
1973 | atomic_inc(&md->event_nr); |
1974 | wake_up(&md->eventq); | |
1975 | } | |
1976 | ||
c217649b MS |
1977 | /* |
1978 | * Protected by md->suspend_lock obtained by dm_swap_table(). | |
1979 | */ | |
4e90188b | 1980 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1981 | { |
4e90188b | 1982 | set_capacity(md->disk, size); |
1da177e4 | 1983 | |
db8fef4f | 1984 | i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1da177e4 LT |
1985 | } |
1986 | ||
042d2a9b AK |
1987 | /* |
1988 | * Returns old map, which caller must destroy. | |
1989 | */ | |
1990 | static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, | |
1991 | struct queue_limits *limits) | |
1da177e4 | 1992 | { |
042d2a9b | 1993 | struct dm_table *old_map; |
165125e1 | 1994 | struct request_queue *q = md->queue; |
1da177e4 | 1995 | sector_t size; |
523d9297 | 1996 | unsigned long flags; |
1da177e4 LT |
1997 | |
1998 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1999 | |
2000 | /* | |
2001 | * Wipe any geometry if the size of the table changed. | |
2002 | */ | |
2003 | if (size != get_capacity(md->disk)) | |
2004 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
2005 | ||
32a926da | 2006 | __set_size(md, size); |
d5816876 | 2007 | |
2ca3310e AK |
2008 | dm_table_event_callback(t, event_callback, md); |
2009 | ||
e6ee8c0b KU |
2010 | /* |
2011 | * The queue hasn't been stopped yet, if the old table type wasn't | |
2012 | * for request-based during suspension. So stop it to prevent | |
2013 | * I/O mapping before resume. | |
2014 | * This must be done before setting the queue restrictions, | |
2015 | * because request-based dm may be run just after the setting. | |
2016 | */ | |
2017 | if (dm_table_request_based(t) && !blk_queue_stopped(q)) | |
2018 | stop_queue(q); | |
2019 | ||
2020 | __bind_mempools(md, t); | |
2021 | ||
523d9297 | 2022 | write_lock_irqsave(&md->map_lock, flags); |
042d2a9b | 2023 | old_map = md->map; |
1da177e4 | 2024 | md->map = t; |
754c5fc7 | 2025 | dm_table_set_restrictions(t, q, limits); |
523d9297 | 2026 | write_unlock_irqrestore(&md->map_lock, flags); |
1da177e4 | 2027 | |
042d2a9b | 2028 | return old_map; |
1da177e4 LT |
2029 | } |
2030 | ||
a7940155 AK |
2031 | /* |
2032 | * Returns unbound table for the caller to free. | |
2033 | */ | |
2034 | static struct dm_table *__unbind(struct mapped_device *md) | |
1da177e4 LT |
2035 | { |
2036 | struct dm_table *map = md->map; | |
523d9297 | 2037 | unsigned long flags; |
1da177e4 LT |
2038 | |
2039 | if (!map) | |
a7940155 | 2040 | return NULL; |
1da177e4 LT |
2041 | |
2042 | dm_table_event_callback(map, NULL, NULL); | |
523d9297 | 2043 | write_lock_irqsave(&md->map_lock, flags); |
1da177e4 | 2044 | md->map = NULL; |
523d9297 | 2045 | write_unlock_irqrestore(&md->map_lock, flags); |
a7940155 AK |
2046 | |
2047 | return map; | |
1da177e4 LT |
2048 | } |
2049 | ||
2050 | /* | |
2051 | * Constructor for a new device. | |
2052 | */ | |
2b06cfff | 2053 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
2054 | { |
2055 | struct mapped_device *md; | |
2056 | ||
2b06cfff | 2057 | md = alloc_dev(minor); |
1da177e4 LT |
2058 | if (!md) |
2059 | return -ENXIO; | |
2060 | ||
784aae73 MB |
2061 | dm_sysfs_init(md); |
2062 | ||
1da177e4 LT |
2063 | *result = md; |
2064 | return 0; | |
2065 | } | |
2066 | ||
a5664dad MS |
2067 | /* |
2068 | * Functions to manage md->type. | |
2069 | * All are required to hold md->type_lock. | |
2070 | */ | |
2071 | void dm_lock_md_type(struct mapped_device *md) | |
2072 | { | |
2073 | mutex_lock(&md->type_lock); | |
2074 | } | |
2075 | ||
2076 | void dm_unlock_md_type(struct mapped_device *md) | |
2077 | { | |
2078 | mutex_unlock(&md->type_lock); | |
2079 | } | |
2080 | ||
2081 | void dm_set_md_type(struct mapped_device *md, unsigned type) | |
2082 | { | |
2083 | md->type = type; | |
2084 | } | |
2085 | ||
2086 | unsigned dm_get_md_type(struct mapped_device *md) | |
2087 | { | |
2088 | return md->type; | |
2089 | } | |
2090 | ||
4a0b4ddf MS |
2091 | /* |
2092 | * Fully initialize a request-based queue (->elevator, ->request_fn, etc). | |
2093 | */ | |
2094 | static int dm_init_request_based_queue(struct mapped_device *md) | |
2095 | { | |
2096 | struct request_queue *q = NULL; | |
2097 | ||
2098 | if (md->queue->elevator) | |
2099 | return 1; | |
2100 | ||
2101 | /* Fully initialize the queue */ | |
2102 | q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); | |
2103 | if (!q) | |
2104 | return 0; | |
2105 | ||
2106 | md->queue = q; | |
2107 | md->saved_make_request_fn = md->queue->make_request_fn; | |
2108 | dm_init_md_queue(md); | |
2109 | blk_queue_softirq_done(md->queue, dm_softirq_done); | |
2110 | blk_queue_prep_rq(md->queue, dm_prep_fn); | |
2111 | blk_queue_lld_busy(md->queue, dm_lld_busy); | |
4a0b4ddf MS |
2112 | |
2113 | elv_register_queue(md->queue); | |
2114 | ||
2115 | return 1; | |
2116 | } | |
2117 | ||
2118 | /* | |
2119 | * Setup the DM device's queue based on md's type | |
2120 | */ | |
2121 | int dm_setup_md_queue(struct mapped_device *md) | |
2122 | { | |
2123 | if ((dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) && | |
2124 | !dm_init_request_based_queue(md)) { | |
2125 | DMWARN("Cannot initialize queue for request-based mapped device"); | |
2126 | return -EINVAL; | |
2127 | } | |
2128 | ||
2129 | return 0; | |
2130 | } | |
2131 | ||
637842cf | 2132 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
2133 | { |
2134 | struct mapped_device *md; | |
1da177e4 LT |
2135 | unsigned minor = MINOR(dev); |
2136 | ||
2137 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
2138 | return NULL; | |
2139 | ||
f32c10b0 | 2140 | spin_lock(&_minor_lock); |
1da177e4 LT |
2141 | |
2142 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 2143 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 2144 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
abdc568b | 2145 | dm_deleting_md(md) || |
17b2f66f | 2146 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 2147 | md = NULL; |
fba9f90e JM |
2148 | goto out; |
2149 | } | |
1da177e4 | 2150 | |
fba9f90e | 2151 | out: |
f32c10b0 | 2152 | spin_unlock(&_minor_lock); |
1da177e4 | 2153 | |
637842cf DT |
2154 | return md; |
2155 | } | |
2156 | ||
d229a958 DT |
2157 | struct mapped_device *dm_get_md(dev_t dev) |
2158 | { | |
2159 | struct mapped_device *md = dm_find_md(dev); | |
2160 | ||
2161 | if (md) | |
2162 | dm_get(md); | |
2163 | ||
2164 | return md; | |
2165 | } | |
2166 | ||
9ade92a9 | 2167 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 2168 | { |
9ade92a9 | 2169 | return md->interface_ptr; |
1da177e4 LT |
2170 | } |
2171 | ||
2172 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
2173 | { | |
2174 | md->interface_ptr = ptr; | |
2175 | } | |
2176 | ||
2177 | void dm_get(struct mapped_device *md) | |
2178 | { | |
2179 | atomic_inc(&md->holders); | |
3f77316d | 2180 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1da177e4 LT |
2181 | } |
2182 | ||
72d94861 AK |
2183 | const char *dm_device_name(struct mapped_device *md) |
2184 | { | |
2185 | return md->name; | |
2186 | } | |
2187 | EXPORT_SYMBOL_GPL(dm_device_name); | |
2188 | ||
3f77316d | 2189 | static void __dm_destroy(struct mapped_device *md, bool wait) |
1da177e4 | 2190 | { |
1134e5ae | 2191 | struct dm_table *map; |
1da177e4 | 2192 | |
3f77316d | 2193 | might_sleep(); |
fba9f90e | 2194 | |
3f77316d KU |
2195 | spin_lock(&_minor_lock); |
2196 | map = dm_get_live_table(md); | |
2197 | idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); | |
2198 | set_bit(DMF_FREEING, &md->flags); | |
2199 | spin_unlock(&_minor_lock); | |
2200 | ||
2201 | if (!dm_suspended_md(md)) { | |
2202 | dm_table_presuspend_targets(map); | |
2203 | dm_table_postsuspend_targets(map); | |
1da177e4 | 2204 | } |
3f77316d KU |
2205 | |
2206 | /* | |
2207 | * Rare, but there may be I/O requests still going to complete, | |
2208 | * for example. Wait for all references to disappear. | |
2209 | * No one should increment the reference count of the mapped_device, | |
2210 | * after the mapped_device state becomes DMF_FREEING. | |
2211 | */ | |
2212 | if (wait) | |
2213 | while (atomic_read(&md->holders)) | |
2214 | msleep(1); | |
2215 | else if (atomic_read(&md->holders)) | |
2216 | DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", | |
2217 | dm_device_name(md), atomic_read(&md->holders)); | |
2218 | ||
2219 | dm_sysfs_exit(md); | |
2220 | dm_table_put(map); | |
2221 | dm_table_destroy(__unbind(md)); | |
2222 | free_dev(md); | |
2223 | } | |
2224 | ||
2225 | void dm_destroy(struct mapped_device *md) | |
2226 | { | |
2227 | __dm_destroy(md, true); | |
2228 | } | |
2229 | ||
2230 | void dm_destroy_immediate(struct mapped_device *md) | |
2231 | { | |
2232 | __dm_destroy(md, false); | |
2233 | } | |
2234 | ||
2235 | void dm_put(struct mapped_device *md) | |
2236 | { | |
2237 | atomic_dec(&md->holders); | |
1da177e4 | 2238 | } |
79eb885c | 2239 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 2240 | |
401600df | 2241 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
46125c1c MB |
2242 | { |
2243 | int r = 0; | |
b44ebeb0 MP |
2244 | DECLARE_WAITQUEUE(wait, current); |
2245 | ||
b44ebeb0 | 2246 | add_wait_queue(&md->wait, &wait); |
46125c1c MB |
2247 | |
2248 | while (1) { | |
401600df | 2249 | set_current_state(interruptible); |
46125c1c MB |
2250 | |
2251 | smp_mb(); | |
b4324fee | 2252 | if (!md_in_flight(md)) |
46125c1c MB |
2253 | break; |
2254 | ||
401600df MP |
2255 | if (interruptible == TASK_INTERRUPTIBLE && |
2256 | signal_pending(current)) { | |
46125c1c MB |
2257 | r = -EINTR; |
2258 | break; | |
2259 | } | |
2260 | ||
2261 | io_schedule(); | |
2262 | } | |
2263 | set_current_state(TASK_RUNNING); | |
2264 | ||
b44ebeb0 MP |
2265 | remove_wait_queue(&md->wait, &wait); |
2266 | ||
46125c1c MB |
2267 | return r; |
2268 | } | |
2269 | ||
1da177e4 LT |
2270 | /* |
2271 | * Process the deferred bios | |
2272 | */ | |
ef208587 | 2273 | static void dm_wq_work(struct work_struct *work) |
1da177e4 | 2274 | { |
ef208587 MP |
2275 | struct mapped_device *md = container_of(work, struct mapped_device, |
2276 | work); | |
6d6f10df | 2277 | struct bio *c; |
1da177e4 | 2278 | |
6a8736d1 | 2279 | down_read(&md->io_lock); |
ef208587 | 2280 | |
3b00b203 | 2281 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
df12ee99 AK |
2282 | spin_lock_irq(&md->deferred_lock); |
2283 | c = bio_list_pop(&md->deferred); | |
2284 | spin_unlock_irq(&md->deferred_lock); | |
2285 | ||
6a8736d1 | 2286 | if (!c) |
df12ee99 | 2287 | break; |
022c2611 | 2288 | |
6a8736d1 | 2289 | up_read(&md->io_lock); |
3b00b203 | 2290 | |
e6ee8c0b KU |
2291 | if (dm_request_based(md)) |
2292 | generic_make_request(c); | |
6a8736d1 TH |
2293 | else |
2294 | __split_and_process_bio(md, c); | |
3b00b203 | 2295 | |
6a8736d1 | 2296 | down_read(&md->io_lock); |
022c2611 | 2297 | } |
73d410c0 | 2298 | |
6a8736d1 | 2299 | up_read(&md->io_lock); |
1da177e4 LT |
2300 | } |
2301 | ||
9a1fb464 | 2302 | static void dm_queue_flush(struct mapped_device *md) |
304f3f6a | 2303 | { |
3b00b203 MP |
2304 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
2305 | smp_mb__after_clear_bit(); | |
53d5914f | 2306 | queue_work(md->wq, &md->work); |
304f3f6a MB |
2307 | } |
2308 | ||
1da177e4 | 2309 | /* |
042d2a9b | 2310 | * Swap in a new table, returning the old one for the caller to destroy. |
1da177e4 | 2311 | */ |
042d2a9b | 2312 | struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) |
1da177e4 | 2313 | { |
042d2a9b | 2314 | struct dm_table *map = ERR_PTR(-EINVAL); |
754c5fc7 | 2315 | struct queue_limits limits; |
042d2a9b | 2316 | int r; |
1da177e4 | 2317 | |
e61290a4 | 2318 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
2319 | |
2320 | /* device must be suspended */ | |
4f186f8b | 2321 | if (!dm_suspended_md(md)) |
93c534ae | 2322 | goto out; |
1da177e4 | 2323 | |
754c5fc7 | 2324 | r = dm_calculate_queue_limits(table, &limits); |
042d2a9b AK |
2325 | if (r) { |
2326 | map = ERR_PTR(r); | |
754c5fc7 | 2327 | goto out; |
042d2a9b | 2328 | } |
754c5fc7 | 2329 | |
042d2a9b | 2330 | map = __bind(md, table, &limits); |
1da177e4 | 2331 | |
93c534ae | 2332 | out: |
e61290a4 | 2333 | mutex_unlock(&md->suspend_lock); |
042d2a9b | 2334 | return map; |
1da177e4 LT |
2335 | } |
2336 | ||
2337 | /* | |
2338 | * Functions to lock and unlock any filesystem running on the | |
2339 | * device. | |
2340 | */ | |
2ca3310e | 2341 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 2342 | { |
e39e2e95 | 2343 | int r; |
1da177e4 LT |
2344 | |
2345 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 2346 | |
db8fef4f | 2347 | md->frozen_sb = freeze_bdev(md->bdev); |
dfbe03f6 | 2348 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 2349 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
2350 | md->frozen_sb = NULL; |
2351 | return r; | |
dfbe03f6 AK |
2352 | } |
2353 | ||
aa8d7c2f AK |
2354 | set_bit(DMF_FROZEN, &md->flags); |
2355 | ||
1da177e4 LT |
2356 | return 0; |
2357 | } | |
2358 | ||
2ca3310e | 2359 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 2360 | { |
aa8d7c2f AK |
2361 | if (!test_bit(DMF_FROZEN, &md->flags)) |
2362 | return; | |
2363 | ||
db8fef4f | 2364 | thaw_bdev(md->bdev, md->frozen_sb); |
1da177e4 | 2365 | md->frozen_sb = NULL; |
aa8d7c2f | 2366 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
2367 | } |
2368 | ||
2369 | /* | |
2370 | * We need to be able to change a mapping table under a mounted | |
2371 | * filesystem. For example we might want to move some data in | |
2372 | * the background. Before the table can be swapped with | |
2373 | * dm_bind_table, dm_suspend must be called to flush any in | |
2374 | * flight bios and ensure that any further io gets deferred. | |
2375 | */ | |
cec47e3d KU |
2376 | /* |
2377 | * Suspend mechanism in request-based dm. | |
2378 | * | |
9f518b27 KU |
2379 | * 1. Flush all I/Os by lock_fs() if needed. |
2380 | * 2. Stop dispatching any I/O by stopping the request_queue. | |
2381 | * 3. Wait for all in-flight I/Os to be completed or requeued. | |
cec47e3d | 2382 | * |
9f518b27 | 2383 | * To abort suspend, start the request_queue. |
cec47e3d | 2384 | */ |
a3d77d35 | 2385 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 2386 | { |
2ca3310e | 2387 | struct dm_table *map = NULL; |
46125c1c | 2388 | int r = 0; |
a3d77d35 | 2389 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 2390 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 2391 | |
e61290a4 | 2392 | mutex_lock(&md->suspend_lock); |
2ca3310e | 2393 | |
4f186f8b | 2394 | if (dm_suspended_md(md)) { |
73d410c0 | 2395 | r = -EINVAL; |
d287483d | 2396 | goto out_unlock; |
73d410c0 | 2397 | } |
1da177e4 | 2398 | |
7c666411 | 2399 | map = dm_get_live_table(md); |
1da177e4 | 2400 | |
2e93ccc1 KU |
2401 | /* |
2402 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
2403 | * This flag is cleared before dm_suspend returns. | |
2404 | */ | |
2405 | if (noflush) | |
2406 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
2407 | ||
cf222b37 AK |
2408 | /* This does not get reverted if there's an error later. */ |
2409 | dm_table_presuspend_targets(map); | |
2410 | ||
32a926da | 2411 | /* |
9f518b27 KU |
2412 | * Flush I/O to the device. |
2413 | * Any I/O submitted after lock_fs() may not be flushed. | |
2414 | * noflush takes precedence over do_lockfs. | |
2415 | * (lock_fs() flushes I/Os and waits for them to complete.) | |
32a926da MP |
2416 | */ |
2417 | if (!noflush && do_lockfs) { | |
2418 | r = lock_fs(md); | |
2419 | if (r) | |
f431d966 | 2420 | goto out; |
aa8d7c2f | 2421 | } |
1da177e4 LT |
2422 | |
2423 | /* | |
3b00b203 MP |
2424 | * Here we must make sure that no processes are submitting requests |
2425 | * to target drivers i.e. no one may be executing | |
2426 | * __split_and_process_bio. This is called from dm_request and | |
2427 | * dm_wq_work. | |
2428 | * | |
2429 | * To get all processes out of __split_and_process_bio in dm_request, | |
2430 | * we take the write lock. To prevent any process from reentering | |
6a8736d1 TH |
2431 | * __split_and_process_bio from dm_request and quiesce the thread |
2432 | * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call | |
2433 | * flush_workqueue(md->wq). | |
1da177e4 | 2434 | */ |
2ca3310e | 2435 | down_write(&md->io_lock); |
1eb787ec | 2436 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
2ca3310e | 2437 | up_write(&md->io_lock); |
1da177e4 | 2438 | |
d0bcb878 | 2439 | /* |
29e4013d TH |
2440 | * Stop md->queue before flushing md->wq in case request-based |
2441 | * dm defers requests to md->wq from md->queue. | |
d0bcb878 | 2442 | */ |
cec47e3d | 2443 | if (dm_request_based(md)) |
9f518b27 | 2444 | stop_queue(md->queue); |
cec47e3d | 2445 | |
d0bcb878 KU |
2446 | flush_workqueue(md->wq); |
2447 | ||
1da177e4 | 2448 | /* |
3b00b203 MP |
2449 | * At this point no more requests are entering target request routines. |
2450 | * We call dm_wait_for_completion to wait for all existing requests | |
2451 | * to finish. | |
1da177e4 | 2452 | */ |
401600df | 2453 | r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE); |
1da177e4 | 2454 | |
2ca3310e | 2455 | down_write(&md->io_lock); |
6d6f10df | 2456 | if (noflush) |
022c2611 | 2457 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
94d6351e | 2458 | up_write(&md->io_lock); |
2e93ccc1 | 2459 | |
1da177e4 | 2460 | /* were we interrupted ? */ |
46125c1c | 2461 | if (r < 0) { |
9a1fb464 | 2462 | dm_queue_flush(md); |
73d410c0 | 2463 | |
cec47e3d | 2464 | if (dm_request_based(md)) |
9f518b27 | 2465 | start_queue(md->queue); |
cec47e3d | 2466 | |
2ca3310e | 2467 | unlock_fs(md); |
2e93ccc1 | 2468 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 2469 | } |
1da177e4 | 2470 | |
3b00b203 MP |
2471 | /* |
2472 | * If dm_wait_for_completion returned 0, the device is completely | |
2473 | * quiescent now. There is no request-processing activity. All new | |
2474 | * requests are being added to md->deferred list. | |
2475 | */ | |
2476 | ||
2ca3310e | 2477 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 2478 | |
4d4471cb KU |
2479 | dm_table_postsuspend_targets(map); |
2480 | ||
2ca3310e AK |
2481 | out: |
2482 | dm_table_put(map); | |
d287483d AK |
2483 | |
2484 | out_unlock: | |
e61290a4 | 2485 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 2486 | return r; |
1da177e4 LT |
2487 | } |
2488 | ||
2489 | int dm_resume(struct mapped_device *md) | |
2490 | { | |
cf222b37 | 2491 | int r = -EINVAL; |
cf222b37 | 2492 | struct dm_table *map = NULL; |
1da177e4 | 2493 | |
e61290a4 | 2494 | mutex_lock(&md->suspend_lock); |
4f186f8b | 2495 | if (!dm_suspended_md(md)) |
cf222b37 | 2496 | goto out; |
cf222b37 | 2497 | |
7c666411 | 2498 | map = dm_get_live_table(md); |
2ca3310e | 2499 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 2500 | goto out; |
1da177e4 | 2501 | |
8757b776 MB |
2502 | r = dm_table_resume_targets(map); |
2503 | if (r) | |
2504 | goto out; | |
2ca3310e | 2505 | |
9a1fb464 | 2506 | dm_queue_flush(md); |
2ca3310e | 2507 | |
cec47e3d KU |
2508 | /* |
2509 | * Flushing deferred I/Os must be done after targets are resumed | |
2510 | * so that mapping of targets can work correctly. | |
2511 | * Request-based dm is queueing the deferred I/Os in its request_queue. | |
2512 | */ | |
2513 | if (dm_request_based(md)) | |
2514 | start_queue(md->queue); | |
2515 | ||
2ca3310e AK |
2516 | unlock_fs(md); |
2517 | ||
2518 | clear_bit(DMF_SUSPENDED, &md->flags); | |
2519 | ||
cf222b37 AK |
2520 | r = 0; |
2521 | out: | |
2522 | dm_table_put(map); | |
e61290a4 | 2523 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 2524 | |
cf222b37 | 2525 | return r; |
1da177e4 LT |
2526 | } |
2527 | ||
2528 | /*----------------------------------------------------------------- | |
2529 | * Event notification. | |
2530 | *---------------------------------------------------------------*/ | |
3abf85b5 | 2531 | int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
60935eb2 | 2532 | unsigned cookie) |
69267a30 | 2533 | { |
60935eb2 MB |
2534 | char udev_cookie[DM_COOKIE_LENGTH]; |
2535 | char *envp[] = { udev_cookie, NULL }; | |
2536 | ||
2537 | if (!cookie) | |
3abf85b5 | 2538 | return kobject_uevent(&disk_to_dev(md->disk)->kobj, action); |
60935eb2 MB |
2539 | else { |
2540 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", | |
2541 | DM_COOKIE_ENV_VAR_NAME, cookie); | |
3abf85b5 PR |
2542 | return kobject_uevent_env(&disk_to_dev(md->disk)->kobj, |
2543 | action, envp); | |
60935eb2 | 2544 | } |
69267a30 AK |
2545 | } |
2546 | ||
7a8c3d3b MA |
2547 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
2548 | { | |
2549 | return atomic_add_return(1, &md->uevent_seq); | |
2550 | } | |
2551 | ||
1da177e4 LT |
2552 | uint32_t dm_get_event_nr(struct mapped_device *md) |
2553 | { | |
2554 | return atomic_read(&md->event_nr); | |
2555 | } | |
2556 | ||
2557 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
2558 | { | |
2559 | return wait_event_interruptible(md->eventq, | |
2560 | (event_nr != atomic_read(&md->event_nr))); | |
2561 | } | |
2562 | ||
7a8c3d3b MA |
2563 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
2564 | { | |
2565 | unsigned long flags; | |
2566 | ||
2567 | spin_lock_irqsave(&md->uevent_lock, flags); | |
2568 | list_add(elist, &md->uevent_list); | |
2569 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
2570 | } | |
2571 | ||
1da177e4 LT |
2572 | /* |
2573 | * The gendisk is only valid as long as you have a reference | |
2574 | * count on 'md'. | |
2575 | */ | |
2576 | struct gendisk *dm_disk(struct mapped_device *md) | |
2577 | { | |
2578 | return md->disk; | |
2579 | } | |
2580 | ||
784aae73 MB |
2581 | struct kobject *dm_kobject(struct mapped_device *md) |
2582 | { | |
2583 | return &md->kobj; | |
2584 | } | |
2585 | ||
2586 | /* | |
2587 | * struct mapped_device should not be exported outside of dm.c | |
2588 | * so use this check to verify that kobj is part of md structure | |
2589 | */ | |
2590 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) | |
2591 | { | |
2592 | struct mapped_device *md; | |
2593 | ||
2594 | md = container_of(kobj, struct mapped_device, kobj); | |
2595 | if (&md->kobj != kobj) | |
2596 | return NULL; | |
2597 | ||
4d89b7b4 | 2598 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 2599 | dm_deleting_md(md)) |
4d89b7b4 MB |
2600 | return NULL; |
2601 | ||
784aae73 MB |
2602 | dm_get(md); |
2603 | return md; | |
2604 | } | |
2605 | ||
4f186f8b | 2606 | int dm_suspended_md(struct mapped_device *md) |
1da177e4 LT |
2607 | { |
2608 | return test_bit(DMF_SUSPENDED, &md->flags); | |
2609 | } | |
2610 | ||
64dbce58 KU |
2611 | int dm_suspended(struct dm_target *ti) |
2612 | { | |
ecdb2e25 | 2613 | return dm_suspended_md(dm_table_get_md(ti->table)); |
64dbce58 KU |
2614 | } |
2615 | EXPORT_SYMBOL_GPL(dm_suspended); | |
2616 | ||
2e93ccc1 KU |
2617 | int dm_noflush_suspending(struct dm_target *ti) |
2618 | { | |
ecdb2e25 | 2619 | return __noflush_suspending(dm_table_get_md(ti->table)); |
2e93ccc1 KU |
2620 | } |
2621 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
2622 | ||
e6ee8c0b KU |
2623 | struct dm_md_mempools *dm_alloc_md_mempools(unsigned type) |
2624 | { | |
2625 | struct dm_md_mempools *pools = kmalloc(sizeof(*pools), GFP_KERNEL); | |
2626 | ||
2627 | if (!pools) | |
2628 | return NULL; | |
2629 | ||
2630 | pools->io_pool = (type == DM_TYPE_BIO_BASED) ? | |
2631 | mempool_create_slab_pool(MIN_IOS, _io_cache) : | |
2632 | mempool_create_slab_pool(MIN_IOS, _rq_bio_info_cache); | |
2633 | if (!pools->io_pool) | |
2634 | goto free_pools_and_out; | |
2635 | ||
2636 | pools->tio_pool = (type == DM_TYPE_BIO_BASED) ? | |
2637 | mempool_create_slab_pool(MIN_IOS, _tio_cache) : | |
2638 | mempool_create_slab_pool(MIN_IOS, _rq_tio_cache); | |
2639 | if (!pools->tio_pool) | |
2640 | goto free_io_pool_and_out; | |
2641 | ||
2642 | pools->bs = (type == DM_TYPE_BIO_BASED) ? | |
2643 | bioset_create(16, 0) : bioset_create(MIN_IOS, 0); | |
2644 | if (!pools->bs) | |
2645 | goto free_tio_pool_and_out; | |
2646 | ||
2647 | return pools; | |
2648 | ||
2649 | free_tio_pool_and_out: | |
2650 | mempool_destroy(pools->tio_pool); | |
2651 | ||
2652 | free_io_pool_and_out: | |
2653 | mempool_destroy(pools->io_pool); | |
2654 | ||
2655 | free_pools_and_out: | |
2656 | kfree(pools); | |
2657 | ||
2658 | return NULL; | |
2659 | } | |
2660 | ||
2661 | void dm_free_md_mempools(struct dm_md_mempools *pools) | |
2662 | { | |
2663 | if (!pools) | |
2664 | return; | |
2665 | ||
2666 | if (pools->io_pool) | |
2667 | mempool_destroy(pools->io_pool); | |
2668 | ||
2669 | if (pools->tio_pool) | |
2670 | mempool_destroy(pools->tio_pool); | |
2671 | ||
2672 | if (pools->bs) | |
2673 | bioset_free(pools->bs); | |
2674 | ||
2675 | kfree(pools); | |
2676 | } | |
2677 | ||
83d5cde4 | 2678 | static const struct block_device_operations dm_blk_dops = { |
1da177e4 LT |
2679 | .open = dm_blk_open, |
2680 | .release = dm_blk_close, | |
aa129a22 | 2681 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 2682 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
2683 | .owner = THIS_MODULE |
2684 | }; | |
2685 | ||
2686 | EXPORT_SYMBOL(dm_get_mapinfo); | |
2687 | ||
2688 | /* | |
2689 | * module hooks | |
2690 | */ | |
2691 | module_init(dm_init); | |
2692 | module_exit(dm_exit); | |
2693 | ||
2694 | module_param(major, uint, 0); | |
2695 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
2696 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
2697 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
2698 | MODULE_LICENSE("GPL"); |