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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Sistina Software (UK) Limited. | |
3 | * Copyright (C) 2004 Red Hat, Inc. All rights reserved. | |
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> |
1da177e4 LT |
18 | #include <asm/atomic.h> |
19 | ||
72d94861 AK |
20 | #define DM_MSG_PREFIX "table" |
21 | ||
1da177e4 LT |
22 | #define MAX_DEPTH 16 |
23 | #define NODE_SIZE L1_CACHE_BYTES | |
24 | #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) | |
25 | #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) | |
26 | ||
27 | struct dm_table { | |
1134e5ae | 28 | struct mapped_device *md; |
1da177e4 LT |
29 | atomic_t holders; |
30 | ||
31 | /* btree table */ | |
32 | unsigned int depth; | |
33 | unsigned int counts[MAX_DEPTH]; /* in nodes */ | |
34 | sector_t *index[MAX_DEPTH]; | |
35 | ||
36 | unsigned int num_targets; | |
37 | unsigned int num_allocated; | |
38 | sector_t *highs; | |
39 | struct dm_target *targets; | |
40 | ||
41 | /* | |
42 | * Indicates the rw permissions for the new logical | |
43 | * device. This should be a combination of FMODE_READ | |
44 | * and FMODE_WRITE. | |
45 | */ | |
46 | int mode; | |
47 | ||
48 | /* a list of devices used by this table */ | |
49 | struct list_head devices; | |
50 | ||
51 | /* | |
52 | * These are optimistic limits taken from all the | |
53 | * targets, some targets will need smaller limits. | |
54 | */ | |
55 | struct io_restrictions limits; | |
56 | ||
57 | /* events get handed up using this callback */ | |
58 | void (*event_fn)(void *); | |
59 | void *event_context; | |
60 | }; | |
61 | ||
62 | /* | |
63 | * Similar to ceiling(log_size(n)) | |
64 | */ | |
65 | static unsigned int int_log(unsigned int n, unsigned int base) | |
66 | { | |
67 | int result = 0; | |
68 | ||
69 | while (n > 1) { | |
70 | n = dm_div_up(n, base); | |
71 | result++; | |
72 | } | |
73 | ||
74 | return result; | |
75 | } | |
76 | ||
77 | /* | |
78 | * Returns the minimum that is _not_ zero, unless both are zero. | |
79 | */ | |
80 | #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) | |
81 | ||
82 | /* | |
83 | * Combine two io_restrictions, always taking the lower value. | |
84 | */ | |
85 | static void combine_restrictions_low(struct io_restrictions *lhs, | |
86 | struct io_restrictions *rhs) | |
87 | { | |
88 | lhs->max_sectors = | |
89 | min_not_zero(lhs->max_sectors, rhs->max_sectors); | |
90 | ||
91 | lhs->max_phys_segments = | |
92 | min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments); | |
93 | ||
94 | lhs->max_hw_segments = | |
95 | min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments); | |
96 | ||
97 | lhs->hardsect_size = max(lhs->hardsect_size, rhs->hardsect_size); | |
98 | ||
99 | lhs->max_segment_size = | |
100 | min_not_zero(lhs->max_segment_size, rhs->max_segment_size); | |
101 | ||
91212507 NB |
102 | lhs->max_hw_sectors = |
103 | min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors); | |
104 | ||
1da177e4 LT |
105 | lhs->seg_boundary_mask = |
106 | min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); | |
969429b5 | 107 | |
5ec140e6 VA |
108 | lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn); |
109 | ||
969429b5 | 110 | lhs->no_cluster |= rhs->no_cluster; |
1da177e4 LT |
111 | } |
112 | ||
113 | /* | |
114 | * Calculate the index of the child node of the n'th node k'th key. | |
115 | */ | |
116 | static inline unsigned int get_child(unsigned int n, unsigned int k) | |
117 | { | |
118 | return (n * CHILDREN_PER_NODE) + k; | |
119 | } | |
120 | ||
121 | /* | |
122 | * Return the n'th node of level l from table t. | |
123 | */ | |
124 | static inline sector_t *get_node(struct dm_table *t, | |
125 | unsigned int l, unsigned int n) | |
126 | { | |
127 | return t->index[l] + (n * KEYS_PER_NODE); | |
128 | } | |
129 | ||
130 | /* | |
131 | * Return the highest key that you could lookup from the n'th | |
132 | * node on level l of the btree. | |
133 | */ | |
134 | static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) | |
135 | { | |
136 | for (; l < t->depth - 1; l++) | |
137 | n = get_child(n, CHILDREN_PER_NODE - 1); | |
138 | ||
139 | if (n >= t->counts[l]) | |
140 | return (sector_t) - 1; | |
141 | ||
142 | return get_node(t, l, n)[KEYS_PER_NODE - 1]; | |
143 | } | |
144 | ||
145 | /* | |
146 | * Fills in a level of the btree based on the highs of the level | |
147 | * below it. | |
148 | */ | |
149 | static int setup_btree_index(unsigned int l, struct dm_table *t) | |
150 | { | |
151 | unsigned int n, k; | |
152 | sector_t *node; | |
153 | ||
154 | for (n = 0U; n < t->counts[l]; n++) { | |
155 | node = get_node(t, l, n); | |
156 | ||
157 | for (k = 0U; k < KEYS_PER_NODE; k++) | |
158 | node[k] = high(t, l + 1, get_child(n, k)); | |
159 | } | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) | |
165 | { | |
166 | unsigned long size; | |
167 | void *addr; | |
168 | ||
169 | /* | |
170 | * Check that we're not going to overflow. | |
171 | */ | |
172 | if (nmemb > (ULONG_MAX / elem_size)) | |
173 | return NULL; | |
174 | ||
175 | size = nmemb * elem_size; | |
176 | addr = vmalloc(size); | |
177 | if (addr) | |
178 | memset(addr, 0, size); | |
179 | ||
180 | return addr; | |
181 | } | |
182 | ||
183 | /* | |
184 | * highs, and targets are managed as dynamic arrays during a | |
185 | * table load. | |
186 | */ | |
187 | static int alloc_targets(struct dm_table *t, unsigned int num) | |
188 | { | |
189 | sector_t *n_highs; | |
190 | struct dm_target *n_targets; | |
191 | int n = t->num_targets; | |
192 | ||
193 | /* | |
194 | * Allocate both the target array and offset array at once. | |
512875bd JN |
195 | * Append an empty entry to catch sectors beyond the end of |
196 | * the device. | |
1da177e4 | 197 | */ |
512875bd | 198 | n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) + |
1da177e4 LT |
199 | sizeof(sector_t)); |
200 | if (!n_highs) | |
201 | return -ENOMEM; | |
202 | ||
203 | n_targets = (struct dm_target *) (n_highs + num); | |
204 | ||
205 | if (n) { | |
206 | memcpy(n_highs, t->highs, sizeof(*n_highs) * n); | |
207 | memcpy(n_targets, t->targets, sizeof(*n_targets) * n); | |
208 | } | |
209 | ||
210 | memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); | |
211 | vfree(t->highs); | |
212 | ||
213 | t->num_allocated = num; | |
214 | t->highs = n_highs; | |
215 | t->targets = n_targets; | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
1134e5ae MA |
220 | int dm_table_create(struct dm_table **result, int mode, |
221 | unsigned num_targets, struct mapped_device *md) | |
1da177e4 | 222 | { |
094262db | 223 | struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL); |
1da177e4 LT |
224 | |
225 | if (!t) | |
226 | return -ENOMEM; | |
227 | ||
1da177e4 LT |
228 | INIT_LIST_HEAD(&t->devices); |
229 | atomic_set(&t->holders, 1); | |
230 | ||
231 | if (!num_targets) | |
232 | num_targets = KEYS_PER_NODE; | |
233 | ||
234 | num_targets = dm_round_up(num_targets, KEYS_PER_NODE); | |
235 | ||
236 | if (alloc_targets(t, num_targets)) { | |
237 | kfree(t); | |
238 | t = NULL; | |
239 | return -ENOMEM; | |
240 | } | |
241 | ||
242 | t->mode = mode; | |
1134e5ae | 243 | t->md = md; |
1da177e4 LT |
244 | *result = t; |
245 | return 0; | |
246 | } | |
247 | ||
248 | static void free_devices(struct list_head *devices) | |
249 | { | |
250 | struct list_head *tmp, *next; | |
251 | ||
afb24528 | 252 | list_for_each_safe(tmp, next, devices) { |
1da177e4 | 253 | struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); |
1da177e4 LT |
254 | kfree(dd); |
255 | } | |
256 | } | |
257 | ||
5e198d94 | 258 | static void table_destroy(struct dm_table *t) |
1da177e4 LT |
259 | { |
260 | unsigned int i; | |
261 | ||
262 | /* free the indexes (see dm_table_complete) */ | |
263 | if (t->depth >= 2) | |
264 | vfree(t->index[t->depth - 2]); | |
265 | ||
266 | /* free the targets */ | |
267 | for (i = 0; i < t->num_targets; i++) { | |
268 | struct dm_target *tgt = t->targets + i; | |
269 | ||
270 | if (tgt->type->dtr) | |
271 | tgt->type->dtr(tgt); | |
272 | ||
273 | dm_put_target_type(tgt->type); | |
274 | } | |
275 | ||
276 | vfree(t->highs); | |
277 | ||
278 | /* free the device list */ | |
279 | if (t->devices.next != &t->devices) { | |
280 | DMWARN("devices still present during destroy: " | |
281 | "dm_table_remove_device calls missing"); | |
282 | ||
283 | free_devices(&t->devices); | |
284 | } | |
285 | ||
286 | kfree(t); | |
287 | } | |
288 | ||
289 | void dm_table_get(struct dm_table *t) | |
290 | { | |
291 | atomic_inc(&t->holders); | |
292 | } | |
293 | ||
294 | void dm_table_put(struct dm_table *t) | |
295 | { | |
296 | if (!t) | |
297 | return; | |
298 | ||
299 | if (atomic_dec_and_test(&t->holders)) | |
300 | table_destroy(t); | |
301 | } | |
302 | ||
303 | /* | |
304 | * Checks to see if we need to extend highs or targets. | |
305 | */ | |
306 | static inline int check_space(struct dm_table *t) | |
307 | { | |
308 | if (t->num_targets >= t->num_allocated) | |
309 | return alloc_targets(t, t->num_allocated * 2); | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | /* | |
315 | * Convert a device path to a dev_t. | |
316 | */ | |
317 | static int lookup_device(const char *path, dev_t *dev) | |
318 | { | |
d5686b44 AV |
319 | struct block_device *bdev = lookup_bdev(path); |
320 | if (IS_ERR(bdev)) | |
321 | return PTR_ERR(bdev); | |
322 | *dev = bdev->bd_dev; | |
323 | bdput(bdev); | |
324 | return 0; | |
1da177e4 LT |
325 | } |
326 | ||
327 | /* | |
328 | * See if we've already got a device in the list. | |
329 | */ | |
330 | static struct dm_dev *find_device(struct list_head *l, dev_t dev) | |
331 | { | |
332 | struct dm_dev *dd; | |
333 | ||
334 | list_for_each_entry (dd, l, list) | |
335 | if (dd->bdev->bd_dev == dev) | |
336 | return dd; | |
337 | ||
338 | return NULL; | |
339 | } | |
340 | ||
341 | /* | |
342 | * Open a device so we can use it as a map destination. | |
343 | */ | |
f165921d | 344 | static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md) |
1da177e4 LT |
345 | { |
346 | static char *_claim_ptr = "I belong to device-mapper"; | |
347 | struct block_device *bdev; | |
348 | ||
349 | int r; | |
350 | ||
547bc926 | 351 | BUG_ON(d->bdev); |
1da177e4 LT |
352 | |
353 | bdev = open_by_devnum(dev, d->mode); | |
354 | if (IS_ERR(bdev)) | |
355 | return PTR_ERR(bdev); | |
f165921d | 356 | r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
1da177e4 LT |
357 | if (r) |
358 | blkdev_put(bdev); | |
359 | else | |
360 | d->bdev = bdev; | |
361 | return r; | |
362 | } | |
363 | ||
364 | /* | |
365 | * Close a device that we've been using. | |
366 | */ | |
f165921d | 367 | static void close_dev(struct dm_dev *d, struct mapped_device *md) |
1da177e4 LT |
368 | { |
369 | if (!d->bdev) | |
370 | return; | |
371 | ||
f165921d | 372 | bd_release_from_disk(d->bdev, dm_disk(md)); |
1da177e4 LT |
373 | blkdev_put(d->bdev); |
374 | d->bdev = NULL; | |
375 | } | |
376 | ||
377 | /* | |
2cd54d9b | 378 | * If possible, this checks an area of a destination device is valid. |
1da177e4 LT |
379 | */ |
380 | static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) | |
381 | { | |
2cd54d9b MA |
382 | sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; |
383 | ||
384 | if (!dev_size) | |
385 | return 1; | |
386 | ||
1da177e4 LT |
387 | return ((start < dev_size) && (len <= (dev_size - start))); |
388 | } | |
389 | ||
390 | /* | |
391 | * This upgrades the mode on an already open dm_dev. Being | |
392 | * careful to leave things as they were if we fail to reopen the | |
393 | * device. | |
394 | */ | |
f165921d | 395 | static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) |
1da177e4 LT |
396 | { |
397 | int r; | |
398 | struct dm_dev dd_copy; | |
399 | dev_t dev = dd->bdev->bd_dev; | |
400 | ||
401 | dd_copy = *dd; | |
402 | ||
403 | dd->mode |= new_mode; | |
404 | dd->bdev = NULL; | |
f165921d | 405 | r = open_dev(dd, dev, md); |
1da177e4 | 406 | if (!r) |
f165921d | 407 | close_dev(&dd_copy, md); |
1da177e4 LT |
408 | else |
409 | *dd = dd_copy; | |
410 | ||
411 | return r; | |
412 | } | |
413 | ||
414 | /* | |
415 | * Add a device to the list, or just increment the usage count if | |
416 | * it's already present. | |
417 | */ | |
418 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
419 | const char *path, sector_t start, sector_t len, | |
420 | int mode, struct dm_dev **result) | |
421 | { | |
422 | int r; | |
69a2ce72 | 423 | dev_t uninitialized_var(dev); |
1da177e4 LT |
424 | struct dm_dev *dd; |
425 | unsigned int major, minor; | |
426 | ||
547bc926 | 427 | BUG_ON(!t); |
1da177e4 LT |
428 | |
429 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
430 | /* Extract the major/minor numbers */ | |
431 | dev = MKDEV(major, minor); | |
432 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
433 | return -EOVERFLOW; | |
434 | } else { | |
435 | /* convert the path to a device */ | |
436 | if ((r = lookup_device(path, &dev))) | |
437 | return r; | |
438 | } | |
439 | ||
440 | dd = find_device(&t->devices, dev); | |
441 | if (!dd) { | |
442 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
443 | if (!dd) | |
444 | return -ENOMEM; | |
445 | ||
446 | dd->mode = mode; | |
447 | dd->bdev = NULL; | |
448 | ||
f165921d | 449 | if ((r = open_dev(dd, dev, t->md))) { |
1da177e4 LT |
450 | kfree(dd); |
451 | return r; | |
452 | } | |
453 | ||
454 | format_dev_t(dd->name, dev); | |
455 | ||
456 | atomic_set(&dd->count, 0); | |
457 | list_add(&dd->list, &t->devices); | |
458 | ||
459 | } else if (dd->mode != (mode | dd->mode)) { | |
f165921d | 460 | r = upgrade_mode(dd, mode, t->md); |
1da177e4 LT |
461 | if (r) |
462 | return r; | |
463 | } | |
464 | atomic_inc(&dd->count); | |
465 | ||
466 | if (!check_device_area(dd, start, len)) { | |
467 | DMWARN("device %s too small for target", path); | |
468 | dm_put_device(ti, dd); | |
469 | return -EINVAL; | |
470 | } | |
471 | ||
472 | *result = dd; | |
473 | ||
474 | return 0; | |
475 | } | |
476 | ||
3cb40214 | 477 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) |
1da177e4 | 478 | { |
165125e1 | 479 | struct request_queue *q = bdev_get_queue(bdev); |
3cb40214 BR |
480 | struct io_restrictions *rs = &ti->limits; |
481 | ||
482 | /* | |
483 | * Combine the device limits low. | |
484 | * | |
485 | * FIXME: if we move an io_restriction struct | |
486 | * into q this would just be a call to | |
487 | * combine_restrictions_low() | |
488 | */ | |
489 | rs->max_sectors = | |
490 | min_not_zero(rs->max_sectors, q->max_sectors); | |
491 | ||
9980c638 MB |
492 | /* |
493 | * Check if merge fn is supported. | |
494 | * If not we'll force DM to use PAGE_SIZE or | |
495 | * smaller I/O, just to be safe. | |
3cb40214 | 496 | */ |
9980c638 MB |
497 | |
498 | if (q->merge_bvec_fn && !ti->type->merge) | |
1da177e4 | 499 | rs->max_sectors = |
3cb40214 BR |
500 | min_not_zero(rs->max_sectors, |
501 | (unsigned int) (PAGE_SIZE >> 9)); | |
1da177e4 | 502 | |
3cb40214 BR |
503 | rs->max_phys_segments = |
504 | min_not_zero(rs->max_phys_segments, | |
505 | q->max_phys_segments); | |
1da177e4 | 506 | |
3cb40214 BR |
507 | rs->max_hw_segments = |
508 | min_not_zero(rs->max_hw_segments, q->max_hw_segments); | |
1da177e4 | 509 | |
3cb40214 | 510 | rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); |
1da177e4 | 511 | |
3cb40214 BR |
512 | rs->max_segment_size = |
513 | min_not_zero(rs->max_segment_size, q->max_segment_size); | |
1da177e4 | 514 | |
91212507 NB |
515 | rs->max_hw_sectors = |
516 | min_not_zero(rs->max_hw_sectors, q->max_hw_sectors); | |
517 | ||
3cb40214 BR |
518 | rs->seg_boundary_mask = |
519 | min_not_zero(rs->seg_boundary_mask, | |
520 | q->seg_boundary_mask); | |
1da177e4 | 521 | |
5ec140e6 VA |
522 | rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn); |
523 | ||
3cb40214 BR |
524 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
525 | } | |
526 | EXPORT_SYMBOL_GPL(dm_set_device_limits); | |
969429b5 | 527 | |
3cb40214 BR |
528 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, |
529 | sector_t len, int mode, struct dm_dev **result) | |
530 | { | |
531 | int r = __table_get_device(ti->table, ti, path, | |
532 | start, len, mode, result); | |
533 | ||
534 | if (!r) | |
535 | dm_set_device_limits(ti, (*result)->bdev); | |
1da177e4 LT |
536 | |
537 | return r; | |
538 | } | |
539 | ||
540 | /* | |
541 | * Decrement a devices use count and remove it if necessary. | |
542 | */ | |
543 | void dm_put_device(struct dm_target *ti, struct dm_dev *dd) | |
544 | { | |
545 | if (atomic_dec_and_test(&dd->count)) { | |
f165921d | 546 | close_dev(dd, ti->table->md); |
1da177e4 LT |
547 | list_del(&dd->list); |
548 | kfree(dd); | |
549 | } | |
550 | } | |
551 | ||
552 | /* | |
553 | * Checks to see if the target joins onto the end of the table. | |
554 | */ | |
555 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
556 | { | |
557 | struct dm_target *prev; | |
558 | ||
559 | if (!table->num_targets) | |
560 | return !ti->begin; | |
561 | ||
562 | prev = &table->targets[table->num_targets - 1]; | |
563 | return (ti->begin == (prev->begin + prev->len)); | |
564 | } | |
565 | ||
566 | /* | |
567 | * Used to dynamically allocate the arg array. | |
568 | */ | |
569 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
570 | { | |
571 | char **argv; | |
572 | unsigned new_size; | |
573 | ||
574 | new_size = *array_size ? *array_size * 2 : 64; | |
575 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
576 | if (argv) { | |
577 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
578 | *array_size = new_size; | |
579 | } | |
580 | ||
581 | kfree(old_argv); | |
582 | return argv; | |
583 | } | |
584 | ||
585 | /* | |
586 | * Destructively splits up the argument list to pass to ctr. | |
587 | */ | |
588 | int dm_split_args(int *argc, char ***argvp, char *input) | |
589 | { | |
590 | char *start, *end = input, *out, **argv = NULL; | |
591 | unsigned array_size = 0; | |
592 | ||
593 | *argc = 0; | |
814d6862 DT |
594 | |
595 | if (!input) { | |
596 | *argvp = NULL; | |
597 | return 0; | |
598 | } | |
599 | ||
1da177e4 LT |
600 | argv = realloc_argv(&array_size, argv); |
601 | if (!argv) | |
602 | return -ENOMEM; | |
603 | ||
604 | while (1) { | |
605 | start = end; | |
606 | ||
607 | /* Skip whitespace */ | |
608 | while (*start && isspace(*start)) | |
609 | start++; | |
610 | ||
611 | if (!*start) | |
612 | break; /* success, we hit the end */ | |
613 | ||
614 | /* 'out' is used to remove any back-quotes */ | |
615 | end = out = start; | |
616 | while (*end) { | |
617 | /* Everything apart from '\0' can be quoted */ | |
618 | if (*end == '\\' && *(end + 1)) { | |
619 | *out++ = *(end + 1); | |
620 | end += 2; | |
621 | continue; | |
622 | } | |
623 | ||
624 | if (isspace(*end)) | |
625 | break; /* end of token */ | |
626 | ||
627 | *out++ = *end++; | |
628 | } | |
629 | ||
630 | /* have we already filled the array ? */ | |
631 | if ((*argc + 1) > array_size) { | |
632 | argv = realloc_argv(&array_size, argv); | |
633 | if (!argv) | |
634 | return -ENOMEM; | |
635 | } | |
636 | ||
637 | /* we know this is whitespace */ | |
638 | if (*end) | |
639 | end++; | |
640 | ||
641 | /* terminate the string and put it in the array */ | |
642 | *out = '\0'; | |
643 | argv[*argc] = start; | |
644 | (*argc)++; | |
645 | } | |
646 | ||
647 | *argvp = argv; | |
648 | return 0; | |
649 | } | |
650 | ||
651 | static void check_for_valid_limits(struct io_restrictions *rs) | |
652 | { | |
653 | if (!rs->max_sectors) | |
defd94b7 | 654 | rs->max_sectors = SAFE_MAX_SECTORS; |
91212507 NB |
655 | if (!rs->max_hw_sectors) |
656 | rs->max_hw_sectors = SAFE_MAX_SECTORS; | |
1da177e4 LT |
657 | if (!rs->max_phys_segments) |
658 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
659 | if (!rs->max_hw_segments) | |
660 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
661 | if (!rs->hardsect_size) | |
662 | rs->hardsect_size = 1 << SECTOR_SHIFT; | |
663 | if (!rs->max_segment_size) | |
664 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
665 | if (!rs->seg_boundary_mask) | |
666 | rs->seg_boundary_mask = -1; | |
5ec140e6 VA |
667 | if (!rs->bounce_pfn) |
668 | rs->bounce_pfn = -1; | |
1da177e4 LT |
669 | } |
670 | ||
671 | int dm_table_add_target(struct dm_table *t, const char *type, | |
672 | sector_t start, sector_t len, char *params) | |
673 | { | |
674 | int r = -EINVAL, argc; | |
675 | char **argv; | |
676 | struct dm_target *tgt; | |
677 | ||
678 | if ((r = check_space(t))) | |
679 | return r; | |
680 | ||
681 | tgt = t->targets + t->num_targets; | |
682 | memset(tgt, 0, sizeof(*tgt)); | |
683 | ||
684 | if (!len) { | |
72d94861 | 685 | DMERR("%s: zero-length target", dm_device_name(t->md)); |
1da177e4 LT |
686 | return -EINVAL; |
687 | } | |
688 | ||
689 | tgt->type = dm_get_target_type(type); | |
690 | if (!tgt->type) { | |
72d94861 AK |
691 | DMERR("%s: %s: unknown target type", dm_device_name(t->md), |
692 | type); | |
1da177e4 LT |
693 | return -EINVAL; |
694 | } | |
695 | ||
696 | tgt->table = t; | |
697 | tgt->begin = start; | |
698 | tgt->len = len; | |
699 | tgt->error = "Unknown error"; | |
700 | ||
701 | /* | |
702 | * Does this target adjoin the previous one ? | |
703 | */ | |
704 | if (!adjoin(t, tgt)) { | |
705 | tgt->error = "Gap in table"; | |
706 | r = -EINVAL; | |
707 | goto bad; | |
708 | } | |
709 | ||
710 | r = dm_split_args(&argc, &argv, params); | |
711 | if (r) { | |
712 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
713 | goto bad; | |
714 | } | |
715 | ||
716 | r = tgt->type->ctr(tgt, argc, argv); | |
717 | kfree(argv); | |
718 | if (r) | |
719 | goto bad; | |
720 | ||
721 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
722 | ||
723 | /* FIXME: the plan is to combine high here and then have | |
724 | * the merge fn apply the target level restrictions. */ | |
725 | combine_restrictions_low(&t->limits, &tgt->limits); | |
726 | return 0; | |
727 | ||
728 | bad: | |
72d94861 | 729 | DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); |
1da177e4 LT |
730 | dm_put_target_type(tgt->type); |
731 | return r; | |
732 | } | |
733 | ||
734 | static int setup_indexes(struct dm_table *t) | |
735 | { | |
736 | int i; | |
737 | unsigned int total = 0; | |
738 | sector_t *indexes; | |
739 | ||
740 | /* allocate the space for *all* the indexes */ | |
741 | for (i = t->depth - 2; i >= 0; i--) { | |
742 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
743 | total += t->counts[i]; | |
744 | } | |
745 | ||
746 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
747 | if (!indexes) | |
748 | return -ENOMEM; | |
749 | ||
750 | /* set up internal nodes, bottom-up */ | |
82d601dc | 751 | for (i = t->depth - 2; i >= 0; i--) { |
1da177e4 LT |
752 | t->index[i] = indexes; |
753 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
754 | setup_btree_index(i, t); | |
755 | } | |
756 | ||
757 | return 0; | |
758 | } | |
759 | ||
760 | /* | |
761 | * Builds the btree to index the map. | |
762 | */ | |
763 | int dm_table_complete(struct dm_table *t) | |
764 | { | |
765 | int r = 0; | |
766 | unsigned int leaf_nodes; | |
767 | ||
768 | check_for_valid_limits(&t->limits); | |
769 | ||
770 | /* how many indexes will the btree have ? */ | |
771 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
772 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
773 | ||
774 | /* leaf layer has already been set up */ | |
775 | t->counts[t->depth - 1] = leaf_nodes; | |
776 | t->index[t->depth - 1] = t->highs; | |
777 | ||
778 | if (t->depth >= 2) | |
779 | r = setup_indexes(t); | |
780 | ||
781 | return r; | |
782 | } | |
783 | ||
48c9c27b | 784 | static DEFINE_MUTEX(_event_lock); |
1da177e4 LT |
785 | void dm_table_event_callback(struct dm_table *t, |
786 | void (*fn)(void *), void *context) | |
787 | { | |
48c9c27b | 788 | mutex_lock(&_event_lock); |
1da177e4 LT |
789 | t->event_fn = fn; |
790 | t->event_context = context; | |
48c9c27b | 791 | mutex_unlock(&_event_lock); |
1da177e4 LT |
792 | } |
793 | ||
794 | void dm_table_event(struct dm_table *t) | |
795 | { | |
796 | /* | |
797 | * You can no longer call dm_table_event() from interrupt | |
798 | * context, use a bottom half instead. | |
799 | */ | |
800 | BUG_ON(in_interrupt()); | |
801 | ||
48c9c27b | 802 | mutex_lock(&_event_lock); |
1da177e4 LT |
803 | if (t->event_fn) |
804 | t->event_fn(t->event_context); | |
48c9c27b | 805 | mutex_unlock(&_event_lock); |
1da177e4 LT |
806 | } |
807 | ||
808 | sector_t dm_table_get_size(struct dm_table *t) | |
809 | { | |
810 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
811 | } | |
812 | ||
813 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
814 | { | |
14353539 | 815 | if (index >= t->num_targets) |
1da177e4 LT |
816 | return NULL; |
817 | ||
818 | return t->targets + index; | |
819 | } | |
820 | ||
821 | /* | |
822 | * Search the btree for the correct target. | |
512875bd JN |
823 | * |
824 | * Caller should check returned pointer with dm_target_is_valid() | |
825 | * to trap I/O beyond end of device. | |
1da177e4 LT |
826 | */ |
827 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
828 | { | |
829 | unsigned int l, n = 0, k = 0; | |
830 | sector_t *node; | |
831 | ||
832 | for (l = 0; l < t->depth; l++) { | |
833 | n = get_child(n, k); | |
834 | node = get_node(t, l, n); | |
835 | ||
836 | for (k = 0; k < KEYS_PER_NODE; k++) | |
837 | if (node[k] >= sector) | |
838 | break; | |
839 | } | |
840 | ||
841 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
842 | } | |
843 | ||
844 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) | |
845 | { | |
846 | /* | |
847 | * Make sure we obey the optimistic sub devices | |
848 | * restrictions. | |
849 | */ | |
850 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
851 | q->max_phys_segments = t->limits.max_phys_segments; | |
852 | q->max_hw_segments = t->limits.max_hw_segments; | |
853 | q->hardsect_size = t->limits.hardsect_size; | |
854 | q->max_segment_size = t->limits.max_segment_size; | |
91212507 | 855 | q->max_hw_sectors = t->limits.max_hw_sectors; |
1da177e4 | 856 | q->seg_boundary_mask = t->limits.seg_boundary_mask; |
5ec140e6 | 857 | q->bounce_pfn = t->limits.bounce_pfn; |
c9a3f6d6 | 858 | |
969429b5 | 859 | if (t->limits.no_cluster) |
c9a3f6d6 | 860 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 861 | else |
c9a3f6d6 | 862 | queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 863 | |
1da177e4 LT |
864 | } |
865 | ||
866 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
867 | { | |
868 | return t->num_targets; | |
869 | } | |
870 | ||
871 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
872 | { | |
873 | return &t->devices; | |
874 | } | |
875 | ||
876 | int dm_table_get_mode(struct dm_table *t) | |
877 | { | |
878 | return t->mode; | |
879 | } | |
880 | ||
881 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
882 | { | |
883 | int i = t->num_targets; | |
884 | struct dm_target *ti = t->targets; | |
885 | ||
886 | while (i--) { | |
887 | if (postsuspend) { | |
888 | if (ti->type->postsuspend) | |
889 | ti->type->postsuspend(ti); | |
890 | } else if (ti->type->presuspend) | |
891 | ti->type->presuspend(ti); | |
892 | ||
893 | ti++; | |
894 | } | |
895 | } | |
896 | ||
897 | void dm_table_presuspend_targets(struct dm_table *t) | |
898 | { | |
cf222b37 AK |
899 | if (!t) |
900 | return; | |
901 | ||
e8488d08 | 902 | suspend_targets(t, 0); |
1da177e4 LT |
903 | } |
904 | ||
905 | void dm_table_postsuspend_targets(struct dm_table *t) | |
906 | { | |
cf222b37 AK |
907 | if (!t) |
908 | return; | |
909 | ||
e8488d08 | 910 | suspend_targets(t, 1); |
1da177e4 LT |
911 | } |
912 | ||
8757b776 | 913 | int dm_table_resume_targets(struct dm_table *t) |
1da177e4 | 914 | { |
8757b776 MB |
915 | int i, r = 0; |
916 | ||
917 | for (i = 0; i < t->num_targets; i++) { | |
918 | struct dm_target *ti = t->targets + i; | |
919 | ||
920 | if (!ti->type->preresume) | |
921 | continue; | |
922 | ||
923 | r = ti->type->preresume(ti); | |
924 | if (r) | |
925 | return r; | |
926 | } | |
1da177e4 LT |
927 | |
928 | for (i = 0; i < t->num_targets; i++) { | |
929 | struct dm_target *ti = t->targets + i; | |
930 | ||
931 | if (ti->type->resume) | |
932 | ti->type->resume(ti); | |
933 | } | |
8757b776 MB |
934 | |
935 | return 0; | |
1da177e4 LT |
936 | } |
937 | ||
938 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
939 | { | |
afb24528 PJ |
940 | struct dm_dev *dd; |
941 | struct list_head *devices = dm_table_get_devices(t); | |
1da177e4 LT |
942 | int r = 0; |
943 | ||
afb24528 | 944 | list_for_each_entry(dd, devices, list) { |
165125e1 | 945 | struct request_queue *q = bdev_get_queue(dd->bdev); |
1da177e4 LT |
946 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); |
947 | } | |
948 | ||
949 | return r; | |
950 | } | |
951 | ||
952 | void dm_table_unplug_all(struct dm_table *t) | |
953 | { | |
afb24528 PJ |
954 | struct dm_dev *dd; |
955 | struct list_head *devices = dm_table_get_devices(t); | |
1da177e4 | 956 | |
afb24528 | 957 | list_for_each_entry(dd, devices, list) { |
165125e1 | 958 | struct request_queue *q = bdev_get_queue(dd->bdev); |
1da177e4 | 959 | |
2ad8b1ef | 960 | blk_unplug(q); |
1da177e4 LT |
961 | } |
962 | } | |
963 | ||
1134e5ae MA |
964 | struct mapped_device *dm_table_get_md(struct dm_table *t) |
965 | { | |
966 | dm_get(t->md); | |
967 | ||
968 | return t->md; | |
969 | } | |
970 | ||
1da177e4 LT |
971 | EXPORT_SYMBOL(dm_vcalloc); |
972 | EXPORT_SYMBOL(dm_get_device); | |
973 | EXPORT_SYMBOL(dm_put_device); | |
974 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 975 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 | 976 | EXPORT_SYMBOL(dm_table_get_mode); |
1134e5ae | 977 | EXPORT_SYMBOL(dm_table_get_md); |
1da177e4 LT |
978 | EXPORT_SYMBOL(dm_table_put); |
979 | EXPORT_SYMBOL(dm_table_get); | |
980 | EXPORT_SYMBOL(dm_table_unplug_all); |