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> | |
6e9624b8 | 18 | #include <linux/smp_lock.h> |
1da177e4 LT |
19 | #include <linux/mempool.h> |
20 | #include <linux/slab.h> | |
21 | #include <linux/idr.h> | |
3ac51e74 | 22 | #include <linux/hdreg.h> |
3f77316d | 23 | #include <linux/delay.h> |
55782138 LZ |
24 | |
25 | #include <trace/events/block.h> | |
1da177e4 | 26 | |
72d94861 AK |
27 | #define DM_MSG_PREFIX "core" |
28 | ||
60935eb2 MB |
29 | /* |
30 | * Cookies are numeric values sent with CHANGE and REMOVE | |
31 | * uevents while resuming, removing or renaming the device. | |
32 | */ | |
33 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" | |
34 | #define DM_COOKIE_LENGTH 24 | |
35 | ||
1da177e4 LT |
36 | static const char *_name = DM_NAME; |
37 | ||
38 | static unsigned int major = 0; | |
39 | static unsigned int _major = 0; | |
40 | ||
f32c10b0 | 41 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 | 42 | /* |
8fbf26ad | 43 | * For bio-based dm. |
1da177e4 LT |
44 | * One of these is allocated per bio. |
45 | */ | |
46 | struct dm_io { | |
47 | struct mapped_device *md; | |
48 | int error; | |
1da177e4 | 49 | atomic_t io_count; |
6ae2fa67 | 50 | struct bio *bio; |
3eaf840e | 51 | unsigned long start_time; |
f88fb981 | 52 | spinlock_t endio_lock; |
1da177e4 LT |
53 | }; |
54 | ||
55 | /* | |
8fbf26ad | 56 | * For bio-based dm. |
1da177e4 LT |
57 | * One of these is allocated per target within a bio. Hopefully |
58 | * this will be simplified out one day. | |
59 | */ | |
028867ac | 60 | struct dm_target_io { |
1da177e4 LT |
61 | struct dm_io *io; |
62 | struct dm_target *ti; | |
63 | union map_info info; | |
64 | }; | |
65 | ||
8fbf26ad KU |
66 | /* |
67 | * For request-based dm. | |
68 | * One of these is allocated per request. | |
69 | */ | |
70 | struct dm_rq_target_io { | |
71 | struct mapped_device *md; | |
72 | struct dm_target *ti; | |
73 | struct request *orig, clone; | |
74 | int error; | |
75 | union map_info info; | |
76 | }; | |
77 | ||
78 | /* | |
79 | * For request-based dm. | |
80 | * One of these is allocated per bio. | |
81 | */ | |
82 | struct dm_rq_clone_bio_info { | |
83 | struct bio *orig; | |
cec47e3d | 84 | struct dm_rq_target_io *tio; |
8fbf26ad KU |
85 | }; |
86 | ||
1da177e4 LT |
87 | union map_info *dm_get_mapinfo(struct bio *bio) |
88 | { | |
17b2f66f | 89 | if (bio && bio->bi_private) |
028867ac | 90 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 91 | return NULL; |
1da177e4 LT |
92 | } |
93 | ||
cec47e3d KU |
94 | union map_info *dm_get_rq_mapinfo(struct request *rq) |
95 | { | |
96 | if (rq && rq->end_io_data) | |
97 | return &((struct dm_rq_target_io *)rq->end_io_data)->info; | |
98 | return NULL; | |
99 | } | |
100 | EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); | |
101 | ||
ba61fdd1 JM |
102 | #define MINOR_ALLOCED ((void *)-1) |
103 | ||
1da177e4 LT |
104 | /* |
105 | * Bits for the md->flags field. | |
106 | */ | |
1eb787ec | 107 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
1da177e4 | 108 | #define DMF_SUSPENDED 1 |
aa8d7c2f | 109 | #define DMF_FROZEN 2 |
fba9f90e | 110 | #define DMF_FREEING 3 |
5c6bd75d | 111 | #define DMF_DELETING 4 |
2e93ccc1 | 112 | #define DMF_NOFLUSH_SUSPENDING 5 |
1eb787ec | 113 | #define DMF_QUEUE_IO_TO_THREAD 6 |
1da177e4 | 114 | |
304f3f6a MB |
115 | /* |
116 | * Work processed by per-device workqueue. | |
117 | */ | |
1da177e4 | 118 | struct mapped_device { |
2ca3310e | 119 | struct rw_semaphore io_lock; |
e61290a4 | 120 | struct mutex suspend_lock; |
1da177e4 LT |
121 | rwlock_t map_lock; |
122 | atomic_t holders; | |
5c6bd75d | 123 | atomic_t open_count; |
1da177e4 LT |
124 | |
125 | unsigned long flags; | |
126 | ||
165125e1 | 127 | struct request_queue *queue; |
a5664dad | 128 | unsigned type; |
4a0b4ddf | 129 | /* Protect queue and type against concurrent access. */ |
a5664dad MS |
130 | struct mutex type_lock; |
131 | ||
1da177e4 | 132 | struct gendisk *disk; |
7e51f257 | 133 | char name[16]; |
1da177e4 LT |
134 | |
135 | void *interface_ptr; | |
136 | ||
137 | /* | |
138 | * A list of ios that arrived while we were suspended. | |
139 | */ | |
316d315b | 140 | atomic_t pending[2]; |
1da177e4 | 141 | wait_queue_head_t wait; |
53d5914f | 142 | struct work_struct work; |
74859364 | 143 | struct bio_list deferred; |
022c2611 | 144 | spinlock_t deferred_lock; |
1da177e4 | 145 | |
af7e466a | 146 | /* |
d87f4c14 | 147 | * An error from the flush request currently being processed. |
af7e466a | 148 | */ |
d87f4c14 | 149 | int flush_error; |
af7e466a | 150 | |
d0bcb878 KU |
151 | /* |
152 | * Protect barrier_error from concurrent endio processing | |
153 | * in request-based dm. | |
154 | */ | |
155 | spinlock_t barrier_error_lock; | |
d87f4c14 | 156 | int barrier_error; |
d0bcb878 | 157 | |
304f3f6a MB |
158 | /* |
159 | * Processing queue (flush/barriers) | |
160 | */ | |
161 | struct workqueue_struct *wq; | |
d0bcb878 KU |
162 | struct work_struct barrier_work; |
163 | ||
164 | /* A pointer to the currently processing pre/post flush request */ | |
165 | struct request *flush_request; | |
304f3f6a | 166 | |
1da177e4 LT |
167 | /* |
168 | * The current mapping. | |
169 | */ | |
170 | struct dm_table *map; | |
171 | ||
172 | /* | |
173 | * io objects are allocated from here. | |
174 | */ | |
175 | mempool_t *io_pool; | |
176 | mempool_t *tio_pool; | |
177 | ||
9faf400f SB |
178 | struct bio_set *bs; |
179 | ||
1da177e4 LT |
180 | /* |
181 | * Event handling. | |
182 | */ | |
183 | atomic_t event_nr; | |
184 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
185 | atomic_t uevent_seq; |
186 | struct list_head uevent_list; | |
187 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
188 | |
189 | /* | |
190 | * freeze/thaw support require holding onto a super block | |
191 | */ | |
192 | struct super_block *frozen_sb; | |
db8fef4f | 193 | struct block_device *bdev; |
3ac51e74 DW |
194 | |
195 | /* forced geometry settings */ | |
196 | struct hd_geometry geometry; | |
784aae73 | 197 | |
cec47e3d KU |
198 | /* For saving the address of __make_request for request based dm */ |
199 | make_request_fn *saved_make_request_fn; | |
200 | ||
784aae73 MB |
201 | /* sysfs handle */ |
202 | struct kobject kobj; | |
52b1fd5a | 203 | |
d87f4c14 TH |
204 | /* zero-length flush that will be cloned and submitted to targets */ |
205 | struct bio flush_bio; | |
1da177e4 LT |
206 | }; |
207 | ||
e6ee8c0b KU |
208 | /* |
209 | * For mempools pre-allocation at the table loading time. | |
210 | */ | |
211 | struct dm_md_mempools { | |
212 | mempool_t *io_pool; | |
213 | mempool_t *tio_pool; | |
214 | struct bio_set *bs; | |
215 | }; | |
216 | ||
1da177e4 | 217 | #define MIN_IOS 256 |
e18b890b CL |
218 | static struct kmem_cache *_io_cache; |
219 | static struct kmem_cache *_tio_cache; | |
8fbf26ad KU |
220 | static struct kmem_cache *_rq_tio_cache; |
221 | static struct kmem_cache *_rq_bio_info_cache; | |
1da177e4 | 222 | |
1da177e4 LT |
223 | static int __init local_init(void) |
224 | { | |
51157b4a | 225 | int r = -ENOMEM; |
1da177e4 | 226 | |
1da177e4 | 227 | /* allocate a slab for the dm_ios */ |
028867ac | 228 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 229 | if (!_io_cache) |
51157b4a | 230 | return r; |
1da177e4 LT |
231 | |
232 | /* allocate a slab for the target ios */ | |
028867ac | 233 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
51157b4a KU |
234 | if (!_tio_cache) |
235 | goto out_free_io_cache; | |
1da177e4 | 236 | |
8fbf26ad KU |
237 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
238 | if (!_rq_tio_cache) | |
239 | goto out_free_tio_cache; | |
240 | ||
241 | _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0); | |
242 | if (!_rq_bio_info_cache) | |
243 | goto out_free_rq_tio_cache; | |
244 | ||
51e5b2bd | 245 | r = dm_uevent_init(); |
51157b4a | 246 | if (r) |
8fbf26ad | 247 | goto out_free_rq_bio_info_cache; |
51e5b2bd | 248 | |
1da177e4 LT |
249 | _major = major; |
250 | r = register_blkdev(_major, _name); | |
51157b4a KU |
251 | if (r < 0) |
252 | goto out_uevent_exit; | |
1da177e4 LT |
253 | |
254 | if (!_major) | |
255 | _major = r; | |
256 | ||
257 | return 0; | |
51157b4a KU |
258 | |
259 | out_uevent_exit: | |
260 | dm_uevent_exit(); | |
8fbf26ad KU |
261 | out_free_rq_bio_info_cache: |
262 | kmem_cache_destroy(_rq_bio_info_cache); | |
263 | out_free_rq_tio_cache: | |
264 | kmem_cache_destroy(_rq_tio_cache); | |
51157b4a KU |
265 | out_free_tio_cache: |
266 | kmem_cache_destroy(_tio_cache); | |
267 | out_free_io_cache: | |
268 | kmem_cache_destroy(_io_cache); | |
269 | ||
270 | return r; | |
1da177e4 LT |
271 | } |
272 | ||
273 | static void local_exit(void) | |
274 | { | |
8fbf26ad KU |
275 | kmem_cache_destroy(_rq_bio_info_cache); |
276 | kmem_cache_destroy(_rq_tio_cache); | |
1da177e4 LT |
277 | kmem_cache_destroy(_tio_cache); |
278 | kmem_cache_destroy(_io_cache); | |
00d59405 | 279 | unregister_blkdev(_major, _name); |
51e5b2bd | 280 | dm_uevent_exit(); |
1da177e4 LT |
281 | |
282 | _major = 0; | |
283 | ||
284 | DMINFO("cleaned up"); | |
285 | } | |
286 | ||
b9249e55 | 287 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
288 | local_init, |
289 | dm_target_init, | |
290 | dm_linear_init, | |
291 | dm_stripe_init, | |
952b3557 | 292 | dm_io_init, |
945fa4d2 | 293 | dm_kcopyd_init, |
1da177e4 LT |
294 | dm_interface_init, |
295 | }; | |
296 | ||
b9249e55 | 297 | static void (*_exits[])(void) = { |
1da177e4 LT |
298 | local_exit, |
299 | dm_target_exit, | |
300 | dm_linear_exit, | |
301 | dm_stripe_exit, | |
952b3557 | 302 | dm_io_exit, |
945fa4d2 | 303 | dm_kcopyd_exit, |
1da177e4 LT |
304 | dm_interface_exit, |
305 | }; | |
306 | ||
307 | static int __init dm_init(void) | |
308 | { | |
309 | const int count = ARRAY_SIZE(_inits); | |
310 | ||
311 | int r, i; | |
312 | ||
313 | for (i = 0; i < count; i++) { | |
314 | r = _inits[i](); | |
315 | if (r) | |
316 | goto bad; | |
317 | } | |
318 | ||
319 | return 0; | |
320 | ||
321 | bad: | |
322 | while (i--) | |
323 | _exits[i](); | |
324 | ||
325 | return r; | |
326 | } | |
327 | ||
328 | static void __exit dm_exit(void) | |
329 | { | |
330 | int i = ARRAY_SIZE(_exits); | |
331 | ||
332 | while (i--) | |
333 | _exits[i](); | |
334 | } | |
335 | ||
336 | /* | |
337 | * Block device functions | |
338 | */ | |
432a212c MA |
339 | int dm_deleting_md(struct mapped_device *md) |
340 | { | |
341 | return test_bit(DMF_DELETING, &md->flags); | |
342 | } | |
343 | ||
fe5f9f2c | 344 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
345 | { |
346 | struct mapped_device *md; | |
347 | ||
6e9624b8 | 348 | lock_kernel(); |
fba9f90e JM |
349 | spin_lock(&_minor_lock); |
350 | ||
fe5f9f2c | 351 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
352 | if (!md) |
353 | goto out; | |
354 | ||
5c6bd75d | 355 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 356 | dm_deleting_md(md)) { |
fba9f90e JM |
357 | md = NULL; |
358 | goto out; | |
359 | } | |
360 | ||
1da177e4 | 361 | dm_get(md); |
5c6bd75d | 362 | atomic_inc(&md->open_count); |
fba9f90e JM |
363 | |
364 | out: | |
365 | spin_unlock(&_minor_lock); | |
6e9624b8 | 366 | unlock_kernel(); |
fba9f90e JM |
367 | |
368 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
369 | } |
370 | ||
fe5f9f2c | 371 | static int dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 372 | { |
fe5f9f2c | 373 | struct mapped_device *md = disk->private_data; |
6e9624b8 AB |
374 | |
375 | lock_kernel(); | |
5c6bd75d | 376 | atomic_dec(&md->open_count); |
1da177e4 | 377 | dm_put(md); |
6e9624b8 AB |
378 | unlock_kernel(); |
379 | ||
1da177e4 LT |
380 | return 0; |
381 | } | |
382 | ||
5c6bd75d AK |
383 | int dm_open_count(struct mapped_device *md) |
384 | { | |
385 | return atomic_read(&md->open_count); | |
386 | } | |
387 | ||
388 | /* | |
389 | * Guarantees nothing is using the device before it's deleted. | |
390 | */ | |
391 | int dm_lock_for_deletion(struct mapped_device *md) | |
392 | { | |
393 | int r = 0; | |
394 | ||
395 | spin_lock(&_minor_lock); | |
396 | ||
397 | if (dm_open_count(md)) | |
398 | r = -EBUSY; | |
399 | else | |
400 | set_bit(DMF_DELETING, &md->flags); | |
401 | ||
402 | spin_unlock(&_minor_lock); | |
403 | ||
404 | return r; | |
405 | } | |
406 | ||
3ac51e74 DW |
407 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
408 | { | |
409 | struct mapped_device *md = bdev->bd_disk->private_data; | |
410 | ||
411 | return dm_get_geometry(md, geo); | |
412 | } | |
413 | ||
fe5f9f2c | 414 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
415 | unsigned int cmd, unsigned long arg) |
416 | { | |
fe5f9f2c | 417 | struct mapped_device *md = bdev->bd_disk->private_data; |
7c666411 | 418 | struct dm_table *map = dm_get_live_table(md); |
aa129a22 MB |
419 | struct dm_target *tgt; |
420 | int r = -ENOTTY; | |
421 | ||
aa129a22 MB |
422 | if (!map || !dm_table_get_size(map)) |
423 | goto out; | |
424 | ||
425 | /* We only support devices that have a single target */ | |
426 | if (dm_table_get_num_targets(map) != 1) | |
427 | goto out; | |
428 | ||
429 | tgt = dm_table_get_target(map, 0); | |
430 | ||
4f186f8b | 431 | if (dm_suspended_md(md)) { |
aa129a22 MB |
432 | r = -EAGAIN; |
433 | goto out; | |
434 | } | |
435 | ||
436 | if (tgt->type->ioctl) | |
647b3d00 | 437 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
438 | |
439 | out: | |
440 | dm_table_put(map); | |
441 | ||
aa129a22 MB |
442 | return r; |
443 | } | |
444 | ||
028867ac | 445 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
446 | { |
447 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
448 | } | |
449 | ||
028867ac | 450 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
451 | { |
452 | mempool_free(io, md->io_pool); | |
453 | } | |
454 | ||
028867ac | 455 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
456 | { |
457 | mempool_free(tio, md->tio_pool); | |
458 | } | |
459 | ||
08885643 KU |
460 | static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md, |
461 | gfp_t gfp_mask) | |
cec47e3d | 462 | { |
08885643 | 463 | return mempool_alloc(md->tio_pool, gfp_mask); |
cec47e3d KU |
464 | } |
465 | ||
466 | static void free_rq_tio(struct dm_rq_target_io *tio) | |
467 | { | |
468 | mempool_free(tio, tio->md->tio_pool); | |
469 | } | |
470 | ||
471 | static struct dm_rq_clone_bio_info *alloc_bio_info(struct mapped_device *md) | |
472 | { | |
473 | return mempool_alloc(md->io_pool, GFP_ATOMIC); | |
474 | } | |
475 | ||
476 | static void free_bio_info(struct dm_rq_clone_bio_info *info) | |
477 | { | |
478 | mempool_free(info, info->tio->md->io_pool); | |
479 | } | |
480 | ||
90abb8c4 KU |
481 | static int md_in_flight(struct mapped_device *md) |
482 | { | |
483 | return atomic_read(&md->pending[READ]) + | |
484 | atomic_read(&md->pending[WRITE]); | |
485 | } | |
486 | ||
3eaf840e JNN |
487 | static void start_io_acct(struct dm_io *io) |
488 | { | |
489 | struct mapped_device *md = io->md; | |
c9959059 | 490 | int cpu; |
316d315b | 491 | int rw = bio_data_dir(io->bio); |
3eaf840e JNN |
492 | |
493 | io->start_time = jiffies; | |
494 | ||
074a7aca TH |
495 | cpu = part_stat_lock(); |
496 | part_round_stats(cpu, &dm_disk(md)->part0); | |
497 | part_stat_unlock(); | |
316d315b | 498 | dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]); |
3eaf840e JNN |
499 | } |
500 | ||
d221d2e7 | 501 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
502 | { |
503 | struct mapped_device *md = io->md; | |
504 | struct bio *bio = io->bio; | |
505 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 506 | int pending, cpu; |
3eaf840e JNN |
507 | int rw = bio_data_dir(bio); |
508 | ||
074a7aca TH |
509 | cpu = part_stat_lock(); |
510 | part_round_stats(cpu, &dm_disk(md)->part0); | |
511 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
512 | part_stat_unlock(); | |
3eaf840e | 513 | |
af7e466a MP |
514 | /* |
515 | * After this is decremented the bio must not be touched if it is | |
d87f4c14 | 516 | * a flush. |
af7e466a | 517 | */ |
316d315b NK |
518 | dm_disk(md)->part0.in_flight[rw] = pending = |
519 | atomic_dec_return(&md->pending[rw]); | |
520 | pending += atomic_read(&md->pending[rw^0x1]); | |
3eaf840e | 521 | |
d221d2e7 MP |
522 | /* nudge anyone waiting on suspend queue */ |
523 | if (!pending) | |
524 | wake_up(&md->wait); | |
3eaf840e JNN |
525 | } |
526 | ||
1da177e4 LT |
527 | /* |
528 | * Add the bio to the list of deferred io. | |
529 | */ | |
92c63902 | 530 | static void queue_io(struct mapped_device *md, struct bio *bio) |
1da177e4 | 531 | { |
2ca3310e | 532 | down_write(&md->io_lock); |
1da177e4 | 533 | |
022c2611 | 534 | spin_lock_irq(&md->deferred_lock); |
1da177e4 | 535 | bio_list_add(&md->deferred, bio); |
022c2611 | 536 | spin_unlock_irq(&md->deferred_lock); |
1da177e4 | 537 | |
92c63902 MP |
538 | if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) |
539 | queue_work(md->wq, &md->work); | |
540 | ||
2ca3310e | 541 | up_write(&md->io_lock); |
1da177e4 LT |
542 | } |
543 | ||
544 | /* | |
545 | * Everyone (including functions in this file), should use this | |
546 | * function to access the md->map field, and make sure they call | |
547 | * dm_table_put() when finished. | |
548 | */ | |
7c666411 | 549 | struct dm_table *dm_get_live_table(struct mapped_device *md) |
1da177e4 LT |
550 | { |
551 | struct dm_table *t; | |
523d9297 | 552 | unsigned long flags; |
1da177e4 | 553 | |
523d9297 | 554 | read_lock_irqsave(&md->map_lock, flags); |
1da177e4 LT |
555 | t = md->map; |
556 | if (t) | |
557 | dm_table_get(t); | |
523d9297 | 558 | read_unlock_irqrestore(&md->map_lock, flags); |
1da177e4 LT |
559 | |
560 | return t; | |
561 | } | |
562 | ||
3ac51e74 DW |
563 | /* |
564 | * Get the geometry associated with a dm device | |
565 | */ | |
566 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
567 | { | |
568 | *geo = md->geometry; | |
569 | ||
570 | return 0; | |
571 | } | |
572 | ||
573 | /* | |
574 | * Set the geometry of a device. | |
575 | */ | |
576 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
577 | { | |
578 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
579 | ||
580 | if (geo->start > sz) { | |
581 | DMWARN("Start sector is beyond the geometry limits."); | |
582 | return -EINVAL; | |
583 | } | |
584 | ||
585 | md->geometry = *geo; | |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
1da177e4 LT |
590 | /*----------------------------------------------------------------- |
591 | * CRUD START: | |
592 | * A more elegant soln is in the works that uses the queue | |
593 | * merge fn, unfortunately there are a couple of changes to | |
594 | * the block layer that I want to make for this. So in the | |
595 | * interests of getting something for people to use I give | |
596 | * you this clearly demarcated crap. | |
597 | *---------------------------------------------------------------*/ | |
598 | ||
2e93ccc1 KU |
599 | static int __noflush_suspending(struct mapped_device *md) |
600 | { | |
601 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
602 | } | |
603 | ||
1da177e4 LT |
604 | /* |
605 | * Decrements the number of outstanding ios that a bio has been | |
606 | * cloned into, completing the original io if necc. | |
607 | */ | |
858119e1 | 608 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 609 | { |
2e93ccc1 | 610 | unsigned long flags; |
b35f8caa MB |
611 | int io_error; |
612 | struct bio *bio; | |
613 | struct mapped_device *md = io->md; | |
2e93ccc1 KU |
614 | |
615 | /* Push-back supersedes any I/O errors */ | |
f88fb981 KU |
616 | if (unlikely(error)) { |
617 | spin_lock_irqsave(&io->endio_lock, flags); | |
618 | if (!(io->error > 0 && __noflush_suspending(md))) | |
619 | io->error = error; | |
620 | spin_unlock_irqrestore(&io->endio_lock, flags); | |
621 | } | |
1da177e4 LT |
622 | |
623 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
624 | if (io->error == DM_ENDIO_REQUEUE) { |
625 | /* | |
626 | * Target requested pushing back the I/O. | |
2e93ccc1 | 627 | */ |
022c2611 | 628 | spin_lock_irqsave(&md->deferred_lock, flags); |
2761e95f | 629 | if (__noflush_suspending(md)) { |
d87f4c14 | 630 | if (!(io->bio->bi_rw & REQ_FLUSH)) |
2761e95f MP |
631 | bio_list_add_head(&md->deferred, |
632 | io->bio); | |
633 | } else | |
2e93ccc1 KU |
634 | /* noflush suspend was interrupted. */ |
635 | io->error = -EIO; | |
022c2611 | 636 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
2e93ccc1 KU |
637 | } |
638 | ||
b35f8caa MB |
639 | io_error = io->error; |
640 | bio = io->bio; | |
2e93ccc1 | 641 | |
d87f4c14 | 642 | if (bio->bi_rw & REQ_FLUSH) { |
af7e466a | 643 | /* |
d87f4c14 | 644 | * There can be just one flush request so we use |
af7e466a MP |
645 | * a per-device variable for error reporting. |
646 | * Note that you can't touch the bio after end_io_acct | |
647 | */ | |
d87f4c14 TH |
648 | if (!md->flush_error) |
649 | md->flush_error = io_error; | |
af7e466a | 650 | end_io_acct(io); |
a97f925a | 651 | free_io(md, io); |
af7e466a MP |
652 | } else { |
653 | end_io_acct(io); | |
a97f925a | 654 | free_io(md, io); |
b35f8caa | 655 | |
af7e466a MP |
656 | if (io_error != DM_ENDIO_REQUEUE) { |
657 | trace_block_bio_complete(md->queue, bio); | |
2056a782 | 658 | |
af7e466a MP |
659 | bio_endio(bio, io_error); |
660 | } | |
b35f8caa | 661 | } |
1da177e4 LT |
662 | } |
663 | } | |
664 | ||
6712ecf8 | 665 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
666 | { |
667 | int r = 0; | |
028867ac | 668 | struct dm_target_io *tio = bio->bi_private; |
b35f8caa | 669 | struct dm_io *io = tio->io; |
9faf400f | 670 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
671 | dm_endio_fn endio = tio->ti->type->end_io; |
672 | ||
1da177e4 LT |
673 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
674 | error = -EIO; | |
675 | ||
676 | if (endio) { | |
677 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
678 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
679 | /* | |
680 | * error and requeue request are handled | |
681 | * in dec_pending(). | |
682 | */ | |
1da177e4 | 683 | error = r; |
45cbcd79 KU |
684 | else if (r == DM_ENDIO_INCOMPLETE) |
685 | /* The target will handle the io */ | |
6712ecf8 | 686 | return; |
45cbcd79 KU |
687 | else if (r) { |
688 | DMWARN("unimplemented target endio return value: %d", r); | |
689 | BUG(); | |
690 | } | |
1da177e4 LT |
691 | } |
692 | ||
9faf400f SB |
693 | /* |
694 | * Store md for cleanup instead of tio which is about to get freed. | |
695 | */ | |
696 | bio->bi_private = md->bs; | |
697 | ||
9faf400f | 698 | free_tio(md, tio); |
b35f8caa MB |
699 | bio_put(bio); |
700 | dec_pending(io, error); | |
1da177e4 LT |
701 | } |
702 | ||
cec47e3d KU |
703 | /* |
704 | * Partial completion handling for request-based dm | |
705 | */ | |
706 | static void end_clone_bio(struct bio *clone, int error) | |
707 | { | |
708 | struct dm_rq_clone_bio_info *info = clone->bi_private; | |
709 | struct dm_rq_target_io *tio = info->tio; | |
710 | struct bio *bio = info->orig; | |
711 | unsigned int nr_bytes = info->orig->bi_size; | |
712 | ||
713 | bio_put(clone); | |
714 | ||
715 | if (tio->error) | |
716 | /* | |
717 | * An error has already been detected on the request. | |
718 | * Once error occurred, just let clone->end_io() handle | |
719 | * the remainder. | |
720 | */ | |
721 | return; | |
722 | else if (error) { | |
723 | /* | |
724 | * Don't notice the error to the upper layer yet. | |
725 | * The error handling decision is made by the target driver, | |
726 | * when the request is completed. | |
727 | */ | |
728 | tio->error = error; | |
729 | return; | |
730 | } | |
731 | ||
732 | /* | |
733 | * I/O for the bio successfully completed. | |
734 | * Notice the data completion to the upper layer. | |
735 | */ | |
736 | ||
737 | /* | |
738 | * bios are processed from the head of the list. | |
739 | * So the completing bio should always be rq->bio. | |
740 | * If it's not, something wrong is happening. | |
741 | */ | |
742 | if (tio->orig->bio != bio) | |
743 | DMERR("bio completion is going in the middle of the request"); | |
744 | ||
745 | /* | |
746 | * Update the original request. | |
747 | * Do not use blk_end_request() here, because it may complete | |
748 | * the original request before the clone, and break the ordering. | |
749 | */ | |
750 | blk_update_request(tio->orig, 0, nr_bytes); | |
751 | } | |
752 | ||
d0bcb878 KU |
753 | static void store_barrier_error(struct mapped_device *md, int error) |
754 | { | |
755 | unsigned long flags; | |
756 | ||
757 | spin_lock_irqsave(&md->barrier_error_lock, flags); | |
758 | /* | |
759 | * Basically, the first error is taken, but: | |
760 | * -EOPNOTSUPP supersedes any I/O error. | |
761 | * Requeue request supersedes any I/O error but -EOPNOTSUPP. | |
762 | */ | |
763 | if (!md->barrier_error || error == -EOPNOTSUPP || | |
764 | (md->barrier_error != -EOPNOTSUPP && | |
765 | error == DM_ENDIO_REQUEUE)) | |
766 | md->barrier_error = error; | |
767 | spin_unlock_irqrestore(&md->barrier_error_lock, flags); | |
768 | } | |
769 | ||
cec47e3d KU |
770 | /* |
771 | * Don't touch any member of the md after calling this function because | |
772 | * the md may be freed in dm_put() at the end of this function. | |
773 | * Or do dm_get() before calling this function and dm_put() later. | |
774 | */ | |
b4324fee | 775 | static void rq_completed(struct mapped_device *md, int rw, int run_queue) |
cec47e3d | 776 | { |
b4324fee | 777 | atomic_dec(&md->pending[rw]); |
cec47e3d KU |
778 | |
779 | /* nudge anyone waiting on suspend queue */ | |
b4324fee | 780 | if (!md_in_flight(md)) |
cec47e3d KU |
781 | wake_up(&md->wait); |
782 | ||
783 | if (run_queue) | |
b4324fee | 784 | blk_run_queue(md->queue); |
cec47e3d KU |
785 | |
786 | /* | |
787 | * dm_put() must be at the end of this function. See the comment above | |
788 | */ | |
789 | dm_put(md); | |
790 | } | |
791 | ||
a77e28c7 KU |
792 | static void free_rq_clone(struct request *clone) |
793 | { | |
794 | struct dm_rq_target_io *tio = clone->end_io_data; | |
795 | ||
796 | blk_rq_unprep_clone(clone); | |
797 | free_rq_tio(tio); | |
798 | } | |
799 | ||
980691e5 KU |
800 | /* |
801 | * Complete the clone and the original request. | |
802 | * Must be called without queue lock. | |
803 | */ | |
804 | static void dm_end_request(struct request *clone, int error) | |
805 | { | |
806 | int rw = rq_data_dir(clone); | |
d0bcb878 | 807 | int run_queue = 1; |
33659ebb | 808 | bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER; |
980691e5 KU |
809 | struct dm_rq_target_io *tio = clone->end_io_data; |
810 | struct mapped_device *md = tio->md; | |
811 | struct request *rq = tio->orig; | |
812 | ||
33659ebb | 813 | if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) { |
980691e5 KU |
814 | rq->errors = clone->errors; |
815 | rq->resid_len = clone->resid_len; | |
816 | ||
817 | if (rq->sense) | |
818 | /* | |
819 | * We are using the sense buffer of the original | |
820 | * request. | |
821 | * So setting the length of the sense data is enough. | |
822 | */ | |
823 | rq->sense_len = clone->sense_len; | |
824 | } | |
825 | ||
826 | free_rq_clone(clone); | |
827 | ||
d0bcb878 KU |
828 | if (unlikely(is_barrier)) { |
829 | if (unlikely(error)) | |
830 | store_barrier_error(md, error); | |
831 | run_queue = 0; | |
832 | } else | |
833 | blk_end_request_all(rq, error); | |
980691e5 | 834 | |
d0bcb878 | 835 | rq_completed(md, rw, run_queue); |
980691e5 KU |
836 | } |
837 | ||
cec47e3d KU |
838 | static void dm_unprep_request(struct request *rq) |
839 | { | |
840 | struct request *clone = rq->special; | |
cec47e3d KU |
841 | |
842 | rq->special = NULL; | |
843 | rq->cmd_flags &= ~REQ_DONTPREP; | |
844 | ||
a77e28c7 | 845 | free_rq_clone(clone); |
cec47e3d KU |
846 | } |
847 | ||
848 | /* | |
849 | * Requeue the original request of a clone. | |
850 | */ | |
851 | void dm_requeue_unmapped_request(struct request *clone) | |
852 | { | |
b4324fee | 853 | int rw = rq_data_dir(clone); |
cec47e3d KU |
854 | struct dm_rq_target_io *tio = clone->end_io_data; |
855 | struct mapped_device *md = tio->md; | |
856 | struct request *rq = tio->orig; | |
857 | struct request_queue *q = rq->q; | |
858 | unsigned long flags; | |
859 | ||
33659ebb | 860 | if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { |
d0bcb878 KU |
861 | /* |
862 | * Barrier clones share an original request. | |
863 | * Leave it to dm_end_request(), which handles this special | |
864 | * case. | |
865 | */ | |
866 | dm_end_request(clone, DM_ENDIO_REQUEUE); | |
867 | return; | |
868 | } | |
869 | ||
cec47e3d KU |
870 | dm_unprep_request(rq); |
871 | ||
872 | spin_lock_irqsave(q->queue_lock, flags); | |
873 | if (elv_queue_empty(q)) | |
874 | blk_plug_device(q); | |
875 | blk_requeue_request(q, rq); | |
876 | spin_unlock_irqrestore(q->queue_lock, flags); | |
877 | ||
b4324fee | 878 | rq_completed(md, rw, 0); |
cec47e3d KU |
879 | } |
880 | EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request); | |
881 | ||
882 | static void __stop_queue(struct request_queue *q) | |
883 | { | |
884 | blk_stop_queue(q); | |
885 | } | |
886 | ||
887 | static void stop_queue(struct request_queue *q) | |
888 | { | |
889 | unsigned long flags; | |
890 | ||
891 | spin_lock_irqsave(q->queue_lock, flags); | |
892 | __stop_queue(q); | |
893 | spin_unlock_irqrestore(q->queue_lock, flags); | |
894 | } | |
895 | ||
896 | static void __start_queue(struct request_queue *q) | |
897 | { | |
898 | if (blk_queue_stopped(q)) | |
899 | blk_start_queue(q); | |
900 | } | |
901 | ||
902 | static void start_queue(struct request_queue *q) | |
903 | { | |
904 | unsigned long flags; | |
905 | ||
906 | spin_lock_irqsave(q->queue_lock, flags); | |
907 | __start_queue(q); | |
908 | spin_unlock_irqrestore(q->queue_lock, flags); | |
909 | } | |
910 | ||
11a68244 | 911 | static void dm_done(struct request *clone, int error, bool mapped) |
cec47e3d | 912 | { |
11a68244 | 913 | int r = error; |
cec47e3d KU |
914 | struct dm_rq_target_io *tio = clone->end_io_data; |
915 | dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io; | |
cec47e3d | 916 | |
11a68244 KU |
917 | if (mapped && rq_end_io) |
918 | r = rq_end_io(tio->ti, clone, error, &tio->info); | |
cec47e3d | 919 | |
11a68244 | 920 | if (r <= 0) |
cec47e3d | 921 | /* The target wants to complete the I/O */ |
11a68244 KU |
922 | dm_end_request(clone, r); |
923 | else if (r == DM_ENDIO_INCOMPLETE) | |
cec47e3d KU |
924 | /* The target will handle the I/O */ |
925 | return; | |
11a68244 | 926 | else if (r == DM_ENDIO_REQUEUE) |
cec47e3d KU |
927 | /* The target wants to requeue the I/O */ |
928 | dm_requeue_unmapped_request(clone); | |
929 | else { | |
11a68244 | 930 | DMWARN("unimplemented target endio return value: %d", r); |
cec47e3d KU |
931 | BUG(); |
932 | } | |
933 | } | |
934 | ||
11a68244 KU |
935 | /* |
936 | * Request completion handler for request-based dm | |
937 | */ | |
938 | static void dm_softirq_done(struct request *rq) | |
939 | { | |
940 | bool mapped = true; | |
941 | struct request *clone = rq->completion_data; | |
942 | struct dm_rq_target_io *tio = clone->end_io_data; | |
943 | ||
944 | if (rq->cmd_flags & REQ_FAILED) | |
945 | mapped = false; | |
946 | ||
947 | dm_done(clone, tio->error, mapped); | |
948 | } | |
949 | ||
cec47e3d KU |
950 | /* |
951 | * Complete the clone and the original request with the error status | |
952 | * through softirq context. | |
953 | */ | |
954 | static void dm_complete_request(struct request *clone, int error) | |
955 | { | |
956 | struct dm_rq_target_io *tio = clone->end_io_data; | |
957 | struct request *rq = tio->orig; | |
958 | ||
33659ebb | 959 | if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { |
d0bcb878 KU |
960 | /* |
961 | * Barrier clones share an original request. So can't use | |
962 | * softirq_done with the original. | |
963 | * Pass the clone to dm_done() directly in this special case. | |
964 | * It is safe (even if clone->q->queue_lock is held here) | |
965 | * because there is no I/O dispatching during the completion | |
966 | * of barrier clone. | |
967 | */ | |
968 | dm_done(clone, error, true); | |
969 | return; | |
970 | } | |
971 | ||
cec47e3d KU |
972 | tio->error = error; |
973 | rq->completion_data = clone; | |
974 | blk_complete_request(rq); | |
975 | } | |
976 | ||
977 | /* | |
978 | * Complete the not-mapped clone and the original request with the error status | |
979 | * through softirq context. | |
980 | * Target's rq_end_io() function isn't called. | |
981 | * This may be used when the target's map_rq() function fails. | |
982 | */ | |
983 | void dm_kill_unmapped_request(struct request *clone, int error) | |
984 | { | |
985 | struct dm_rq_target_io *tio = clone->end_io_data; | |
986 | struct request *rq = tio->orig; | |
987 | ||
33659ebb | 988 | if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { |
d0bcb878 KU |
989 | /* |
990 | * Barrier clones share an original request. | |
991 | * Leave it to dm_end_request(), which handles this special | |
992 | * case. | |
993 | */ | |
994 | BUG_ON(error > 0); | |
995 | dm_end_request(clone, error); | |
996 | return; | |
997 | } | |
998 | ||
cec47e3d KU |
999 | rq->cmd_flags |= REQ_FAILED; |
1000 | dm_complete_request(clone, error); | |
1001 | } | |
1002 | EXPORT_SYMBOL_GPL(dm_kill_unmapped_request); | |
1003 | ||
1004 | /* | |
1005 | * Called with the queue lock held | |
1006 | */ | |
1007 | static void end_clone_request(struct request *clone, int error) | |
1008 | { | |
1009 | /* | |
1010 | * For just cleaning up the information of the queue in which | |
1011 | * the clone was dispatched. | |
1012 | * The clone is *NOT* freed actually here because it is alloced from | |
1013 | * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags. | |
1014 | */ | |
1015 | __blk_put_request(clone->q, clone); | |
1016 | ||
1017 | /* | |
1018 | * Actual request completion is done in a softirq context which doesn't | |
1019 | * hold the queue lock. Otherwise, deadlock could occur because: | |
1020 | * - another request may be submitted by the upper level driver | |
1021 | * of the stacking during the completion | |
1022 | * - the submission which requires queue lock may be done | |
1023 | * against this queue | |
1024 | */ | |
1025 | dm_complete_request(clone, error); | |
1026 | } | |
1027 | ||
56a67df7 MS |
1028 | /* |
1029 | * Return maximum size of I/O possible at the supplied sector up to the current | |
1030 | * target boundary. | |
1031 | */ | |
1032 | static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti) | |
1033 | { | |
1034 | sector_t target_offset = dm_target_offset(ti, sector); | |
1035 | ||
1036 | return ti->len - target_offset; | |
1037 | } | |
1038 | ||
1039 | static sector_t max_io_len(sector_t sector, struct dm_target *ti) | |
1da177e4 | 1040 | { |
56a67df7 | 1041 | sector_t len = max_io_len_target_boundary(sector, ti); |
1da177e4 LT |
1042 | |
1043 | /* | |
1044 | * Does the target need to split even further ? | |
1045 | */ | |
1046 | if (ti->split_io) { | |
1047 | sector_t boundary; | |
56a67df7 | 1048 | sector_t offset = dm_target_offset(ti, sector); |
1da177e4 LT |
1049 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) |
1050 | - offset; | |
1051 | if (len > boundary) | |
1052 | len = boundary; | |
1053 | } | |
1054 | ||
1055 | return len; | |
1056 | } | |
1057 | ||
1058 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 1059 | struct dm_target_io *tio) |
1da177e4 LT |
1060 | { |
1061 | int r; | |
2056a782 | 1062 | sector_t sector; |
9faf400f | 1063 | struct mapped_device *md; |
1da177e4 | 1064 | |
1da177e4 LT |
1065 | clone->bi_end_io = clone_endio; |
1066 | clone->bi_private = tio; | |
1067 | ||
1068 | /* | |
1069 | * Map the clone. If r == 0 we don't need to do | |
1070 | * anything, the target has assumed ownership of | |
1071 | * this io. | |
1072 | */ | |
1073 | atomic_inc(&tio->io->io_count); | |
2056a782 | 1074 | sector = clone->bi_sector; |
1da177e4 | 1075 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 1076 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 1077 | /* the bio has been remapped so dispatch it */ |
2056a782 | 1078 | |
5f3ea37c | 1079 | trace_block_remap(bdev_get_queue(clone->bi_bdev), clone, |
22a7c31a | 1080 | tio->io->bio->bi_bdev->bd_dev, sector); |
2056a782 | 1081 | |
1da177e4 | 1082 | generic_make_request(clone); |
2e93ccc1 KU |
1083 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
1084 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
1085 | md = tio->io->md; |
1086 | dec_pending(tio->io, r); | |
1087 | /* | |
1088 | * Store bio_set for cleanup. | |
1089 | */ | |
1090 | clone->bi_private = md->bs; | |
1da177e4 | 1091 | bio_put(clone); |
9faf400f | 1092 | free_tio(md, tio); |
45cbcd79 KU |
1093 | } else if (r) { |
1094 | DMWARN("unimplemented target map return value: %d", r); | |
1095 | BUG(); | |
1da177e4 LT |
1096 | } |
1097 | } | |
1098 | ||
1099 | struct clone_info { | |
1100 | struct mapped_device *md; | |
1101 | struct dm_table *map; | |
1102 | struct bio *bio; | |
1103 | struct dm_io *io; | |
1104 | sector_t sector; | |
1105 | sector_t sector_count; | |
1106 | unsigned short idx; | |
1107 | }; | |
1108 | ||
3676347a PO |
1109 | static void dm_bio_destructor(struct bio *bio) |
1110 | { | |
9faf400f SB |
1111 | struct bio_set *bs = bio->bi_private; |
1112 | ||
1113 | bio_free(bio, bs); | |
3676347a PO |
1114 | } |
1115 | ||
1da177e4 | 1116 | /* |
d87f4c14 | 1117 | * Creates a little bio that just does part of a bvec. |
1da177e4 LT |
1118 | */ |
1119 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
1120 | unsigned short idx, unsigned int offset, | |
9faf400f | 1121 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
1122 | { |
1123 | struct bio *clone; | |
1124 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
1125 | ||
9faf400f | 1126 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 1127 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
1128 | *clone->bi_io_vec = *bv; |
1129 | ||
1130 | clone->bi_sector = sector; | |
1131 | clone->bi_bdev = bio->bi_bdev; | |
d87f4c14 | 1132 | clone->bi_rw = bio->bi_rw; |
1da177e4 LT |
1133 | clone->bi_vcnt = 1; |
1134 | clone->bi_size = to_bytes(len); | |
1135 | clone->bi_io_vec->bv_offset = offset; | |
1136 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 1137 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 | 1138 | |
9c47008d | 1139 | if (bio_integrity(bio)) { |
7878cba9 | 1140 | bio_integrity_clone(clone, bio, GFP_NOIO, bs); |
9c47008d MP |
1141 | bio_integrity_trim(clone, |
1142 | bio_sector_offset(bio, idx, offset), len); | |
1143 | } | |
1144 | ||
1da177e4 LT |
1145 | return clone; |
1146 | } | |
1147 | ||
1148 | /* | |
1149 | * Creates a bio that consists of range of complete bvecs. | |
1150 | */ | |
1151 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
1152 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 1153 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
1154 | { |
1155 | struct bio *clone; | |
1156 | ||
9faf400f SB |
1157 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
1158 | __bio_clone(clone, bio); | |
1159 | clone->bi_destructor = dm_bio_destructor; | |
1da177e4 LT |
1160 | clone->bi_sector = sector; |
1161 | clone->bi_idx = idx; | |
1162 | clone->bi_vcnt = idx + bv_count; | |
1163 | clone->bi_size = to_bytes(len); | |
1164 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
1165 | ||
9c47008d | 1166 | if (bio_integrity(bio)) { |
7878cba9 | 1167 | bio_integrity_clone(clone, bio, GFP_NOIO, bs); |
9c47008d MP |
1168 | |
1169 | if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) | |
1170 | bio_integrity_trim(clone, | |
1171 | bio_sector_offset(bio, idx, 0), len); | |
1172 | } | |
1173 | ||
1da177e4 LT |
1174 | return clone; |
1175 | } | |
1176 | ||
9015df24 AK |
1177 | static struct dm_target_io *alloc_tio(struct clone_info *ci, |
1178 | struct dm_target *ti) | |
f9ab94ce | 1179 | { |
9015df24 | 1180 | struct dm_target_io *tio = mempool_alloc(ci->md->tio_pool, GFP_NOIO); |
f9ab94ce MP |
1181 | |
1182 | tio->io = ci->io; | |
1183 | tio->ti = ti; | |
f9ab94ce | 1184 | memset(&tio->info, 0, sizeof(tio->info)); |
9015df24 AK |
1185 | |
1186 | return tio; | |
1187 | } | |
1188 | ||
06a426ce | 1189 | static void __issue_target_request(struct clone_info *ci, struct dm_target *ti, |
a79245b3 | 1190 | unsigned request_nr, sector_t len) |
9015df24 AK |
1191 | { |
1192 | struct dm_target_io *tio = alloc_tio(ci, ti); | |
1193 | struct bio *clone; | |
1194 | ||
57cba5d3 | 1195 | tio->info.target_request_nr = request_nr; |
f9ab94ce | 1196 | |
06a426ce MS |
1197 | /* |
1198 | * Discard requests require the bio's inline iovecs be initialized. | |
1199 | * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush | |
1200 | * and discard, so no need for concern about wasted bvec allocations. | |
1201 | */ | |
1202 | clone = bio_alloc_bioset(GFP_NOIO, ci->bio->bi_max_vecs, ci->md->bs); | |
f9ab94ce MP |
1203 | __bio_clone(clone, ci->bio); |
1204 | clone->bi_destructor = dm_bio_destructor; | |
a79245b3 MS |
1205 | if (len) { |
1206 | clone->bi_sector = ci->sector; | |
1207 | clone->bi_size = to_bytes(len); | |
1208 | } | |
f9ab94ce MP |
1209 | |
1210 | __map_bio(ti, clone, tio); | |
1211 | } | |
1212 | ||
06a426ce | 1213 | static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, |
a79245b3 | 1214 | unsigned num_requests, sector_t len) |
06a426ce MS |
1215 | { |
1216 | unsigned request_nr; | |
1217 | ||
1218 | for (request_nr = 0; request_nr < num_requests; request_nr++) | |
a79245b3 | 1219 | __issue_target_request(ci, ti, request_nr, len); |
06a426ce MS |
1220 | } |
1221 | ||
d87f4c14 | 1222 | static int __clone_and_map_flush(struct clone_info *ci) |
f9ab94ce | 1223 | { |
06a426ce | 1224 | unsigned target_nr = 0; |
f9ab94ce MP |
1225 | struct dm_target *ti; |
1226 | ||
1227 | while ((ti = dm_table_get_target(ci->map, target_nr++))) | |
a79245b3 | 1228 | __issue_target_requests(ci, ti, ti->num_flush_requests, 0); |
f9ab94ce MP |
1229 | |
1230 | ci->sector_count = 0; | |
1231 | ||
1232 | return 0; | |
1233 | } | |
1234 | ||
5ae89a87 MS |
1235 | /* |
1236 | * Perform all io with a single clone. | |
1237 | */ | |
1238 | static void __clone_and_map_simple(struct clone_info *ci, struct dm_target *ti) | |
1239 | { | |
1240 | struct bio *clone, *bio = ci->bio; | |
1241 | struct dm_target_io *tio; | |
1242 | ||
1243 | tio = alloc_tio(ci, ti); | |
1244 | clone = clone_bio(bio, ci->sector, ci->idx, | |
1245 | bio->bi_vcnt - ci->idx, ci->sector_count, | |
1246 | ci->md->bs); | |
1247 | __map_bio(ti, clone, tio); | |
1248 | ci->sector_count = 0; | |
1249 | } | |
1250 | ||
1251 | static int __clone_and_map_discard(struct clone_info *ci) | |
1252 | { | |
1253 | struct dm_target *ti; | |
a79245b3 | 1254 | sector_t len; |
5ae89a87 | 1255 | |
a79245b3 MS |
1256 | do { |
1257 | ti = dm_table_find_target(ci->map, ci->sector); | |
1258 | if (!dm_target_is_valid(ti)) | |
1259 | return -EIO; | |
5ae89a87 | 1260 | |
5ae89a87 | 1261 | /* |
a79245b3 MS |
1262 | * Even though the device advertised discard support, |
1263 | * reconfiguration might have changed that since the | |
1264 | * check was performed. | |
5ae89a87 | 1265 | */ |
a79245b3 MS |
1266 | if (!ti->num_discard_requests) |
1267 | return -EOPNOTSUPP; | |
5ae89a87 | 1268 | |
a79245b3 | 1269 | len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti)); |
06a426ce | 1270 | |
a79245b3 MS |
1271 | __issue_target_requests(ci, ti, ti->num_discard_requests, len); |
1272 | ||
1273 | ci->sector += len; | |
1274 | } while (ci->sector_count -= len); | |
5ae89a87 MS |
1275 | |
1276 | return 0; | |
1277 | } | |
1278 | ||
512875bd | 1279 | static int __clone_and_map(struct clone_info *ci) |
1da177e4 LT |
1280 | { |
1281 | struct bio *clone, *bio = ci->bio; | |
512875bd JN |
1282 | struct dm_target *ti; |
1283 | sector_t len = 0, max; | |
028867ac | 1284 | struct dm_target_io *tio; |
1da177e4 | 1285 | |
5ae89a87 MS |
1286 | if (unlikely(bio->bi_rw & REQ_DISCARD)) |
1287 | return __clone_and_map_discard(ci); | |
1288 | ||
512875bd JN |
1289 | ti = dm_table_find_target(ci->map, ci->sector); |
1290 | if (!dm_target_is_valid(ti)) | |
1291 | return -EIO; | |
1292 | ||
56a67df7 | 1293 | max = max_io_len(ci->sector, ti); |
512875bd | 1294 | |
1da177e4 LT |
1295 | if (ci->sector_count <= max) { |
1296 | /* | |
1297 | * Optimise for the simple case where we can do all of | |
1298 | * the remaining io with a single clone. | |
1299 | */ | |
5ae89a87 | 1300 | __clone_and_map_simple(ci, ti); |
1da177e4 LT |
1301 | |
1302 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
1303 | /* | |
1304 | * There are some bvecs that don't span targets. | |
1305 | * Do as many of these as possible. | |
1306 | */ | |
1307 | int i; | |
1308 | sector_t remaining = max; | |
1309 | sector_t bv_len; | |
1310 | ||
1311 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
1312 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
1313 | ||
1314 | if (bv_len > remaining) | |
1315 | break; | |
1316 | ||
1317 | remaining -= bv_len; | |
1318 | len += bv_len; | |
1319 | } | |
1320 | ||
5ae89a87 | 1321 | tio = alloc_tio(ci, ti); |
9faf400f SB |
1322 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
1323 | ci->md->bs); | |
1da177e4 LT |
1324 | __map_bio(ti, clone, tio); |
1325 | ||
1326 | ci->sector += len; | |
1327 | ci->sector_count -= len; | |
1328 | ci->idx = i; | |
1329 | ||
1330 | } else { | |
1331 | /* | |
d2044a94 | 1332 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
1333 | */ |
1334 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
1335 | sector_t remaining = to_sector(bv->bv_len); |
1336 | unsigned int offset = 0; | |
1da177e4 | 1337 | |
d2044a94 AK |
1338 | do { |
1339 | if (offset) { | |
1340 | ti = dm_table_find_target(ci->map, ci->sector); | |
512875bd JN |
1341 | if (!dm_target_is_valid(ti)) |
1342 | return -EIO; | |
1343 | ||
56a67df7 | 1344 | max = max_io_len(ci->sector, ti); |
d2044a94 AK |
1345 | } |
1346 | ||
1347 | len = min(remaining, max); | |
1348 | ||
5ae89a87 | 1349 | tio = alloc_tio(ci, ti); |
d2044a94 | 1350 | clone = split_bvec(bio, ci->sector, ci->idx, |
9faf400f SB |
1351 | bv->bv_offset + offset, len, |
1352 | ci->md->bs); | |
d2044a94 AK |
1353 | |
1354 | __map_bio(ti, clone, tio); | |
1355 | ||
1356 | ci->sector += len; | |
1357 | ci->sector_count -= len; | |
1358 | offset += to_bytes(len); | |
1359 | } while (remaining -= len); | |
1da177e4 | 1360 | |
1da177e4 LT |
1361 | ci->idx++; |
1362 | } | |
512875bd JN |
1363 | |
1364 | return 0; | |
1da177e4 LT |
1365 | } |
1366 | ||
1367 | /* | |
8a53c28d | 1368 | * Split the bio into several clones and submit it to targets. |
1da177e4 | 1369 | */ |
f0b9a450 | 1370 | static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) |
1da177e4 LT |
1371 | { |
1372 | struct clone_info ci; | |
512875bd | 1373 | int error = 0; |
1da177e4 | 1374 | |
7c666411 | 1375 | ci.map = dm_get_live_table(md); |
f0b9a450 | 1376 | if (unlikely(!ci.map)) { |
d87f4c14 | 1377 | if (!(bio->bi_rw & REQ_FLUSH)) |
af7e466a MP |
1378 | bio_io_error(bio); |
1379 | else | |
d87f4c14 TH |
1380 | if (!md->flush_error) |
1381 | md->flush_error = -EIO; | |
f0b9a450 MP |
1382 | return; |
1383 | } | |
692d0eb9 | 1384 | |
1da177e4 LT |
1385 | ci.md = md; |
1386 | ci.bio = bio; | |
1387 | ci.io = alloc_io(md); | |
1388 | ci.io->error = 0; | |
1389 | atomic_set(&ci.io->io_count, 1); | |
1390 | ci.io->bio = bio; | |
1391 | ci.io->md = md; | |
f88fb981 | 1392 | spin_lock_init(&ci.io->endio_lock); |
1da177e4 | 1393 | ci.sector = bio->bi_sector; |
d87f4c14 TH |
1394 | if (!(bio->bi_rw & REQ_FLUSH)) |
1395 | ci.sector_count = bio_sectors(bio); | |
1396 | else { | |
1397 | /* all FLUSH bio's reaching here should be empty */ | |
1398 | WARN_ON_ONCE(bio_has_data(bio)); | |
f9ab94ce | 1399 | ci.sector_count = 1; |
d87f4c14 | 1400 | } |
1da177e4 LT |
1401 | ci.idx = bio->bi_idx; |
1402 | ||
3eaf840e | 1403 | start_io_acct(ci.io); |
d87f4c14 TH |
1404 | while (ci.sector_count && !error) { |
1405 | if (!(bio->bi_rw & REQ_FLUSH)) | |
1406 | error = __clone_and_map(&ci); | |
1407 | else | |
1408 | error = __clone_and_map_flush(&ci); | |
1409 | } | |
1da177e4 LT |
1410 | |
1411 | /* drop the extra reference count */ | |
512875bd | 1412 | dec_pending(ci.io, error); |
1da177e4 LT |
1413 | dm_table_put(ci.map); |
1414 | } | |
1415 | /*----------------------------------------------------------------- | |
1416 | * CRUD END | |
1417 | *---------------------------------------------------------------*/ | |
1418 | ||
f6fccb12 MB |
1419 | static int dm_merge_bvec(struct request_queue *q, |
1420 | struct bvec_merge_data *bvm, | |
1421 | struct bio_vec *biovec) | |
1422 | { | |
1423 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1424 | struct dm_table *map = dm_get_live_table(md); |
f6fccb12 MB |
1425 | struct dm_target *ti; |
1426 | sector_t max_sectors; | |
5037108a | 1427 | int max_size = 0; |
f6fccb12 MB |
1428 | |
1429 | if (unlikely(!map)) | |
5037108a | 1430 | goto out; |
f6fccb12 MB |
1431 | |
1432 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac MP |
1433 | if (!dm_target_is_valid(ti)) |
1434 | goto out_table; | |
f6fccb12 MB |
1435 | |
1436 | /* | |
1437 | * Find maximum amount of I/O that won't need splitting | |
1438 | */ | |
56a67df7 | 1439 | max_sectors = min(max_io_len(bvm->bi_sector, ti), |
f6fccb12 MB |
1440 | (sector_t) BIO_MAX_SECTORS); |
1441 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
1442 | if (max_size < 0) | |
1443 | max_size = 0; | |
1444 | ||
1445 | /* | |
1446 | * merge_bvec_fn() returns number of bytes | |
1447 | * it can accept at this offset | |
1448 | * max is precomputed maximal io size | |
1449 | */ | |
1450 | if (max_size && ti->type->merge) | |
1451 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
8cbeb67a MP |
1452 | /* |
1453 | * If the target doesn't support merge method and some of the devices | |
1454 | * provided their merge_bvec method (we know this by looking at | |
1455 | * queue_max_hw_sectors), then we can't allow bios with multiple vector | |
1456 | * entries. So always set max_size to 0, and the code below allows | |
1457 | * just one page. | |
1458 | */ | |
1459 | else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) | |
1460 | ||
1461 | max_size = 0; | |
f6fccb12 | 1462 | |
b01cd5ac | 1463 | out_table: |
5037108a MP |
1464 | dm_table_put(map); |
1465 | ||
1466 | out: | |
f6fccb12 MB |
1467 | /* |
1468 | * Always allow an entire first page | |
1469 | */ | |
1470 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
1471 | max_size = biovec->bv_len; | |
1472 | ||
f6fccb12 MB |
1473 | return max_size; |
1474 | } | |
1475 | ||
1da177e4 LT |
1476 | /* |
1477 | * The request function that just remaps the bio built up by | |
1478 | * dm_merge_bvec. | |
1479 | */ | |
cec47e3d | 1480 | static int _dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 1481 | { |
12f03a49 | 1482 | int rw = bio_data_dir(bio); |
1da177e4 | 1483 | struct mapped_device *md = q->queuedata; |
c9959059 | 1484 | int cpu; |
1da177e4 | 1485 | |
2ca3310e | 1486 | down_read(&md->io_lock); |
1da177e4 | 1487 | |
074a7aca TH |
1488 | cpu = part_stat_lock(); |
1489 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
1490 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
1491 | part_stat_unlock(); | |
12f03a49 | 1492 | |
1da177e4 | 1493 | /* |
d87f4c14 | 1494 | * If we're suspended or the thread is processing flushes |
1eb787ec | 1495 | * we have to queue this io for later. |
1da177e4 | 1496 | */ |
af7e466a | 1497 | if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) || |
d87f4c14 | 1498 | (bio->bi_rw & REQ_FLUSH)) { |
2ca3310e | 1499 | up_read(&md->io_lock); |
1da177e4 | 1500 | |
54d9a1b4 AK |
1501 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && |
1502 | bio_rw(bio) == READA) { | |
1503 | bio_io_error(bio); | |
1504 | return 0; | |
1505 | } | |
1da177e4 | 1506 | |
92c63902 | 1507 | queue_io(md, bio); |
1da177e4 | 1508 | |
92c63902 | 1509 | return 0; |
1da177e4 LT |
1510 | } |
1511 | ||
f0b9a450 | 1512 | __split_and_process_bio(md, bio); |
2ca3310e | 1513 | up_read(&md->io_lock); |
f0b9a450 | 1514 | return 0; |
1da177e4 LT |
1515 | } |
1516 | ||
cec47e3d KU |
1517 | static int dm_make_request(struct request_queue *q, struct bio *bio) |
1518 | { | |
1519 | struct mapped_device *md = q->queuedata; | |
1520 | ||
cec47e3d KU |
1521 | return md->saved_make_request_fn(q, bio); /* call __make_request() */ |
1522 | } | |
1523 | ||
1524 | static int dm_request_based(struct mapped_device *md) | |
1525 | { | |
1526 | return blk_queue_stackable(md->queue); | |
1527 | } | |
1528 | ||
1529 | static int dm_request(struct request_queue *q, struct bio *bio) | |
1530 | { | |
1531 | struct mapped_device *md = q->queuedata; | |
1532 | ||
1533 | if (dm_request_based(md)) | |
1534 | return dm_make_request(q, bio); | |
1535 | ||
1536 | return _dm_request(q, bio); | |
1537 | } | |
1538 | ||
d0bcb878 KU |
1539 | static bool dm_rq_is_flush_request(struct request *rq) |
1540 | { | |
144d6ed5 | 1541 | if (rq->cmd_flags & REQ_FLUSH) |
d0bcb878 KU |
1542 | return true; |
1543 | else | |
1544 | return false; | |
1545 | } | |
1546 | ||
cec47e3d KU |
1547 | void dm_dispatch_request(struct request *rq) |
1548 | { | |
1549 | int r; | |
1550 | ||
1551 | if (blk_queue_io_stat(rq->q)) | |
1552 | rq->cmd_flags |= REQ_IO_STAT; | |
1553 | ||
1554 | rq->start_time = jiffies; | |
1555 | r = blk_insert_cloned_request(rq->q, rq); | |
1556 | if (r) | |
1557 | dm_complete_request(rq, r); | |
1558 | } | |
1559 | EXPORT_SYMBOL_GPL(dm_dispatch_request); | |
1560 | ||
1561 | static void dm_rq_bio_destructor(struct bio *bio) | |
1562 | { | |
1563 | struct dm_rq_clone_bio_info *info = bio->bi_private; | |
1564 | struct mapped_device *md = info->tio->md; | |
1565 | ||
1566 | free_bio_info(info); | |
1567 | bio_free(bio, md->bs); | |
1568 | } | |
1569 | ||
1570 | static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, | |
1571 | void *data) | |
1572 | { | |
1573 | struct dm_rq_target_io *tio = data; | |
1574 | struct mapped_device *md = tio->md; | |
1575 | struct dm_rq_clone_bio_info *info = alloc_bio_info(md); | |
1576 | ||
1577 | if (!info) | |
1578 | return -ENOMEM; | |
1579 | ||
1580 | info->orig = bio_orig; | |
1581 | info->tio = tio; | |
1582 | bio->bi_end_io = end_clone_bio; | |
1583 | bio->bi_private = info; | |
1584 | bio->bi_destructor = dm_rq_bio_destructor; | |
1585 | ||
1586 | return 0; | |
1587 | } | |
1588 | ||
1589 | static int setup_clone(struct request *clone, struct request *rq, | |
1590 | struct dm_rq_target_io *tio) | |
1591 | { | |
d0bcb878 | 1592 | int r; |
cec47e3d | 1593 | |
d0bcb878 KU |
1594 | if (dm_rq_is_flush_request(rq)) { |
1595 | blk_rq_init(NULL, clone); | |
1596 | clone->cmd_type = REQ_TYPE_FS; | |
1597 | clone->cmd_flags |= (REQ_HARDBARRIER | WRITE); | |
1598 | } else { | |
1599 | r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC, | |
1600 | dm_rq_bio_constructor, tio); | |
1601 | if (r) | |
1602 | return r; | |
1603 | ||
1604 | clone->cmd = rq->cmd; | |
1605 | clone->cmd_len = rq->cmd_len; | |
1606 | clone->sense = rq->sense; | |
1607 | clone->buffer = rq->buffer; | |
1608 | } | |
cec47e3d | 1609 | |
cec47e3d KU |
1610 | clone->end_io = end_clone_request; |
1611 | clone->end_io_data = tio; | |
1612 | ||
1613 | return 0; | |
1614 | } | |
1615 | ||
6facdaff KU |
1616 | static struct request *clone_rq(struct request *rq, struct mapped_device *md, |
1617 | gfp_t gfp_mask) | |
1618 | { | |
1619 | struct request *clone; | |
1620 | struct dm_rq_target_io *tio; | |
1621 | ||
1622 | tio = alloc_rq_tio(md, gfp_mask); | |
1623 | if (!tio) | |
1624 | return NULL; | |
1625 | ||
1626 | tio->md = md; | |
1627 | tio->ti = NULL; | |
1628 | tio->orig = rq; | |
1629 | tio->error = 0; | |
1630 | memset(&tio->info, 0, sizeof(tio->info)); | |
1631 | ||
1632 | clone = &tio->clone; | |
1633 | if (setup_clone(clone, rq, tio)) { | |
1634 | /* -ENOMEM */ | |
1635 | free_rq_tio(tio); | |
1636 | return NULL; | |
1637 | } | |
1638 | ||
1639 | return clone; | |
1640 | } | |
1641 | ||
cec47e3d KU |
1642 | /* |
1643 | * Called with the queue lock held. | |
1644 | */ | |
1645 | static int dm_prep_fn(struct request_queue *q, struct request *rq) | |
1646 | { | |
1647 | struct mapped_device *md = q->queuedata; | |
cec47e3d KU |
1648 | struct request *clone; |
1649 | ||
d0bcb878 KU |
1650 | if (unlikely(dm_rq_is_flush_request(rq))) |
1651 | return BLKPREP_OK; | |
1652 | ||
cec47e3d KU |
1653 | if (unlikely(rq->special)) { |
1654 | DMWARN("Already has something in rq->special."); | |
1655 | return BLKPREP_KILL; | |
1656 | } | |
1657 | ||
6facdaff KU |
1658 | clone = clone_rq(rq, md, GFP_ATOMIC); |
1659 | if (!clone) | |
cec47e3d | 1660 | return BLKPREP_DEFER; |
cec47e3d KU |
1661 | |
1662 | rq->special = clone; | |
1663 | rq->cmd_flags |= REQ_DONTPREP; | |
1664 | ||
1665 | return BLKPREP_OK; | |
1666 | } | |
1667 | ||
9eef87da KU |
1668 | /* |
1669 | * Returns: | |
1670 | * 0 : the request has been processed (not requeued) | |
1671 | * !0 : the request has been requeued | |
1672 | */ | |
1673 | static int map_request(struct dm_target *ti, struct request *clone, | |
1674 | struct mapped_device *md) | |
cec47e3d | 1675 | { |
9eef87da | 1676 | int r, requeued = 0; |
cec47e3d KU |
1677 | struct dm_rq_target_io *tio = clone->end_io_data; |
1678 | ||
1679 | /* | |
1680 | * Hold the md reference here for the in-flight I/O. | |
1681 | * We can't rely on the reference count by device opener, | |
1682 | * because the device may be closed during the request completion | |
1683 | * when all bios are completed. | |
1684 | * See the comment in rq_completed() too. | |
1685 | */ | |
1686 | dm_get(md); | |
1687 | ||
1688 | tio->ti = ti; | |
1689 | r = ti->type->map_rq(ti, clone, &tio->info); | |
1690 | switch (r) { | |
1691 | case DM_MAPIO_SUBMITTED: | |
1692 | /* The target has taken the I/O to submit by itself later */ | |
1693 | break; | |
1694 | case DM_MAPIO_REMAPPED: | |
1695 | /* The target has remapped the I/O so dispatch it */ | |
6db4ccd6 JN |
1696 | trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)), |
1697 | blk_rq_pos(tio->orig)); | |
cec47e3d KU |
1698 | dm_dispatch_request(clone); |
1699 | break; | |
1700 | case DM_MAPIO_REQUEUE: | |
1701 | /* The target wants to requeue the I/O */ | |
1702 | dm_requeue_unmapped_request(clone); | |
9eef87da | 1703 | requeued = 1; |
cec47e3d KU |
1704 | break; |
1705 | default: | |
1706 | if (r > 0) { | |
1707 | DMWARN("unimplemented target map return value: %d", r); | |
1708 | BUG(); | |
1709 | } | |
1710 | ||
1711 | /* The target wants to complete the I/O */ | |
1712 | dm_kill_unmapped_request(clone, r); | |
1713 | break; | |
1714 | } | |
9eef87da KU |
1715 | |
1716 | return requeued; | |
cec47e3d KU |
1717 | } |
1718 | ||
1719 | /* | |
1720 | * q->request_fn for request-based dm. | |
1721 | * Called with the queue lock held. | |
1722 | */ | |
1723 | static void dm_request_fn(struct request_queue *q) | |
1724 | { | |
1725 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1726 | struct dm_table *map = dm_get_live_table(md); |
cec47e3d | 1727 | struct dm_target *ti; |
b4324fee | 1728 | struct request *rq, *clone; |
cec47e3d KU |
1729 | |
1730 | /* | |
b4324fee KU |
1731 | * For suspend, check blk_queue_stopped() and increment |
1732 | * ->pending within a single queue_lock not to increment the | |
1733 | * number of in-flight I/Os after the queue is stopped in | |
1734 | * dm_suspend(). | |
cec47e3d KU |
1735 | */ |
1736 | while (!blk_queue_plugged(q) && !blk_queue_stopped(q)) { | |
1737 | rq = blk_peek_request(q); | |
1738 | if (!rq) | |
1739 | goto plug_and_out; | |
1740 | ||
d0bcb878 KU |
1741 | if (unlikely(dm_rq_is_flush_request(rq))) { |
1742 | BUG_ON(md->flush_request); | |
1743 | md->flush_request = rq; | |
1744 | blk_start_request(rq); | |
1745 | queue_work(md->wq, &md->barrier_work); | |
1746 | goto out; | |
1747 | } | |
1748 | ||
cec47e3d KU |
1749 | ti = dm_table_find_target(map, blk_rq_pos(rq)); |
1750 | if (ti->type->busy && ti->type->busy(ti)) | |
1751 | goto plug_and_out; | |
1752 | ||
1753 | blk_start_request(rq); | |
b4324fee KU |
1754 | clone = rq->special; |
1755 | atomic_inc(&md->pending[rq_data_dir(clone)]); | |
1756 | ||
cec47e3d | 1757 | spin_unlock(q->queue_lock); |
9eef87da KU |
1758 | if (map_request(ti, clone, md)) |
1759 | goto requeued; | |
1760 | ||
cec47e3d KU |
1761 | spin_lock_irq(q->queue_lock); |
1762 | } | |
1763 | ||
1764 | goto out; | |
1765 | ||
9eef87da KU |
1766 | requeued: |
1767 | spin_lock_irq(q->queue_lock); | |
1768 | ||
cec47e3d KU |
1769 | plug_and_out: |
1770 | if (!elv_queue_empty(q)) | |
1771 | /* Some requests still remain, retry later */ | |
1772 | blk_plug_device(q); | |
1773 | ||
1774 | out: | |
1775 | dm_table_put(map); | |
1776 | ||
1777 | return; | |
1778 | } | |
1779 | ||
1780 | int dm_underlying_device_busy(struct request_queue *q) | |
1781 | { | |
1782 | return blk_lld_busy(q); | |
1783 | } | |
1784 | EXPORT_SYMBOL_GPL(dm_underlying_device_busy); | |
1785 | ||
1786 | static int dm_lld_busy(struct request_queue *q) | |
1787 | { | |
1788 | int r; | |
1789 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1790 | struct dm_table *map = dm_get_live_table(md); |
cec47e3d KU |
1791 | |
1792 | if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) | |
1793 | r = 1; | |
1794 | else | |
1795 | r = dm_table_any_busy_target(map); | |
1796 | ||
1797 | dm_table_put(map); | |
1798 | ||
1799 | return r; | |
1800 | } | |
1801 | ||
165125e1 | 1802 | static void dm_unplug_all(struct request_queue *q) |
1da177e4 LT |
1803 | { |
1804 | struct mapped_device *md = q->queuedata; | |
7c666411 | 1805 | struct dm_table *map = dm_get_live_table(md); |
1da177e4 LT |
1806 | |
1807 | if (map) { | |
cec47e3d KU |
1808 | if (dm_request_based(md)) |
1809 | generic_unplug_device(q); | |
1810 | ||
1da177e4 LT |
1811 | dm_table_unplug_all(map); |
1812 | dm_table_put(map); | |
1813 | } | |
1814 | } | |
1815 | ||
1816 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
1817 | { | |
8a57dfc6 CS |
1818 | int r = bdi_bits; |
1819 | struct mapped_device *md = congested_data; | |
1820 | struct dm_table *map; | |
1da177e4 | 1821 | |
1eb787ec | 1822 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
7c666411 | 1823 | map = dm_get_live_table(md); |
8a57dfc6 | 1824 | if (map) { |
cec47e3d KU |
1825 | /* |
1826 | * Request-based dm cares about only own queue for | |
1827 | * the query about congestion status of request_queue | |
1828 | */ | |
1829 | if (dm_request_based(md)) | |
1830 | r = md->queue->backing_dev_info.state & | |
1831 | bdi_bits; | |
1832 | else | |
1833 | r = dm_table_any_congested(map, bdi_bits); | |
1834 | ||
8a57dfc6 CS |
1835 | dm_table_put(map); |
1836 | } | |
1837 | } | |
1838 | ||
1da177e4 LT |
1839 | return r; |
1840 | } | |
1841 | ||
1842 | /*----------------------------------------------------------------- | |
1843 | * An IDR is used to keep track of allocated minor numbers. | |
1844 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
1845 | static DEFINE_IDR(_minor_idr); |
1846 | ||
2b06cfff | 1847 | static void free_minor(int minor) |
1da177e4 | 1848 | { |
f32c10b0 | 1849 | spin_lock(&_minor_lock); |
1da177e4 | 1850 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 1851 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1852 | } |
1853 | ||
1854 | /* | |
1855 | * See if the device with a specific minor # is free. | |
1856 | */ | |
cf13ab8e | 1857 | static int specific_minor(int minor) |
1da177e4 LT |
1858 | { |
1859 | int r, m; | |
1860 | ||
1861 | if (minor >= (1 << MINORBITS)) | |
1862 | return -EINVAL; | |
1863 | ||
62f75c2f JM |
1864 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
1865 | if (!r) | |
1866 | return -ENOMEM; | |
1867 | ||
f32c10b0 | 1868 | spin_lock(&_minor_lock); |
1da177e4 LT |
1869 | |
1870 | if (idr_find(&_minor_idr, minor)) { | |
1871 | r = -EBUSY; | |
1872 | goto out; | |
1873 | } | |
1874 | ||
ba61fdd1 | 1875 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 1876 | if (r) |
1da177e4 | 1877 | goto out; |
1da177e4 LT |
1878 | |
1879 | if (m != minor) { | |
1880 | idr_remove(&_minor_idr, m); | |
1881 | r = -EBUSY; | |
1882 | goto out; | |
1883 | } | |
1884 | ||
1885 | out: | |
f32c10b0 | 1886 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1887 | return r; |
1888 | } | |
1889 | ||
cf13ab8e | 1890 | static int next_free_minor(int *minor) |
1da177e4 | 1891 | { |
2b06cfff | 1892 | int r, m; |
1da177e4 | 1893 | |
1da177e4 | 1894 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
1895 | if (!r) |
1896 | return -ENOMEM; | |
1897 | ||
f32c10b0 | 1898 | spin_lock(&_minor_lock); |
1da177e4 | 1899 | |
ba61fdd1 | 1900 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
cf13ab8e | 1901 | if (r) |
1da177e4 | 1902 | goto out; |
1da177e4 LT |
1903 | |
1904 | if (m >= (1 << MINORBITS)) { | |
1905 | idr_remove(&_minor_idr, m); | |
1906 | r = -ENOSPC; | |
1907 | goto out; | |
1908 | } | |
1909 | ||
1910 | *minor = m; | |
1911 | ||
1912 | out: | |
f32c10b0 | 1913 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1914 | return r; |
1915 | } | |
1916 | ||
83d5cde4 | 1917 | static const struct block_device_operations dm_blk_dops; |
1da177e4 | 1918 | |
53d5914f | 1919 | static void dm_wq_work(struct work_struct *work); |
d0bcb878 | 1920 | static void dm_rq_barrier_work(struct work_struct *work); |
53d5914f | 1921 | |
4a0b4ddf MS |
1922 | static void dm_init_md_queue(struct mapped_device *md) |
1923 | { | |
1924 | /* | |
1925 | * Request-based dm devices cannot be stacked on top of bio-based dm | |
1926 | * devices. The type of this dm device has not been decided yet. | |
1927 | * The type is decided at the first table loading time. | |
1928 | * To prevent problematic device stacking, clear the queue flag | |
1929 | * for request stacking support until then. | |
1930 | * | |
1931 | * This queue is new, so no concurrency on the queue_flags. | |
1932 | */ | |
1933 | queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); | |
1934 | ||
1935 | md->queue->queuedata = md; | |
1936 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1937 | md->queue->backing_dev_info.congested_data = md; | |
1938 | blk_queue_make_request(md->queue, dm_request); | |
1939 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); | |
1940 | md->queue->unplug_fn = dm_unplug_all; | |
1941 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); | |
d87f4c14 | 1942 | blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA); |
4a0b4ddf MS |
1943 | } |
1944 | ||
1da177e4 LT |
1945 | /* |
1946 | * Allocate and initialise a blank device with a given minor. | |
1947 | */ | |
2b06cfff | 1948 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1949 | { |
1950 | int r; | |
cf13ab8e | 1951 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1952 | void *old_md; |
1da177e4 LT |
1953 | |
1954 | if (!md) { | |
1955 | DMWARN("unable to allocate device, out of memory."); | |
1956 | return NULL; | |
1957 | } | |
1958 | ||
10da4f79 | 1959 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 1960 | goto bad_module_get; |
10da4f79 | 1961 | |
1da177e4 | 1962 | /* get a minor number for the dev */ |
2b06cfff | 1963 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 1964 | r = next_free_minor(&minor); |
2b06cfff | 1965 | else |
cf13ab8e | 1966 | r = specific_minor(minor); |
1da177e4 | 1967 | if (r < 0) |
6ed7ade8 | 1968 | goto bad_minor; |
1da177e4 | 1969 | |
a5664dad | 1970 | md->type = DM_TYPE_NONE; |
2ca3310e | 1971 | init_rwsem(&md->io_lock); |
e61290a4 | 1972 | mutex_init(&md->suspend_lock); |
a5664dad | 1973 | mutex_init(&md->type_lock); |
022c2611 | 1974 | spin_lock_init(&md->deferred_lock); |
d0bcb878 | 1975 | spin_lock_init(&md->barrier_error_lock); |
1da177e4 LT |
1976 | rwlock_init(&md->map_lock); |
1977 | atomic_set(&md->holders, 1); | |
5c6bd75d | 1978 | atomic_set(&md->open_count, 0); |
1da177e4 | 1979 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
1980 | atomic_set(&md->uevent_seq, 0); |
1981 | INIT_LIST_HEAD(&md->uevent_list); | |
1982 | spin_lock_init(&md->uevent_lock); | |
1da177e4 | 1983 | |
4a0b4ddf | 1984 | md->queue = blk_alloc_queue(GFP_KERNEL); |
1da177e4 | 1985 | if (!md->queue) |
6ed7ade8 | 1986 | goto bad_queue; |
1da177e4 | 1987 | |
4a0b4ddf | 1988 | dm_init_md_queue(md); |
9faf400f | 1989 | |
1da177e4 LT |
1990 | md->disk = alloc_disk(1); |
1991 | if (!md->disk) | |
6ed7ade8 | 1992 | goto bad_disk; |
1da177e4 | 1993 | |
316d315b NK |
1994 | atomic_set(&md->pending[0], 0); |
1995 | atomic_set(&md->pending[1], 0); | |
f0b04115 | 1996 | init_waitqueue_head(&md->wait); |
53d5914f | 1997 | INIT_WORK(&md->work, dm_wq_work); |
d0bcb878 | 1998 | INIT_WORK(&md->barrier_work, dm_rq_barrier_work); |
f0b04115 JM |
1999 | init_waitqueue_head(&md->eventq); |
2000 | ||
1da177e4 LT |
2001 | md->disk->major = _major; |
2002 | md->disk->first_minor = minor; | |
2003 | md->disk->fops = &dm_blk_dops; | |
2004 | md->disk->queue = md->queue; | |
2005 | md->disk->private_data = md; | |
2006 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
2007 | add_disk(md->disk); | |
7e51f257 | 2008 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 2009 | |
304f3f6a MB |
2010 | md->wq = create_singlethread_workqueue("kdmflush"); |
2011 | if (!md->wq) | |
2012 | goto bad_thread; | |
2013 | ||
32a926da MP |
2014 | md->bdev = bdget_disk(md->disk, 0); |
2015 | if (!md->bdev) | |
2016 | goto bad_bdev; | |
2017 | ||
ba61fdd1 | 2018 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 2019 | spin_lock(&_minor_lock); |
ba61fdd1 | 2020 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 2021 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
2022 | |
2023 | BUG_ON(old_md != MINOR_ALLOCED); | |
2024 | ||
1da177e4 LT |
2025 | return md; |
2026 | ||
32a926da MP |
2027 | bad_bdev: |
2028 | destroy_workqueue(md->wq); | |
304f3f6a | 2029 | bad_thread: |
03022c54 | 2030 | del_gendisk(md->disk); |
304f3f6a | 2031 | put_disk(md->disk); |
6ed7ade8 | 2032 | bad_disk: |
1312f40e | 2033 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 2034 | bad_queue: |
1da177e4 | 2035 | free_minor(minor); |
6ed7ade8 | 2036 | bad_minor: |
10da4f79 | 2037 | module_put(THIS_MODULE); |
6ed7ade8 | 2038 | bad_module_get: |
1da177e4 LT |
2039 | kfree(md); |
2040 | return NULL; | |
2041 | } | |
2042 | ||
ae9da83f JN |
2043 | static void unlock_fs(struct mapped_device *md); |
2044 | ||
1da177e4 LT |
2045 | static void free_dev(struct mapped_device *md) |
2046 | { | |
f331c029 | 2047 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 2048 | |
32a926da MP |
2049 | unlock_fs(md); |
2050 | bdput(md->bdev); | |
304f3f6a | 2051 | destroy_workqueue(md->wq); |
e6ee8c0b KU |
2052 | if (md->tio_pool) |
2053 | mempool_destroy(md->tio_pool); | |
2054 | if (md->io_pool) | |
2055 | mempool_destroy(md->io_pool); | |
2056 | if (md->bs) | |
2057 | bioset_free(md->bs); | |
9c47008d | 2058 | blk_integrity_unregister(md->disk); |
1da177e4 | 2059 | del_gendisk(md->disk); |
63d94e48 | 2060 | free_minor(minor); |
fba9f90e JM |
2061 | |
2062 | spin_lock(&_minor_lock); | |
2063 | md->disk->private_data = NULL; | |
2064 | spin_unlock(&_minor_lock); | |
2065 | ||
1da177e4 | 2066 | put_disk(md->disk); |
1312f40e | 2067 | blk_cleanup_queue(md->queue); |
10da4f79 | 2068 | module_put(THIS_MODULE); |
1da177e4 LT |
2069 | kfree(md); |
2070 | } | |
2071 | ||
e6ee8c0b KU |
2072 | static void __bind_mempools(struct mapped_device *md, struct dm_table *t) |
2073 | { | |
2074 | struct dm_md_mempools *p; | |
2075 | ||
2076 | if (md->io_pool && md->tio_pool && md->bs) | |
2077 | /* the md already has necessary mempools */ | |
2078 | goto out; | |
2079 | ||
2080 | p = dm_table_get_md_mempools(t); | |
2081 | BUG_ON(!p || md->io_pool || md->tio_pool || md->bs); | |
2082 | ||
2083 | md->io_pool = p->io_pool; | |
2084 | p->io_pool = NULL; | |
2085 | md->tio_pool = p->tio_pool; | |
2086 | p->tio_pool = NULL; | |
2087 | md->bs = p->bs; | |
2088 | p->bs = NULL; | |
2089 | ||
2090 | out: | |
2091 | /* mempool bind completed, now no need any mempools in the table */ | |
2092 | dm_table_free_md_mempools(t); | |
2093 | } | |
2094 | ||
1da177e4 LT |
2095 | /* |
2096 | * Bind a table to the device. | |
2097 | */ | |
2098 | static void event_callback(void *context) | |
2099 | { | |
7a8c3d3b MA |
2100 | unsigned long flags; |
2101 | LIST_HEAD(uevents); | |
1da177e4 LT |
2102 | struct mapped_device *md = (struct mapped_device *) context; |
2103 | ||
7a8c3d3b MA |
2104 | spin_lock_irqsave(&md->uevent_lock, flags); |
2105 | list_splice_init(&md->uevent_list, &uevents); | |
2106 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
2107 | ||
ed9e1982 | 2108 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 2109 | |
1da177e4 LT |
2110 | atomic_inc(&md->event_nr); |
2111 | wake_up(&md->eventq); | |
2112 | } | |
2113 | ||
4e90188b | 2114 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 2115 | { |
4e90188b | 2116 | set_capacity(md->disk, size); |
1da177e4 | 2117 | |
db8fef4f MP |
2118 | mutex_lock(&md->bdev->bd_inode->i_mutex); |
2119 | i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); | |
2120 | mutex_unlock(&md->bdev->bd_inode->i_mutex); | |
1da177e4 LT |
2121 | } |
2122 | ||
042d2a9b AK |
2123 | /* |
2124 | * Returns old map, which caller must destroy. | |
2125 | */ | |
2126 | static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, | |
2127 | struct queue_limits *limits) | |
1da177e4 | 2128 | { |
042d2a9b | 2129 | struct dm_table *old_map; |
165125e1 | 2130 | struct request_queue *q = md->queue; |
1da177e4 | 2131 | sector_t size; |
523d9297 | 2132 | unsigned long flags; |
1da177e4 LT |
2133 | |
2134 | size = dm_table_get_size(t); | |
3ac51e74 DW |
2135 | |
2136 | /* | |
2137 | * Wipe any geometry if the size of the table changed. | |
2138 | */ | |
2139 | if (size != get_capacity(md->disk)) | |
2140 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
2141 | ||
32a926da | 2142 | __set_size(md, size); |
d5816876 | 2143 | |
2ca3310e AK |
2144 | dm_table_event_callback(t, event_callback, md); |
2145 | ||
e6ee8c0b KU |
2146 | /* |
2147 | * The queue hasn't been stopped yet, if the old table type wasn't | |
2148 | * for request-based during suspension. So stop it to prevent | |
2149 | * I/O mapping before resume. | |
2150 | * This must be done before setting the queue restrictions, | |
2151 | * because request-based dm may be run just after the setting. | |
2152 | */ | |
2153 | if (dm_table_request_based(t) && !blk_queue_stopped(q)) | |
2154 | stop_queue(q); | |
2155 | ||
2156 | __bind_mempools(md, t); | |
2157 | ||
523d9297 | 2158 | write_lock_irqsave(&md->map_lock, flags); |
042d2a9b | 2159 | old_map = md->map; |
1da177e4 | 2160 | md->map = t; |
754c5fc7 | 2161 | dm_table_set_restrictions(t, q, limits); |
523d9297 | 2162 | write_unlock_irqrestore(&md->map_lock, flags); |
1da177e4 | 2163 | |
042d2a9b | 2164 | return old_map; |
1da177e4 LT |
2165 | } |
2166 | ||
a7940155 AK |
2167 | /* |
2168 | * Returns unbound table for the caller to free. | |
2169 | */ | |
2170 | static struct dm_table *__unbind(struct mapped_device *md) | |
1da177e4 LT |
2171 | { |
2172 | struct dm_table *map = md->map; | |
523d9297 | 2173 | unsigned long flags; |
1da177e4 LT |
2174 | |
2175 | if (!map) | |
a7940155 | 2176 | return NULL; |
1da177e4 LT |
2177 | |
2178 | dm_table_event_callback(map, NULL, NULL); | |
523d9297 | 2179 | write_lock_irqsave(&md->map_lock, flags); |
1da177e4 | 2180 | md->map = NULL; |
523d9297 | 2181 | write_unlock_irqrestore(&md->map_lock, flags); |
a7940155 AK |
2182 | |
2183 | return map; | |
1da177e4 LT |
2184 | } |
2185 | ||
2186 | /* | |
2187 | * Constructor for a new device. | |
2188 | */ | |
2b06cfff | 2189 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
2190 | { |
2191 | struct mapped_device *md; | |
2192 | ||
2b06cfff | 2193 | md = alloc_dev(minor); |
1da177e4 LT |
2194 | if (!md) |
2195 | return -ENXIO; | |
2196 | ||
784aae73 MB |
2197 | dm_sysfs_init(md); |
2198 | ||
1da177e4 LT |
2199 | *result = md; |
2200 | return 0; | |
2201 | } | |
2202 | ||
a5664dad MS |
2203 | /* |
2204 | * Functions to manage md->type. | |
2205 | * All are required to hold md->type_lock. | |
2206 | */ | |
2207 | void dm_lock_md_type(struct mapped_device *md) | |
2208 | { | |
2209 | mutex_lock(&md->type_lock); | |
2210 | } | |
2211 | ||
2212 | void dm_unlock_md_type(struct mapped_device *md) | |
2213 | { | |
2214 | mutex_unlock(&md->type_lock); | |
2215 | } | |
2216 | ||
2217 | void dm_set_md_type(struct mapped_device *md, unsigned type) | |
2218 | { | |
2219 | md->type = type; | |
2220 | } | |
2221 | ||
2222 | unsigned dm_get_md_type(struct mapped_device *md) | |
2223 | { | |
2224 | return md->type; | |
2225 | } | |
2226 | ||
4a0b4ddf MS |
2227 | /* |
2228 | * Fully initialize a request-based queue (->elevator, ->request_fn, etc). | |
2229 | */ | |
2230 | static int dm_init_request_based_queue(struct mapped_device *md) | |
2231 | { | |
2232 | struct request_queue *q = NULL; | |
2233 | ||
2234 | if (md->queue->elevator) | |
2235 | return 1; | |
2236 | ||
2237 | /* Fully initialize the queue */ | |
2238 | q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); | |
2239 | if (!q) | |
2240 | return 0; | |
2241 | ||
2242 | md->queue = q; | |
2243 | md->saved_make_request_fn = md->queue->make_request_fn; | |
2244 | dm_init_md_queue(md); | |
2245 | blk_queue_softirq_done(md->queue, dm_softirq_done); | |
2246 | blk_queue_prep_rq(md->queue, dm_prep_fn); | |
2247 | blk_queue_lld_busy(md->queue, dm_lld_busy); | |
d87f4c14 TH |
2248 | /* no flush support for request based dm yet */ |
2249 | blk_queue_flush(md->queue, 0); | |
4a0b4ddf MS |
2250 | |
2251 | elv_register_queue(md->queue); | |
2252 | ||
2253 | return 1; | |
2254 | } | |
2255 | ||
2256 | /* | |
2257 | * Setup the DM device's queue based on md's type | |
2258 | */ | |
2259 | int dm_setup_md_queue(struct mapped_device *md) | |
2260 | { | |
2261 | if ((dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) && | |
2262 | !dm_init_request_based_queue(md)) { | |
2263 | DMWARN("Cannot initialize queue for request-based mapped device"); | |
2264 | return -EINVAL; | |
2265 | } | |
2266 | ||
2267 | return 0; | |
2268 | } | |
2269 | ||
637842cf | 2270 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
2271 | { |
2272 | struct mapped_device *md; | |
1da177e4 LT |
2273 | unsigned minor = MINOR(dev); |
2274 | ||
2275 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
2276 | return NULL; | |
2277 | ||
f32c10b0 | 2278 | spin_lock(&_minor_lock); |
1da177e4 LT |
2279 | |
2280 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 2281 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 2282 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
abdc568b | 2283 | dm_deleting_md(md) || |
17b2f66f | 2284 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 2285 | md = NULL; |
fba9f90e JM |
2286 | goto out; |
2287 | } | |
1da177e4 | 2288 | |
fba9f90e | 2289 | out: |
f32c10b0 | 2290 | spin_unlock(&_minor_lock); |
1da177e4 | 2291 | |
637842cf DT |
2292 | return md; |
2293 | } | |
2294 | ||
d229a958 DT |
2295 | struct mapped_device *dm_get_md(dev_t dev) |
2296 | { | |
2297 | struct mapped_device *md = dm_find_md(dev); | |
2298 | ||
2299 | if (md) | |
2300 | dm_get(md); | |
2301 | ||
2302 | return md; | |
2303 | } | |
2304 | ||
9ade92a9 | 2305 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 2306 | { |
9ade92a9 | 2307 | return md->interface_ptr; |
1da177e4 LT |
2308 | } |
2309 | ||
2310 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
2311 | { | |
2312 | md->interface_ptr = ptr; | |
2313 | } | |
2314 | ||
2315 | void dm_get(struct mapped_device *md) | |
2316 | { | |
2317 | atomic_inc(&md->holders); | |
3f77316d | 2318 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1da177e4 LT |
2319 | } |
2320 | ||
72d94861 AK |
2321 | const char *dm_device_name(struct mapped_device *md) |
2322 | { | |
2323 | return md->name; | |
2324 | } | |
2325 | EXPORT_SYMBOL_GPL(dm_device_name); | |
2326 | ||
3f77316d | 2327 | static void __dm_destroy(struct mapped_device *md, bool wait) |
1da177e4 | 2328 | { |
1134e5ae | 2329 | struct dm_table *map; |
1da177e4 | 2330 | |
3f77316d | 2331 | might_sleep(); |
fba9f90e | 2332 | |
3f77316d KU |
2333 | spin_lock(&_minor_lock); |
2334 | map = dm_get_live_table(md); | |
2335 | idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); | |
2336 | set_bit(DMF_FREEING, &md->flags); | |
2337 | spin_unlock(&_minor_lock); | |
2338 | ||
2339 | if (!dm_suspended_md(md)) { | |
2340 | dm_table_presuspend_targets(map); | |
2341 | dm_table_postsuspend_targets(map); | |
1da177e4 | 2342 | } |
3f77316d KU |
2343 | |
2344 | /* | |
2345 | * Rare, but there may be I/O requests still going to complete, | |
2346 | * for example. Wait for all references to disappear. | |
2347 | * No one should increment the reference count of the mapped_device, | |
2348 | * after the mapped_device state becomes DMF_FREEING. | |
2349 | */ | |
2350 | if (wait) | |
2351 | while (atomic_read(&md->holders)) | |
2352 | msleep(1); | |
2353 | else if (atomic_read(&md->holders)) | |
2354 | DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", | |
2355 | dm_device_name(md), atomic_read(&md->holders)); | |
2356 | ||
2357 | dm_sysfs_exit(md); | |
2358 | dm_table_put(map); | |
2359 | dm_table_destroy(__unbind(md)); | |
2360 | free_dev(md); | |
2361 | } | |
2362 | ||
2363 | void dm_destroy(struct mapped_device *md) | |
2364 | { | |
2365 | __dm_destroy(md, true); | |
2366 | } | |
2367 | ||
2368 | void dm_destroy_immediate(struct mapped_device *md) | |
2369 | { | |
2370 | __dm_destroy(md, false); | |
2371 | } | |
2372 | ||
2373 | void dm_put(struct mapped_device *md) | |
2374 | { | |
2375 | atomic_dec(&md->holders); | |
1da177e4 | 2376 | } |
79eb885c | 2377 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 2378 | |
401600df | 2379 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
46125c1c MB |
2380 | { |
2381 | int r = 0; | |
b44ebeb0 MP |
2382 | DECLARE_WAITQUEUE(wait, current); |
2383 | ||
2384 | dm_unplug_all(md->queue); | |
2385 | ||
2386 | add_wait_queue(&md->wait, &wait); | |
46125c1c MB |
2387 | |
2388 | while (1) { | |
401600df | 2389 | set_current_state(interruptible); |
46125c1c MB |
2390 | |
2391 | smp_mb(); | |
b4324fee | 2392 | if (!md_in_flight(md)) |
46125c1c MB |
2393 | break; |
2394 | ||
401600df MP |
2395 | if (interruptible == TASK_INTERRUPTIBLE && |
2396 | signal_pending(current)) { | |
46125c1c MB |
2397 | r = -EINTR; |
2398 | break; | |
2399 | } | |
2400 | ||
2401 | io_schedule(); | |
2402 | } | |
2403 | set_current_state(TASK_RUNNING); | |
2404 | ||
b44ebeb0 MP |
2405 | remove_wait_queue(&md->wait, &wait); |
2406 | ||
46125c1c MB |
2407 | return r; |
2408 | } | |
2409 | ||
d87f4c14 | 2410 | static void process_flush(struct mapped_device *md, struct bio *bio) |
af7e466a | 2411 | { |
d87f4c14 | 2412 | md->flush_error = 0; |
52b1fd5a | 2413 | |
d87f4c14 | 2414 | /* handle REQ_FLUSH */ |
52b1fd5a | 2415 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); |
af7e466a | 2416 | |
d87f4c14 TH |
2417 | bio_init(&md->flush_bio); |
2418 | md->flush_bio.bi_bdev = md->bdev; | |
2419 | md->flush_bio.bi_rw = WRITE_FLUSH; | |
2420 | __split_and_process_bio(md, &md->flush_bio); | |
5aa2781d | 2421 | |
d87f4c14 | 2422 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); |
af7e466a | 2423 | |
d87f4c14 TH |
2424 | /* if it's an empty flush or the preflush failed, we're done */ |
2425 | if (!bio_has_data(bio) || md->flush_error) { | |
2426 | if (md->flush_error != DM_ENDIO_REQUEUE) | |
2427 | bio_endio(bio, md->flush_error); | |
2428 | else { | |
2429 | spin_lock_irq(&md->deferred_lock); | |
2430 | bio_list_add_head(&md->deferred, bio); | |
2431 | spin_unlock_irq(&md->deferred_lock); | |
2432 | } | |
2433 | return; | |
af7e466a MP |
2434 | } |
2435 | ||
d87f4c14 TH |
2436 | /* issue data + REQ_FUA */ |
2437 | bio->bi_rw &= ~REQ_FLUSH; | |
2438 | __split_and_process_bio(md, bio); | |
af7e466a MP |
2439 | } |
2440 | ||
1da177e4 LT |
2441 | /* |
2442 | * Process the deferred bios | |
2443 | */ | |
ef208587 | 2444 | static void dm_wq_work(struct work_struct *work) |
1da177e4 | 2445 | { |
ef208587 MP |
2446 | struct mapped_device *md = container_of(work, struct mapped_device, |
2447 | work); | |
6d6f10df | 2448 | struct bio *c; |
1da177e4 | 2449 | |
ef208587 MP |
2450 | down_write(&md->io_lock); |
2451 | ||
3b00b203 | 2452 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
df12ee99 AK |
2453 | spin_lock_irq(&md->deferred_lock); |
2454 | c = bio_list_pop(&md->deferred); | |
2455 | spin_unlock_irq(&md->deferred_lock); | |
2456 | ||
2457 | if (!c) { | |
1eb787ec | 2458 | clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); |
df12ee99 AK |
2459 | break; |
2460 | } | |
022c2611 | 2461 | |
3b00b203 MP |
2462 | up_write(&md->io_lock); |
2463 | ||
e6ee8c0b KU |
2464 | if (dm_request_based(md)) |
2465 | generic_make_request(c); | |
2466 | else { | |
d87f4c14 TH |
2467 | if (c->bi_rw & REQ_FLUSH) |
2468 | process_flush(md, c); | |
e6ee8c0b KU |
2469 | else |
2470 | __split_and_process_bio(md, c); | |
2471 | } | |
3b00b203 MP |
2472 | |
2473 | down_write(&md->io_lock); | |
022c2611 | 2474 | } |
73d410c0 | 2475 | |
ef208587 | 2476 | up_write(&md->io_lock); |
1da177e4 LT |
2477 | } |
2478 | ||
9a1fb464 | 2479 | static void dm_queue_flush(struct mapped_device *md) |
304f3f6a | 2480 | { |
3b00b203 MP |
2481 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
2482 | smp_mb__after_clear_bit(); | |
53d5914f | 2483 | queue_work(md->wq, &md->work); |
304f3f6a MB |
2484 | } |
2485 | ||
57cba5d3 | 2486 | static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr) |
d0bcb878 KU |
2487 | { |
2488 | struct dm_rq_target_io *tio = clone->end_io_data; | |
2489 | ||
57cba5d3 | 2490 | tio->info.target_request_nr = request_nr; |
d0bcb878 KU |
2491 | } |
2492 | ||
2493 | /* Issue barrier requests to targets and wait for their completion. */ | |
2494 | static int dm_rq_barrier(struct mapped_device *md) | |
2495 | { | |
2496 | int i, j; | |
7c666411 | 2497 | struct dm_table *map = dm_get_live_table(md); |
d0bcb878 KU |
2498 | unsigned num_targets = dm_table_get_num_targets(map); |
2499 | struct dm_target *ti; | |
2500 | struct request *clone; | |
2501 | ||
2502 | md->barrier_error = 0; | |
2503 | ||
2504 | for (i = 0; i < num_targets; i++) { | |
2505 | ti = dm_table_get_target(map, i); | |
2506 | for (j = 0; j < ti->num_flush_requests; j++) { | |
2507 | clone = clone_rq(md->flush_request, md, GFP_NOIO); | |
57cba5d3 | 2508 | dm_rq_set_target_request_nr(clone, j); |
d0bcb878 KU |
2509 | atomic_inc(&md->pending[rq_data_dir(clone)]); |
2510 | map_request(ti, clone, md); | |
2511 | } | |
2512 | } | |
2513 | ||
2514 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); | |
2515 | dm_table_put(map); | |
2516 | ||
2517 | return md->barrier_error; | |
2518 | } | |
2519 | ||
2520 | static void dm_rq_barrier_work(struct work_struct *work) | |
2521 | { | |
2522 | int error; | |
2523 | struct mapped_device *md = container_of(work, struct mapped_device, | |
2524 | barrier_work); | |
2525 | struct request_queue *q = md->queue; | |
2526 | struct request *rq; | |
2527 | unsigned long flags; | |
2528 | ||
2529 | /* | |
2530 | * Hold the md reference here and leave it at the last part so that | |
2531 | * the md can't be deleted by device opener when the barrier request | |
2532 | * completes. | |
2533 | */ | |
2534 | dm_get(md); | |
2535 | ||
2536 | error = dm_rq_barrier(md); | |
2537 | ||
2538 | rq = md->flush_request; | |
2539 | md->flush_request = NULL; | |
2540 | ||
2541 | if (error == DM_ENDIO_REQUEUE) { | |
2542 | spin_lock_irqsave(q->queue_lock, flags); | |
2543 | blk_requeue_request(q, rq); | |
2544 | spin_unlock_irqrestore(q->queue_lock, flags); | |
2545 | } else | |
2546 | blk_end_request_all(rq, error); | |
2547 | ||
2548 | blk_run_queue(q); | |
2549 | ||
2550 | dm_put(md); | |
2551 | } | |
2552 | ||
1da177e4 | 2553 | /* |
042d2a9b | 2554 | * Swap in a new table, returning the old one for the caller to destroy. |
1da177e4 | 2555 | */ |
042d2a9b | 2556 | struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) |
1da177e4 | 2557 | { |
042d2a9b | 2558 | struct dm_table *map = ERR_PTR(-EINVAL); |
754c5fc7 | 2559 | struct queue_limits limits; |
042d2a9b | 2560 | int r; |
1da177e4 | 2561 | |
e61290a4 | 2562 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
2563 | |
2564 | /* device must be suspended */ | |
4f186f8b | 2565 | if (!dm_suspended_md(md)) |
93c534ae | 2566 | goto out; |
1da177e4 | 2567 | |
754c5fc7 | 2568 | r = dm_calculate_queue_limits(table, &limits); |
042d2a9b AK |
2569 | if (r) { |
2570 | map = ERR_PTR(r); | |
754c5fc7 | 2571 | goto out; |
042d2a9b | 2572 | } |
754c5fc7 | 2573 | |
042d2a9b | 2574 | map = __bind(md, table, &limits); |
1da177e4 | 2575 | |
93c534ae | 2576 | out: |
e61290a4 | 2577 | mutex_unlock(&md->suspend_lock); |
042d2a9b | 2578 | return map; |
1da177e4 LT |
2579 | } |
2580 | ||
2581 | /* | |
2582 | * Functions to lock and unlock any filesystem running on the | |
2583 | * device. | |
2584 | */ | |
2ca3310e | 2585 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 2586 | { |
e39e2e95 | 2587 | int r; |
1da177e4 LT |
2588 | |
2589 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 2590 | |
db8fef4f | 2591 | md->frozen_sb = freeze_bdev(md->bdev); |
dfbe03f6 | 2592 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 2593 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
2594 | md->frozen_sb = NULL; |
2595 | return r; | |
dfbe03f6 AK |
2596 | } |
2597 | ||
aa8d7c2f AK |
2598 | set_bit(DMF_FROZEN, &md->flags); |
2599 | ||
1da177e4 LT |
2600 | return 0; |
2601 | } | |
2602 | ||
2ca3310e | 2603 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 2604 | { |
aa8d7c2f AK |
2605 | if (!test_bit(DMF_FROZEN, &md->flags)) |
2606 | return; | |
2607 | ||
db8fef4f | 2608 | thaw_bdev(md->bdev, md->frozen_sb); |
1da177e4 | 2609 | md->frozen_sb = NULL; |
aa8d7c2f | 2610 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
2611 | } |
2612 | ||
2613 | /* | |
2614 | * We need to be able to change a mapping table under a mounted | |
2615 | * filesystem. For example we might want to move some data in | |
2616 | * the background. Before the table can be swapped with | |
2617 | * dm_bind_table, dm_suspend must be called to flush any in | |
2618 | * flight bios and ensure that any further io gets deferred. | |
2619 | */ | |
cec47e3d KU |
2620 | /* |
2621 | * Suspend mechanism in request-based dm. | |
2622 | * | |
9f518b27 KU |
2623 | * 1. Flush all I/Os by lock_fs() if needed. |
2624 | * 2. Stop dispatching any I/O by stopping the request_queue. | |
2625 | * 3. Wait for all in-flight I/Os to be completed or requeued. | |
cec47e3d | 2626 | * |
9f518b27 | 2627 | * To abort suspend, start the request_queue. |
cec47e3d | 2628 | */ |
a3d77d35 | 2629 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 2630 | { |
2ca3310e | 2631 | struct dm_table *map = NULL; |
46125c1c | 2632 | int r = 0; |
a3d77d35 | 2633 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 2634 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 2635 | |
e61290a4 | 2636 | mutex_lock(&md->suspend_lock); |
2ca3310e | 2637 | |
4f186f8b | 2638 | if (dm_suspended_md(md)) { |
73d410c0 | 2639 | r = -EINVAL; |
d287483d | 2640 | goto out_unlock; |
73d410c0 | 2641 | } |
1da177e4 | 2642 | |
7c666411 | 2643 | map = dm_get_live_table(md); |
1da177e4 | 2644 | |
2e93ccc1 KU |
2645 | /* |
2646 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
2647 | * This flag is cleared before dm_suspend returns. | |
2648 | */ | |
2649 | if (noflush) | |
2650 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
2651 | ||
cf222b37 AK |
2652 | /* This does not get reverted if there's an error later. */ |
2653 | dm_table_presuspend_targets(map); | |
2654 | ||
32a926da | 2655 | /* |
9f518b27 KU |
2656 | * Flush I/O to the device. |
2657 | * Any I/O submitted after lock_fs() may not be flushed. | |
2658 | * noflush takes precedence over do_lockfs. | |
2659 | * (lock_fs() flushes I/Os and waits for them to complete.) | |
32a926da MP |
2660 | */ |
2661 | if (!noflush && do_lockfs) { | |
2662 | r = lock_fs(md); | |
2663 | if (r) | |
f431d966 | 2664 | goto out; |
aa8d7c2f | 2665 | } |
1da177e4 LT |
2666 | |
2667 | /* | |
3b00b203 MP |
2668 | * Here we must make sure that no processes are submitting requests |
2669 | * to target drivers i.e. no one may be executing | |
2670 | * __split_and_process_bio. This is called from dm_request and | |
2671 | * dm_wq_work. | |
2672 | * | |
2673 | * To get all processes out of __split_and_process_bio in dm_request, | |
2674 | * we take the write lock. To prevent any process from reentering | |
2675 | * __split_and_process_bio from dm_request, we set | |
2676 | * DMF_QUEUE_IO_TO_THREAD. | |
2677 | * | |
2678 | * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND | |
2679 | * and call flush_workqueue(md->wq). flush_workqueue will wait until | |
2680 | * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any | |
2681 | * further calls to __split_and_process_bio from dm_wq_work. | |
1da177e4 | 2682 | */ |
2ca3310e | 2683 | down_write(&md->io_lock); |
1eb787ec AK |
2684 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
2685 | set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); | |
2ca3310e | 2686 | up_write(&md->io_lock); |
1da177e4 | 2687 | |
d0bcb878 KU |
2688 | /* |
2689 | * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which | |
2690 | * can be kicked until md->queue is stopped. So stop md->queue before | |
2691 | * flushing md->wq. | |
2692 | */ | |
cec47e3d | 2693 | if (dm_request_based(md)) |
9f518b27 | 2694 | stop_queue(md->queue); |
cec47e3d | 2695 | |
d0bcb878 KU |
2696 | flush_workqueue(md->wq); |
2697 | ||
1da177e4 | 2698 | /* |
3b00b203 MP |
2699 | * At this point no more requests are entering target request routines. |
2700 | * We call dm_wait_for_completion to wait for all existing requests | |
2701 | * to finish. | |
1da177e4 | 2702 | */ |
401600df | 2703 | r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE); |
1da177e4 | 2704 | |
2ca3310e | 2705 | down_write(&md->io_lock); |
6d6f10df | 2706 | if (noflush) |
022c2611 | 2707 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
94d6351e | 2708 | up_write(&md->io_lock); |
2e93ccc1 | 2709 | |
1da177e4 | 2710 | /* were we interrupted ? */ |
46125c1c | 2711 | if (r < 0) { |
9a1fb464 | 2712 | dm_queue_flush(md); |
73d410c0 | 2713 | |
cec47e3d | 2714 | if (dm_request_based(md)) |
9f518b27 | 2715 | start_queue(md->queue); |
cec47e3d | 2716 | |
2ca3310e | 2717 | unlock_fs(md); |
2e93ccc1 | 2718 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 2719 | } |
1da177e4 | 2720 | |
3b00b203 MP |
2721 | /* |
2722 | * If dm_wait_for_completion returned 0, the device is completely | |
2723 | * quiescent now. There is no request-processing activity. All new | |
2724 | * requests are being added to md->deferred list. | |
2725 | */ | |
2726 | ||
2ca3310e | 2727 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 2728 | |
4d4471cb KU |
2729 | dm_table_postsuspend_targets(map); |
2730 | ||
2ca3310e AK |
2731 | out: |
2732 | dm_table_put(map); | |
d287483d AK |
2733 | |
2734 | out_unlock: | |
e61290a4 | 2735 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 2736 | return r; |
1da177e4 LT |
2737 | } |
2738 | ||
2739 | int dm_resume(struct mapped_device *md) | |
2740 | { | |
cf222b37 | 2741 | int r = -EINVAL; |
cf222b37 | 2742 | struct dm_table *map = NULL; |
1da177e4 | 2743 | |
e61290a4 | 2744 | mutex_lock(&md->suspend_lock); |
4f186f8b | 2745 | if (!dm_suspended_md(md)) |
cf222b37 | 2746 | goto out; |
cf222b37 | 2747 | |
7c666411 | 2748 | map = dm_get_live_table(md); |
2ca3310e | 2749 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 2750 | goto out; |
1da177e4 | 2751 | |
8757b776 MB |
2752 | r = dm_table_resume_targets(map); |
2753 | if (r) | |
2754 | goto out; | |
2ca3310e | 2755 | |
9a1fb464 | 2756 | dm_queue_flush(md); |
2ca3310e | 2757 | |
cec47e3d KU |
2758 | /* |
2759 | * Flushing deferred I/Os must be done after targets are resumed | |
2760 | * so that mapping of targets can work correctly. | |
2761 | * Request-based dm is queueing the deferred I/Os in its request_queue. | |
2762 | */ | |
2763 | if (dm_request_based(md)) | |
2764 | start_queue(md->queue); | |
2765 | ||
2ca3310e AK |
2766 | unlock_fs(md); |
2767 | ||
2768 | clear_bit(DMF_SUSPENDED, &md->flags); | |
2769 | ||
1da177e4 | 2770 | dm_table_unplug_all(map); |
cf222b37 AK |
2771 | r = 0; |
2772 | out: | |
2773 | dm_table_put(map); | |
e61290a4 | 2774 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 2775 | |
cf222b37 | 2776 | return r; |
1da177e4 LT |
2777 | } |
2778 | ||
2779 | /*----------------------------------------------------------------- | |
2780 | * Event notification. | |
2781 | *---------------------------------------------------------------*/ | |
3abf85b5 | 2782 | int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
60935eb2 | 2783 | unsigned cookie) |
69267a30 | 2784 | { |
60935eb2 MB |
2785 | char udev_cookie[DM_COOKIE_LENGTH]; |
2786 | char *envp[] = { udev_cookie, NULL }; | |
2787 | ||
2788 | if (!cookie) | |
3abf85b5 | 2789 | return kobject_uevent(&disk_to_dev(md->disk)->kobj, action); |
60935eb2 MB |
2790 | else { |
2791 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", | |
2792 | DM_COOKIE_ENV_VAR_NAME, cookie); | |
3abf85b5 PR |
2793 | return kobject_uevent_env(&disk_to_dev(md->disk)->kobj, |
2794 | action, envp); | |
60935eb2 | 2795 | } |
69267a30 AK |
2796 | } |
2797 | ||
7a8c3d3b MA |
2798 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
2799 | { | |
2800 | return atomic_add_return(1, &md->uevent_seq); | |
2801 | } | |
2802 | ||
1da177e4 LT |
2803 | uint32_t dm_get_event_nr(struct mapped_device *md) |
2804 | { | |
2805 | return atomic_read(&md->event_nr); | |
2806 | } | |
2807 | ||
2808 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
2809 | { | |
2810 | return wait_event_interruptible(md->eventq, | |
2811 | (event_nr != atomic_read(&md->event_nr))); | |
2812 | } | |
2813 | ||
7a8c3d3b MA |
2814 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
2815 | { | |
2816 | unsigned long flags; | |
2817 | ||
2818 | spin_lock_irqsave(&md->uevent_lock, flags); | |
2819 | list_add(elist, &md->uevent_list); | |
2820 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
2821 | } | |
2822 | ||
1da177e4 LT |
2823 | /* |
2824 | * The gendisk is only valid as long as you have a reference | |
2825 | * count on 'md'. | |
2826 | */ | |
2827 | struct gendisk *dm_disk(struct mapped_device *md) | |
2828 | { | |
2829 | return md->disk; | |
2830 | } | |
2831 | ||
784aae73 MB |
2832 | struct kobject *dm_kobject(struct mapped_device *md) |
2833 | { | |
2834 | return &md->kobj; | |
2835 | } | |
2836 | ||
2837 | /* | |
2838 | * struct mapped_device should not be exported outside of dm.c | |
2839 | * so use this check to verify that kobj is part of md structure | |
2840 | */ | |
2841 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) | |
2842 | { | |
2843 | struct mapped_device *md; | |
2844 | ||
2845 | md = container_of(kobj, struct mapped_device, kobj); | |
2846 | if (&md->kobj != kobj) | |
2847 | return NULL; | |
2848 | ||
4d89b7b4 | 2849 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 2850 | dm_deleting_md(md)) |
4d89b7b4 MB |
2851 | return NULL; |
2852 | ||
784aae73 MB |
2853 | dm_get(md); |
2854 | return md; | |
2855 | } | |
2856 | ||
4f186f8b | 2857 | int dm_suspended_md(struct mapped_device *md) |
1da177e4 LT |
2858 | { |
2859 | return test_bit(DMF_SUSPENDED, &md->flags); | |
2860 | } | |
2861 | ||
64dbce58 KU |
2862 | int dm_suspended(struct dm_target *ti) |
2863 | { | |
ecdb2e25 | 2864 | return dm_suspended_md(dm_table_get_md(ti->table)); |
64dbce58 KU |
2865 | } |
2866 | EXPORT_SYMBOL_GPL(dm_suspended); | |
2867 | ||
2e93ccc1 KU |
2868 | int dm_noflush_suspending(struct dm_target *ti) |
2869 | { | |
ecdb2e25 | 2870 | return __noflush_suspending(dm_table_get_md(ti->table)); |
2e93ccc1 KU |
2871 | } |
2872 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
2873 | ||
e6ee8c0b KU |
2874 | struct dm_md_mempools *dm_alloc_md_mempools(unsigned type) |
2875 | { | |
2876 | struct dm_md_mempools *pools = kmalloc(sizeof(*pools), GFP_KERNEL); | |
2877 | ||
2878 | if (!pools) | |
2879 | return NULL; | |
2880 | ||
2881 | pools->io_pool = (type == DM_TYPE_BIO_BASED) ? | |
2882 | mempool_create_slab_pool(MIN_IOS, _io_cache) : | |
2883 | mempool_create_slab_pool(MIN_IOS, _rq_bio_info_cache); | |
2884 | if (!pools->io_pool) | |
2885 | goto free_pools_and_out; | |
2886 | ||
2887 | pools->tio_pool = (type == DM_TYPE_BIO_BASED) ? | |
2888 | mempool_create_slab_pool(MIN_IOS, _tio_cache) : | |
2889 | mempool_create_slab_pool(MIN_IOS, _rq_tio_cache); | |
2890 | if (!pools->tio_pool) | |
2891 | goto free_io_pool_and_out; | |
2892 | ||
2893 | pools->bs = (type == DM_TYPE_BIO_BASED) ? | |
2894 | bioset_create(16, 0) : bioset_create(MIN_IOS, 0); | |
2895 | if (!pools->bs) | |
2896 | goto free_tio_pool_and_out; | |
2897 | ||
2898 | return pools; | |
2899 | ||
2900 | free_tio_pool_and_out: | |
2901 | mempool_destroy(pools->tio_pool); | |
2902 | ||
2903 | free_io_pool_and_out: | |
2904 | mempool_destroy(pools->io_pool); | |
2905 | ||
2906 | free_pools_and_out: | |
2907 | kfree(pools); | |
2908 | ||
2909 | return NULL; | |
2910 | } | |
2911 | ||
2912 | void dm_free_md_mempools(struct dm_md_mempools *pools) | |
2913 | { | |
2914 | if (!pools) | |
2915 | return; | |
2916 | ||
2917 | if (pools->io_pool) | |
2918 | mempool_destroy(pools->io_pool); | |
2919 | ||
2920 | if (pools->tio_pool) | |
2921 | mempool_destroy(pools->tio_pool); | |
2922 | ||
2923 | if (pools->bs) | |
2924 | bioset_free(pools->bs); | |
2925 | ||
2926 | kfree(pools); | |
2927 | } | |
2928 | ||
83d5cde4 | 2929 | static const struct block_device_operations dm_blk_dops = { |
1da177e4 LT |
2930 | .open = dm_blk_open, |
2931 | .release = dm_blk_close, | |
aa129a22 | 2932 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 2933 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
2934 | .owner = THIS_MODULE |
2935 | }; | |
2936 | ||
2937 | EXPORT_SYMBOL(dm_get_mapinfo); | |
2938 | ||
2939 | /* | |
2940 | * module hooks | |
2941 | */ | |
2942 | module_init(dm_init); | |
2943 | module_exit(dm_exit); | |
2944 | ||
2945 | module_param(major, uint, 0); | |
2946 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
2947 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
2948 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
2949 | MODULE_LICENSE("GPL"); |