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Commit | Line | Data |
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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> | |
1da177e4 LT |
17 | #include <linux/mempool.h> |
18 | #include <linux/slab.h> | |
19 | #include <linux/idr.h> | |
3ac51e74 | 20 | #include <linux/hdreg.h> |
3f77316d | 21 | #include <linux/delay.h> |
55782138 LZ |
22 | |
23 | #include <trace/events/block.h> | |
1da177e4 | 24 | |
72d94861 AK |
25 | #define DM_MSG_PREFIX "core" |
26 | ||
71a16736 NK |
27 | #ifdef CONFIG_PRINTK |
28 | /* | |
29 | * ratelimit state to be used in DMXXX_LIMIT(). | |
30 | */ | |
31 | DEFINE_RATELIMIT_STATE(dm_ratelimit_state, | |
32 | DEFAULT_RATELIMIT_INTERVAL, | |
33 | DEFAULT_RATELIMIT_BURST); | |
34 | EXPORT_SYMBOL(dm_ratelimit_state); | |
35 | #endif | |
36 | ||
60935eb2 MB |
37 | /* |
38 | * Cookies are numeric values sent with CHANGE and REMOVE | |
39 | * uevents while resuming, removing or renaming the device. | |
40 | */ | |
41 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" | |
42 | #define DM_COOKIE_LENGTH 24 | |
43 | ||
1da177e4 LT |
44 | static const char *_name = DM_NAME; |
45 | ||
46 | static unsigned int major = 0; | |
47 | static unsigned int _major = 0; | |
48 | ||
d15b774c AK |
49 | static DEFINE_IDR(_minor_idr); |
50 | ||
f32c10b0 | 51 | static DEFINE_SPINLOCK(_minor_lock); |
2c140a24 MP |
52 | |
53 | static void do_deferred_remove(struct work_struct *w); | |
54 | ||
55 | static DECLARE_WORK(deferred_remove_work, do_deferred_remove); | |
56 | ||
1da177e4 | 57 | /* |
8fbf26ad | 58 | * For bio-based dm. |
1da177e4 LT |
59 | * One of these is allocated per bio. |
60 | */ | |
61 | struct dm_io { | |
62 | struct mapped_device *md; | |
63 | int error; | |
1da177e4 | 64 | atomic_t io_count; |
6ae2fa67 | 65 | struct bio *bio; |
3eaf840e | 66 | unsigned long start_time; |
f88fb981 | 67 | spinlock_t endio_lock; |
fd2ed4d2 | 68 | struct dm_stats_aux stats_aux; |
1da177e4 LT |
69 | }; |
70 | ||
8fbf26ad KU |
71 | /* |
72 | * For request-based dm. | |
73 | * One of these is allocated per request. | |
74 | */ | |
75 | struct dm_rq_target_io { | |
76 | struct mapped_device *md; | |
77 | struct dm_target *ti; | |
78 | struct request *orig, clone; | |
79 | int error; | |
80 | union map_info info; | |
81 | }; | |
82 | ||
83 | /* | |
94818742 KO |
84 | * For request-based dm - the bio clones we allocate are embedded in these |
85 | * structs. | |
86 | * | |
87 | * We allocate these with bio_alloc_bioset, using the front_pad parameter when | |
88 | * the bioset is created - this means the bio has to come at the end of the | |
89 | * struct. | |
8fbf26ad KU |
90 | */ |
91 | struct dm_rq_clone_bio_info { | |
92 | struct bio *orig; | |
cec47e3d | 93 | struct dm_rq_target_io *tio; |
94818742 | 94 | struct bio clone; |
8fbf26ad KU |
95 | }; |
96 | ||
1da177e4 LT |
97 | union map_info *dm_get_mapinfo(struct bio *bio) |
98 | { | |
17b2f66f | 99 | if (bio && bio->bi_private) |
028867ac | 100 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 101 | return NULL; |
1da177e4 LT |
102 | } |
103 | ||
cec47e3d KU |
104 | union map_info *dm_get_rq_mapinfo(struct request *rq) |
105 | { | |
106 | if (rq && rq->end_io_data) | |
107 | return &((struct dm_rq_target_io *)rq->end_io_data)->info; | |
108 | return NULL; | |
109 | } | |
110 | EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); | |
111 | ||
ba61fdd1 JM |
112 | #define MINOR_ALLOCED ((void *)-1) |
113 | ||
1da177e4 LT |
114 | /* |
115 | * Bits for the md->flags field. | |
116 | */ | |
1eb787ec | 117 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
1da177e4 | 118 | #define DMF_SUSPENDED 1 |
aa8d7c2f | 119 | #define DMF_FROZEN 2 |
fba9f90e | 120 | #define DMF_FREEING 3 |
5c6bd75d | 121 | #define DMF_DELETING 4 |
2e93ccc1 | 122 | #define DMF_NOFLUSH_SUSPENDING 5 |
d5b9dd04 | 123 | #define DMF_MERGE_IS_OPTIONAL 6 |
2c140a24 | 124 | #define DMF_DEFERRED_REMOVE 7 |
1da177e4 | 125 | |
83d5e5b0 MP |
126 | /* |
127 | * A dummy definition to make RCU happy. | |
128 | * struct dm_table should never be dereferenced in this file. | |
129 | */ | |
130 | struct dm_table { | |
131 | int undefined__; | |
132 | }; | |
133 | ||
304f3f6a MB |
134 | /* |
135 | * Work processed by per-device workqueue. | |
136 | */ | |
1da177e4 | 137 | struct mapped_device { |
83d5e5b0 | 138 | struct srcu_struct io_barrier; |
e61290a4 | 139 | struct mutex suspend_lock; |
1da177e4 | 140 | atomic_t holders; |
5c6bd75d | 141 | atomic_t open_count; |
1da177e4 | 142 | |
2a7faeb1 MP |
143 | /* |
144 | * The current mapping. | |
145 | * Use dm_get_live_table{_fast} or take suspend_lock for | |
146 | * dereference. | |
147 | */ | |
148 | struct dm_table *map; | |
149 | ||
1da177e4 LT |
150 | unsigned long flags; |
151 | ||
165125e1 | 152 | struct request_queue *queue; |
a5664dad | 153 | unsigned type; |
4a0b4ddf | 154 | /* Protect queue and type against concurrent access. */ |
a5664dad MS |
155 | struct mutex type_lock; |
156 | ||
36a0456f AK |
157 | struct target_type *immutable_target_type; |
158 | ||
1da177e4 | 159 | struct gendisk *disk; |
7e51f257 | 160 | char name[16]; |
1da177e4 LT |
161 | |
162 | void *interface_ptr; | |
163 | ||
164 | /* | |
165 | * A list of ios that arrived while we were suspended. | |
166 | */ | |
316d315b | 167 | atomic_t pending[2]; |
1da177e4 | 168 | wait_queue_head_t wait; |
53d5914f | 169 | struct work_struct work; |
74859364 | 170 | struct bio_list deferred; |
022c2611 | 171 | spinlock_t deferred_lock; |
1da177e4 | 172 | |
af7e466a | 173 | /* |
29e4013d | 174 | * Processing queue (flush) |
304f3f6a MB |
175 | */ |
176 | struct workqueue_struct *wq; | |
177 | ||
1da177e4 LT |
178 | /* |
179 | * io objects are allocated from here. | |
180 | */ | |
181 | mempool_t *io_pool; | |
1da177e4 | 182 | |
9faf400f SB |
183 | struct bio_set *bs; |
184 | ||
1da177e4 LT |
185 | /* |
186 | * Event handling. | |
187 | */ | |
188 | atomic_t event_nr; | |
189 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
190 | atomic_t uevent_seq; |
191 | struct list_head uevent_list; | |
192 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
193 | |
194 | /* | |
195 | * freeze/thaw support require holding onto a super block | |
196 | */ | |
197 | struct super_block *frozen_sb; | |
db8fef4f | 198 | struct block_device *bdev; |
3ac51e74 DW |
199 | |
200 | /* forced geometry settings */ | |
201 | struct hd_geometry geometry; | |
784aae73 MB |
202 | |
203 | /* sysfs handle */ | |
204 | struct kobject kobj; | |
52b1fd5a | 205 | |
be35f486 MP |
206 | /* wait until the kobject is released */ |
207 | struct completion kobj_completion; | |
208 | ||
d87f4c14 TH |
209 | /* zero-length flush that will be cloned and submitted to targets */ |
210 | struct bio flush_bio; | |
fd2ed4d2 MP |
211 | |
212 | struct dm_stats stats; | |
1da177e4 LT |
213 | }; |
214 | ||
e6ee8c0b KU |
215 | /* |
216 | * For mempools pre-allocation at the table loading time. | |
217 | */ | |
218 | struct dm_md_mempools { | |
219 | mempool_t *io_pool; | |
e6ee8c0b KU |
220 | struct bio_set *bs; |
221 | }; | |
222 | ||
6cfa5857 MS |
223 | #define RESERVED_BIO_BASED_IOS 16 |
224 | #define RESERVED_REQUEST_BASED_IOS 256 | |
f4790826 | 225 | #define RESERVED_MAX_IOS 1024 |
e18b890b | 226 | static struct kmem_cache *_io_cache; |
8fbf26ad | 227 | static struct kmem_cache *_rq_tio_cache; |
94818742 | 228 | |
e8603136 MS |
229 | /* |
230 | * Bio-based DM's mempools' reserved IOs set by the user. | |
231 | */ | |
232 | static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; | |
233 | ||
f4790826 MS |
234 | /* |
235 | * Request-based DM's mempools' reserved IOs set by the user. | |
236 | */ | |
237 | static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS; | |
238 | ||
239 | static unsigned __dm_get_reserved_ios(unsigned *reserved_ios, | |
240 | unsigned def, unsigned max) | |
241 | { | |
242 | unsigned ios = ACCESS_ONCE(*reserved_ios); | |
243 | unsigned modified_ios = 0; | |
244 | ||
245 | if (!ios) | |
246 | modified_ios = def; | |
247 | else if (ios > max) | |
248 | modified_ios = max; | |
249 | ||
250 | if (modified_ios) { | |
251 | (void)cmpxchg(reserved_ios, ios, modified_ios); | |
252 | ios = modified_ios; | |
253 | } | |
254 | ||
255 | return ios; | |
256 | } | |
257 | ||
e8603136 MS |
258 | unsigned dm_get_reserved_bio_based_ios(void) |
259 | { | |
260 | return __dm_get_reserved_ios(&reserved_bio_based_ios, | |
261 | RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS); | |
262 | } | |
263 | EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); | |
264 | ||
f4790826 MS |
265 | unsigned dm_get_reserved_rq_based_ios(void) |
266 | { | |
267 | return __dm_get_reserved_ios(&reserved_rq_based_ios, | |
268 | RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS); | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios); | |
271 | ||
1da177e4 LT |
272 | static int __init local_init(void) |
273 | { | |
51157b4a | 274 | int r = -ENOMEM; |
1da177e4 | 275 | |
1da177e4 | 276 | /* allocate a slab for the dm_ios */ |
028867ac | 277 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 278 | if (!_io_cache) |
51157b4a | 279 | return r; |
1da177e4 | 280 | |
8fbf26ad KU |
281 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
282 | if (!_rq_tio_cache) | |
dba14160 | 283 | goto out_free_io_cache; |
8fbf26ad | 284 | |
51e5b2bd | 285 | r = dm_uevent_init(); |
51157b4a | 286 | if (r) |
23e5083b | 287 | goto out_free_rq_tio_cache; |
51e5b2bd | 288 | |
1da177e4 LT |
289 | _major = major; |
290 | r = register_blkdev(_major, _name); | |
51157b4a KU |
291 | if (r < 0) |
292 | goto out_uevent_exit; | |
1da177e4 LT |
293 | |
294 | if (!_major) | |
295 | _major = r; | |
296 | ||
297 | return 0; | |
51157b4a KU |
298 | |
299 | out_uevent_exit: | |
300 | dm_uevent_exit(); | |
8fbf26ad KU |
301 | out_free_rq_tio_cache: |
302 | kmem_cache_destroy(_rq_tio_cache); | |
51157b4a KU |
303 | out_free_io_cache: |
304 | kmem_cache_destroy(_io_cache); | |
305 | ||
306 | return r; | |
1da177e4 LT |
307 | } |
308 | ||
309 | static void local_exit(void) | |
310 | { | |
2c140a24 MP |
311 | flush_scheduled_work(); |
312 | ||
8fbf26ad | 313 | kmem_cache_destroy(_rq_tio_cache); |
1da177e4 | 314 | kmem_cache_destroy(_io_cache); |
00d59405 | 315 | unregister_blkdev(_major, _name); |
51e5b2bd | 316 | dm_uevent_exit(); |
1da177e4 LT |
317 | |
318 | _major = 0; | |
319 | ||
320 | DMINFO("cleaned up"); | |
321 | } | |
322 | ||
b9249e55 | 323 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
324 | local_init, |
325 | dm_target_init, | |
326 | dm_linear_init, | |
327 | dm_stripe_init, | |
952b3557 | 328 | dm_io_init, |
945fa4d2 | 329 | dm_kcopyd_init, |
1da177e4 | 330 | dm_interface_init, |
fd2ed4d2 | 331 | dm_statistics_init, |
1da177e4 LT |
332 | }; |
333 | ||
b9249e55 | 334 | static void (*_exits[])(void) = { |
1da177e4 LT |
335 | local_exit, |
336 | dm_target_exit, | |
337 | dm_linear_exit, | |
338 | dm_stripe_exit, | |
952b3557 | 339 | dm_io_exit, |
945fa4d2 | 340 | dm_kcopyd_exit, |
1da177e4 | 341 | dm_interface_exit, |
fd2ed4d2 | 342 | dm_statistics_exit, |
1da177e4 LT |
343 | }; |
344 | ||
345 | static int __init dm_init(void) | |
346 | { | |
347 | const int count = ARRAY_SIZE(_inits); | |
348 | ||
349 | int r, i; | |
350 | ||
351 | for (i = 0; i < count; i++) { | |
352 | r = _inits[i](); | |
353 | if (r) | |
354 | goto bad; | |
355 | } | |
356 | ||
357 | return 0; | |
358 | ||
359 | bad: | |
360 | while (i--) | |
361 | _exits[i](); | |
362 | ||
363 | return r; | |
364 | } | |
365 | ||
366 | static void __exit dm_exit(void) | |
367 | { | |
368 | int i = ARRAY_SIZE(_exits); | |
369 | ||
370 | while (i--) | |
371 | _exits[i](); | |
d15b774c AK |
372 | |
373 | /* | |
374 | * Should be empty by this point. | |
375 | */ | |
d15b774c | 376 | idr_destroy(&_minor_idr); |
1da177e4 LT |
377 | } |
378 | ||
379 | /* | |
380 | * Block device functions | |
381 | */ | |
432a212c MA |
382 | int dm_deleting_md(struct mapped_device *md) |
383 | { | |
384 | return test_bit(DMF_DELETING, &md->flags); | |
385 | } | |
386 | ||
fe5f9f2c | 387 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
388 | { |
389 | struct mapped_device *md; | |
390 | ||
fba9f90e JM |
391 | spin_lock(&_minor_lock); |
392 | ||
fe5f9f2c | 393 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
394 | if (!md) |
395 | goto out; | |
396 | ||
5c6bd75d | 397 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 398 | dm_deleting_md(md)) { |
fba9f90e JM |
399 | md = NULL; |
400 | goto out; | |
401 | } | |
402 | ||
1da177e4 | 403 | dm_get(md); |
5c6bd75d | 404 | atomic_inc(&md->open_count); |
fba9f90e JM |
405 | |
406 | out: | |
407 | spin_unlock(&_minor_lock); | |
408 | ||
409 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
410 | } |
411 | ||
db2a144b | 412 | static void dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 413 | { |
fe5f9f2c | 414 | struct mapped_device *md = disk->private_data; |
6e9624b8 | 415 | |
4a1aeb98 MB |
416 | spin_lock(&_minor_lock); |
417 | ||
2c140a24 MP |
418 | if (atomic_dec_and_test(&md->open_count) && |
419 | (test_bit(DMF_DEFERRED_REMOVE, &md->flags))) | |
420 | schedule_work(&deferred_remove_work); | |
421 | ||
1da177e4 | 422 | dm_put(md); |
4a1aeb98 MB |
423 | |
424 | spin_unlock(&_minor_lock); | |
1da177e4 LT |
425 | } |
426 | ||
5c6bd75d AK |
427 | int dm_open_count(struct mapped_device *md) |
428 | { | |
429 | return atomic_read(&md->open_count); | |
430 | } | |
431 | ||
432 | /* | |
433 | * Guarantees nothing is using the device before it's deleted. | |
434 | */ | |
2c140a24 | 435 | int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) |
5c6bd75d AK |
436 | { |
437 | int r = 0; | |
438 | ||
439 | spin_lock(&_minor_lock); | |
440 | ||
2c140a24 | 441 | if (dm_open_count(md)) { |
5c6bd75d | 442 | r = -EBUSY; |
2c140a24 MP |
443 | if (mark_deferred) |
444 | set_bit(DMF_DEFERRED_REMOVE, &md->flags); | |
445 | } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) | |
446 | r = -EEXIST; | |
5c6bd75d AK |
447 | else |
448 | set_bit(DMF_DELETING, &md->flags); | |
449 | ||
450 | spin_unlock(&_minor_lock); | |
451 | ||
452 | return r; | |
453 | } | |
454 | ||
2c140a24 MP |
455 | int dm_cancel_deferred_remove(struct mapped_device *md) |
456 | { | |
457 | int r = 0; | |
458 | ||
459 | spin_lock(&_minor_lock); | |
460 | ||
461 | if (test_bit(DMF_DELETING, &md->flags)) | |
462 | r = -EBUSY; | |
463 | else | |
464 | clear_bit(DMF_DEFERRED_REMOVE, &md->flags); | |
465 | ||
466 | spin_unlock(&_minor_lock); | |
467 | ||
468 | return r; | |
469 | } | |
470 | ||
471 | static void do_deferred_remove(struct work_struct *w) | |
472 | { | |
473 | dm_deferred_remove(); | |
474 | } | |
475 | ||
fd2ed4d2 MP |
476 | sector_t dm_get_size(struct mapped_device *md) |
477 | { | |
478 | return get_capacity(md->disk); | |
479 | } | |
480 | ||
481 | struct dm_stats *dm_get_stats(struct mapped_device *md) | |
482 | { | |
483 | return &md->stats; | |
484 | } | |
485 | ||
3ac51e74 DW |
486 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
487 | { | |
488 | struct mapped_device *md = bdev->bd_disk->private_data; | |
489 | ||
490 | return dm_get_geometry(md, geo); | |
491 | } | |
492 | ||
fe5f9f2c | 493 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
494 | unsigned int cmd, unsigned long arg) |
495 | { | |
fe5f9f2c | 496 | struct mapped_device *md = bdev->bd_disk->private_data; |
83d5e5b0 | 497 | int srcu_idx; |
6c182cd8 | 498 | struct dm_table *map; |
aa129a22 MB |
499 | struct dm_target *tgt; |
500 | int r = -ENOTTY; | |
501 | ||
6c182cd8 | 502 | retry: |
83d5e5b0 MP |
503 | map = dm_get_live_table(md, &srcu_idx); |
504 | ||
aa129a22 MB |
505 | if (!map || !dm_table_get_size(map)) |
506 | goto out; | |
507 | ||
508 | /* We only support devices that have a single target */ | |
509 | if (dm_table_get_num_targets(map) != 1) | |
510 | goto out; | |
511 | ||
512 | tgt = dm_table_get_target(map, 0); | |
513 | ||
4f186f8b | 514 | if (dm_suspended_md(md)) { |
aa129a22 MB |
515 | r = -EAGAIN; |
516 | goto out; | |
517 | } | |
518 | ||
519 | if (tgt->type->ioctl) | |
647b3d00 | 520 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
521 | |
522 | out: | |
83d5e5b0 | 523 | dm_put_live_table(md, srcu_idx); |
aa129a22 | 524 | |
6c182cd8 HR |
525 | if (r == -ENOTCONN) { |
526 | msleep(10); | |
527 | goto retry; | |
528 | } | |
529 | ||
aa129a22 MB |
530 | return r; |
531 | } | |
532 | ||
028867ac | 533 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
534 | { |
535 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
536 | } | |
537 | ||
028867ac | 538 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
539 | { |
540 | mempool_free(io, md->io_pool); | |
541 | } | |
542 | ||
028867ac | 543 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 | 544 | { |
dba14160 | 545 | bio_put(&tio->clone); |
1da177e4 LT |
546 | } |
547 | ||
08885643 KU |
548 | static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md, |
549 | gfp_t gfp_mask) | |
cec47e3d | 550 | { |
5f015204 | 551 | return mempool_alloc(md->io_pool, gfp_mask); |
cec47e3d KU |
552 | } |
553 | ||
554 | static void free_rq_tio(struct dm_rq_target_io *tio) | |
555 | { | |
5f015204 | 556 | mempool_free(tio, tio->md->io_pool); |
cec47e3d KU |
557 | } |
558 | ||
90abb8c4 KU |
559 | static int md_in_flight(struct mapped_device *md) |
560 | { | |
561 | return atomic_read(&md->pending[READ]) + | |
562 | atomic_read(&md->pending[WRITE]); | |
563 | } | |
564 | ||
3eaf840e JNN |
565 | static void start_io_acct(struct dm_io *io) |
566 | { | |
567 | struct mapped_device *md = io->md; | |
fd2ed4d2 | 568 | struct bio *bio = io->bio; |
c9959059 | 569 | int cpu; |
fd2ed4d2 | 570 | int rw = bio_data_dir(bio); |
3eaf840e JNN |
571 | |
572 | io->start_time = jiffies; | |
573 | ||
074a7aca TH |
574 | cpu = part_stat_lock(); |
575 | part_round_stats(cpu, &dm_disk(md)->part0); | |
576 | part_stat_unlock(); | |
1e9bb880 SL |
577 | atomic_set(&dm_disk(md)->part0.in_flight[rw], |
578 | atomic_inc_return(&md->pending[rw])); | |
fd2ed4d2 MP |
579 | |
580 | if (unlikely(dm_stats_used(&md->stats))) | |
581 | dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector, | |
582 | bio_sectors(bio), false, 0, &io->stats_aux); | |
3eaf840e JNN |
583 | } |
584 | ||
d221d2e7 | 585 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
586 | { |
587 | struct mapped_device *md = io->md; | |
588 | struct bio *bio = io->bio; | |
589 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 590 | int pending, cpu; |
3eaf840e JNN |
591 | int rw = bio_data_dir(bio); |
592 | ||
074a7aca TH |
593 | cpu = part_stat_lock(); |
594 | part_round_stats(cpu, &dm_disk(md)->part0); | |
595 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
596 | part_stat_unlock(); | |
3eaf840e | 597 | |
fd2ed4d2 MP |
598 | if (unlikely(dm_stats_used(&md->stats))) |
599 | dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector, | |
600 | bio_sectors(bio), true, duration, &io->stats_aux); | |
601 | ||
af7e466a MP |
602 | /* |
603 | * After this is decremented the bio must not be touched if it is | |
d87f4c14 | 604 | * a flush. |
af7e466a | 605 | */ |
1e9bb880 SL |
606 | pending = atomic_dec_return(&md->pending[rw]); |
607 | atomic_set(&dm_disk(md)->part0.in_flight[rw], pending); | |
316d315b | 608 | pending += atomic_read(&md->pending[rw^0x1]); |
3eaf840e | 609 | |
d221d2e7 MP |
610 | /* nudge anyone waiting on suspend queue */ |
611 | if (!pending) | |
612 | wake_up(&md->wait); | |
3eaf840e JNN |
613 | } |
614 | ||
1da177e4 LT |
615 | /* |
616 | * Add the bio to the list of deferred io. | |
617 | */ | |
92c63902 | 618 | static void queue_io(struct mapped_device *md, struct bio *bio) |
1da177e4 | 619 | { |
05447420 | 620 | unsigned long flags; |
1da177e4 | 621 | |
05447420 | 622 | spin_lock_irqsave(&md->deferred_lock, flags); |
1da177e4 | 623 | bio_list_add(&md->deferred, bio); |
05447420 | 624 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
6a8736d1 | 625 | queue_work(md->wq, &md->work); |
1da177e4 LT |
626 | } |
627 | ||
628 | /* | |
629 | * Everyone (including functions in this file), should use this | |
630 | * function to access the md->map field, and make sure they call | |
83d5e5b0 | 631 | * dm_put_live_table() when finished. |
1da177e4 | 632 | */ |
83d5e5b0 | 633 | struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier) |
1da177e4 | 634 | { |
83d5e5b0 MP |
635 | *srcu_idx = srcu_read_lock(&md->io_barrier); |
636 | ||
637 | return srcu_dereference(md->map, &md->io_barrier); | |
638 | } | |
1da177e4 | 639 | |
83d5e5b0 MP |
640 | void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier) |
641 | { | |
642 | srcu_read_unlock(&md->io_barrier, srcu_idx); | |
643 | } | |
644 | ||
645 | void dm_sync_table(struct mapped_device *md) | |
646 | { | |
647 | synchronize_srcu(&md->io_barrier); | |
648 | synchronize_rcu_expedited(); | |
649 | } | |
650 | ||
651 | /* | |
652 | * A fast alternative to dm_get_live_table/dm_put_live_table. | |
653 | * The caller must not block between these two functions. | |
654 | */ | |
655 | static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU) | |
656 | { | |
657 | rcu_read_lock(); | |
658 | return rcu_dereference(md->map); | |
659 | } | |
1da177e4 | 660 | |
83d5e5b0 MP |
661 | static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) |
662 | { | |
663 | rcu_read_unlock(); | |
1da177e4 LT |
664 | } |
665 | ||
3ac51e74 DW |
666 | /* |
667 | * Get the geometry associated with a dm device | |
668 | */ | |
669 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
670 | { | |
671 | *geo = md->geometry; | |
672 | ||
673 | return 0; | |
674 | } | |
675 | ||
676 | /* | |
677 | * Set the geometry of a device. | |
678 | */ | |
679 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
680 | { | |
681 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
682 | ||
683 | if (geo->start > sz) { | |
684 | DMWARN("Start sector is beyond the geometry limits."); | |
685 | return -EINVAL; | |
686 | } | |
687 | ||
688 | md->geometry = *geo; | |
689 | ||
690 | return 0; | |
691 | } | |
692 | ||
1da177e4 LT |
693 | /*----------------------------------------------------------------- |
694 | * CRUD START: | |
695 | * A more elegant soln is in the works that uses the queue | |
696 | * merge fn, unfortunately there are a couple of changes to | |
697 | * the block layer that I want to make for this. So in the | |
698 | * interests of getting something for people to use I give | |
699 | * you this clearly demarcated crap. | |
700 | *---------------------------------------------------------------*/ | |
701 | ||
2e93ccc1 KU |
702 | static int __noflush_suspending(struct mapped_device *md) |
703 | { | |
704 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
705 | } | |
706 | ||
1da177e4 LT |
707 | /* |
708 | * Decrements the number of outstanding ios that a bio has been | |
709 | * cloned into, completing the original io if necc. | |
710 | */ | |
858119e1 | 711 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 712 | { |
2e93ccc1 | 713 | unsigned long flags; |
b35f8caa MB |
714 | int io_error; |
715 | struct bio *bio; | |
716 | struct mapped_device *md = io->md; | |
2e93ccc1 KU |
717 | |
718 | /* Push-back supersedes any I/O errors */ | |
f88fb981 KU |
719 | if (unlikely(error)) { |
720 | spin_lock_irqsave(&io->endio_lock, flags); | |
721 | if (!(io->error > 0 && __noflush_suspending(md))) | |
722 | io->error = error; | |
723 | spin_unlock_irqrestore(&io->endio_lock, flags); | |
724 | } | |
1da177e4 LT |
725 | |
726 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
727 | if (io->error == DM_ENDIO_REQUEUE) { |
728 | /* | |
729 | * Target requested pushing back the I/O. | |
2e93ccc1 | 730 | */ |
022c2611 | 731 | spin_lock_irqsave(&md->deferred_lock, flags); |
6a8736d1 TH |
732 | if (__noflush_suspending(md)) |
733 | bio_list_add_head(&md->deferred, io->bio); | |
734 | else | |
2e93ccc1 KU |
735 | /* noflush suspend was interrupted. */ |
736 | io->error = -EIO; | |
022c2611 | 737 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
2e93ccc1 KU |
738 | } |
739 | ||
b35f8caa MB |
740 | io_error = io->error; |
741 | bio = io->bio; | |
6a8736d1 TH |
742 | end_io_acct(io); |
743 | free_io(md, io); | |
744 | ||
745 | if (io_error == DM_ENDIO_REQUEUE) | |
746 | return; | |
2e93ccc1 | 747 | |
b372d360 | 748 | if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) { |
af7e466a | 749 | /* |
6a8736d1 TH |
750 | * Preflush done for flush with data, reissue |
751 | * without REQ_FLUSH. | |
af7e466a | 752 | */ |
6a8736d1 TH |
753 | bio->bi_rw &= ~REQ_FLUSH; |
754 | queue_io(md, bio); | |
af7e466a | 755 | } else { |
b372d360 | 756 | /* done with normal IO or empty flush */ |
0a82a8d1 | 757 | trace_block_bio_complete(md->queue, bio, io_error); |
b372d360 | 758 | bio_endio(bio, io_error); |
b35f8caa | 759 | } |
1da177e4 LT |
760 | } |
761 | } | |
762 | ||
6712ecf8 | 763 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
764 | { |
765 | int r = 0; | |
028867ac | 766 | struct dm_target_io *tio = bio->bi_private; |
b35f8caa | 767 | struct dm_io *io = tio->io; |
9faf400f | 768 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
769 | dm_endio_fn endio = tio->ti->type->end_io; |
770 | ||
1da177e4 LT |
771 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
772 | error = -EIO; | |
773 | ||
774 | if (endio) { | |
7de3ee57 | 775 | r = endio(tio->ti, bio, error); |
2e93ccc1 KU |
776 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
777 | /* | |
778 | * error and requeue request are handled | |
779 | * in dec_pending(). | |
780 | */ | |
1da177e4 | 781 | error = r; |
45cbcd79 KU |
782 | else if (r == DM_ENDIO_INCOMPLETE) |
783 | /* The target will handle the io */ | |
6712ecf8 | 784 | return; |
45cbcd79 KU |
785 | else if (r) { |
786 | DMWARN("unimplemented target endio return value: %d", r); | |
787 | BUG(); | |
788 | } | |
1da177e4 LT |
789 | } |
790 | ||
9faf400f | 791 | free_tio(md, tio); |
b35f8caa | 792 | dec_pending(io, error); |
1da177e4 LT |
793 | } |
794 | ||
cec47e3d KU |
795 | /* |
796 | * Partial completion handling for request-based dm | |
797 | */ | |
798 | static void end_clone_bio(struct bio *clone, int error) | |
799 | { | |
800 | struct dm_rq_clone_bio_info *info = clone->bi_private; | |
801 | struct dm_rq_target_io *tio = info->tio; | |
802 | struct bio *bio = info->orig; | |
803 | unsigned int nr_bytes = info->orig->bi_size; | |
804 | ||
805 | bio_put(clone); | |
806 | ||
807 | if (tio->error) | |
808 | /* | |
809 | * An error has already been detected on the request. | |
810 | * Once error occurred, just let clone->end_io() handle | |
811 | * the remainder. | |
812 | */ | |
813 | return; | |
814 | else if (error) { | |
815 | /* | |
816 | * Don't notice the error to the upper layer yet. | |
817 | * The error handling decision is made by the target driver, | |
818 | * when the request is completed. | |
819 | */ | |
820 | tio->error = error; | |
821 | return; | |
822 | } | |
823 | ||
824 | /* | |
825 | * I/O for the bio successfully completed. | |
826 | * Notice the data completion to the upper layer. | |
827 | */ | |
828 | ||
829 | /* | |
830 | * bios are processed from the head of the list. | |
831 | * So the completing bio should always be rq->bio. | |
832 | * If it's not, something wrong is happening. | |
833 | */ | |
834 | if (tio->orig->bio != bio) | |
835 | DMERR("bio completion is going in the middle of the request"); | |
836 | ||
837 | /* | |
838 | * Update the original request. | |
839 | * Do not use blk_end_request() here, because it may complete | |
840 | * the original request before the clone, and break the ordering. | |
841 | */ | |
842 | blk_update_request(tio->orig, 0, nr_bytes); | |
843 | } | |
844 | ||
845 | /* | |
846 | * Don't touch any member of the md after calling this function because | |
847 | * the md may be freed in dm_put() at the end of this function. | |
848 | * Or do dm_get() before calling this function and dm_put() later. | |
849 | */ | |
b4324fee | 850 | static void rq_completed(struct mapped_device *md, int rw, int run_queue) |
cec47e3d | 851 | { |
b4324fee | 852 | atomic_dec(&md->pending[rw]); |
cec47e3d KU |
853 | |
854 | /* nudge anyone waiting on suspend queue */ | |
b4324fee | 855 | if (!md_in_flight(md)) |
cec47e3d KU |
856 | wake_up(&md->wait); |
857 | ||
a8c32a5c JA |
858 | /* |
859 | * Run this off this callpath, as drivers could invoke end_io while | |
860 | * inside their request_fn (and holding the queue lock). Calling | |
861 | * back into ->request_fn() could deadlock attempting to grab the | |
862 | * queue lock again. | |
863 | */ | |
cec47e3d | 864 | if (run_queue) |
a8c32a5c | 865 | blk_run_queue_async(md->queue); |
cec47e3d KU |
866 | |
867 | /* | |
868 | * dm_put() must be at the end of this function. See the comment above | |
869 | */ | |
870 | dm_put(md); | |
871 | } | |
872 | ||
a77e28c7 KU |
873 | static void free_rq_clone(struct request *clone) |
874 | { | |
875 | struct dm_rq_target_io *tio = clone->end_io_data; | |
876 | ||
877 | blk_rq_unprep_clone(clone); | |
878 | free_rq_tio(tio); | |
879 | } | |
880 | ||
980691e5 KU |
881 | /* |
882 | * Complete the clone and the original request. | |
883 | * Must be called without queue lock. | |
884 | */ | |
885 | static void dm_end_request(struct request *clone, int error) | |
886 | { | |
887 | int rw = rq_data_dir(clone); | |
888 | struct dm_rq_target_io *tio = clone->end_io_data; | |
889 | struct mapped_device *md = tio->md; | |
890 | struct request *rq = tio->orig; | |
891 | ||
29e4013d | 892 | if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { |
980691e5 KU |
893 | rq->errors = clone->errors; |
894 | rq->resid_len = clone->resid_len; | |
895 | ||
896 | if (rq->sense) | |
897 | /* | |
898 | * We are using the sense buffer of the original | |
899 | * request. | |
900 | * So setting the length of the sense data is enough. | |
901 | */ | |
902 | rq->sense_len = clone->sense_len; | |
903 | } | |
904 | ||
905 | free_rq_clone(clone); | |
29e4013d TH |
906 | blk_end_request_all(rq, error); |
907 | rq_completed(md, rw, true); | |
980691e5 KU |
908 | } |
909 | ||
cec47e3d KU |
910 | static void dm_unprep_request(struct request *rq) |
911 | { | |
912 | struct request *clone = rq->special; | |
cec47e3d KU |
913 | |
914 | rq->special = NULL; | |
915 | rq->cmd_flags &= ~REQ_DONTPREP; | |
916 | ||
a77e28c7 | 917 | free_rq_clone(clone); |
cec47e3d KU |
918 | } |
919 | ||
920 | /* | |
921 | * Requeue the original request of a clone. | |
922 | */ | |
923 | void dm_requeue_unmapped_request(struct request *clone) | |
924 | { | |
b4324fee | 925 | int rw = rq_data_dir(clone); |
cec47e3d KU |
926 | struct dm_rq_target_io *tio = clone->end_io_data; |
927 | struct mapped_device *md = tio->md; | |
928 | struct request *rq = tio->orig; | |
929 | struct request_queue *q = rq->q; | |
930 | unsigned long flags; | |
931 | ||
932 | dm_unprep_request(rq); | |
933 | ||
934 | spin_lock_irqsave(q->queue_lock, flags); | |
cec47e3d KU |
935 | blk_requeue_request(q, rq); |
936 | spin_unlock_irqrestore(q->queue_lock, flags); | |
937 | ||
b4324fee | 938 | rq_completed(md, rw, 0); |
cec47e3d KU |
939 | } |
940 | EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request); | |
941 | ||
942 | static void __stop_queue(struct request_queue *q) | |
943 | { | |
944 | blk_stop_queue(q); | |
945 | } | |
946 | ||
947 | static void stop_queue(struct request_queue *q) | |
948 | { | |
949 | unsigned long flags; | |
950 | ||
951 | spin_lock_irqsave(q->queue_lock, flags); | |
952 | __stop_queue(q); | |
953 | spin_unlock_irqrestore(q->queue_lock, flags); | |
954 | } | |
955 | ||
956 | static void __start_queue(struct request_queue *q) | |
957 | { | |
958 | if (blk_queue_stopped(q)) | |
959 | blk_start_queue(q); | |
960 | } | |
961 | ||
962 | static void start_queue(struct request_queue *q) | |
963 | { | |
964 | unsigned long flags; | |
965 | ||
966 | spin_lock_irqsave(q->queue_lock, flags); | |
967 | __start_queue(q); | |
968 | spin_unlock_irqrestore(q->queue_lock, flags); | |
969 | } | |
970 | ||
11a68244 | 971 | static void dm_done(struct request *clone, int error, bool mapped) |
cec47e3d | 972 | { |
11a68244 | 973 | int r = error; |
cec47e3d | 974 | struct dm_rq_target_io *tio = clone->end_io_data; |
ba1cbad9 | 975 | dm_request_endio_fn rq_end_io = NULL; |
cec47e3d | 976 | |
ba1cbad9 MS |
977 | if (tio->ti) { |
978 | rq_end_io = tio->ti->type->rq_end_io; | |
979 | ||
980 | if (mapped && rq_end_io) | |
981 | r = rq_end_io(tio->ti, clone, error, &tio->info); | |
982 | } | |
cec47e3d | 983 | |
11a68244 | 984 | if (r <= 0) |
cec47e3d | 985 | /* The target wants to complete the I/O */ |
11a68244 KU |
986 | dm_end_request(clone, r); |
987 | else if (r == DM_ENDIO_INCOMPLETE) | |
cec47e3d KU |
988 | /* The target will handle the I/O */ |
989 | return; | |
11a68244 | 990 | else if (r == DM_ENDIO_REQUEUE) |
cec47e3d KU |
991 | /* The target wants to requeue the I/O */ |
992 | dm_requeue_unmapped_request(clone); | |
993 | else { | |
11a68244 | 994 | DMWARN("unimplemented target endio return value: %d", r); |
cec47e3d KU |
995 | BUG(); |
996 | } | |
997 | } | |
998 | ||
11a68244 KU |
999 | /* |
1000 | * Request completion handler for request-based dm | |
1001 | */ | |
1002 | static void dm_softirq_done(struct request *rq) | |
1003 | { | |
1004 | bool mapped = true; | |
1005 | struct request *clone = rq->completion_data; | |
1006 | struct dm_rq_target_io *tio = clone->end_io_data; | |
1007 | ||
1008 | if (rq->cmd_flags & REQ_FAILED) | |
1009 | mapped = false; | |
1010 | ||
1011 | dm_done(clone, tio->error, mapped); | |
1012 | } | |
1013 | ||
cec47e3d KU |
1014 | /* |
1015 | * Complete the clone and the original request with the error status | |
1016 | * through softirq context. | |
1017 | */ | |
1018 | static void dm_complete_request(struct request *clone, int error) | |
1019 | { | |
1020 | struct dm_rq_target_io *tio = clone->end_io_data; | |
1021 | struct request *rq = tio->orig; | |
1022 | ||
1023 | tio->error = error; | |
1024 | rq->completion_data = clone; | |
1025 | blk_complete_request(rq); | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * Complete the not-mapped clone and the original request with the error status | |
1030 | * through softirq context. | |
1031 | * Target's rq_end_io() function isn't called. | |
1032 | * This may be used when the target's map_rq() function fails. | |
1033 | */ | |
1034 | void dm_kill_unmapped_request(struct request *clone, int error) | |
1035 | { | |
1036 | struct dm_rq_target_io *tio = clone->end_io_data; | |
1037 | struct request *rq = tio->orig; | |
1038 | ||
1039 | rq->cmd_flags |= REQ_FAILED; | |
1040 | dm_complete_request(clone, error); | |
1041 | } | |
1042 | EXPORT_SYMBOL_GPL(dm_kill_unmapped_request); | |
1043 | ||
1044 | /* | |
1045 | * Called with the queue lock held | |
1046 | */ | |
1047 | static void end_clone_request(struct request *clone, int error) | |
1048 | { | |
1049 | /* | |
1050 | * For just cleaning up the information of the queue in which | |
1051 | * the clone was dispatched. | |
1052 | * The clone is *NOT* freed actually here because it is alloced from | |
1053 | * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags. | |
1054 | */ | |
1055 | __blk_put_request(clone->q, clone); | |
1056 | ||
1057 | /* | |
1058 | * Actual request completion is done in a softirq context which doesn't | |
1059 | * hold the queue lock. Otherwise, deadlock could occur because: | |
1060 | * - another request may be submitted by the upper level driver | |
1061 | * of the stacking during the completion | |
1062 | * - the submission which requires queue lock may be done | |
1063 | * against this queue | |
1064 | */ | |
1065 | dm_complete_request(clone, error); | |
1066 | } | |
1067 | ||
56a67df7 MS |
1068 | /* |
1069 | * Return maximum size of I/O possible at the supplied sector up to the current | |
1070 | * target boundary. | |
1071 | */ | |
1072 | static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti) | |
1073 | { | |
1074 | sector_t target_offset = dm_target_offset(ti, sector); | |
1075 | ||
1076 | return ti->len - target_offset; | |
1077 | } | |
1078 | ||
1079 | static sector_t max_io_len(sector_t sector, struct dm_target *ti) | |
1da177e4 | 1080 | { |
56a67df7 | 1081 | sector_t len = max_io_len_target_boundary(sector, ti); |
542f9038 | 1082 | sector_t offset, max_len; |
1da177e4 LT |
1083 | |
1084 | /* | |
542f9038 | 1085 | * Does the target need to split even further? |
1da177e4 | 1086 | */ |
542f9038 MS |
1087 | if (ti->max_io_len) { |
1088 | offset = dm_target_offset(ti, sector); | |
1089 | if (unlikely(ti->max_io_len & (ti->max_io_len - 1))) | |
1090 | max_len = sector_div(offset, ti->max_io_len); | |
1091 | else | |
1092 | max_len = offset & (ti->max_io_len - 1); | |
1093 | max_len = ti->max_io_len - max_len; | |
1094 | ||
1095 | if (len > max_len) | |
1096 | len = max_len; | |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | return len; | |
1100 | } | |
1101 | ||
542f9038 MS |
1102 | int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) |
1103 | { | |
1104 | if (len > UINT_MAX) { | |
1105 | DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)", | |
1106 | (unsigned long long)len, UINT_MAX); | |
1107 | ti->error = "Maximum size of target IO is too large"; | |
1108 | return -EINVAL; | |
1109 | } | |
1110 | ||
1111 | ti->max_io_len = (uint32_t) len; | |
1112 | ||
1113 | return 0; | |
1114 | } | |
1115 | EXPORT_SYMBOL_GPL(dm_set_target_max_io_len); | |
1116 | ||
bd2a49b8 | 1117 | static void __map_bio(struct dm_target_io *tio) |
1da177e4 LT |
1118 | { |
1119 | int r; | |
2056a782 | 1120 | sector_t sector; |
9faf400f | 1121 | struct mapped_device *md; |
dba14160 | 1122 | struct bio *clone = &tio->clone; |
bd2a49b8 | 1123 | struct dm_target *ti = tio->ti; |
1da177e4 | 1124 | |
1da177e4 LT |
1125 | clone->bi_end_io = clone_endio; |
1126 | clone->bi_private = tio; | |
1127 | ||
1128 | /* | |
1129 | * Map the clone. If r == 0 we don't need to do | |
1130 | * anything, the target has assumed ownership of | |
1131 | * this io. | |
1132 | */ | |
1133 | atomic_inc(&tio->io->io_count); | |
2056a782 | 1134 | sector = clone->bi_sector; |
7de3ee57 | 1135 | r = ti->type->map(ti, clone); |
45cbcd79 | 1136 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 1137 | /* the bio has been remapped so dispatch it */ |
2056a782 | 1138 | |
d07335e5 MS |
1139 | trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone, |
1140 | tio->io->bio->bi_bdev->bd_dev, sector); | |
2056a782 | 1141 | |
1da177e4 | 1142 | generic_make_request(clone); |
2e93ccc1 KU |
1143 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
1144 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
1145 | md = tio->io->md; |
1146 | dec_pending(tio->io, r); | |
9faf400f | 1147 | free_tio(md, tio); |
45cbcd79 KU |
1148 | } else if (r) { |
1149 | DMWARN("unimplemented target map return value: %d", r); | |
1150 | BUG(); | |
1da177e4 LT |
1151 | } |
1152 | } | |
1153 | ||
1154 | struct clone_info { | |
1155 | struct mapped_device *md; | |
1156 | struct dm_table *map; | |
1157 | struct bio *bio; | |
1158 | struct dm_io *io; | |
1159 | sector_t sector; | |
1160 | sector_t sector_count; | |
1161 | unsigned short idx; | |
1162 | }; | |
1163 | ||
bd2a49b8 AK |
1164 | static void bio_setup_sector(struct bio *bio, sector_t sector, sector_t len) |
1165 | { | |
1166 | bio->bi_sector = sector; | |
1167 | bio->bi_size = to_bytes(len); | |
1168 | } | |
1169 | ||
1170 | static void bio_setup_bv(struct bio *bio, unsigned short idx, unsigned short bv_count) | |
1171 | { | |
1172 | bio->bi_idx = idx; | |
1173 | bio->bi_vcnt = idx + bv_count; | |
1174 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); | |
1175 | } | |
1176 | ||
1177 | static void clone_bio_integrity(struct bio *bio, struct bio *clone, | |
1178 | unsigned short idx, unsigned len, unsigned offset, | |
1179 | unsigned trim) | |
1180 | { | |
1181 | if (!bio_integrity(bio)) | |
1182 | return; | |
1183 | ||
1184 | bio_integrity_clone(clone, bio, GFP_NOIO); | |
1185 | ||
1186 | if (trim) | |
1187 | bio_integrity_trim(clone, bio_sector_offset(bio, idx, offset), len); | |
1188 | } | |
1189 | ||
1da177e4 | 1190 | /* |
d87f4c14 | 1191 | * Creates a little bio that just does part of a bvec. |
1da177e4 | 1192 | */ |
14fe594d AK |
1193 | static void clone_split_bio(struct dm_target_io *tio, struct bio *bio, |
1194 | sector_t sector, unsigned short idx, | |
1195 | unsigned offset, unsigned len) | |
1da177e4 | 1196 | { |
dba14160 | 1197 | struct bio *clone = &tio->clone; |
1da177e4 LT |
1198 | struct bio_vec *bv = bio->bi_io_vec + idx; |
1199 | ||
1da177e4 LT |
1200 | *clone->bi_io_vec = *bv; |
1201 | ||
bd2a49b8 AK |
1202 | bio_setup_sector(clone, sector, len); |
1203 | ||
1da177e4 | 1204 | clone->bi_bdev = bio->bi_bdev; |
d87f4c14 | 1205 | clone->bi_rw = bio->bi_rw; |
1da177e4 | 1206 | clone->bi_vcnt = 1; |
1da177e4 LT |
1207 | clone->bi_io_vec->bv_offset = offset; |
1208 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 1209 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 | 1210 | |
bd2a49b8 | 1211 | clone_bio_integrity(bio, clone, idx, len, offset, 1); |
1da177e4 LT |
1212 | } |
1213 | ||
1214 | /* | |
1215 | * Creates a bio that consists of range of complete bvecs. | |
1216 | */ | |
dba14160 MP |
1217 | static void clone_bio(struct dm_target_io *tio, struct bio *bio, |
1218 | sector_t sector, unsigned short idx, | |
e4c93811 | 1219 | unsigned short bv_count, unsigned len) |
1da177e4 | 1220 | { |
dba14160 | 1221 | struct bio *clone = &tio->clone; |
bd2a49b8 | 1222 | unsigned trim = 0; |
1da177e4 | 1223 | |
9faf400f | 1224 | __bio_clone(clone, bio); |
bd2a49b8 AK |
1225 | bio_setup_sector(clone, sector, len); |
1226 | bio_setup_bv(clone, idx, bv_count); | |
1227 | ||
1228 | if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) | |
1229 | trim = 1; | |
1230 | clone_bio_integrity(bio, clone, idx, len, 0, trim); | |
1da177e4 LT |
1231 | } |
1232 | ||
9015df24 | 1233 | static struct dm_target_io *alloc_tio(struct clone_info *ci, |
bd2a49b8 | 1234 | struct dm_target *ti, int nr_iovecs, |
55a62eef | 1235 | unsigned target_bio_nr) |
f9ab94ce | 1236 | { |
dba14160 MP |
1237 | struct dm_target_io *tio; |
1238 | struct bio *clone; | |
1239 | ||
1240 | clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, ci->md->bs); | |
1241 | tio = container_of(clone, struct dm_target_io, clone); | |
f9ab94ce MP |
1242 | |
1243 | tio->io = ci->io; | |
1244 | tio->ti = ti; | |
f9ab94ce | 1245 | memset(&tio->info, 0, sizeof(tio->info)); |
55a62eef | 1246 | tio->target_bio_nr = target_bio_nr; |
9015df24 AK |
1247 | |
1248 | return tio; | |
1249 | } | |
1250 | ||
14fe594d AK |
1251 | static void __clone_and_map_simple_bio(struct clone_info *ci, |
1252 | struct dm_target *ti, | |
1253 | unsigned target_bio_nr, sector_t len) | |
9015df24 | 1254 | { |
55a62eef | 1255 | struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs, target_bio_nr); |
dba14160 | 1256 | struct bio *clone = &tio->clone; |
9015df24 | 1257 | |
06a426ce MS |
1258 | /* |
1259 | * Discard requests require the bio's inline iovecs be initialized. | |
1260 | * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush | |
1261 | * and discard, so no need for concern about wasted bvec allocations. | |
1262 | */ | |
dba14160 | 1263 | __bio_clone(clone, ci->bio); |
bd2a49b8 AK |
1264 | if (len) |
1265 | bio_setup_sector(clone, ci->sector, len); | |
f9ab94ce | 1266 | |
bd2a49b8 | 1267 | __map_bio(tio); |
f9ab94ce MP |
1268 | } |
1269 | ||
14fe594d AK |
1270 | static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, |
1271 | unsigned num_bios, sector_t len) | |
06a426ce | 1272 | { |
55a62eef | 1273 | unsigned target_bio_nr; |
06a426ce | 1274 | |
55a62eef | 1275 | for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++) |
14fe594d | 1276 | __clone_and_map_simple_bio(ci, ti, target_bio_nr, len); |
06a426ce MS |
1277 | } |
1278 | ||
14fe594d | 1279 | static int __send_empty_flush(struct clone_info *ci) |
f9ab94ce | 1280 | { |
06a426ce | 1281 | unsigned target_nr = 0; |
f9ab94ce MP |
1282 | struct dm_target *ti; |
1283 | ||
b372d360 | 1284 | BUG_ON(bio_has_data(ci->bio)); |
f9ab94ce | 1285 | while ((ti = dm_table_get_target(ci->map, target_nr++))) |
14fe594d | 1286 | __send_duplicate_bios(ci, ti, ti->num_flush_bios, 0); |
f9ab94ce | 1287 | |
f9ab94ce MP |
1288 | return 0; |
1289 | } | |
1290 | ||
e4c93811 AK |
1291 | static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti, |
1292 | sector_t sector, int nr_iovecs, | |
1293 | unsigned short idx, unsigned short bv_count, | |
1294 | unsigned offset, unsigned len, | |
1295 | unsigned split_bvec) | |
5ae89a87 | 1296 | { |
dba14160 | 1297 | struct bio *bio = ci->bio; |
5ae89a87 | 1298 | struct dm_target_io *tio; |
b0d8ed4d AK |
1299 | unsigned target_bio_nr; |
1300 | unsigned num_target_bios = 1; | |
5ae89a87 | 1301 | |
b0d8ed4d AK |
1302 | /* |
1303 | * Does the target want to receive duplicate copies of the bio? | |
1304 | */ | |
1305 | if (bio_data_dir(bio) == WRITE && ti->num_write_bios) | |
1306 | num_target_bios = ti->num_write_bios(ti, bio); | |
e4c93811 | 1307 | |
b0d8ed4d AK |
1308 | for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) { |
1309 | tio = alloc_tio(ci, ti, nr_iovecs, target_bio_nr); | |
1310 | if (split_bvec) | |
1311 | clone_split_bio(tio, bio, sector, idx, offset, len); | |
1312 | else | |
1313 | clone_bio(tio, bio, sector, idx, bv_count, len); | |
1314 | __map_bio(tio); | |
1315 | } | |
5ae89a87 MS |
1316 | } |
1317 | ||
55a62eef | 1318 | typedef unsigned (*get_num_bios_fn)(struct dm_target *ti); |
23508a96 | 1319 | |
55a62eef | 1320 | static unsigned get_num_discard_bios(struct dm_target *ti) |
23508a96 | 1321 | { |
55a62eef | 1322 | return ti->num_discard_bios; |
23508a96 MS |
1323 | } |
1324 | ||
55a62eef | 1325 | static unsigned get_num_write_same_bios(struct dm_target *ti) |
23508a96 | 1326 | { |
55a62eef | 1327 | return ti->num_write_same_bios; |
23508a96 MS |
1328 | } |
1329 | ||
1330 | typedef bool (*is_split_required_fn)(struct dm_target *ti); | |
1331 | ||
1332 | static bool is_split_required_for_discard(struct dm_target *ti) | |
1333 | { | |
55a62eef | 1334 | return ti->split_discard_bios; |
23508a96 MS |
1335 | } |
1336 | ||
14fe594d AK |
1337 | static int __send_changing_extent_only(struct clone_info *ci, |
1338 | get_num_bios_fn get_num_bios, | |
1339 | is_split_required_fn is_split_required) | |
5ae89a87 MS |
1340 | { |
1341 | struct dm_target *ti; | |
a79245b3 | 1342 | sector_t len; |
55a62eef | 1343 | unsigned num_bios; |
5ae89a87 | 1344 | |
a79245b3 MS |
1345 | do { |
1346 | ti = dm_table_find_target(ci->map, ci->sector); | |
1347 | if (!dm_target_is_valid(ti)) | |
1348 | return -EIO; | |
5ae89a87 | 1349 | |
5ae89a87 | 1350 | /* |
23508a96 MS |
1351 | * Even though the device advertised support for this type of |
1352 | * request, that does not mean every target supports it, and | |
936688d7 | 1353 | * reconfiguration might also have changed that since the |
a79245b3 | 1354 | * check was performed. |
5ae89a87 | 1355 | */ |
55a62eef AK |
1356 | num_bios = get_num_bios ? get_num_bios(ti) : 0; |
1357 | if (!num_bios) | |
a79245b3 | 1358 | return -EOPNOTSUPP; |
5ae89a87 | 1359 | |
23508a96 | 1360 | if (is_split_required && !is_split_required(ti)) |
7acf0277 MP |
1361 | len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti)); |
1362 | else | |
1363 | len = min(ci->sector_count, max_io_len(ci->sector, ti)); | |
06a426ce | 1364 | |
14fe594d | 1365 | __send_duplicate_bios(ci, ti, num_bios, len); |
a79245b3 MS |
1366 | |
1367 | ci->sector += len; | |
1368 | } while (ci->sector_count -= len); | |
5ae89a87 MS |
1369 | |
1370 | return 0; | |
1371 | } | |
1372 | ||
14fe594d | 1373 | static int __send_discard(struct clone_info *ci) |
23508a96 | 1374 | { |
14fe594d AK |
1375 | return __send_changing_extent_only(ci, get_num_discard_bios, |
1376 | is_split_required_for_discard); | |
23508a96 MS |
1377 | } |
1378 | ||
14fe594d | 1379 | static int __send_write_same(struct clone_info *ci) |
23508a96 | 1380 | { |
14fe594d | 1381 | return __send_changing_extent_only(ci, get_num_write_same_bios, NULL); |
23508a96 MS |
1382 | } |
1383 | ||
e4c93811 AK |
1384 | /* |
1385 | * Find maximum number of sectors / bvecs we can process with a single bio. | |
1386 | */ | |
1387 | static sector_t __len_within_target(struct clone_info *ci, sector_t max, int *idx) | |
1388 | { | |
1389 | struct bio *bio = ci->bio; | |
1390 | sector_t bv_len, total_len = 0; | |
1391 | ||
1392 | for (*idx = ci->idx; max && (*idx < bio->bi_vcnt); (*idx)++) { | |
1393 | bv_len = to_sector(bio->bi_io_vec[*idx].bv_len); | |
1394 | ||
1395 | if (bv_len > max) | |
1396 | break; | |
1397 | ||
1398 | max -= bv_len; | |
1399 | total_len += bv_len; | |
1400 | } | |
1401 | ||
1402 | return total_len; | |
1403 | } | |
1404 | ||
1405 | static int __split_bvec_across_targets(struct clone_info *ci, | |
1406 | struct dm_target *ti, sector_t max) | |
1407 | { | |
1408 | struct bio *bio = ci->bio; | |
1409 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
1410 | sector_t remaining = to_sector(bv->bv_len); | |
1411 | unsigned offset = 0; | |
1412 | sector_t len; | |
1413 | ||
1414 | do { | |
1415 | if (offset) { | |
1416 | ti = dm_table_find_target(ci->map, ci->sector); | |
1417 | if (!dm_target_is_valid(ti)) | |
1418 | return -EIO; | |
1419 | ||
1420 | max = max_io_len(ci->sector, ti); | |
1421 | } | |
1422 | ||
1423 | len = min(remaining, max); | |
1424 | ||
1425 | __clone_and_map_data_bio(ci, ti, ci->sector, 1, ci->idx, 0, | |
1426 | bv->bv_offset + offset, len, 1); | |
1427 | ||
1428 | ci->sector += len; | |
1429 | ci->sector_count -= len; | |
1430 | offset += to_bytes(len); | |
1431 | } while (remaining -= len); | |
1432 | ||
1433 | ci->idx++; | |
1434 | ||
1435 | return 0; | |
1436 | } | |
1437 | ||
1438 | /* | |
1439 | * Select the correct strategy for processing a non-flush bio. | |
1440 | */ | |
14fe594d | 1441 | static int __split_and_process_non_flush(struct clone_info *ci) |
1da177e4 | 1442 | { |
dba14160 | 1443 | struct bio *bio = ci->bio; |
512875bd | 1444 | struct dm_target *ti; |
e4c93811 AK |
1445 | sector_t len, max; |
1446 | int idx; | |
1da177e4 | 1447 | |
5ae89a87 | 1448 | if (unlikely(bio->bi_rw & REQ_DISCARD)) |
14fe594d | 1449 | return __send_discard(ci); |
23508a96 | 1450 | else if (unlikely(bio->bi_rw & REQ_WRITE_SAME)) |
14fe594d | 1451 | return __send_write_same(ci); |
5ae89a87 | 1452 | |
512875bd JN |
1453 | ti = dm_table_find_target(ci->map, ci->sector); |
1454 | if (!dm_target_is_valid(ti)) | |
1455 | return -EIO; | |
1456 | ||
56a67df7 | 1457 | max = max_io_len(ci->sector, ti); |
512875bd | 1458 | |
e4c93811 AK |
1459 | /* |
1460 | * Optimise for the simple case where we can do all of | |
1461 | * the remaining io with a single clone. | |
1462 | */ | |
1da177e4 | 1463 | if (ci->sector_count <= max) { |
e4c93811 AK |
1464 | __clone_and_map_data_bio(ci, ti, ci->sector, bio->bi_max_vecs, |
1465 | ci->idx, bio->bi_vcnt - ci->idx, 0, | |
1466 | ci->sector_count, 0); | |
1467 | ci->sector_count = 0; | |
1468 | return 0; | |
1469 | } | |
1da177e4 | 1470 | |
e4c93811 AK |
1471 | /* |
1472 | * There are some bvecs that don't span targets. | |
1473 | * Do as many of these as possible. | |
1474 | */ | |
1475 | if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
1476 | len = __len_within_target(ci, max, &idx); | |
1da177e4 | 1477 | |
e4c93811 AK |
1478 | __clone_and_map_data_bio(ci, ti, ci->sector, bio->bi_max_vecs, |
1479 | ci->idx, idx - ci->idx, 0, len, 0); | |
1da177e4 LT |
1480 | |
1481 | ci->sector += len; | |
1482 | ci->sector_count -= len; | |
e4c93811 | 1483 | ci->idx = idx; |
d2044a94 | 1484 | |
e4c93811 | 1485 | return 0; |
1da177e4 | 1486 | } |
512875bd | 1487 | |
e4c93811 AK |
1488 | /* |
1489 | * Handle a bvec that must be split between two or more targets. | |
1490 | */ | |
1491 | return __split_bvec_across_targets(ci, ti, max); | |
1da177e4 LT |
1492 | } |
1493 | ||
1494 | /* | |
14fe594d | 1495 | * Entry point to split a bio into clones and submit them to the targets. |
1da177e4 | 1496 | */ |
83d5e5b0 MP |
1497 | static void __split_and_process_bio(struct mapped_device *md, |
1498 | struct dm_table *map, struct bio *bio) | |
1da177e4 LT |
1499 | { |
1500 | struct clone_info ci; | |
512875bd | 1501 | int error = 0; |
1da177e4 | 1502 | |
83d5e5b0 | 1503 | if (unlikely(!map)) { |
6a8736d1 | 1504 | bio_io_error(bio); |
f0b9a450 MP |
1505 | return; |
1506 | } | |
692d0eb9 | 1507 | |
83d5e5b0 | 1508 | ci.map = map; |
1da177e4 | 1509 | ci.md = md; |
1da177e4 LT |
1510 | ci.io = alloc_io(md); |
1511 | ci.io->error = 0; | |
1512 | atomic_set(&ci.io->io_count, 1); | |
1513 | ci.io->bio = bio; | |
1514 | ci.io->md = md; | |
f88fb981 | 1515 | spin_lock_init(&ci.io->endio_lock); |
1da177e4 | 1516 | ci.sector = bio->bi_sector; |
1da177e4 LT |
1517 | ci.idx = bio->bi_idx; |
1518 | ||
3eaf840e | 1519 | start_io_acct(ci.io); |
bd2a49b8 | 1520 | |
b372d360 MS |
1521 | if (bio->bi_rw & REQ_FLUSH) { |
1522 | ci.bio = &ci.md->flush_bio; | |
1523 | ci.sector_count = 0; | |
14fe594d | 1524 | error = __send_empty_flush(&ci); |
b372d360 MS |
1525 | /* dec_pending submits any data associated with flush */ |
1526 | } else { | |
6a8736d1 | 1527 | ci.bio = bio; |
d87f4c14 | 1528 | ci.sector_count = bio_sectors(bio); |
b372d360 | 1529 | while (ci.sector_count && !error) |
14fe594d | 1530 | error = __split_and_process_non_flush(&ci); |
d87f4c14 | 1531 | } |
1da177e4 LT |
1532 | |
1533 | /* drop the extra reference count */ | |
512875bd | 1534 | dec_pending(ci.io, error); |
1da177e4 LT |
1535 | } |
1536 | /*----------------------------------------------------------------- | |
1537 | * CRUD END | |
1538 | *---------------------------------------------------------------*/ | |
1539 | ||
f6fccb12 MB |
1540 | static int dm_merge_bvec(struct request_queue *q, |
1541 | struct bvec_merge_data *bvm, | |
1542 | struct bio_vec *biovec) | |
1543 | { | |
1544 | struct mapped_device *md = q->queuedata; | |
83d5e5b0 | 1545 | struct dm_table *map = dm_get_live_table_fast(md); |
f6fccb12 MB |
1546 | struct dm_target *ti; |
1547 | sector_t max_sectors; | |
5037108a | 1548 | int max_size = 0; |
f6fccb12 MB |
1549 | |
1550 | if (unlikely(!map)) | |
5037108a | 1551 | goto out; |
f6fccb12 MB |
1552 | |
1553 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac | 1554 | if (!dm_target_is_valid(ti)) |
83d5e5b0 | 1555 | goto out; |
f6fccb12 MB |
1556 | |
1557 | /* | |
1558 | * Find maximum amount of I/O that won't need splitting | |
1559 | */ | |
56a67df7 | 1560 | max_sectors = min(max_io_len(bvm->bi_sector, ti), |
f6fccb12 MB |
1561 | (sector_t) BIO_MAX_SECTORS); |
1562 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
1563 | if (max_size < 0) | |
1564 | max_size = 0; | |
1565 | ||
1566 | /* | |
1567 | * merge_bvec_fn() returns number of bytes | |
1568 | * it can accept at this offset | |
1569 | * max is precomputed maximal io size | |
1570 | */ | |
1571 | if (max_size && ti->type->merge) | |
1572 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
8cbeb67a MP |
1573 | /* |
1574 | * If the target doesn't support merge method and some of the devices | |
1575 | * provided their merge_bvec method (we know this by looking at | |
1576 | * queue_max_hw_sectors), then we can't allow bios with multiple vector | |
1577 | * entries. So always set max_size to 0, and the code below allows | |
1578 | * just one page. | |
1579 | */ | |
1580 | else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) | |
1581 | ||
1582 | max_size = 0; | |
f6fccb12 | 1583 | |
5037108a | 1584 | out: |
83d5e5b0 | 1585 | dm_put_live_table_fast(md); |
f6fccb12 MB |
1586 | /* |
1587 | * Always allow an entire first page | |
1588 | */ | |
1589 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
1590 | max_size = biovec->bv_len; | |
1591 | ||
f6fccb12 MB |
1592 | return max_size; |
1593 | } | |
1594 | ||
1da177e4 LT |
1595 | /* |
1596 | * The request function that just remaps the bio built up by | |
1597 | * dm_merge_bvec. | |
1598 | */ | |
5a7bbad2 | 1599 | static void _dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 1600 | { |
12f03a49 | 1601 | int rw = bio_data_dir(bio); |
1da177e4 | 1602 | struct mapped_device *md = q->queuedata; |
c9959059 | 1603 | int cpu; |
83d5e5b0 MP |
1604 | int srcu_idx; |
1605 | struct dm_table *map; | |
1da177e4 | 1606 | |
83d5e5b0 | 1607 | map = dm_get_live_table(md, &srcu_idx); |
1da177e4 | 1608 | |
074a7aca TH |
1609 | cpu = part_stat_lock(); |
1610 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
1611 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
1612 | part_stat_unlock(); | |
12f03a49 | 1613 | |
6a8736d1 TH |
1614 | /* if we're suspended, we have to queue this io for later */ |
1615 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { | |
83d5e5b0 | 1616 | dm_put_live_table(md, srcu_idx); |
1da177e4 | 1617 | |
6a8736d1 TH |
1618 | if (bio_rw(bio) != READA) |
1619 | queue_io(md, bio); | |
1620 | else | |
54d9a1b4 | 1621 | bio_io_error(bio); |
5a7bbad2 | 1622 | return; |
1da177e4 LT |
1623 | } |
1624 | ||
83d5e5b0 MP |
1625 | __split_and_process_bio(md, map, bio); |
1626 | dm_put_live_table(md, srcu_idx); | |
5a7bbad2 | 1627 | return; |
cec47e3d KU |
1628 | } |
1629 | ||
fd2ed4d2 | 1630 | int dm_request_based(struct mapped_device *md) |
cec47e3d KU |
1631 | { |
1632 | return blk_queue_stackable(md->queue); | |
1633 | } | |
1634 | ||
5a7bbad2 | 1635 | static void dm_request(struct request_queue *q, struct bio *bio) |
cec47e3d KU |
1636 | { |
1637 | struct mapped_device *md = q->queuedata; | |
1638 | ||
1639 | if (dm_request_based(md)) | |
5a7bbad2 CH |
1640 | blk_queue_bio(q, bio); |
1641 | else | |
1642 | _dm_request(q, bio); | |
cec47e3d KU |
1643 | } |
1644 | ||
1645 | void dm_dispatch_request(struct request *rq) | |
1646 | { | |
1647 | int r; | |
1648 | ||
1649 | if (blk_queue_io_stat(rq->q)) | |
1650 | rq->cmd_flags |= REQ_IO_STAT; | |
1651 | ||
1652 | rq->start_time = jiffies; | |
1653 | r = blk_insert_cloned_request(rq->q, rq); | |
1654 | if (r) | |
1655 | dm_complete_request(rq, r); | |
1656 | } | |
1657 | EXPORT_SYMBOL_GPL(dm_dispatch_request); | |
1658 | ||
cec47e3d KU |
1659 | static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, |
1660 | void *data) | |
1661 | { | |
1662 | struct dm_rq_target_io *tio = data; | |
94818742 KO |
1663 | struct dm_rq_clone_bio_info *info = |
1664 | container_of(bio, struct dm_rq_clone_bio_info, clone); | |
cec47e3d KU |
1665 | |
1666 | info->orig = bio_orig; | |
1667 | info->tio = tio; | |
1668 | bio->bi_end_io = end_clone_bio; | |
1669 | bio->bi_private = info; | |
cec47e3d KU |
1670 | |
1671 | return 0; | |
1672 | } | |
1673 | ||
1674 | static int setup_clone(struct request *clone, struct request *rq, | |
1675 | struct dm_rq_target_io *tio) | |
1676 | { | |
d0bcb878 | 1677 | int r; |
cec47e3d | 1678 | |
29e4013d TH |
1679 | r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC, |
1680 | dm_rq_bio_constructor, tio); | |
1681 | if (r) | |
1682 | return r; | |
cec47e3d | 1683 | |
29e4013d TH |
1684 | clone->cmd = rq->cmd; |
1685 | clone->cmd_len = rq->cmd_len; | |
1686 | clone->sense = rq->sense; | |
1687 | clone->buffer = rq->buffer; | |
cec47e3d KU |
1688 | clone->end_io = end_clone_request; |
1689 | clone->end_io_data = tio; | |
1690 | ||
1691 | return 0; | |
1692 | } | |
1693 | ||
6facdaff KU |
1694 | static struct request *clone_rq(struct request *rq, struct mapped_device *md, |
1695 | gfp_t gfp_mask) | |
1696 | { | |
1697 | struct request *clone; | |
1698 | struct dm_rq_target_io *tio; | |
1699 | ||
1700 | tio = alloc_rq_tio(md, gfp_mask); | |
1701 | if (!tio) | |
1702 | return NULL; | |
1703 | ||
1704 | tio->md = md; | |
1705 | tio->ti = NULL; | |
1706 | tio->orig = rq; | |
1707 | tio->error = 0; | |
1708 | memset(&tio->info, 0, sizeof(tio->info)); | |
1709 | ||
1710 | clone = &tio->clone; | |
1711 | if (setup_clone(clone, rq, tio)) { | |
1712 | /* -ENOMEM */ | |
1713 | free_rq_tio(tio); | |
1714 | return NULL; | |
1715 | } | |
1716 | ||
1717 | return clone; | |
1718 | } | |
1719 | ||
cec47e3d KU |
1720 | /* |
1721 | * Called with the queue lock held. | |
1722 | */ | |
1723 | static int dm_prep_fn(struct request_queue *q, struct request *rq) | |
1724 | { | |
1725 | struct mapped_device *md = q->queuedata; | |
cec47e3d KU |
1726 | struct request *clone; |
1727 | ||
cec47e3d KU |
1728 | if (unlikely(rq->special)) { |
1729 | DMWARN("Already has something in rq->special."); | |
1730 | return BLKPREP_KILL; | |
1731 | } | |
1732 | ||
6facdaff KU |
1733 | clone = clone_rq(rq, md, GFP_ATOMIC); |
1734 | if (!clone) | |
cec47e3d | 1735 | return BLKPREP_DEFER; |
cec47e3d KU |
1736 | |
1737 | rq->special = clone; | |
1738 | rq->cmd_flags |= REQ_DONTPREP; | |
1739 | ||
1740 | return BLKPREP_OK; | |
1741 | } | |
1742 | ||
9eef87da KU |
1743 | /* |
1744 | * Returns: | |
1745 | * 0 : the request has been processed (not requeued) | |
1746 | * !0 : the request has been requeued | |
1747 | */ | |
1748 | static int map_request(struct dm_target *ti, struct request *clone, | |
1749 | struct mapped_device *md) | |
cec47e3d | 1750 | { |
9eef87da | 1751 | int r, requeued = 0; |
cec47e3d KU |
1752 | struct dm_rq_target_io *tio = clone->end_io_data; |
1753 | ||
cec47e3d KU |
1754 | tio->ti = ti; |
1755 | r = ti->type->map_rq(ti, clone, &tio->info); | |
1756 | switch (r) { | |
1757 | case DM_MAPIO_SUBMITTED: | |
1758 | /* The target has taken the I/O to submit by itself later */ | |
1759 | break; | |
1760 | case DM_MAPIO_REMAPPED: | |
1761 | /* The target has remapped the I/O so dispatch it */ | |
6db4ccd6 JN |
1762 | trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)), |
1763 | blk_rq_pos(tio->orig)); | |
cec47e3d KU |
1764 | dm_dispatch_request(clone); |
1765 | break; | |
1766 | case DM_MAPIO_REQUEUE: | |
1767 | /* The target wants to requeue the I/O */ | |
1768 | dm_requeue_unmapped_request(clone); | |
9eef87da | 1769 | requeued = 1; |
cec47e3d KU |
1770 | break; |
1771 | default: | |
1772 | if (r > 0) { | |
1773 | DMWARN("unimplemented target map return value: %d", r); | |
1774 | BUG(); | |
1775 | } | |
1776 | ||
1777 | /* The target wants to complete the I/O */ | |
1778 | dm_kill_unmapped_request(clone, r); | |
1779 | break; | |
1780 | } | |
9eef87da KU |
1781 | |
1782 | return requeued; | |
cec47e3d KU |
1783 | } |
1784 | ||
ba1cbad9 MS |
1785 | static struct request *dm_start_request(struct mapped_device *md, struct request *orig) |
1786 | { | |
1787 | struct request *clone; | |
1788 | ||
1789 | blk_start_request(orig); | |
1790 | clone = orig->special; | |
1791 | atomic_inc(&md->pending[rq_data_dir(clone)]); | |
1792 | ||
1793 | /* | |
1794 | * Hold the md reference here for the in-flight I/O. | |
1795 | * We can't rely on the reference count by device opener, | |
1796 | * because the device may be closed during the request completion | |
1797 | * when all bios are completed. | |
1798 | * See the comment in rq_completed() too. | |
1799 | */ | |
1800 | dm_get(md); | |
1801 | ||
1802 | return clone; | |
1803 | } | |
1804 | ||
cec47e3d KU |
1805 | /* |
1806 | * q->request_fn for request-based dm. | |
1807 | * Called with the queue lock held. | |
1808 | */ | |
1809 | static void dm_request_fn(struct request_queue *q) | |
1810 | { | |
1811 | struct mapped_device *md = q->queuedata; | |
83d5e5b0 MP |
1812 | int srcu_idx; |
1813 | struct dm_table *map = dm_get_live_table(md, &srcu_idx); | |
cec47e3d | 1814 | struct dm_target *ti; |
b4324fee | 1815 | struct request *rq, *clone; |
29e4013d | 1816 | sector_t pos; |
cec47e3d KU |
1817 | |
1818 | /* | |
b4324fee KU |
1819 | * For suspend, check blk_queue_stopped() and increment |
1820 | * ->pending within a single queue_lock not to increment the | |
1821 | * number of in-flight I/Os after the queue is stopped in | |
1822 | * dm_suspend(). | |
cec47e3d | 1823 | */ |
7eaceacc | 1824 | while (!blk_queue_stopped(q)) { |
cec47e3d KU |
1825 | rq = blk_peek_request(q); |
1826 | if (!rq) | |
7eaceacc | 1827 | goto delay_and_out; |
cec47e3d | 1828 | |
29e4013d TH |
1829 | /* always use block 0 to find the target for flushes for now */ |
1830 | pos = 0; | |
1831 | if (!(rq->cmd_flags & REQ_FLUSH)) | |
1832 | pos = blk_rq_pos(rq); | |
1833 | ||
1834 | ti = dm_table_find_target(map, pos); | |
ba1cbad9 MS |
1835 | if (!dm_target_is_valid(ti)) { |
1836 | /* | |
1837 | * Must perform setup, that dm_done() requires, | |
1838 | * before calling dm_kill_unmapped_request | |
1839 | */ | |
1840 | DMERR_LIMIT("request attempted access beyond the end of device"); | |
1841 | clone = dm_start_request(md, rq); | |
1842 | dm_kill_unmapped_request(clone, -EIO); | |
1843 | continue; | |
1844 | } | |
d0bcb878 | 1845 | |
cec47e3d | 1846 | if (ti->type->busy && ti->type->busy(ti)) |
7eaceacc | 1847 | goto delay_and_out; |
cec47e3d | 1848 | |
ba1cbad9 | 1849 | clone = dm_start_request(md, rq); |
b4324fee | 1850 | |
cec47e3d | 1851 | spin_unlock(q->queue_lock); |
9eef87da KU |
1852 | if (map_request(ti, clone, md)) |
1853 | goto requeued; | |
1854 | ||
052189a2 KU |
1855 | BUG_ON(!irqs_disabled()); |
1856 | spin_lock(q->queue_lock); | |
cec47e3d KU |
1857 | } |
1858 | ||
1859 | goto out; | |
1860 | ||
9eef87da | 1861 | requeued: |
052189a2 KU |
1862 | BUG_ON(!irqs_disabled()); |
1863 | spin_lock(q->queue_lock); | |
9eef87da | 1864 | |
7eaceacc JA |
1865 | delay_and_out: |
1866 | blk_delay_queue(q, HZ / 10); | |
cec47e3d | 1867 | out: |
83d5e5b0 | 1868 | dm_put_live_table(md, srcu_idx); |
cec47e3d KU |
1869 | } |
1870 | ||
1871 | int dm_underlying_device_busy(struct request_queue *q) | |
1872 | { | |
1873 | return blk_lld_busy(q); | |
1874 | } | |
1875 | EXPORT_SYMBOL_GPL(dm_underlying_device_busy); | |
1876 | ||
1877 | static int dm_lld_busy(struct request_queue *q) | |
1878 | { | |
1879 | int r; | |
1880 | struct mapped_device *md = q->queuedata; | |
83d5e5b0 | 1881 | struct dm_table *map = dm_get_live_table_fast(md); |
cec47e3d KU |
1882 | |
1883 | if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) | |
1884 | r = 1; | |
1885 | else | |
1886 | r = dm_table_any_busy_target(map); | |
1887 | ||
83d5e5b0 | 1888 | dm_put_live_table_fast(md); |
cec47e3d KU |
1889 | |
1890 | return r; | |
1891 | } | |
1892 | ||
1da177e4 LT |
1893 | static int dm_any_congested(void *congested_data, int bdi_bits) |
1894 | { | |
8a57dfc6 CS |
1895 | int r = bdi_bits; |
1896 | struct mapped_device *md = congested_data; | |
1897 | struct dm_table *map; | |
1da177e4 | 1898 | |
1eb787ec | 1899 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
83d5e5b0 | 1900 | map = dm_get_live_table_fast(md); |
8a57dfc6 | 1901 | if (map) { |
cec47e3d KU |
1902 | /* |
1903 | * Request-based dm cares about only own queue for | |
1904 | * the query about congestion status of request_queue | |
1905 | */ | |
1906 | if (dm_request_based(md)) | |
1907 | r = md->queue->backing_dev_info.state & | |
1908 | bdi_bits; | |
1909 | else | |
1910 | r = dm_table_any_congested(map, bdi_bits); | |
8a57dfc6 | 1911 | } |
83d5e5b0 | 1912 | dm_put_live_table_fast(md); |
8a57dfc6 CS |
1913 | } |
1914 | ||
1da177e4 LT |
1915 | return r; |
1916 | } | |
1917 | ||
1918 | /*----------------------------------------------------------------- | |
1919 | * An IDR is used to keep track of allocated minor numbers. | |
1920 | *---------------------------------------------------------------*/ | |
2b06cfff | 1921 | static void free_minor(int minor) |
1da177e4 | 1922 | { |
f32c10b0 | 1923 | spin_lock(&_minor_lock); |
1da177e4 | 1924 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 1925 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1926 | } |
1927 | ||
1928 | /* | |
1929 | * See if the device with a specific minor # is free. | |
1930 | */ | |
cf13ab8e | 1931 | static int specific_minor(int minor) |
1da177e4 | 1932 | { |
c9d76be6 | 1933 | int r; |
1da177e4 LT |
1934 | |
1935 | if (minor >= (1 << MINORBITS)) | |
1936 | return -EINVAL; | |
1937 | ||
c9d76be6 | 1938 | idr_preload(GFP_KERNEL); |
f32c10b0 | 1939 | spin_lock(&_minor_lock); |
1da177e4 | 1940 | |
c9d76be6 | 1941 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT); |
1da177e4 | 1942 | |
f32c10b0 | 1943 | spin_unlock(&_minor_lock); |
c9d76be6 TH |
1944 | idr_preload_end(); |
1945 | if (r < 0) | |
1946 | return r == -ENOSPC ? -EBUSY : r; | |
1947 | return 0; | |
1da177e4 LT |
1948 | } |
1949 | ||
cf13ab8e | 1950 | static int next_free_minor(int *minor) |
1da177e4 | 1951 | { |
c9d76be6 | 1952 | int r; |
62f75c2f | 1953 | |
c9d76be6 | 1954 | idr_preload(GFP_KERNEL); |
f32c10b0 | 1955 | spin_lock(&_minor_lock); |
1da177e4 | 1956 | |
c9d76be6 | 1957 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT); |
1da177e4 | 1958 | |
f32c10b0 | 1959 | spin_unlock(&_minor_lock); |
c9d76be6 TH |
1960 | idr_preload_end(); |
1961 | if (r < 0) | |
1962 | return r; | |
1963 | *minor = r; | |
1964 | return 0; | |
1da177e4 LT |
1965 | } |
1966 | ||
83d5cde4 | 1967 | static const struct block_device_operations dm_blk_dops; |
1da177e4 | 1968 | |
53d5914f MP |
1969 | static void dm_wq_work(struct work_struct *work); |
1970 | ||
4a0b4ddf MS |
1971 | static void dm_init_md_queue(struct mapped_device *md) |
1972 | { | |
1973 | /* | |
1974 | * Request-based dm devices cannot be stacked on top of bio-based dm | |
1975 | * devices. The type of this dm device has not been decided yet. | |
1976 | * The type is decided at the first table loading time. | |
1977 | * To prevent problematic device stacking, clear the queue flag | |
1978 | * for request stacking support until then. | |
1979 | * | |
1980 | * This queue is new, so no concurrency on the queue_flags. | |
1981 | */ | |
1982 | queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); | |
1983 | ||
1984 | md->queue->queuedata = md; | |
1985 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1986 | md->queue->backing_dev_info.congested_data = md; | |
1987 | blk_queue_make_request(md->queue, dm_request); | |
1988 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); | |
4a0b4ddf MS |
1989 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
1990 | } | |
1991 | ||
1da177e4 LT |
1992 | /* |
1993 | * Allocate and initialise a blank device with a given minor. | |
1994 | */ | |
2b06cfff | 1995 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1996 | { |
1997 | int r; | |
cf13ab8e | 1998 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1999 | void *old_md; |
1da177e4 LT |
2000 | |
2001 | if (!md) { | |
2002 | DMWARN("unable to allocate device, out of memory."); | |
2003 | return NULL; | |
2004 | } | |
2005 | ||
10da4f79 | 2006 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 2007 | goto bad_module_get; |
10da4f79 | 2008 | |
1da177e4 | 2009 | /* get a minor number for the dev */ |
2b06cfff | 2010 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 2011 | r = next_free_minor(&minor); |
2b06cfff | 2012 | else |
cf13ab8e | 2013 | r = specific_minor(minor); |
1da177e4 | 2014 | if (r < 0) |
6ed7ade8 | 2015 | goto bad_minor; |
1da177e4 | 2016 | |
83d5e5b0 MP |
2017 | r = init_srcu_struct(&md->io_barrier); |
2018 | if (r < 0) | |
2019 | goto bad_io_barrier; | |
2020 | ||
a5664dad | 2021 | md->type = DM_TYPE_NONE; |
e61290a4 | 2022 | mutex_init(&md->suspend_lock); |
a5664dad | 2023 | mutex_init(&md->type_lock); |
022c2611 | 2024 | spin_lock_init(&md->deferred_lock); |
1da177e4 | 2025 | atomic_set(&md->holders, 1); |
5c6bd75d | 2026 | atomic_set(&md->open_count, 0); |
1da177e4 | 2027 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
2028 | atomic_set(&md->uevent_seq, 0); |
2029 | INIT_LIST_HEAD(&md->uevent_list); | |
2030 | spin_lock_init(&md->uevent_lock); | |
1da177e4 | 2031 | |
4a0b4ddf | 2032 | md->queue = blk_alloc_queue(GFP_KERNEL); |
1da177e4 | 2033 | if (!md->queue) |
6ed7ade8 | 2034 | goto bad_queue; |
1da177e4 | 2035 | |
4a0b4ddf | 2036 | dm_init_md_queue(md); |
9faf400f | 2037 | |
1da177e4 LT |
2038 | md->disk = alloc_disk(1); |
2039 | if (!md->disk) | |
6ed7ade8 | 2040 | goto bad_disk; |
1da177e4 | 2041 | |
316d315b NK |
2042 | atomic_set(&md->pending[0], 0); |
2043 | atomic_set(&md->pending[1], 0); | |
f0b04115 | 2044 | init_waitqueue_head(&md->wait); |
53d5914f | 2045 | INIT_WORK(&md->work, dm_wq_work); |
f0b04115 | 2046 | init_waitqueue_head(&md->eventq); |
be35f486 | 2047 | init_completion(&md->kobj_completion); |
f0b04115 | 2048 | |
1da177e4 LT |
2049 | md->disk->major = _major; |
2050 | md->disk->first_minor = minor; | |
2051 | md->disk->fops = &dm_blk_dops; | |
2052 | md->disk->queue = md->queue; | |
2053 | md->disk->private_data = md; | |
2054 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
2055 | add_disk(md->disk); | |
7e51f257 | 2056 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 2057 | |
670368a8 | 2058 | md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0); |
304f3f6a MB |
2059 | if (!md->wq) |
2060 | goto bad_thread; | |
2061 | ||
32a926da MP |
2062 | md->bdev = bdget_disk(md->disk, 0); |
2063 | if (!md->bdev) | |
2064 | goto bad_bdev; | |
2065 | ||
6a8736d1 TH |
2066 | bio_init(&md->flush_bio); |
2067 | md->flush_bio.bi_bdev = md->bdev; | |
2068 | md->flush_bio.bi_rw = WRITE_FLUSH; | |
2069 | ||
fd2ed4d2 MP |
2070 | dm_stats_init(&md->stats); |
2071 | ||
ba61fdd1 | 2072 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 2073 | spin_lock(&_minor_lock); |
ba61fdd1 | 2074 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 2075 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
2076 | |
2077 | BUG_ON(old_md != MINOR_ALLOCED); | |
2078 | ||
1da177e4 LT |
2079 | return md; |
2080 | ||
32a926da MP |
2081 | bad_bdev: |
2082 | destroy_workqueue(md->wq); | |
304f3f6a | 2083 | bad_thread: |
03022c54 | 2084 | del_gendisk(md->disk); |
304f3f6a | 2085 | put_disk(md->disk); |
6ed7ade8 | 2086 | bad_disk: |
1312f40e | 2087 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 2088 | bad_queue: |
83d5e5b0 MP |
2089 | cleanup_srcu_struct(&md->io_barrier); |
2090 | bad_io_barrier: | |
1da177e4 | 2091 | free_minor(minor); |
6ed7ade8 | 2092 | bad_minor: |
10da4f79 | 2093 | module_put(THIS_MODULE); |
6ed7ade8 | 2094 | bad_module_get: |
1da177e4 LT |
2095 | kfree(md); |
2096 | return NULL; | |
2097 | } | |
2098 | ||
ae9da83f JN |
2099 | static void unlock_fs(struct mapped_device *md); |
2100 | ||
1da177e4 LT |
2101 | static void free_dev(struct mapped_device *md) |
2102 | { | |
f331c029 | 2103 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 2104 | |
32a926da MP |
2105 | unlock_fs(md); |
2106 | bdput(md->bdev); | |
304f3f6a | 2107 | destroy_workqueue(md->wq); |
e6ee8c0b KU |
2108 | if (md->io_pool) |
2109 | mempool_destroy(md->io_pool); | |
2110 | if (md->bs) | |
2111 | bioset_free(md->bs); | |
9c47008d | 2112 | blk_integrity_unregister(md->disk); |
1da177e4 | 2113 | del_gendisk(md->disk); |
83d5e5b0 | 2114 | cleanup_srcu_struct(&md->io_barrier); |
63d94e48 | 2115 | free_minor(minor); |
fba9f90e JM |
2116 | |
2117 | spin_lock(&_minor_lock); | |
2118 | md->disk->private_data = NULL; | |
2119 | spin_unlock(&_minor_lock); | |
2120 | ||
1da177e4 | 2121 | put_disk(md->disk); |
1312f40e | 2122 | blk_cleanup_queue(md->queue); |
fd2ed4d2 | 2123 | dm_stats_cleanup(&md->stats); |
10da4f79 | 2124 | module_put(THIS_MODULE); |
1da177e4 LT |
2125 | kfree(md); |
2126 | } | |
2127 | ||
e6ee8c0b KU |
2128 | static void __bind_mempools(struct mapped_device *md, struct dm_table *t) |
2129 | { | |
c0820cf5 | 2130 | struct dm_md_mempools *p = dm_table_get_md_mempools(t); |
e6ee8c0b | 2131 | |
5f015204 | 2132 | if (md->io_pool && md->bs) { |
16245bdc JN |
2133 | /* The md already has necessary mempools. */ |
2134 | if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) { | |
2135 | /* | |
2136 | * Reload bioset because front_pad may have changed | |
2137 | * because a different table was loaded. | |
2138 | */ | |
2139 | bioset_free(md->bs); | |
2140 | md->bs = p->bs; | |
2141 | p->bs = NULL; | |
2142 | } else if (dm_table_get_type(t) == DM_TYPE_REQUEST_BASED) { | |
16245bdc JN |
2143 | /* |
2144 | * There's no need to reload with request-based dm | |
2145 | * because the size of front_pad doesn't change. | |
2146 | * Note for future: If you are to reload bioset, | |
2147 | * prep-ed requests in the queue may refer | |
2148 | * to bio from the old bioset, so you must walk | |
2149 | * through the queue to unprep. | |
2150 | */ | |
2151 | } | |
e6ee8c0b | 2152 | goto out; |
c0820cf5 | 2153 | } |
e6ee8c0b | 2154 | |
5f015204 | 2155 | BUG_ON(!p || md->io_pool || md->bs); |
e6ee8c0b KU |
2156 | |
2157 | md->io_pool = p->io_pool; | |
2158 | p->io_pool = NULL; | |
e6ee8c0b KU |
2159 | md->bs = p->bs; |
2160 | p->bs = NULL; | |
2161 | ||
2162 | out: | |
2163 | /* mempool bind completed, now no need any mempools in the table */ | |
2164 | dm_table_free_md_mempools(t); | |
2165 | } | |
2166 | ||
1da177e4 LT |
2167 | /* |
2168 | * Bind a table to the device. | |
2169 | */ | |
2170 | static void event_callback(void *context) | |
2171 | { | |
7a8c3d3b MA |
2172 | unsigned long flags; |
2173 | LIST_HEAD(uevents); | |
1da177e4 LT |
2174 | struct mapped_device *md = (struct mapped_device *) context; |
2175 | ||
7a8c3d3b MA |
2176 | spin_lock_irqsave(&md->uevent_lock, flags); |
2177 | list_splice_init(&md->uevent_list, &uevents); | |
2178 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
2179 | ||
ed9e1982 | 2180 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 2181 | |
1da177e4 LT |
2182 | atomic_inc(&md->event_nr); |
2183 | wake_up(&md->eventq); | |
2184 | } | |
2185 | ||
c217649b MS |
2186 | /* |
2187 | * Protected by md->suspend_lock obtained by dm_swap_table(). | |
2188 | */ | |
4e90188b | 2189 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 2190 | { |
4e90188b | 2191 | set_capacity(md->disk, size); |
1da177e4 | 2192 | |
db8fef4f | 2193 | i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
1da177e4 LT |
2194 | } |
2195 | ||
d5b9dd04 MP |
2196 | /* |
2197 | * Return 1 if the queue has a compulsory merge_bvec_fn function. | |
2198 | * | |
2199 | * If this function returns 0, then the device is either a non-dm | |
2200 | * device without a merge_bvec_fn, or it is a dm device that is | |
2201 | * able to split any bios it receives that are too big. | |
2202 | */ | |
2203 | int dm_queue_merge_is_compulsory(struct request_queue *q) | |
2204 | { | |
2205 | struct mapped_device *dev_md; | |
2206 | ||
2207 | if (!q->merge_bvec_fn) | |
2208 | return 0; | |
2209 | ||
2210 | if (q->make_request_fn == dm_request) { | |
2211 | dev_md = q->queuedata; | |
2212 | if (test_bit(DMF_MERGE_IS_OPTIONAL, &dev_md->flags)) | |
2213 | return 0; | |
2214 | } | |
2215 | ||
2216 | return 1; | |
2217 | } | |
2218 | ||
2219 | static int dm_device_merge_is_compulsory(struct dm_target *ti, | |
2220 | struct dm_dev *dev, sector_t start, | |
2221 | sector_t len, void *data) | |
2222 | { | |
2223 | struct block_device *bdev = dev->bdev; | |
2224 | struct request_queue *q = bdev_get_queue(bdev); | |
2225 | ||
2226 | return dm_queue_merge_is_compulsory(q); | |
2227 | } | |
2228 | ||
2229 | /* | |
2230 | * Return 1 if it is acceptable to ignore merge_bvec_fn based | |
2231 | * on the properties of the underlying devices. | |
2232 | */ | |
2233 | static int dm_table_merge_is_optional(struct dm_table *table) | |
2234 | { | |
2235 | unsigned i = 0; | |
2236 | struct dm_target *ti; | |
2237 | ||
2238 | while (i < dm_table_get_num_targets(table)) { | |
2239 | ti = dm_table_get_target(table, i++); | |
2240 | ||
2241 | if (ti->type->iterate_devices && | |
2242 | ti->type->iterate_devices(ti, dm_device_merge_is_compulsory, NULL)) | |
2243 | return 0; | |
2244 | } | |
2245 | ||
2246 | return 1; | |
2247 | } | |
2248 | ||
042d2a9b AK |
2249 | /* |
2250 | * Returns old map, which caller must destroy. | |
2251 | */ | |
2252 | static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, | |
2253 | struct queue_limits *limits) | |
1da177e4 | 2254 | { |
042d2a9b | 2255 | struct dm_table *old_map; |
165125e1 | 2256 | struct request_queue *q = md->queue; |
1da177e4 | 2257 | sector_t size; |
d5b9dd04 | 2258 | int merge_is_optional; |
1da177e4 LT |
2259 | |
2260 | size = dm_table_get_size(t); | |
3ac51e74 DW |
2261 | |
2262 | /* | |
2263 | * Wipe any geometry if the size of the table changed. | |
2264 | */ | |
fd2ed4d2 | 2265 | if (size != dm_get_size(md)) |
3ac51e74 DW |
2266 | memset(&md->geometry, 0, sizeof(md->geometry)); |
2267 | ||
32a926da | 2268 | __set_size(md, size); |
d5816876 | 2269 | |
2ca3310e AK |
2270 | dm_table_event_callback(t, event_callback, md); |
2271 | ||
e6ee8c0b KU |
2272 | /* |
2273 | * The queue hasn't been stopped yet, if the old table type wasn't | |
2274 | * for request-based during suspension. So stop it to prevent | |
2275 | * I/O mapping before resume. | |
2276 | * This must be done before setting the queue restrictions, | |
2277 | * because request-based dm may be run just after the setting. | |
2278 | */ | |
2279 | if (dm_table_request_based(t) && !blk_queue_stopped(q)) | |
2280 | stop_queue(q); | |
2281 | ||
2282 | __bind_mempools(md, t); | |
2283 | ||
d5b9dd04 MP |
2284 | merge_is_optional = dm_table_merge_is_optional(t); |
2285 | ||
042d2a9b | 2286 | old_map = md->map; |
83d5e5b0 | 2287 | rcu_assign_pointer(md->map, t); |
36a0456f AK |
2288 | md->immutable_target_type = dm_table_get_immutable_target_type(t); |
2289 | ||
754c5fc7 | 2290 | dm_table_set_restrictions(t, q, limits); |
d5b9dd04 MP |
2291 | if (merge_is_optional) |
2292 | set_bit(DMF_MERGE_IS_OPTIONAL, &md->flags); | |
2293 | else | |
2294 | clear_bit(DMF_MERGE_IS_OPTIONAL, &md->flags); | |
83d5e5b0 | 2295 | dm_sync_table(md); |
1da177e4 | 2296 | |
042d2a9b | 2297 | return old_map; |
1da177e4 LT |
2298 | } |
2299 | ||
a7940155 AK |
2300 | /* |
2301 | * Returns unbound table for the caller to free. | |
2302 | */ | |
2303 | static struct dm_table *__unbind(struct mapped_device *md) | |
1da177e4 LT |
2304 | { |
2305 | struct dm_table *map = md->map; | |
2306 | ||
2307 | if (!map) | |
a7940155 | 2308 | return NULL; |
1da177e4 LT |
2309 | |
2310 | dm_table_event_callback(map, NULL, NULL); | |
83d5e5b0 MP |
2311 | rcu_assign_pointer(md->map, NULL); |
2312 | dm_sync_table(md); | |
a7940155 AK |
2313 | |
2314 | return map; | |
1da177e4 LT |
2315 | } |
2316 | ||
2317 | /* | |
2318 | * Constructor for a new device. | |
2319 | */ | |
2b06cfff | 2320 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
2321 | { |
2322 | struct mapped_device *md; | |
2323 | ||
2b06cfff | 2324 | md = alloc_dev(minor); |
1da177e4 LT |
2325 | if (!md) |
2326 | return -ENXIO; | |
2327 | ||
784aae73 MB |
2328 | dm_sysfs_init(md); |
2329 | ||
1da177e4 LT |
2330 | *result = md; |
2331 | return 0; | |
2332 | } | |
2333 | ||
a5664dad MS |
2334 | /* |
2335 | * Functions to manage md->type. | |
2336 | * All are required to hold md->type_lock. | |
2337 | */ | |
2338 | void dm_lock_md_type(struct mapped_device *md) | |
2339 | { | |
2340 | mutex_lock(&md->type_lock); | |
2341 | } | |
2342 | ||
2343 | void dm_unlock_md_type(struct mapped_device *md) | |
2344 | { | |
2345 | mutex_unlock(&md->type_lock); | |
2346 | } | |
2347 | ||
2348 | void dm_set_md_type(struct mapped_device *md, unsigned type) | |
2349 | { | |
00c4fc3b | 2350 | BUG_ON(!mutex_is_locked(&md->type_lock)); |
a5664dad MS |
2351 | md->type = type; |
2352 | } | |
2353 | ||
2354 | unsigned dm_get_md_type(struct mapped_device *md) | |
2355 | { | |
00c4fc3b | 2356 | BUG_ON(!mutex_is_locked(&md->type_lock)); |
a5664dad MS |
2357 | return md->type; |
2358 | } | |
2359 | ||
36a0456f AK |
2360 | struct target_type *dm_get_immutable_target_type(struct mapped_device *md) |
2361 | { | |
2362 | return md->immutable_target_type; | |
2363 | } | |
2364 | ||
f84cb8a4 MS |
2365 | /* |
2366 | * The queue_limits are only valid as long as you have a reference | |
2367 | * count on 'md'. | |
2368 | */ | |
2369 | struct queue_limits *dm_get_queue_limits(struct mapped_device *md) | |
2370 | { | |
2371 | BUG_ON(!atomic_read(&md->holders)); | |
2372 | return &md->queue->limits; | |
2373 | } | |
2374 | EXPORT_SYMBOL_GPL(dm_get_queue_limits); | |
2375 | ||
4a0b4ddf MS |
2376 | /* |
2377 | * Fully initialize a request-based queue (->elevator, ->request_fn, etc). | |
2378 | */ | |
2379 | static int dm_init_request_based_queue(struct mapped_device *md) | |
2380 | { | |
2381 | struct request_queue *q = NULL; | |
2382 | ||
2383 | if (md->queue->elevator) | |
2384 | return 1; | |
2385 | ||
2386 | /* Fully initialize the queue */ | |
2387 | q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); | |
2388 | if (!q) | |
2389 | return 0; | |
2390 | ||
2391 | md->queue = q; | |
4a0b4ddf MS |
2392 | dm_init_md_queue(md); |
2393 | blk_queue_softirq_done(md->queue, dm_softirq_done); | |
2394 | blk_queue_prep_rq(md->queue, dm_prep_fn); | |
2395 | blk_queue_lld_busy(md->queue, dm_lld_busy); | |
4a0b4ddf MS |
2396 | |
2397 | elv_register_queue(md->queue); | |
2398 | ||
2399 | return 1; | |
2400 | } | |
2401 | ||
2402 | /* | |
2403 | * Setup the DM device's queue based on md's type | |
2404 | */ | |
2405 | int dm_setup_md_queue(struct mapped_device *md) | |
2406 | { | |
2407 | if ((dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) && | |
2408 | !dm_init_request_based_queue(md)) { | |
2409 | DMWARN("Cannot initialize queue for request-based mapped device"); | |
2410 | return -EINVAL; | |
2411 | } | |
2412 | ||
2413 | return 0; | |
2414 | } | |
2415 | ||
637842cf | 2416 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
2417 | { |
2418 | struct mapped_device *md; | |
1da177e4 LT |
2419 | unsigned minor = MINOR(dev); |
2420 | ||
2421 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
2422 | return NULL; | |
2423 | ||
f32c10b0 | 2424 | spin_lock(&_minor_lock); |
1da177e4 LT |
2425 | |
2426 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 2427 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 2428 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
abdc568b | 2429 | dm_deleting_md(md) || |
17b2f66f | 2430 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 2431 | md = NULL; |
fba9f90e JM |
2432 | goto out; |
2433 | } | |
1da177e4 | 2434 | |
fba9f90e | 2435 | out: |
f32c10b0 | 2436 | spin_unlock(&_minor_lock); |
1da177e4 | 2437 | |
637842cf DT |
2438 | return md; |
2439 | } | |
2440 | ||
d229a958 DT |
2441 | struct mapped_device *dm_get_md(dev_t dev) |
2442 | { | |
2443 | struct mapped_device *md = dm_find_md(dev); | |
2444 | ||
2445 | if (md) | |
2446 | dm_get(md); | |
2447 | ||
2448 | return md; | |
2449 | } | |
3cf2e4ba | 2450 | EXPORT_SYMBOL_GPL(dm_get_md); |
d229a958 | 2451 | |
9ade92a9 | 2452 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 2453 | { |
9ade92a9 | 2454 | return md->interface_ptr; |
1da177e4 LT |
2455 | } |
2456 | ||
2457 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
2458 | { | |
2459 | md->interface_ptr = ptr; | |
2460 | } | |
2461 | ||
2462 | void dm_get(struct mapped_device *md) | |
2463 | { | |
2464 | atomic_inc(&md->holders); | |
3f77316d | 2465 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1da177e4 LT |
2466 | } |
2467 | ||
72d94861 AK |
2468 | const char *dm_device_name(struct mapped_device *md) |
2469 | { | |
2470 | return md->name; | |
2471 | } | |
2472 | EXPORT_SYMBOL_GPL(dm_device_name); | |
2473 | ||
3f77316d | 2474 | static void __dm_destroy(struct mapped_device *md, bool wait) |
1da177e4 | 2475 | { |
1134e5ae | 2476 | struct dm_table *map; |
83d5e5b0 | 2477 | int srcu_idx; |
1da177e4 | 2478 | |
3f77316d | 2479 | might_sleep(); |
fba9f90e | 2480 | |
3f77316d | 2481 | spin_lock(&_minor_lock); |
83d5e5b0 | 2482 | map = dm_get_live_table(md, &srcu_idx); |
3f77316d KU |
2483 | idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); |
2484 | set_bit(DMF_FREEING, &md->flags); | |
2485 | spin_unlock(&_minor_lock); | |
2486 | ||
2487 | if (!dm_suspended_md(md)) { | |
2488 | dm_table_presuspend_targets(map); | |
2489 | dm_table_postsuspend_targets(map); | |
1da177e4 | 2490 | } |
3f77316d | 2491 | |
83d5e5b0 MP |
2492 | /* dm_put_live_table must be before msleep, otherwise deadlock is possible */ |
2493 | dm_put_live_table(md, srcu_idx); | |
2494 | ||
3f77316d KU |
2495 | /* |
2496 | * Rare, but there may be I/O requests still going to complete, | |
2497 | * for example. Wait for all references to disappear. | |
2498 | * No one should increment the reference count of the mapped_device, | |
2499 | * after the mapped_device state becomes DMF_FREEING. | |
2500 | */ | |
2501 | if (wait) | |
2502 | while (atomic_read(&md->holders)) | |
2503 | msleep(1); | |
2504 | else if (atomic_read(&md->holders)) | |
2505 | DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", | |
2506 | dm_device_name(md), atomic_read(&md->holders)); | |
2507 | ||
2508 | dm_sysfs_exit(md); | |
3f77316d KU |
2509 | dm_table_destroy(__unbind(md)); |
2510 | free_dev(md); | |
2511 | } | |
2512 | ||
2513 | void dm_destroy(struct mapped_device *md) | |
2514 | { | |
2515 | __dm_destroy(md, true); | |
2516 | } | |
2517 | ||
2518 | void dm_destroy_immediate(struct mapped_device *md) | |
2519 | { | |
2520 | __dm_destroy(md, false); | |
2521 | } | |
2522 | ||
2523 | void dm_put(struct mapped_device *md) | |
2524 | { | |
2525 | atomic_dec(&md->holders); | |
1da177e4 | 2526 | } |
79eb885c | 2527 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 2528 | |
401600df | 2529 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
46125c1c MB |
2530 | { |
2531 | int r = 0; | |
b44ebeb0 MP |
2532 | DECLARE_WAITQUEUE(wait, current); |
2533 | ||
b44ebeb0 | 2534 | add_wait_queue(&md->wait, &wait); |
46125c1c MB |
2535 | |
2536 | while (1) { | |
401600df | 2537 | set_current_state(interruptible); |
46125c1c | 2538 | |
b4324fee | 2539 | if (!md_in_flight(md)) |
46125c1c MB |
2540 | break; |
2541 | ||
401600df MP |
2542 | if (interruptible == TASK_INTERRUPTIBLE && |
2543 | signal_pending(current)) { | |
46125c1c MB |
2544 | r = -EINTR; |
2545 | break; | |
2546 | } | |
2547 | ||
2548 | io_schedule(); | |
2549 | } | |
2550 | set_current_state(TASK_RUNNING); | |
2551 | ||
b44ebeb0 MP |
2552 | remove_wait_queue(&md->wait, &wait); |
2553 | ||
46125c1c MB |
2554 | return r; |
2555 | } | |
2556 | ||
1da177e4 LT |
2557 | /* |
2558 | * Process the deferred bios | |
2559 | */ | |
ef208587 | 2560 | static void dm_wq_work(struct work_struct *work) |
1da177e4 | 2561 | { |
ef208587 MP |
2562 | struct mapped_device *md = container_of(work, struct mapped_device, |
2563 | work); | |
6d6f10df | 2564 | struct bio *c; |
83d5e5b0 MP |
2565 | int srcu_idx; |
2566 | struct dm_table *map; | |
1da177e4 | 2567 | |
83d5e5b0 | 2568 | map = dm_get_live_table(md, &srcu_idx); |
ef208587 | 2569 | |
3b00b203 | 2570 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
df12ee99 AK |
2571 | spin_lock_irq(&md->deferred_lock); |
2572 | c = bio_list_pop(&md->deferred); | |
2573 | spin_unlock_irq(&md->deferred_lock); | |
2574 | ||
6a8736d1 | 2575 | if (!c) |
df12ee99 | 2576 | break; |
022c2611 | 2577 | |
e6ee8c0b KU |
2578 | if (dm_request_based(md)) |
2579 | generic_make_request(c); | |
6a8736d1 | 2580 | else |
83d5e5b0 | 2581 | __split_and_process_bio(md, map, c); |
022c2611 | 2582 | } |
73d410c0 | 2583 | |
83d5e5b0 | 2584 | dm_put_live_table(md, srcu_idx); |
1da177e4 LT |
2585 | } |
2586 | ||
9a1fb464 | 2587 | static void dm_queue_flush(struct mapped_device *md) |
304f3f6a | 2588 | { |
3b00b203 MP |
2589 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
2590 | smp_mb__after_clear_bit(); | |
53d5914f | 2591 | queue_work(md->wq, &md->work); |
304f3f6a MB |
2592 | } |
2593 | ||
1da177e4 | 2594 | /* |
042d2a9b | 2595 | * Swap in a new table, returning the old one for the caller to destroy. |
1da177e4 | 2596 | */ |
042d2a9b | 2597 | struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) |
1da177e4 | 2598 | { |
87eb5b21 | 2599 | struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL); |
754c5fc7 | 2600 | struct queue_limits limits; |
042d2a9b | 2601 | int r; |
1da177e4 | 2602 | |
e61290a4 | 2603 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
2604 | |
2605 | /* device must be suspended */ | |
4f186f8b | 2606 | if (!dm_suspended_md(md)) |
93c534ae | 2607 | goto out; |
1da177e4 | 2608 | |
3ae70656 MS |
2609 | /* |
2610 | * If the new table has no data devices, retain the existing limits. | |
2611 | * This helps multipath with queue_if_no_path if all paths disappear, | |
2612 | * then new I/O is queued based on these limits, and then some paths | |
2613 | * reappear. | |
2614 | */ | |
2615 | if (dm_table_has_no_data_devices(table)) { | |
83d5e5b0 | 2616 | live_map = dm_get_live_table_fast(md); |
3ae70656 MS |
2617 | if (live_map) |
2618 | limits = md->queue->limits; | |
83d5e5b0 | 2619 | dm_put_live_table_fast(md); |
3ae70656 MS |
2620 | } |
2621 | ||
87eb5b21 MC |
2622 | if (!live_map) { |
2623 | r = dm_calculate_queue_limits(table, &limits); | |
2624 | if (r) { | |
2625 | map = ERR_PTR(r); | |
2626 | goto out; | |
2627 | } | |
042d2a9b | 2628 | } |
754c5fc7 | 2629 | |
042d2a9b | 2630 | map = __bind(md, table, &limits); |
1da177e4 | 2631 | |
93c534ae | 2632 | out: |
e61290a4 | 2633 | mutex_unlock(&md->suspend_lock); |
042d2a9b | 2634 | return map; |
1da177e4 LT |
2635 | } |
2636 | ||
2637 | /* | |
2638 | * Functions to lock and unlock any filesystem running on the | |
2639 | * device. | |
2640 | */ | |
2ca3310e | 2641 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 2642 | { |
e39e2e95 | 2643 | int r; |
1da177e4 LT |
2644 | |
2645 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 2646 | |
db8fef4f | 2647 | md->frozen_sb = freeze_bdev(md->bdev); |
dfbe03f6 | 2648 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 2649 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
2650 | md->frozen_sb = NULL; |
2651 | return r; | |
dfbe03f6 AK |
2652 | } |
2653 | ||
aa8d7c2f AK |
2654 | set_bit(DMF_FROZEN, &md->flags); |
2655 | ||
1da177e4 LT |
2656 | return 0; |
2657 | } | |
2658 | ||
2ca3310e | 2659 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 2660 | { |
aa8d7c2f AK |
2661 | if (!test_bit(DMF_FROZEN, &md->flags)) |
2662 | return; | |
2663 | ||
db8fef4f | 2664 | thaw_bdev(md->bdev, md->frozen_sb); |
1da177e4 | 2665 | md->frozen_sb = NULL; |
aa8d7c2f | 2666 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
2667 | } |
2668 | ||
2669 | /* | |
2670 | * We need to be able to change a mapping table under a mounted | |
2671 | * filesystem. For example we might want to move some data in | |
2672 | * the background. Before the table can be swapped with | |
2673 | * dm_bind_table, dm_suspend must be called to flush any in | |
2674 | * flight bios and ensure that any further io gets deferred. | |
2675 | */ | |
cec47e3d KU |
2676 | /* |
2677 | * Suspend mechanism in request-based dm. | |
2678 | * | |
9f518b27 KU |
2679 | * 1. Flush all I/Os by lock_fs() if needed. |
2680 | * 2. Stop dispatching any I/O by stopping the request_queue. | |
2681 | * 3. Wait for all in-flight I/Os to be completed or requeued. | |
cec47e3d | 2682 | * |
9f518b27 | 2683 | * To abort suspend, start the request_queue. |
cec47e3d | 2684 | */ |
a3d77d35 | 2685 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 2686 | { |
2ca3310e | 2687 | struct dm_table *map = NULL; |
46125c1c | 2688 | int r = 0; |
a3d77d35 | 2689 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 2690 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 2691 | |
e61290a4 | 2692 | mutex_lock(&md->suspend_lock); |
2ca3310e | 2693 | |
4f186f8b | 2694 | if (dm_suspended_md(md)) { |
73d410c0 | 2695 | r = -EINVAL; |
d287483d | 2696 | goto out_unlock; |
73d410c0 | 2697 | } |
1da177e4 | 2698 | |
83d5e5b0 | 2699 | map = md->map; |
1da177e4 | 2700 | |
2e93ccc1 KU |
2701 | /* |
2702 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
2703 | * This flag is cleared before dm_suspend returns. | |
2704 | */ | |
2705 | if (noflush) | |
2706 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
2707 | ||
cf222b37 AK |
2708 | /* This does not get reverted if there's an error later. */ |
2709 | dm_table_presuspend_targets(map); | |
2710 | ||
32a926da | 2711 | /* |
9f518b27 KU |
2712 | * Flush I/O to the device. |
2713 | * Any I/O submitted after lock_fs() may not be flushed. | |
2714 | * noflush takes precedence over do_lockfs. | |
2715 | * (lock_fs() flushes I/Os and waits for them to complete.) | |
32a926da MP |
2716 | */ |
2717 | if (!noflush && do_lockfs) { | |
2718 | r = lock_fs(md); | |
2719 | if (r) | |
83d5e5b0 | 2720 | goto out_unlock; |
aa8d7c2f | 2721 | } |
1da177e4 LT |
2722 | |
2723 | /* | |
3b00b203 MP |
2724 | * Here we must make sure that no processes are submitting requests |
2725 | * to target drivers i.e. no one may be executing | |
2726 | * __split_and_process_bio. This is called from dm_request and | |
2727 | * dm_wq_work. | |
2728 | * | |
2729 | * To get all processes out of __split_and_process_bio in dm_request, | |
2730 | * we take the write lock. To prevent any process from reentering | |
6a8736d1 TH |
2731 | * __split_and_process_bio from dm_request and quiesce the thread |
2732 | * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call | |
2733 | * flush_workqueue(md->wq). | |
1da177e4 | 2734 | */ |
1eb787ec | 2735 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
83d5e5b0 | 2736 | synchronize_srcu(&md->io_barrier); |
1da177e4 | 2737 | |
d0bcb878 | 2738 | /* |
29e4013d TH |
2739 | * Stop md->queue before flushing md->wq in case request-based |
2740 | * dm defers requests to md->wq from md->queue. | |
d0bcb878 | 2741 | */ |
cec47e3d | 2742 | if (dm_request_based(md)) |
9f518b27 | 2743 | stop_queue(md->queue); |
cec47e3d | 2744 | |
d0bcb878 KU |
2745 | flush_workqueue(md->wq); |
2746 | ||
1da177e4 | 2747 | /* |
3b00b203 MP |
2748 | * At this point no more requests are entering target request routines. |
2749 | * We call dm_wait_for_completion to wait for all existing requests | |
2750 | * to finish. | |
1da177e4 | 2751 | */ |
401600df | 2752 | r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE); |
1da177e4 | 2753 | |
6d6f10df | 2754 | if (noflush) |
022c2611 | 2755 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
83d5e5b0 | 2756 | synchronize_srcu(&md->io_barrier); |
2e93ccc1 | 2757 | |
1da177e4 | 2758 | /* were we interrupted ? */ |
46125c1c | 2759 | if (r < 0) { |
9a1fb464 | 2760 | dm_queue_flush(md); |
73d410c0 | 2761 | |
cec47e3d | 2762 | if (dm_request_based(md)) |
9f518b27 | 2763 | start_queue(md->queue); |
cec47e3d | 2764 | |
2ca3310e | 2765 | unlock_fs(md); |
83d5e5b0 | 2766 | goto out_unlock; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 2767 | } |
1da177e4 | 2768 | |
3b00b203 MP |
2769 | /* |
2770 | * If dm_wait_for_completion returned 0, the device is completely | |
2771 | * quiescent now. There is no request-processing activity. All new | |
2772 | * requests are being added to md->deferred list. | |
2773 | */ | |
2774 | ||
2ca3310e | 2775 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 2776 | |
4d4471cb KU |
2777 | dm_table_postsuspend_targets(map); |
2778 | ||
d287483d | 2779 | out_unlock: |
e61290a4 | 2780 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 2781 | return r; |
1da177e4 LT |
2782 | } |
2783 | ||
2784 | int dm_resume(struct mapped_device *md) | |
2785 | { | |
cf222b37 | 2786 | int r = -EINVAL; |
cf222b37 | 2787 | struct dm_table *map = NULL; |
1da177e4 | 2788 | |
e61290a4 | 2789 | mutex_lock(&md->suspend_lock); |
4f186f8b | 2790 | if (!dm_suspended_md(md)) |
cf222b37 | 2791 | goto out; |
cf222b37 | 2792 | |
83d5e5b0 | 2793 | map = md->map; |
2ca3310e | 2794 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 2795 | goto out; |
1da177e4 | 2796 | |
8757b776 MB |
2797 | r = dm_table_resume_targets(map); |
2798 | if (r) | |
2799 | goto out; | |
2ca3310e | 2800 | |
9a1fb464 | 2801 | dm_queue_flush(md); |
2ca3310e | 2802 | |
cec47e3d KU |
2803 | /* |
2804 | * Flushing deferred I/Os must be done after targets are resumed | |
2805 | * so that mapping of targets can work correctly. | |
2806 | * Request-based dm is queueing the deferred I/Os in its request_queue. | |
2807 | */ | |
2808 | if (dm_request_based(md)) | |
2809 | start_queue(md->queue); | |
2810 | ||
2ca3310e AK |
2811 | unlock_fs(md); |
2812 | ||
2813 | clear_bit(DMF_SUSPENDED, &md->flags); | |
2814 | ||
cf222b37 AK |
2815 | r = 0; |
2816 | out: | |
e61290a4 | 2817 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 2818 | |
cf222b37 | 2819 | return r; |
1da177e4 LT |
2820 | } |
2821 | ||
fd2ed4d2 MP |
2822 | /* |
2823 | * Internal suspend/resume works like userspace-driven suspend. It waits | |
2824 | * until all bios finish and prevents issuing new bios to the target drivers. | |
2825 | * It may be used only from the kernel. | |
2826 | * | |
2827 | * Internal suspend holds md->suspend_lock, which prevents interaction with | |
2828 | * userspace-driven suspend. | |
2829 | */ | |
2830 | ||
2831 | void dm_internal_suspend(struct mapped_device *md) | |
2832 | { | |
2833 | mutex_lock(&md->suspend_lock); | |
2834 | if (dm_suspended_md(md)) | |
2835 | return; | |
2836 | ||
2837 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); | |
2838 | synchronize_srcu(&md->io_barrier); | |
2839 | flush_workqueue(md->wq); | |
2840 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); | |
2841 | } | |
2842 | ||
2843 | void dm_internal_resume(struct mapped_device *md) | |
2844 | { | |
2845 | if (dm_suspended_md(md)) | |
2846 | goto done; | |
2847 | ||
2848 | dm_queue_flush(md); | |
2849 | ||
2850 | done: | |
2851 | mutex_unlock(&md->suspend_lock); | |
2852 | } | |
2853 | ||
1da177e4 LT |
2854 | /*----------------------------------------------------------------- |
2855 | * Event notification. | |
2856 | *---------------------------------------------------------------*/ | |
3abf85b5 | 2857 | int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
60935eb2 | 2858 | unsigned cookie) |
69267a30 | 2859 | { |
60935eb2 MB |
2860 | char udev_cookie[DM_COOKIE_LENGTH]; |
2861 | char *envp[] = { udev_cookie, NULL }; | |
2862 | ||
2863 | if (!cookie) | |
3abf85b5 | 2864 | return kobject_uevent(&disk_to_dev(md->disk)->kobj, action); |
60935eb2 MB |
2865 | else { |
2866 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", | |
2867 | DM_COOKIE_ENV_VAR_NAME, cookie); | |
3abf85b5 PR |
2868 | return kobject_uevent_env(&disk_to_dev(md->disk)->kobj, |
2869 | action, envp); | |
60935eb2 | 2870 | } |
69267a30 AK |
2871 | } |
2872 | ||
7a8c3d3b MA |
2873 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
2874 | { | |
2875 | return atomic_add_return(1, &md->uevent_seq); | |
2876 | } | |
2877 | ||
1da177e4 LT |
2878 | uint32_t dm_get_event_nr(struct mapped_device *md) |
2879 | { | |
2880 | return atomic_read(&md->event_nr); | |
2881 | } | |
2882 | ||
2883 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
2884 | { | |
2885 | return wait_event_interruptible(md->eventq, | |
2886 | (event_nr != atomic_read(&md->event_nr))); | |
2887 | } | |
2888 | ||
7a8c3d3b MA |
2889 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
2890 | { | |
2891 | unsigned long flags; | |
2892 | ||
2893 | spin_lock_irqsave(&md->uevent_lock, flags); | |
2894 | list_add(elist, &md->uevent_list); | |
2895 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
2896 | } | |
2897 | ||
1da177e4 LT |
2898 | /* |
2899 | * The gendisk is only valid as long as you have a reference | |
2900 | * count on 'md'. | |
2901 | */ | |
2902 | struct gendisk *dm_disk(struct mapped_device *md) | |
2903 | { | |
2904 | return md->disk; | |
2905 | } | |
2906 | ||
784aae73 MB |
2907 | struct kobject *dm_kobject(struct mapped_device *md) |
2908 | { | |
2909 | return &md->kobj; | |
2910 | } | |
2911 | ||
784aae73 MB |
2912 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) |
2913 | { | |
2914 | struct mapped_device *md; | |
2915 | ||
2916 | md = container_of(kobj, struct mapped_device, kobj); | |
784aae73 | 2917 | |
4d89b7b4 | 2918 | if (test_bit(DMF_FREEING, &md->flags) || |
432a212c | 2919 | dm_deleting_md(md)) |
4d89b7b4 MB |
2920 | return NULL; |
2921 | ||
784aae73 MB |
2922 | dm_get(md); |
2923 | return md; | |
2924 | } | |
2925 | ||
be35f486 MP |
2926 | struct completion *dm_get_completion_from_kobject(struct kobject *kobj) |
2927 | { | |
2928 | struct mapped_device *md = container_of(kobj, struct mapped_device, kobj); | |
2929 | ||
2930 | return &md->kobj_completion; | |
2931 | } | |
2932 | ||
4f186f8b | 2933 | int dm_suspended_md(struct mapped_device *md) |
1da177e4 LT |
2934 | { |
2935 | return test_bit(DMF_SUSPENDED, &md->flags); | |
2936 | } | |
2937 | ||
2c140a24 MP |
2938 | int dm_test_deferred_remove_flag(struct mapped_device *md) |
2939 | { | |
2940 | return test_bit(DMF_DEFERRED_REMOVE, &md->flags); | |
2941 | } | |
2942 | ||
64dbce58 KU |
2943 | int dm_suspended(struct dm_target *ti) |
2944 | { | |
ecdb2e25 | 2945 | return dm_suspended_md(dm_table_get_md(ti->table)); |
64dbce58 KU |
2946 | } |
2947 | EXPORT_SYMBOL_GPL(dm_suspended); | |
2948 | ||
2e93ccc1 KU |
2949 | int dm_noflush_suspending(struct dm_target *ti) |
2950 | { | |
ecdb2e25 | 2951 | return __noflush_suspending(dm_table_get_md(ti->table)); |
2e93ccc1 KU |
2952 | } |
2953 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
2954 | ||
c0820cf5 | 2955 | struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size) |
e6ee8c0b | 2956 | { |
5f015204 JN |
2957 | struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL); |
2958 | struct kmem_cache *cachep; | |
2959 | unsigned int pool_size; | |
2960 | unsigned int front_pad; | |
e6ee8c0b KU |
2961 | |
2962 | if (!pools) | |
2963 | return NULL; | |
2964 | ||
23e5083b | 2965 | if (type == DM_TYPE_BIO_BASED) { |
5f015204 | 2966 | cachep = _io_cache; |
e8603136 | 2967 | pool_size = dm_get_reserved_bio_based_ios(); |
5f015204 JN |
2968 | front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone); |
2969 | } else if (type == DM_TYPE_REQUEST_BASED) { | |
2970 | cachep = _rq_tio_cache; | |
f4790826 | 2971 | pool_size = dm_get_reserved_rq_based_ios(); |
5f015204 JN |
2972 | front_pad = offsetof(struct dm_rq_clone_bio_info, clone); |
2973 | /* per_bio_data_size is not used. See __bind_mempools(). */ | |
2974 | WARN_ON(per_bio_data_size != 0); | |
2975 | } else | |
2976 | goto out; | |
e6ee8c0b | 2977 | |
6cfa5857 | 2978 | pools->io_pool = mempool_create_slab_pool(pool_size, cachep); |
5f015204 JN |
2979 | if (!pools->io_pool) |
2980 | goto out; | |
e6ee8c0b | 2981 | |
5f015204 | 2982 | pools->bs = bioset_create(pool_size, front_pad); |
e6ee8c0b | 2983 | if (!pools->bs) |
5f015204 | 2984 | goto out; |
e6ee8c0b | 2985 | |
a91a2785 | 2986 | if (integrity && bioset_integrity_create(pools->bs, pool_size)) |
5f015204 | 2987 | goto out; |
a91a2785 | 2988 | |
e6ee8c0b KU |
2989 | return pools; |
2990 | ||
5f015204 JN |
2991 | out: |
2992 | dm_free_md_mempools(pools); | |
e6ee8c0b KU |
2993 | |
2994 | return NULL; | |
2995 | } | |
2996 | ||
2997 | void dm_free_md_mempools(struct dm_md_mempools *pools) | |
2998 | { | |
2999 | if (!pools) | |
3000 | return; | |
3001 | ||
3002 | if (pools->io_pool) | |
3003 | mempool_destroy(pools->io_pool); | |
3004 | ||
e6ee8c0b KU |
3005 | if (pools->bs) |
3006 | bioset_free(pools->bs); | |
3007 | ||
3008 | kfree(pools); | |
3009 | } | |
3010 | ||
83d5cde4 | 3011 | static const struct block_device_operations dm_blk_dops = { |
1da177e4 LT |
3012 | .open = dm_blk_open, |
3013 | .release = dm_blk_close, | |
aa129a22 | 3014 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 3015 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
3016 | .owner = THIS_MODULE |
3017 | }; | |
3018 | ||
3019 | EXPORT_SYMBOL(dm_get_mapinfo); | |
3020 | ||
3021 | /* | |
3022 | * module hooks | |
3023 | */ | |
3024 | module_init(dm_init); | |
3025 | module_exit(dm_exit); | |
3026 | ||
3027 | module_param(major, uint, 0); | |
3028 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
f4790826 | 3029 | |
e8603136 MS |
3030 | module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR); |
3031 | MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); | |
3032 | ||
f4790826 MS |
3033 | module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR); |
3034 | MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools"); | |
3035 | ||
1da177e4 LT |
3036 | MODULE_DESCRIPTION(DM_NAME " driver"); |
3037 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
3038 | MODULE_LICENSE("GPL"); |