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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Sistina Software (UK) Limited. | |
d5816876 | 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" | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/blkdev.h> | |
13 | #include <linux/namei.h> | |
14 | #include <linux/ctype.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/interrupt.h> | |
48c9c27b | 17 | #include <linux/mutex.h> |
d5816876 | 18 | #include <linux/delay.h> |
1da177e4 LT |
19 | #include <asm/atomic.h> |
20 | ||
72d94861 AK |
21 | #define DM_MSG_PREFIX "table" |
22 | ||
1da177e4 LT |
23 | #define MAX_DEPTH 16 |
24 | #define NODE_SIZE L1_CACHE_BYTES | |
25 | #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) | |
26 | #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) | |
27 | ||
d5816876 MP |
28 | /* |
29 | * The table has always exactly one reference from either mapped_device->map | |
30 | * or hash_cell->new_map. This reference is not counted in table->holders. | |
31 | * A pair of dm_create_table/dm_destroy_table functions is used for table | |
32 | * creation/destruction. | |
33 | * | |
34 | * Temporary references from the other code increase table->holders. A pair | |
35 | * of dm_table_get/dm_table_put functions is used to manipulate it. | |
36 | * | |
37 | * When the table is about to be destroyed, we wait for table->holders to | |
38 | * drop to zero. | |
39 | */ | |
40 | ||
1da177e4 | 41 | struct dm_table { |
1134e5ae | 42 | struct mapped_device *md; |
1da177e4 LT |
43 | atomic_t holders; |
44 | ||
45 | /* btree table */ | |
46 | unsigned int depth; | |
47 | unsigned int counts[MAX_DEPTH]; /* in nodes */ | |
48 | sector_t *index[MAX_DEPTH]; | |
49 | ||
50 | unsigned int num_targets; | |
51 | unsigned int num_allocated; | |
52 | sector_t *highs; | |
53 | struct dm_target *targets; | |
54 | ||
55 | /* | |
56 | * Indicates the rw permissions for the new logical | |
57 | * device. This should be a combination of FMODE_READ | |
58 | * and FMODE_WRITE. | |
59 | */ | |
aeb5d727 | 60 | fmode_t mode; |
1da177e4 LT |
61 | |
62 | /* a list of devices used by this table */ | |
63 | struct list_head devices; | |
64 | ||
65 | /* | |
66 | * These are optimistic limits taken from all the | |
67 | * targets, some targets will need smaller limits. | |
68 | */ | |
69 | struct io_restrictions limits; | |
70 | ||
71 | /* events get handed up using this callback */ | |
72 | void (*event_fn)(void *); | |
73 | void *event_context; | |
74 | }; | |
75 | ||
76 | /* | |
77 | * Similar to ceiling(log_size(n)) | |
78 | */ | |
79 | static unsigned int int_log(unsigned int n, unsigned int base) | |
80 | { | |
81 | int result = 0; | |
82 | ||
83 | while (n > 1) { | |
84 | n = dm_div_up(n, base); | |
85 | result++; | |
86 | } | |
87 | ||
88 | return result; | |
89 | } | |
90 | ||
91 | /* | |
92 | * Returns the minimum that is _not_ zero, unless both are zero. | |
93 | */ | |
94 | #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) | |
95 | ||
96 | /* | |
97 | * Combine two io_restrictions, always taking the lower value. | |
98 | */ | |
99 | static void combine_restrictions_low(struct io_restrictions *lhs, | |
100 | struct io_restrictions *rhs) | |
101 | { | |
102 | lhs->max_sectors = | |
103 | min_not_zero(lhs->max_sectors, rhs->max_sectors); | |
104 | ||
105 | lhs->max_phys_segments = | |
106 | min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments); | |
107 | ||
108 | lhs->max_hw_segments = | |
109 | min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments); | |
110 | ||
e1defc4f MP |
111 | lhs->logical_block_size = max(lhs->logical_block_size, |
112 | rhs->logical_block_size); | |
1da177e4 LT |
113 | |
114 | lhs->max_segment_size = | |
115 | min_not_zero(lhs->max_segment_size, rhs->max_segment_size); | |
116 | ||
91212507 NB |
117 | lhs->max_hw_sectors = |
118 | min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors); | |
119 | ||
1da177e4 LT |
120 | lhs->seg_boundary_mask = |
121 | min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); | |
969429b5 | 122 | |
5ec140e6 VA |
123 | lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn); |
124 | ||
969429b5 | 125 | lhs->no_cluster |= rhs->no_cluster; |
1da177e4 LT |
126 | } |
127 | ||
128 | /* | |
129 | * Calculate the index of the child node of the n'th node k'th key. | |
130 | */ | |
131 | static inline unsigned int get_child(unsigned int n, unsigned int k) | |
132 | { | |
133 | return (n * CHILDREN_PER_NODE) + k; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Return the n'th node of level l from table t. | |
138 | */ | |
139 | static inline sector_t *get_node(struct dm_table *t, | |
140 | unsigned int l, unsigned int n) | |
141 | { | |
142 | return t->index[l] + (n * KEYS_PER_NODE); | |
143 | } | |
144 | ||
145 | /* | |
146 | * Return the highest key that you could lookup from the n'th | |
147 | * node on level l of the btree. | |
148 | */ | |
149 | static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) | |
150 | { | |
151 | for (; l < t->depth - 1; l++) | |
152 | n = get_child(n, CHILDREN_PER_NODE - 1); | |
153 | ||
154 | if (n >= t->counts[l]) | |
155 | return (sector_t) - 1; | |
156 | ||
157 | return get_node(t, l, n)[KEYS_PER_NODE - 1]; | |
158 | } | |
159 | ||
160 | /* | |
161 | * Fills in a level of the btree based on the highs of the level | |
162 | * below it. | |
163 | */ | |
164 | static int setup_btree_index(unsigned int l, struct dm_table *t) | |
165 | { | |
166 | unsigned int n, k; | |
167 | sector_t *node; | |
168 | ||
169 | for (n = 0U; n < t->counts[l]; n++) { | |
170 | node = get_node(t, l, n); | |
171 | ||
172 | for (k = 0U; k < KEYS_PER_NODE; k++) | |
173 | node[k] = high(t, l + 1, get_child(n, k)); | |
174 | } | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) | |
180 | { | |
181 | unsigned long size; | |
182 | void *addr; | |
183 | ||
184 | /* | |
185 | * Check that we're not going to overflow. | |
186 | */ | |
187 | if (nmemb > (ULONG_MAX / elem_size)) | |
188 | return NULL; | |
189 | ||
190 | size = nmemb * elem_size; | |
191 | addr = vmalloc(size); | |
192 | if (addr) | |
193 | memset(addr, 0, size); | |
194 | ||
195 | return addr; | |
196 | } | |
197 | ||
198 | /* | |
199 | * highs, and targets are managed as dynamic arrays during a | |
200 | * table load. | |
201 | */ | |
202 | static int alloc_targets(struct dm_table *t, unsigned int num) | |
203 | { | |
204 | sector_t *n_highs; | |
205 | struct dm_target *n_targets; | |
206 | int n = t->num_targets; | |
207 | ||
208 | /* | |
209 | * Allocate both the target array and offset array at once. | |
512875bd JN |
210 | * Append an empty entry to catch sectors beyond the end of |
211 | * the device. | |
1da177e4 | 212 | */ |
512875bd | 213 | n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) + |
1da177e4 LT |
214 | sizeof(sector_t)); |
215 | if (!n_highs) | |
216 | return -ENOMEM; | |
217 | ||
218 | n_targets = (struct dm_target *) (n_highs + num); | |
219 | ||
220 | if (n) { | |
221 | memcpy(n_highs, t->highs, sizeof(*n_highs) * n); | |
222 | memcpy(n_targets, t->targets, sizeof(*n_targets) * n); | |
223 | } | |
224 | ||
225 | memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); | |
226 | vfree(t->highs); | |
227 | ||
228 | t->num_allocated = num; | |
229 | t->highs = n_highs; | |
230 | t->targets = n_targets; | |
231 | ||
232 | return 0; | |
233 | } | |
234 | ||
aeb5d727 | 235 | int dm_table_create(struct dm_table **result, fmode_t mode, |
1134e5ae | 236 | unsigned num_targets, struct mapped_device *md) |
1da177e4 | 237 | { |
094262db | 238 | struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL); |
1da177e4 LT |
239 | |
240 | if (!t) | |
241 | return -ENOMEM; | |
242 | ||
1da177e4 | 243 | INIT_LIST_HEAD(&t->devices); |
d5816876 | 244 | atomic_set(&t->holders, 0); |
1da177e4 LT |
245 | |
246 | if (!num_targets) | |
247 | num_targets = KEYS_PER_NODE; | |
248 | ||
249 | num_targets = dm_round_up(num_targets, KEYS_PER_NODE); | |
250 | ||
251 | if (alloc_targets(t, num_targets)) { | |
252 | kfree(t); | |
253 | t = NULL; | |
254 | return -ENOMEM; | |
255 | } | |
256 | ||
257 | t->mode = mode; | |
1134e5ae | 258 | t->md = md; |
1da177e4 LT |
259 | *result = t; |
260 | return 0; | |
261 | } | |
262 | ||
263 | static void free_devices(struct list_head *devices) | |
264 | { | |
265 | struct list_head *tmp, *next; | |
266 | ||
afb24528 | 267 | list_for_each_safe(tmp, next, devices) { |
82b1519b MP |
268 | struct dm_dev_internal *dd = |
269 | list_entry(tmp, struct dm_dev_internal, list); | |
1da177e4 LT |
270 | kfree(dd); |
271 | } | |
272 | } | |
273 | ||
d5816876 | 274 | void dm_table_destroy(struct dm_table *t) |
1da177e4 LT |
275 | { |
276 | unsigned int i; | |
277 | ||
d5816876 MP |
278 | while (atomic_read(&t->holders)) |
279 | msleep(1); | |
280 | smp_mb(); | |
281 | ||
1da177e4 LT |
282 | /* free the indexes (see dm_table_complete) */ |
283 | if (t->depth >= 2) | |
284 | vfree(t->index[t->depth - 2]); | |
285 | ||
286 | /* free the targets */ | |
287 | for (i = 0; i < t->num_targets; i++) { | |
288 | struct dm_target *tgt = t->targets + i; | |
289 | ||
290 | if (tgt->type->dtr) | |
291 | tgt->type->dtr(tgt); | |
292 | ||
293 | dm_put_target_type(tgt->type); | |
294 | } | |
295 | ||
296 | vfree(t->highs); | |
297 | ||
298 | /* free the device list */ | |
299 | if (t->devices.next != &t->devices) { | |
300 | DMWARN("devices still present during destroy: " | |
301 | "dm_table_remove_device calls missing"); | |
302 | ||
303 | free_devices(&t->devices); | |
304 | } | |
305 | ||
306 | kfree(t); | |
307 | } | |
308 | ||
309 | void dm_table_get(struct dm_table *t) | |
310 | { | |
311 | atomic_inc(&t->holders); | |
312 | } | |
313 | ||
314 | void dm_table_put(struct dm_table *t) | |
315 | { | |
316 | if (!t) | |
317 | return; | |
318 | ||
d5816876 MP |
319 | smp_mb__before_atomic_dec(); |
320 | atomic_dec(&t->holders); | |
1da177e4 LT |
321 | } |
322 | ||
323 | /* | |
324 | * Checks to see if we need to extend highs or targets. | |
325 | */ | |
326 | static inline int check_space(struct dm_table *t) | |
327 | { | |
328 | if (t->num_targets >= t->num_allocated) | |
329 | return alloc_targets(t, t->num_allocated * 2); | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
1da177e4 LT |
334 | /* |
335 | * See if we've already got a device in the list. | |
336 | */ | |
82b1519b | 337 | static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev) |
1da177e4 | 338 | { |
82b1519b | 339 | struct dm_dev_internal *dd; |
1da177e4 LT |
340 | |
341 | list_for_each_entry (dd, l, list) | |
82b1519b | 342 | if (dd->dm_dev.bdev->bd_dev == dev) |
1da177e4 LT |
343 | return dd; |
344 | ||
345 | return NULL; | |
346 | } | |
347 | ||
348 | /* | |
349 | * Open a device so we can use it as a map destination. | |
350 | */ | |
82b1519b MP |
351 | static int open_dev(struct dm_dev_internal *d, dev_t dev, |
352 | struct mapped_device *md) | |
1da177e4 LT |
353 | { |
354 | static char *_claim_ptr = "I belong to device-mapper"; | |
355 | struct block_device *bdev; | |
356 | ||
357 | int r; | |
358 | ||
82b1519b | 359 | BUG_ON(d->dm_dev.bdev); |
1da177e4 | 360 | |
82b1519b | 361 | bdev = open_by_devnum(dev, d->dm_dev.mode); |
1da177e4 LT |
362 | if (IS_ERR(bdev)) |
363 | return PTR_ERR(bdev); | |
f165921d | 364 | r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
1da177e4 | 365 | if (r) |
9a1c3542 | 366 | blkdev_put(bdev, d->dm_dev.mode); |
1da177e4 | 367 | else |
82b1519b | 368 | d->dm_dev.bdev = bdev; |
1da177e4 LT |
369 | return r; |
370 | } | |
371 | ||
372 | /* | |
373 | * Close a device that we've been using. | |
374 | */ | |
82b1519b | 375 | static void close_dev(struct dm_dev_internal *d, struct mapped_device *md) |
1da177e4 | 376 | { |
82b1519b | 377 | if (!d->dm_dev.bdev) |
1da177e4 LT |
378 | return; |
379 | ||
82b1519b | 380 | bd_release_from_disk(d->dm_dev.bdev, dm_disk(md)); |
9a1c3542 | 381 | blkdev_put(d->dm_dev.bdev, d->dm_dev.mode); |
82b1519b | 382 | d->dm_dev.bdev = NULL; |
1da177e4 LT |
383 | } |
384 | ||
385 | /* | |
2cd54d9b | 386 | * If possible, this checks an area of a destination device is valid. |
1da177e4 | 387 | */ |
82b1519b MP |
388 | static int check_device_area(struct dm_dev_internal *dd, sector_t start, |
389 | sector_t len) | |
1da177e4 | 390 | { |
5657e8fa MP |
391 | sector_t dev_size = i_size_read(dd->dm_dev.bdev->bd_inode) >> |
392 | SECTOR_SHIFT; | |
2cd54d9b MA |
393 | |
394 | if (!dev_size) | |
395 | return 1; | |
396 | ||
1da177e4 LT |
397 | return ((start < dev_size) && (len <= (dev_size - start))); |
398 | } | |
399 | ||
400 | /* | |
570b9d96 | 401 | * This upgrades the mode on an already open dm_dev, being |
1da177e4 | 402 | * careful to leave things as they were if we fail to reopen the |
570b9d96 AK |
403 | * device and not to touch the existing bdev field in case |
404 | * it is accessed concurrently inside dm_table_any_congested(). | |
1da177e4 | 405 | */ |
aeb5d727 | 406 | static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, |
82b1519b | 407 | struct mapped_device *md) |
1da177e4 LT |
408 | { |
409 | int r; | |
570b9d96 | 410 | struct dm_dev_internal dd_new, dd_old; |
1da177e4 | 411 | |
570b9d96 AK |
412 | dd_new = dd_old = *dd; |
413 | ||
414 | dd_new.dm_dev.mode |= new_mode; | |
415 | dd_new.dm_dev.bdev = NULL; | |
416 | ||
417 | r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md); | |
418 | if (r) | |
419 | return r; | |
1da177e4 | 420 | |
82b1519b | 421 | dd->dm_dev.mode |= new_mode; |
570b9d96 | 422 | close_dev(&dd_old, md); |
1da177e4 | 423 | |
570b9d96 | 424 | return 0; |
1da177e4 LT |
425 | } |
426 | ||
427 | /* | |
428 | * Add a device to the list, or just increment the usage count if | |
429 | * it's already present. | |
430 | */ | |
431 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
432 | const char *path, sector_t start, sector_t len, | |
aeb5d727 | 433 | fmode_t mode, struct dm_dev **result) |
1da177e4 LT |
434 | { |
435 | int r; | |
69a2ce72 | 436 | dev_t uninitialized_var(dev); |
82b1519b | 437 | struct dm_dev_internal *dd; |
1da177e4 LT |
438 | unsigned int major, minor; |
439 | ||
547bc926 | 440 | BUG_ON(!t); |
1da177e4 LT |
441 | |
442 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
443 | /* Extract the major/minor numbers */ | |
444 | dev = MKDEV(major, minor); | |
445 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
446 | return -EOVERFLOW; | |
447 | } else { | |
448 | /* convert the path to a device */ | |
72e8264e CH |
449 | struct block_device *bdev = lookup_bdev(path); |
450 | ||
451 | if (IS_ERR(bdev)) | |
452 | return PTR_ERR(bdev); | |
453 | dev = bdev->bd_dev; | |
454 | bdput(bdev); | |
1da177e4 LT |
455 | } |
456 | ||
457 | dd = find_device(&t->devices, dev); | |
458 | if (!dd) { | |
459 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
460 | if (!dd) | |
461 | return -ENOMEM; | |
462 | ||
82b1519b MP |
463 | dd->dm_dev.mode = mode; |
464 | dd->dm_dev.bdev = NULL; | |
1da177e4 | 465 | |
f165921d | 466 | if ((r = open_dev(dd, dev, t->md))) { |
1da177e4 LT |
467 | kfree(dd); |
468 | return r; | |
469 | } | |
470 | ||
82b1519b | 471 | format_dev_t(dd->dm_dev.name, dev); |
1da177e4 LT |
472 | |
473 | atomic_set(&dd->count, 0); | |
474 | list_add(&dd->list, &t->devices); | |
475 | ||
82b1519b | 476 | } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) { |
f165921d | 477 | r = upgrade_mode(dd, mode, t->md); |
1da177e4 LT |
478 | if (r) |
479 | return r; | |
480 | } | |
481 | atomic_inc(&dd->count); | |
482 | ||
483 | if (!check_device_area(dd, start, len)) { | |
484 | DMWARN("device %s too small for target", path); | |
82b1519b | 485 | dm_put_device(ti, &dd->dm_dev); |
1da177e4 LT |
486 | return -EINVAL; |
487 | } | |
488 | ||
82b1519b | 489 | *result = &dd->dm_dev; |
1da177e4 LT |
490 | |
491 | return 0; | |
492 | } | |
493 | ||
3cb40214 | 494 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) |
1da177e4 | 495 | { |
165125e1 | 496 | struct request_queue *q = bdev_get_queue(bdev); |
3cb40214 | 497 | struct io_restrictions *rs = &ti->limits; |
0c2322e4 AK |
498 | char b[BDEVNAME_SIZE]; |
499 | ||
500 | if (unlikely(!q)) { | |
501 | DMWARN("%s: Cannot set limits for nonexistent device %s", | |
502 | dm_device_name(ti->table->md), bdevname(bdev, b)); | |
503 | return; | |
504 | } | |
3cb40214 BR |
505 | |
506 | /* | |
507 | * Combine the device limits low. | |
508 | * | |
509 | * FIXME: if we move an io_restriction struct | |
510 | * into q this would just be a call to | |
511 | * combine_restrictions_low() | |
512 | */ | |
513 | rs->max_sectors = | |
ae03bf63 | 514 | min_not_zero(rs->max_sectors, queue_max_sectors(q)); |
3cb40214 | 515 | |
9980c638 MB |
516 | /* |
517 | * Check if merge fn is supported. | |
518 | * If not we'll force DM to use PAGE_SIZE or | |
519 | * smaller I/O, just to be safe. | |
3cb40214 | 520 | */ |
9980c638 MB |
521 | |
522 | if (q->merge_bvec_fn && !ti->type->merge) | |
1da177e4 | 523 | rs->max_sectors = |
3cb40214 BR |
524 | min_not_zero(rs->max_sectors, |
525 | (unsigned int) (PAGE_SIZE >> 9)); | |
1da177e4 | 526 | |
3cb40214 BR |
527 | rs->max_phys_segments = |
528 | min_not_zero(rs->max_phys_segments, | |
ae03bf63 | 529 | queue_max_phys_segments(q)); |
1da177e4 | 530 | |
3cb40214 | 531 | rs->max_hw_segments = |
ae03bf63 | 532 | min_not_zero(rs->max_hw_segments, queue_max_hw_segments(q)); |
1da177e4 | 533 | |
e1defc4f MP |
534 | rs->logical_block_size = max(rs->logical_block_size, |
535 | queue_logical_block_size(q)); | |
1da177e4 | 536 | |
3cb40214 | 537 | rs->max_segment_size = |
ae03bf63 | 538 | min_not_zero(rs->max_segment_size, queue_max_segment_size(q)); |
1da177e4 | 539 | |
91212507 | 540 | rs->max_hw_sectors = |
ae03bf63 | 541 | min_not_zero(rs->max_hw_sectors, queue_max_hw_sectors(q)); |
91212507 | 542 | |
3cb40214 BR |
543 | rs->seg_boundary_mask = |
544 | min_not_zero(rs->seg_boundary_mask, | |
ae03bf63 | 545 | queue_segment_boundary(q)); |
1da177e4 | 546 | |
ae03bf63 | 547 | rs->bounce_pfn = min_not_zero(rs->bounce_pfn, queue_bounce_pfn(q)); |
5ec140e6 | 548 | |
3cb40214 BR |
549 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
550 | } | |
551 | EXPORT_SYMBOL_GPL(dm_set_device_limits); | |
969429b5 | 552 | |
3cb40214 | 553 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, |
aeb5d727 | 554 | sector_t len, fmode_t mode, struct dm_dev **result) |
3cb40214 BR |
555 | { |
556 | int r = __table_get_device(ti->table, ti, path, | |
557 | start, len, mode, result); | |
558 | ||
559 | if (!r) | |
560 | dm_set_device_limits(ti, (*result)->bdev); | |
1da177e4 LT |
561 | |
562 | return r; | |
563 | } | |
564 | ||
565 | /* | |
566 | * Decrement a devices use count and remove it if necessary. | |
567 | */ | |
82b1519b | 568 | void dm_put_device(struct dm_target *ti, struct dm_dev *d) |
1da177e4 | 569 | { |
82b1519b MP |
570 | struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal, |
571 | dm_dev); | |
572 | ||
1da177e4 | 573 | if (atomic_dec_and_test(&dd->count)) { |
f165921d | 574 | close_dev(dd, ti->table->md); |
1da177e4 LT |
575 | list_del(&dd->list); |
576 | kfree(dd); | |
577 | } | |
578 | } | |
579 | ||
580 | /* | |
581 | * Checks to see if the target joins onto the end of the table. | |
582 | */ | |
583 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
584 | { | |
585 | struct dm_target *prev; | |
586 | ||
587 | if (!table->num_targets) | |
588 | return !ti->begin; | |
589 | ||
590 | prev = &table->targets[table->num_targets - 1]; | |
591 | return (ti->begin == (prev->begin + prev->len)); | |
592 | } | |
593 | ||
594 | /* | |
595 | * Used to dynamically allocate the arg array. | |
596 | */ | |
597 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
598 | { | |
599 | char **argv; | |
600 | unsigned new_size; | |
601 | ||
602 | new_size = *array_size ? *array_size * 2 : 64; | |
603 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
604 | if (argv) { | |
605 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
606 | *array_size = new_size; | |
607 | } | |
608 | ||
609 | kfree(old_argv); | |
610 | return argv; | |
611 | } | |
612 | ||
613 | /* | |
614 | * Destructively splits up the argument list to pass to ctr. | |
615 | */ | |
616 | int dm_split_args(int *argc, char ***argvp, char *input) | |
617 | { | |
618 | char *start, *end = input, *out, **argv = NULL; | |
619 | unsigned array_size = 0; | |
620 | ||
621 | *argc = 0; | |
814d6862 DT |
622 | |
623 | if (!input) { | |
624 | *argvp = NULL; | |
625 | return 0; | |
626 | } | |
627 | ||
1da177e4 LT |
628 | argv = realloc_argv(&array_size, argv); |
629 | if (!argv) | |
630 | return -ENOMEM; | |
631 | ||
632 | while (1) { | |
633 | start = end; | |
634 | ||
635 | /* Skip whitespace */ | |
636 | while (*start && isspace(*start)) | |
637 | start++; | |
638 | ||
639 | if (!*start) | |
640 | break; /* success, we hit the end */ | |
641 | ||
642 | /* 'out' is used to remove any back-quotes */ | |
643 | end = out = start; | |
644 | while (*end) { | |
645 | /* Everything apart from '\0' can be quoted */ | |
646 | if (*end == '\\' && *(end + 1)) { | |
647 | *out++ = *(end + 1); | |
648 | end += 2; | |
649 | continue; | |
650 | } | |
651 | ||
652 | if (isspace(*end)) | |
653 | break; /* end of token */ | |
654 | ||
655 | *out++ = *end++; | |
656 | } | |
657 | ||
658 | /* have we already filled the array ? */ | |
659 | if ((*argc + 1) > array_size) { | |
660 | argv = realloc_argv(&array_size, argv); | |
661 | if (!argv) | |
662 | return -ENOMEM; | |
663 | } | |
664 | ||
665 | /* we know this is whitespace */ | |
666 | if (*end) | |
667 | end++; | |
668 | ||
669 | /* terminate the string and put it in the array */ | |
670 | *out = '\0'; | |
671 | argv[*argc] = start; | |
672 | (*argc)++; | |
673 | } | |
674 | ||
675 | *argvp = argv; | |
676 | return 0; | |
677 | } | |
678 | ||
679 | static void check_for_valid_limits(struct io_restrictions *rs) | |
680 | { | |
681 | if (!rs->max_sectors) | |
defd94b7 | 682 | rs->max_sectors = SAFE_MAX_SECTORS; |
91212507 NB |
683 | if (!rs->max_hw_sectors) |
684 | rs->max_hw_sectors = SAFE_MAX_SECTORS; | |
1da177e4 LT |
685 | if (!rs->max_phys_segments) |
686 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
687 | if (!rs->max_hw_segments) | |
688 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
e1defc4f MP |
689 | if (!rs->logical_block_size) |
690 | rs->logical_block_size = 1 << SECTOR_SHIFT; | |
1da177e4 LT |
691 | if (!rs->max_segment_size) |
692 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
693 | if (!rs->seg_boundary_mask) | |
0e435ac2 | 694 | rs->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; |
5ec140e6 VA |
695 | if (!rs->bounce_pfn) |
696 | rs->bounce_pfn = -1; | |
1da177e4 LT |
697 | } |
698 | ||
699 | int dm_table_add_target(struct dm_table *t, const char *type, | |
700 | sector_t start, sector_t len, char *params) | |
701 | { | |
702 | int r = -EINVAL, argc; | |
703 | char **argv; | |
704 | struct dm_target *tgt; | |
705 | ||
706 | if ((r = check_space(t))) | |
707 | return r; | |
708 | ||
709 | tgt = t->targets + t->num_targets; | |
710 | memset(tgt, 0, sizeof(*tgt)); | |
711 | ||
712 | if (!len) { | |
72d94861 | 713 | DMERR("%s: zero-length target", dm_device_name(t->md)); |
1da177e4 LT |
714 | return -EINVAL; |
715 | } | |
716 | ||
717 | tgt->type = dm_get_target_type(type); | |
718 | if (!tgt->type) { | |
72d94861 AK |
719 | DMERR("%s: %s: unknown target type", dm_device_name(t->md), |
720 | type); | |
1da177e4 LT |
721 | return -EINVAL; |
722 | } | |
723 | ||
724 | tgt->table = t; | |
725 | tgt->begin = start; | |
726 | tgt->len = len; | |
727 | tgt->error = "Unknown error"; | |
728 | ||
729 | /* | |
730 | * Does this target adjoin the previous one ? | |
731 | */ | |
732 | if (!adjoin(t, tgt)) { | |
733 | tgt->error = "Gap in table"; | |
734 | r = -EINVAL; | |
735 | goto bad; | |
736 | } | |
737 | ||
738 | r = dm_split_args(&argc, &argv, params); | |
739 | if (r) { | |
740 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
741 | goto bad; | |
742 | } | |
743 | ||
744 | r = tgt->type->ctr(tgt, argc, argv); | |
745 | kfree(argv); | |
746 | if (r) | |
747 | goto bad; | |
748 | ||
749 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
750 | ||
751 | /* FIXME: the plan is to combine high here and then have | |
752 | * the merge fn apply the target level restrictions. */ | |
753 | combine_restrictions_low(&t->limits, &tgt->limits); | |
754 | return 0; | |
755 | ||
756 | bad: | |
72d94861 | 757 | DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); |
1da177e4 LT |
758 | dm_put_target_type(tgt->type); |
759 | return r; | |
760 | } | |
761 | ||
762 | static int setup_indexes(struct dm_table *t) | |
763 | { | |
764 | int i; | |
765 | unsigned int total = 0; | |
766 | sector_t *indexes; | |
767 | ||
768 | /* allocate the space for *all* the indexes */ | |
769 | for (i = t->depth - 2; i >= 0; i--) { | |
770 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
771 | total += t->counts[i]; | |
772 | } | |
773 | ||
774 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
775 | if (!indexes) | |
776 | return -ENOMEM; | |
777 | ||
778 | /* set up internal nodes, bottom-up */ | |
82d601dc | 779 | for (i = t->depth - 2; i >= 0; i--) { |
1da177e4 LT |
780 | t->index[i] = indexes; |
781 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
782 | setup_btree_index(i, t); | |
783 | } | |
784 | ||
785 | return 0; | |
786 | } | |
787 | ||
788 | /* | |
789 | * Builds the btree to index the map. | |
790 | */ | |
791 | int dm_table_complete(struct dm_table *t) | |
792 | { | |
793 | int r = 0; | |
794 | unsigned int leaf_nodes; | |
795 | ||
796 | check_for_valid_limits(&t->limits); | |
797 | ||
798 | /* how many indexes will the btree have ? */ | |
799 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
800 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
801 | ||
802 | /* leaf layer has already been set up */ | |
803 | t->counts[t->depth - 1] = leaf_nodes; | |
804 | t->index[t->depth - 1] = t->highs; | |
805 | ||
806 | if (t->depth >= 2) | |
807 | r = setup_indexes(t); | |
808 | ||
809 | return r; | |
810 | } | |
811 | ||
48c9c27b | 812 | static DEFINE_MUTEX(_event_lock); |
1da177e4 LT |
813 | void dm_table_event_callback(struct dm_table *t, |
814 | void (*fn)(void *), void *context) | |
815 | { | |
48c9c27b | 816 | mutex_lock(&_event_lock); |
1da177e4 LT |
817 | t->event_fn = fn; |
818 | t->event_context = context; | |
48c9c27b | 819 | mutex_unlock(&_event_lock); |
1da177e4 LT |
820 | } |
821 | ||
822 | void dm_table_event(struct dm_table *t) | |
823 | { | |
824 | /* | |
825 | * You can no longer call dm_table_event() from interrupt | |
826 | * context, use a bottom half instead. | |
827 | */ | |
828 | BUG_ON(in_interrupt()); | |
829 | ||
48c9c27b | 830 | mutex_lock(&_event_lock); |
1da177e4 LT |
831 | if (t->event_fn) |
832 | t->event_fn(t->event_context); | |
48c9c27b | 833 | mutex_unlock(&_event_lock); |
1da177e4 LT |
834 | } |
835 | ||
836 | sector_t dm_table_get_size(struct dm_table *t) | |
837 | { | |
838 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
839 | } | |
840 | ||
841 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
842 | { | |
14353539 | 843 | if (index >= t->num_targets) |
1da177e4 LT |
844 | return NULL; |
845 | ||
846 | return t->targets + index; | |
847 | } | |
848 | ||
849 | /* | |
850 | * Search the btree for the correct target. | |
512875bd JN |
851 | * |
852 | * Caller should check returned pointer with dm_target_is_valid() | |
853 | * to trap I/O beyond end of device. | |
1da177e4 LT |
854 | */ |
855 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
856 | { | |
857 | unsigned int l, n = 0, k = 0; | |
858 | sector_t *node; | |
859 | ||
860 | for (l = 0; l < t->depth; l++) { | |
861 | n = get_child(n, k); | |
862 | node = get_node(t, l, n); | |
863 | ||
864 | for (k = 0; k < KEYS_PER_NODE; k++) | |
865 | if (node[k] >= sector) | |
866 | break; | |
867 | } | |
868 | ||
869 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
870 | } | |
871 | ||
9c47008d MP |
872 | /* |
873 | * Set the integrity profile for this device if all devices used have | |
874 | * matching profiles. | |
875 | */ | |
876 | static void dm_table_set_integrity(struct dm_table *t) | |
877 | { | |
878 | struct list_head *devices = dm_table_get_devices(t); | |
879 | struct dm_dev_internal *prev = NULL, *dd = NULL; | |
880 | ||
881 | if (!blk_get_integrity(dm_disk(t->md))) | |
882 | return; | |
883 | ||
884 | list_for_each_entry(dd, devices, list) { | |
885 | if (prev && | |
886 | blk_integrity_compare(prev->dm_dev.bdev->bd_disk, | |
887 | dd->dm_dev.bdev->bd_disk) < 0) { | |
888 | DMWARN("%s: integrity not set: %s and %s mismatch", | |
889 | dm_device_name(t->md), | |
890 | prev->dm_dev.bdev->bd_disk->disk_name, | |
891 | dd->dm_dev.bdev->bd_disk->disk_name); | |
892 | goto no_integrity; | |
893 | } | |
894 | prev = dd; | |
895 | } | |
896 | ||
897 | if (!prev || !bdev_get_integrity(prev->dm_dev.bdev)) | |
898 | goto no_integrity; | |
899 | ||
900 | blk_integrity_register(dm_disk(t->md), | |
901 | bdev_get_integrity(prev->dm_dev.bdev)); | |
902 | ||
903 | return; | |
904 | ||
905 | no_integrity: | |
906 | blk_integrity_register(dm_disk(t->md), NULL); | |
907 | ||
908 | return; | |
909 | } | |
910 | ||
1da177e4 LT |
911 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) |
912 | { | |
913 | /* | |
914 | * Make sure we obey the optimistic sub devices | |
915 | * restrictions. | |
916 | */ | |
917 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
ae03bf63 MP |
918 | blk_queue_max_phys_segments(q, t->limits.max_phys_segments); |
919 | blk_queue_max_hw_segments(q, t->limits.max_hw_segments); | |
920 | blk_queue_logical_block_size(q, t->limits.logical_block_size); | |
921 | blk_queue_max_segment_size(q, t->limits.max_segment_size); | |
922 | blk_queue_max_hw_sectors(q, t->limits.max_hw_sectors); | |
923 | blk_queue_segment_boundary(q, t->limits.seg_boundary_mask); | |
9df1bb9b | 924 | blk_queue_bounce_limit(q, t->limits.bounce_pfn); |
c9a3f6d6 | 925 | |
969429b5 | 926 | if (t->limits.no_cluster) |
c9a3f6d6 | 927 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 928 | else |
c9a3f6d6 | 929 | queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 930 | |
9c47008d | 931 | dm_table_set_integrity(t); |
1da177e4 LT |
932 | } |
933 | ||
934 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
935 | { | |
936 | return t->num_targets; | |
937 | } | |
938 | ||
939 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
940 | { | |
941 | return &t->devices; | |
942 | } | |
943 | ||
aeb5d727 | 944 | fmode_t dm_table_get_mode(struct dm_table *t) |
1da177e4 LT |
945 | { |
946 | return t->mode; | |
947 | } | |
948 | ||
949 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
950 | { | |
951 | int i = t->num_targets; | |
952 | struct dm_target *ti = t->targets; | |
953 | ||
954 | while (i--) { | |
955 | if (postsuspend) { | |
956 | if (ti->type->postsuspend) | |
957 | ti->type->postsuspend(ti); | |
958 | } else if (ti->type->presuspend) | |
959 | ti->type->presuspend(ti); | |
960 | ||
961 | ti++; | |
962 | } | |
963 | } | |
964 | ||
965 | void dm_table_presuspend_targets(struct dm_table *t) | |
966 | { | |
cf222b37 AK |
967 | if (!t) |
968 | return; | |
969 | ||
e8488d08 | 970 | suspend_targets(t, 0); |
1da177e4 LT |
971 | } |
972 | ||
973 | void dm_table_postsuspend_targets(struct dm_table *t) | |
974 | { | |
cf222b37 AK |
975 | if (!t) |
976 | return; | |
977 | ||
e8488d08 | 978 | suspend_targets(t, 1); |
1da177e4 LT |
979 | } |
980 | ||
8757b776 | 981 | int dm_table_resume_targets(struct dm_table *t) |
1da177e4 | 982 | { |
8757b776 MB |
983 | int i, r = 0; |
984 | ||
985 | for (i = 0; i < t->num_targets; i++) { | |
986 | struct dm_target *ti = t->targets + i; | |
987 | ||
988 | if (!ti->type->preresume) | |
989 | continue; | |
990 | ||
991 | r = ti->type->preresume(ti); | |
992 | if (r) | |
993 | return r; | |
994 | } | |
1da177e4 LT |
995 | |
996 | for (i = 0; i < t->num_targets; i++) { | |
997 | struct dm_target *ti = t->targets + i; | |
998 | ||
999 | if (ti->type->resume) | |
1000 | ti->type->resume(ti); | |
1001 | } | |
8757b776 MB |
1002 | |
1003 | return 0; | |
1da177e4 LT |
1004 | } |
1005 | ||
1006 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
1007 | { | |
82b1519b | 1008 | struct dm_dev_internal *dd; |
afb24528 | 1009 | struct list_head *devices = dm_table_get_devices(t); |
1da177e4 LT |
1010 | int r = 0; |
1011 | ||
afb24528 | 1012 | list_for_each_entry(dd, devices, list) { |
82b1519b | 1013 | struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); |
0c2322e4 AK |
1014 | char b[BDEVNAME_SIZE]; |
1015 | ||
1016 | if (likely(q)) | |
1017 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); | |
1018 | else | |
1019 | DMWARN_LIMIT("%s: any_congested: nonexistent device %s", | |
1020 | dm_device_name(t->md), | |
1021 | bdevname(dd->dm_dev.bdev, b)); | |
1da177e4 LT |
1022 | } |
1023 | ||
1024 | return r; | |
1025 | } | |
1026 | ||
1027 | void dm_table_unplug_all(struct dm_table *t) | |
1028 | { | |
82b1519b | 1029 | struct dm_dev_internal *dd; |
afb24528 | 1030 | struct list_head *devices = dm_table_get_devices(t); |
1da177e4 | 1031 | |
afb24528 | 1032 | list_for_each_entry(dd, devices, list) { |
82b1519b | 1033 | struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); |
0c2322e4 AK |
1034 | char b[BDEVNAME_SIZE]; |
1035 | ||
1036 | if (likely(q)) | |
1037 | blk_unplug(q); | |
1038 | else | |
1039 | DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s", | |
1040 | dm_device_name(t->md), | |
1041 | bdevname(dd->dm_dev.bdev, b)); | |
1da177e4 LT |
1042 | } |
1043 | } | |
1044 | ||
1134e5ae MA |
1045 | struct mapped_device *dm_table_get_md(struct dm_table *t) |
1046 | { | |
1047 | dm_get(t->md); | |
1048 | ||
1049 | return t->md; | |
1050 | } | |
1051 | ||
1da177e4 LT |
1052 | EXPORT_SYMBOL(dm_vcalloc); |
1053 | EXPORT_SYMBOL(dm_get_device); | |
1054 | EXPORT_SYMBOL(dm_put_device); | |
1055 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 1056 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 | 1057 | EXPORT_SYMBOL(dm_table_get_mode); |
1134e5ae | 1058 | EXPORT_SYMBOL(dm_table_get_md); |
1da177e4 LT |
1059 | EXPORT_SYMBOL(dm_table_put); |
1060 | EXPORT_SYMBOL(dm_table_get); | |
1061 | EXPORT_SYMBOL(dm_table_unplug_all); |