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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 | ||
102 | lhs->seg_boundary_mask = | |
103 | min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); | |
969429b5 | 104 | |
5ec140e6 VA |
105 | lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn); |
106 | ||
969429b5 | 107 | lhs->no_cluster |= rhs->no_cluster; |
1da177e4 LT |
108 | } |
109 | ||
110 | /* | |
111 | * Calculate the index of the child node of the n'th node k'th key. | |
112 | */ | |
113 | static inline unsigned int get_child(unsigned int n, unsigned int k) | |
114 | { | |
115 | return (n * CHILDREN_PER_NODE) + k; | |
116 | } | |
117 | ||
118 | /* | |
119 | * Return the n'th node of level l from table t. | |
120 | */ | |
121 | static inline sector_t *get_node(struct dm_table *t, | |
122 | unsigned int l, unsigned int n) | |
123 | { | |
124 | return t->index[l] + (n * KEYS_PER_NODE); | |
125 | } | |
126 | ||
127 | /* | |
128 | * Return the highest key that you could lookup from the n'th | |
129 | * node on level l of the btree. | |
130 | */ | |
131 | static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) | |
132 | { | |
133 | for (; l < t->depth - 1; l++) | |
134 | n = get_child(n, CHILDREN_PER_NODE - 1); | |
135 | ||
136 | if (n >= t->counts[l]) | |
137 | return (sector_t) - 1; | |
138 | ||
139 | return get_node(t, l, n)[KEYS_PER_NODE - 1]; | |
140 | } | |
141 | ||
142 | /* | |
143 | * Fills in a level of the btree based on the highs of the level | |
144 | * below it. | |
145 | */ | |
146 | static int setup_btree_index(unsigned int l, struct dm_table *t) | |
147 | { | |
148 | unsigned int n, k; | |
149 | sector_t *node; | |
150 | ||
151 | for (n = 0U; n < t->counts[l]; n++) { | |
152 | node = get_node(t, l, n); | |
153 | ||
154 | for (k = 0U; k < KEYS_PER_NODE; k++) | |
155 | node[k] = high(t, l + 1, get_child(n, k)); | |
156 | } | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) | |
162 | { | |
163 | unsigned long size; | |
164 | void *addr; | |
165 | ||
166 | /* | |
167 | * Check that we're not going to overflow. | |
168 | */ | |
169 | if (nmemb > (ULONG_MAX / elem_size)) | |
170 | return NULL; | |
171 | ||
172 | size = nmemb * elem_size; | |
173 | addr = vmalloc(size); | |
174 | if (addr) | |
175 | memset(addr, 0, size); | |
176 | ||
177 | return addr; | |
178 | } | |
179 | ||
180 | /* | |
181 | * highs, and targets are managed as dynamic arrays during a | |
182 | * table load. | |
183 | */ | |
184 | static int alloc_targets(struct dm_table *t, unsigned int num) | |
185 | { | |
186 | sector_t *n_highs; | |
187 | struct dm_target *n_targets; | |
188 | int n = t->num_targets; | |
189 | ||
190 | /* | |
191 | * Allocate both the target array and offset array at once. | |
192 | */ | |
193 | n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) + | |
194 | sizeof(sector_t)); | |
195 | if (!n_highs) | |
196 | return -ENOMEM; | |
197 | ||
198 | n_targets = (struct dm_target *) (n_highs + num); | |
199 | ||
200 | if (n) { | |
201 | memcpy(n_highs, t->highs, sizeof(*n_highs) * n); | |
202 | memcpy(n_targets, t->targets, sizeof(*n_targets) * n); | |
203 | } | |
204 | ||
205 | memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); | |
206 | vfree(t->highs); | |
207 | ||
208 | t->num_allocated = num; | |
209 | t->highs = n_highs; | |
210 | t->targets = n_targets; | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
1134e5ae MA |
215 | int dm_table_create(struct dm_table **result, int mode, |
216 | unsigned num_targets, struct mapped_device *md) | |
1da177e4 | 217 | { |
094262db | 218 | struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL); |
1da177e4 LT |
219 | |
220 | if (!t) | |
221 | return -ENOMEM; | |
222 | ||
1da177e4 LT |
223 | INIT_LIST_HEAD(&t->devices); |
224 | atomic_set(&t->holders, 1); | |
225 | ||
226 | if (!num_targets) | |
227 | num_targets = KEYS_PER_NODE; | |
228 | ||
229 | num_targets = dm_round_up(num_targets, KEYS_PER_NODE); | |
230 | ||
231 | if (alloc_targets(t, num_targets)) { | |
232 | kfree(t); | |
233 | t = NULL; | |
234 | return -ENOMEM; | |
235 | } | |
236 | ||
237 | t->mode = mode; | |
1134e5ae | 238 | t->md = md; |
1da177e4 LT |
239 | *result = t; |
240 | return 0; | |
241 | } | |
242 | ||
c2ade42d DT |
243 | int dm_create_error_table(struct dm_table **result, struct mapped_device *md) |
244 | { | |
245 | struct dm_table *t; | |
246 | sector_t dev_size = 1; | |
247 | int r; | |
248 | ||
249 | /* | |
250 | * Find current size of device. | |
251 | * Default to 1 sector if inactive. | |
252 | */ | |
253 | t = dm_get_table(md); | |
254 | if (t) { | |
255 | dev_size = dm_table_get_size(t); | |
256 | dm_table_put(t); | |
257 | } | |
258 | ||
259 | r = dm_table_create(&t, FMODE_READ, 1, md); | |
260 | if (r) | |
261 | return r; | |
262 | ||
263 | r = dm_table_add_target(t, "error", 0, dev_size, NULL); | |
264 | if (r) | |
265 | goto out; | |
266 | ||
267 | r = dm_table_complete(t); | |
268 | if (r) | |
269 | goto out; | |
270 | ||
271 | *result = t; | |
272 | ||
273 | out: | |
274 | if (r) | |
275 | dm_table_put(t); | |
276 | ||
277 | return r; | |
278 | } | |
279 | EXPORT_SYMBOL_GPL(dm_create_error_table); | |
280 | ||
1da177e4 LT |
281 | static void free_devices(struct list_head *devices) |
282 | { | |
283 | struct list_head *tmp, *next; | |
284 | ||
285 | for (tmp = devices->next; tmp != devices; tmp = next) { | |
286 | struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); | |
287 | next = tmp->next; | |
288 | kfree(dd); | |
289 | } | |
290 | } | |
291 | ||
5e198d94 | 292 | static void table_destroy(struct dm_table *t) |
1da177e4 LT |
293 | { |
294 | unsigned int i; | |
295 | ||
296 | /* free the indexes (see dm_table_complete) */ | |
297 | if (t->depth >= 2) | |
298 | vfree(t->index[t->depth - 2]); | |
299 | ||
300 | /* free the targets */ | |
301 | for (i = 0; i < t->num_targets; i++) { | |
302 | struct dm_target *tgt = t->targets + i; | |
303 | ||
304 | if (tgt->type->dtr) | |
305 | tgt->type->dtr(tgt); | |
306 | ||
307 | dm_put_target_type(tgt->type); | |
308 | } | |
309 | ||
310 | vfree(t->highs); | |
311 | ||
312 | /* free the device list */ | |
313 | if (t->devices.next != &t->devices) { | |
314 | DMWARN("devices still present during destroy: " | |
315 | "dm_table_remove_device calls missing"); | |
316 | ||
317 | free_devices(&t->devices); | |
318 | } | |
319 | ||
320 | kfree(t); | |
321 | } | |
322 | ||
323 | void dm_table_get(struct dm_table *t) | |
324 | { | |
325 | atomic_inc(&t->holders); | |
326 | } | |
327 | ||
328 | void dm_table_put(struct dm_table *t) | |
329 | { | |
330 | if (!t) | |
331 | return; | |
332 | ||
333 | if (atomic_dec_and_test(&t->holders)) | |
334 | table_destroy(t); | |
335 | } | |
336 | ||
337 | /* | |
338 | * Checks to see if we need to extend highs or targets. | |
339 | */ | |
340 | static inline int check_space(struct dm_table *t) | |
341 | { | |
342 | if (t->num_targets >= t->num_allocated) | |
343 | return alloc_targets(t, t->num_allocated * 2); | |
344 | ||
345 | return 0; | |
346 | } | |
347 | ||
348 | /* | |
349 | * Convert a device path to a dev_t. | |
350 | */ | |
351 | static int lookup_device(const char *path, dev_t *dev) | |
352 | { | |
353 | int r; | |
354 | struct nameidata nd; | |
355 | struct inode *inode; | |
356 | ||
357 | if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd))) | |
358 | return r; | |
359 | ||
360 | inode = nd.dentry->d_inode; | |
361 | if (!inode) { | |
362 | r = -ENOENT; | |
363 | goto out; | |
364 | } | |
365 | ||
366 | if (!S_ISBLK(inode->i_mode)) { | |
367 | r = -ENOTBLK; | |
368 | goto out; | |
369 | } | |
370 | ||
371 | *dev = inode->i_rdev; | |
372 | ||
373 | out: | |
374 | path_release(&nd); | |
375 | return r; | |
376 | } | |
377 | ||
378 | /* | |
379 | * See if we've already got a device in the list. | |
380 | */ | |
381 | static struct dm_dev *find_device(struct list_head *l, dev_t dev) | |
382 | { | |
383 | struct dm_dev *dd; | |
384 | ||
385 | list_for_each_entry (dd, l, list) | |
386 | if (dd->bdev->bd_dev == dev) | |
387 | return dd; | |
388 | ||
389 | return NULL; | |
390 | } | |
391 | ||
392 | /* | |
393 | * Open a device so we can use it as a map destination. | |
394 | */ | |
f165921d | 395 | static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md) |
1da177e4 LT |
396 | { |
397 | static char *_claim_ptr = "I belong to device-mapper"; | |
398 | struct block_device *bdev; | |
399 | ||
400 | int r; | |
401 | ||
547bc926 | 402 | BUG_ON(d->bdev); |
1da177e4 LT |
403 | |
404 | bdev = open_by_devnum(dev, d->mode); | |
405 | if (IS_ERR(bdev)) | |
406 | return PTR_ERR(bdev); | |
f165921d | 407 | r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
1da177e4 LT |
408 | if (r) |
409 | blkdev_put(bdev); | |
410 | else | |
411 | d->bdev = bdev; | |
412 | return r; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Close a device that we've been using. | |
417 | */ | |
f165921d | 418 | static void close_dev(struct dm_dev *d, struct mapped_device *md) |
1da177e4 LT |
419 | { |
420 | if (!d->bdev) | |
421 | return; | |
422 | ||
f165921d | 423 | bd_release_from_disk(d->bdev, dm_disk(md)); |
1da177e4 LT |
424 | blkdev_put(d->bdev); |
425 | d->bdev = NULL; | |
426 | } | |
427 | ||
428 | /* | |
2cd54d9b | 429 | * If possible, this checks an area of a destination device is valid. |
1da177e4 LT |
430 | */ |
431 | static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) | |
432 | { | |
2cd54d9b MA |
433 | sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; |
434 | ||
435 | if (!dev_size) | |
436 | return 1; | |
437 | ||
1da177e4 LT |
438 | return ((start < dev_size) && (len <= (dev_size - start))); |
439 | } | |
440 | ||
441 | /* | |
442 | * This upgrades the mode on an already open dm_dev. Being | |
443 | * careful to leave things as they were if we fail to reopen the | |
444 | * device. | |
445 | */ | |
f165921d | 446 | static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) |
1da177e4 LT |
447 | { |
448 | int r; | |
449 | struct dm_dev dd_copy; | |
450 | dev_t dev = dd->bdev->bd_dev; | |
451 | ||
452 | dd_copy = *dd; | |
453 | ||
454 | dd->mode |= new_mode; | |
455 | dd->bdev = NULL; | |
f165921d | 456 | r = open_dev(dd, dev, md); |
1da177e4 | 457 | if (!r) |
f165921d | 458 | close_dev(&dd_copy, md); |
1da177e4 LT |
459 | else |
460 | *dd = dd_copy; | |
461 | ||
462 | return r; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Add a device to the list, or just increment the usage count if | |
467 | * it's already present. | |
468 | */ | |
469 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
470 | const char *path, sector_t start, sector_t len, | |
471 | int mode, struct dm_dev **result) | |
472 | { | |
473 | int r; | |
474 | dev_t dev; | |
475 | struct dm_dev *dd; | |
476 | unsigned int major, minor; | |
477 | ||
547bc926 | 478 | BUG_ON(!t); |
1da177e4 LT |
479 | |
480 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
481 | /* Extract the major/minor numbers */ | |
482 | dev = MKDEV(major, minor); | |
483 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
484 | return -EOVERFLOW; | |
485 | } else { | |
486 | /* convert the path to a device */ | |
487 | if ((r = lookup_device(path, &dev))) | |
488 | return r; | |
489 | } | |
490 | ||
491 | dd = find_device(&t->devices, dev); | |
492 | if (!dd) { | |
493 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
494 | if (!dd) | |
495 | return -ENOMEM; | |
496 | ||
497 | dd->mode = mode; | |
498 | dd->bdev = NULL; | |
499 | ||
f165921d | 500 | if ((r = open_dev(dd, dev, t->md))) { |
1da177e4 LT |
501 | kfree(dd); |
502 | return r; | |
503 | } | |
504 | ||
505 | format_dev_t(dd->name, dev); | |
506 | ||
507 | atomic_set(&dd->count, 0); | |
508 | list_add(&dd->list, &t->devices); | |
509 | ||
510 | } else if (dd->mode != (mode | dd->mode)) { | |
f165921d | 511 | r = upgrade_mode(dd, mode, t->md); |
1da177e4 LT |
512 | if (r) |
513 | return r; | |
514 | } | |
515 | atomic_inc(&dd->count); | |
516 | ||
517 | if (!check_device_area(dd, start, len)) { | |
518 | DMWARN("device %s too small for target", path); | |
519 | dm_put_device(ti, dd); | |
520 | return -EINVAL; | |
521 | } | |
522 | ||
523 | *result = dd; | |
524 | ||
525 | return 0; | |
526 | } | |
527 | ||
3cb40214 | 528 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) |
1da177e4 | 529 | { |
165125e1 | 530 | struct request_queue *q = bdev_get_queue(bdev); |
3cb40214 BR |
531 | struct io_restrictions *rs = &ti->limits; |
532 | ||
533 | /* | |
534 | * Combine the device limits low. | |
535 | * | |
536 | * FIXME: if we move an io_restriction struct | |
537 | * into q this would just be a call to | |
538 | * combine_restrictions_low() | |
539 | */ | |
540 | rs->max_sectors = | |
541 | min_not_zero(rs->max_sectors, q->max_sectors); | |
542 | ||
543 | /* FIXME: Device-Mapper on top of RAID-0 breaks because DM | |
544 | * currently doesn't honor MD's merge_bvec_fn routine. | |
545 | * In this case, we'll force DM to use PAGE_SIZE or | |
546 | * smaller I/O, just to be safe. A better fix is in the | |
547 | * works, but add this for the time being so it will at | |
548 | * least operate correctly. | |
549 | */ | |
550 | if (q->merge_bvec_fn) | |
1da177e4 | 551 | rs->max_sectors = |
3cb40214 BR |
552 | min_not_zero(rs->max_sectors, |
553 | (unsigned int) (PAGE_SIZE >> 9)); | |
1da177e4 | 554 | |
3cb40214 BR |
555 | rs->max_phys_segments = |
556 | min_not_zero(rs->max_phys_segments, | |
557 | q->max_phys_segments); | |
1da177e4 | 558 | |
3cb40214 BR |
559 | rs->max_hw_segments = |
560 | min_not_zero(rs->max_hw_segments, q->max_hw_segments); | |
1da177e4 | 561 | |
3cb40214 | 562 | rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); |
1da177e4 | 563 | |
3cb40214 BR |
564 | rs->max_segment_size = |
565 | min_not_zero(rs->max_segment_size, q->max_segment_size); | |
1da177e4 | 566 | |
3cb40214 BR |
567 | rs->seg_boundary_mask = |
568 | min_not_zero(rs->seg_boundary_mask, | |
569 | q->seg_boundary_mask); | |
1da177e4 | 570 | |
5ec140e6 VA |
571 | rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn); |
572 | ||
3cb40214 BR |
573 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
574 | } | |
575 | EXPORT_SYMBOL_GPL(dm_set_device_limits); | |
969429b5 | 576 | |
3cb40214 BR |
577 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, |
578 | sector_t len, int mode, struct dm_dev **result) | |
579 | { | |
580 | int r = __table_get_device(ti->table, ti, path, | |
581 | start, len, mode, result); | |
582 | ||
583 | if (!r) | |
584 | dm_set_device_limits(ti, (*result)->bdev); | |
1da177e4 LT |
585 | |
586 | return r; | |
587 | } | |
588 | ||
589 | /* | |
590 | * Decrement a devices use count and remove it if necessary. | |
591 | */ | |
592 | void dm_put_device(struct dm_target *ti, struct dm_dev *dd) | |
593 | { | |
594 | if (atomic_dec_and_test(&dd->count)) { | |
f165921d | 595 | close_dev(dd, ti->table->md); |
1da177e4 LT |
596 | list_del(&dd->list); |
597 | kfree(dd); | |
598 | } | |
599 | } | |
600 | ||
601 | /* | |
602 | * Checks to see if the target joins onto the end of the table. | |
603 | */ | |
604 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
605 | { | |
606 | struct dm_target *prev; | |
607 | ||
608 | if (!table->num_targets) | |
609 | return !ti->begin; | |
610 | ||
611 | prev = &table->targets[table->num_targets - 1]; | |
612 | return (ti->begin == (prev->begin + prev->len)); | |
613 | } | |
614 | ||
615 | /* | |
616 | * Used to dynamically allocate the arg array. | |
617 | */ | |
618 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
619 | { | |
620 | char **argv; | |
621 | unsigned new_size; | |
622 | ||
623 | new_size = *array_size ? *array_size * 2 : 64; | |
624 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
625 | if (argv) { | |
626 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
627 | *array_size = new_size; | |
628 | } | |
629 | ||
630 | kfree(old_argv); | |
631 | return argv; | |
632 | } | |
633 | ||
634 | /* | |
635 | * Destructively splits up the argument list to pass to ctr. | |
636 | */ | |
637 | int dm_split_args(int *argc, char ***argvp, char *input) | |
638 | { | |
639 | char *start, *end = input, *out, **argv = NULL; | |
640 | unsigned array_size = 0; | |
641 | ||
642 | *argc = 0; | |
814d6862 DT |
643 | |
644 | if (!input) { | |
645 | *argvp = NULL; | |
646 | return 0; | |
647 | } | |
648 | ||
1da177e4 LT |
649 | argv = realloc_argv(&array_size, argv); |
650 | if (!argv) | |
651 | return -ENOMEM; | |
652 | ||
653 | while (1) { | |
654 | start = end; | |
655 | ||
656 | /* Skip whitespace */ | |
657 | while (*start && isspace(*start)) | |
658 | start++; | |
659 | ||
660 | if (!*start) | |
661 | break; /* success, we hit the end */ | |
662 | ||
663 | /* 'out' is used to remove any back-quotes */ | |
664 | end = out = start; | |
665 | while (*end) { | |
666 | /* Everything apart from '\0' can be quoted */ | |
667 | if (*end == '\\' && *(end + 1)) { | |
668 | *out++ = *(end + 1); | |
669 | end += 2; | |
670 | continue; | |
671 | } | |
672 | ||
673 | if (isspace(*end)) | |
674 | break; /* end of token */ | |
675 | ||
676 | *out++ = *end++; | |
677 | } | |
678 | ||
679 | /* have we already filled the array ? */ | |
680 | if ((*argc + 1) > array_size) { | |
681 | argv = realloc_argv(&array_size, argv); | |
682 | if (!argv) | |
683 | return -ENOMEM; | |
684 | } | |
685 | ||
686 | /* we know this is whitespace */ | |
687 | if (*end) | |
688 | end++; | |
689 | ||
690 | /* terminate the string and put it in the array */ | |
691 | *out = '\0'; | |
692 | argv[*argc] = start; | |
693 | (*argc)++; | |
694 | } | |
695 | ||
696 | *argvp = argv; | |
697 | return 0; | |
698 | } | |
699 | ||
700 | static void check_for_valid_limits(struct io_restrictions *rs) | |
701 | { | |
702 | if (!rs->max_sectors) | |
defd94b7 | 703 | rs->max_sectors = SAFE_MAX_SECTORS; |
1da177e4 LT |
704 | if (!rs->max_phys_segments) |
705 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
706 | if (!rs->max_hw_segments) | |
707 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
708 | if (!rs->hardsect_size) | |
709 | rs->hardsect_size = 1 << SECTOR_SHIFT; | |
710 | if (!rs->max_segment_size) | |
711 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
712 | if (!rs->seg_boundary_mask) | |
713 | rs->seg_boundary_mask = -1; | |
5ec140e6 VA |
714 | if (!rs->bounce_pfn) |
715 | rs->bounce_pfn = -1; | |
1da177e4 LT |
716 | } |
717 | ||
718 | int dm_table_add_target(struct dm_table *t, const char *type, | |
719 | sector_t start, sector_t len, char *params) | |
720 | { | |
721 | int r = -EINVAL, argc; | |
722 | char **argv; | |
723 | struct dm_target *tgt; | |
724 | ||
725 | if ((r = check_space(t))) | |
726 | return r; | |
727 | ||
728 | tgt = t->targets + t->num_targets; | |
729 | memset(tgt, 0, sizeof(*tgt)); | |
730 | ||
731 | if (!len) { | |
72d94861 | 732 | DMERR("%s: zero-length target", dm_device_name(t->md)); |
1da177e4 LT |
733 | return -EINVAL; |
734 | } | |
735 | ||
736 | tgt->type = dm_get_target_type(type); | |
737 | if (!tgt->type) { | |
72d94861 AK |
738 | DMERR("%s: %s: unknown target type", dm_device_name(t->md), |
739 | type); | |
1da177e4 LT |
740 | return -EINVAL; |
741 | } | |
742 | ||
743 | tgt->table = t; | |
744 | tgt->begin = start; | |
745 | tgt->len = len; | |
746 | tgt->error = "Unknown error"; | |
747 | ||
748 | /* | |
749 | * Does this target adjoin the previous one ? | |
750 | */ | |
751 | if (!adjoin(t, tgt)) { | |
752 | tgt->error = "Gap in table"; | |
753 | r = -EINVAL; | |
754 | goto bad; | |
755 | } | |
756 | ||
757 | r = dm_split_args(&argc, &argv, params); | |
758 | if (r) { | |
759 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
760 | goto bad; | |
761 | } | |
762 | ||
763 | r = tgt->type->ctr(tgt, argc, argv); | |
764 | kfree(argv); | |
765 | if (r) | |
766 | goto bad; | |
767 | ||
768 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
769 | ||
770 | /* FIXME: the plan is to combine high here and then have | |
771 | * the merge fn apply the target level restrictions. */ | |
772 | combine_restrictions_low(&t->limits, &tgt->limits); | |
773 | return 0; | |
774 | ||
775 | bad: | |
72d94861 | 776 | DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); |
1da177e4 LT |
777 | dm_put_target_type(tgt->type); |
778 | return r; | |
779 | } | |
780 | ||
781 | static int setup_indexes(struct dm_table *t) | |
782 | { | |
783 | int i; | |
784 | unsigned int total = 0; | |
785 | sector_t *indexes; | |
786 | ||
787 | /* allocate the space for *all* the indexes */ | |
788 | for (i = t->depth - 2; i >= 0; i--) { | |
789 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
790 | total += t->counts[i]; | |
791 | } | |
792 | ||
793 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
794 | if (!indexes) | |
795 | return -ENOMEM; | |
796 | ||
797 | /* set up internal nodes, bottom-up */ | |
798 | for (i = t->depth - 2, total = 0; i >= 0; i--) { | |
799 | t->index[i] = indexes; | |
800 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
801 | setup_btree_index(i, t); | |
802 | } | |
803 | ||
804 | return 0; | |
805 | } | |
806 | ||
807 | /* | |
808 | * Builds the btree to index the map. | |
809 | */ | |
810 | int dm_table_complete(struct dm_table *t) | |
811 | { | |
812 | int r = 0; | |
813 | unsigned int leaf_nodes; | |
814 | ||
815 | check_for_valid_limits(&t->limits); | |
816 | ||
817 | /* how many indexes will the btree have ? */ | |
818 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
819 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
820 | ||
821 | /* leaf layer has already been set up */ | |
822 | t->counts[t->depth - 1] = leaf_nodes; | |
823 | t->index[t->depth - 1] = t->highs; | |
824 | ||
825 | if (t->depth >= 2) | |
826 | r = setup_indexes(t); | |
827 | ||
828 | return r; | |
829 | } | |
830 | ||
48c9c27b | 831 | static DEFINE_MUTEX(_event_lock); |
1da177e4 LT |
832 | void dm_table_event_callback(struct dm_table *t, |
833 | void (*fn)(void *), void *context) | |
834 | { | |
48c9c27b | 835 | mutex_lock(&_event_lock); |
1da177e4 LT |
836 | t->event_fn = fn; |
837 | t->event_context = context; | |
48c9c27b | 838 | mutex_unlock(&_event_lock); |
1da177e4 LT |
839 | } |
840 | ||
841 | void dm_table_event(struct dm_table *t) | |
842 | { | |
843 | /* | |
844 | * You can no longer call dm_table_event() from interrupt | |
845 | * context, use a bottom half instead. | |
846 | */ | |
847 | BUG_ON(in_interrupt()); | |
848 | ||
48c9c27b | 849 | mutex_lock(&_event_lock); |
1da177e4 LT |
850 | if (t->event_fn) |
851 | t->event_fn(t->event_context); | |
48c9c27b | 852 | mutex_unlock(&_event_lock); |
1da177e4 LT |
853 | } |
854 | ||
855 | sector_t dm_table_get_size(struct dm_table *t) | |
856 | { | |
857 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
858 | } | |
859 | ||
860 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
861 | { | |
14353539 | 862 | if (index >= t->num_targets) |
1da177e4 LT |
863 | return NULL; |
864 | ||
865 | return t->targets + index; | |
866 | } | |
867 | ||
868 | /* | |
869 | * Search the btree for the correct target. | |
870 | */ | |
871 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
872 | { | |
873 | unsigned int l, n = 0, k = 0; | |
874 | sector_t *node; | |
875 | ||
876 | for (l = 0; l < t->depth; l++) { | |
877 | n = get_child(n, k); | |
878 | node = get_node(t, l, n); | |
879 | ||
880 | for (k = 0; k < KEYS_PER_NODE; k++) | |
881 | if (node[k] >= sector) | |
882 | break; | |
883 | } | |
884 | ||
885 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
886 | } | |
887 | ||
888 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) | |
889 | { | |
890 | /* | |
891 | * Make sure we obey the optimistic sub devices | |
892 | * restrictions. | |
893 | */ | |
894 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
895 | q->max_phys_segments = t->limits.max_phys_segments; | |
896 | q->max_hw_segments = t->limits.max_hw_segments; | |
897 | q->hardsect_size = t->limits.hardsect_size; | |
898 | q->max_segment_size = t->limits.max_segment_size; | |
899 | q->seg_boundary_mask = t->limits.seg_boundary_mask; | |
5ec140e6 | 900 | q->bounce_pfn = t->limits.bounce_pfn; |
969429b5 N |
901 | if (t->limits.no_cluster) |
902 | q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER); | |
903 | else | |
904 | q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER); | |
905 | ||
1da177e4 LT |
906 | } |
907 | ||
908 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
909 | { | |
910 | return t->num_targets; | |
911 | } | |
912 | ||
913 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
914 | { | |
915 | return &t->devices; | |
916 | } | |
917 | ||
918 | int dm_table_get_mode(struct dm_table *t) | |
919 | { | |
920 | return t->mode; | |
921 | } | |
922 | ||
923 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
924 | { | |
925 | int i = t->num_targets; | |
926 | struct dm_target *ti = t->targets; | |
927 | ||
928 | while (i--) { | |
929 | if (postsuspend) { | |
930 | if (ti->type->postsuspend) | |
931 | ti->type->postsuspend(ti); | |
932 | } else if (ti->type->presuspend) | |
933 | ti->type->presuspend(ti); | |
934 | ||
935 | ti++; | |
936 | } | |
937 | } | |
938 | ||
939 | void dm_table_presuspend_targets(struct dm_table *t) | |
940 | { | |
cf222b37 AK |
941 | if (!t) |
942 | return; | |
943 | ||
1da177e4 LT |
944 | return suspend_targets(t, 0); |
945 | } | |
946 | ||
947 | void dm_table_postsuspend_targets(struct dm_table *t) | |
948 | { | |
cf222b37 AK |
949 | if (!t) |
950 | return; | |
951 | ||
1da177e4 LT |
952 | return suspend_targets(t, 1); |
953 | } | |
954 | ||
8757b776 | 955 | int dm_table_resume_targets(struct dm_table *t) |
1da177e4 | 956 | { |
8757b776 MB |
957 | int i, r = 0; |
958 | ||
959 | for (i = 0; i < t->num_targets; i++) { | |
960 | struct dm_target *ti = t->targets + i; | |
961 | ||
962 | if (!ti->type->preresume) | |
963 | continue; | |
964 | ||
965 | r = ti->type->preresume(ti); | |
966 | if (r) | |
967 | return r; | |
968 | } | |
1da177e4 LT |
969 | |
970 | for (i = 0; i < t->num_targets; i++) { | |
971 | struct dm_target *ti = t->targets + i; | |
972 | ||
973 | if (ti->type->resume) | |
974 | ti->type->resume(ti); | |
975 | } | |
8757b776 MB |
976 | |
977 | return 0; | |
1da177e4 LT |
978 | } |
979 | ||
980 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
981 | { | |
982 | struct list_head *d, *devices; | |
983 | int r = 0; | |
984 | ||
985 | devices = dm_table_get_devices(t); | |
986 | for (d = devices->next; d != devices; d = d->next) { | |
987 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
165125e1 | 988 | struct request_queue *q = bdev_get_queue(dd->bdev); |
1da177e4 LT |
989 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); |
990 | } | |
991 | ||
992 | return r; | |
993 | } | |
994 | ||
995 | void dm_table_unplug_all(struct dm_table *t) | |
996 | { | |
997 | struct list_head *d, *devices = dm_table_get_devices(t); | |
998 | ||
999 | for (d = devices->next; d != devices; d = d->next) { | |
1000 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
165125e1 | 1001 | struct request_queue *q = bdev_get_queue(dd->bdev); |
1da177e4 | 1002 | |
2ad8b1ef | 1003 | blk_unplug(q); |
1da177e4 LT |
1004 | } |
1005 | } | |
1006 | ||
1134e5ae MA |
1007 | struct mapped_device *dm_table_get_md(struct dm_table *t) |
1008 | { | |
1009 | dm_get(t->md); | |
1010 | ||
1011 | return t->md; | |
1012 | } | |
1013 | ||
1da177e4 LT |
1014 | EXPORT_SYMBOL(dm_vcalloc); |
1015 | EXPORT_SYMBOL(dm_get_device); | |
1016 | EXPORT_SYMBOL(dm_put_device); | |
1017 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 1018 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 | 1019 | EXPORT_SYMBOL(dm_table_get_mode); |
1134e5ae | 1020 | EXPORT_SYMBOL(dm_table_get_md); |
1da177e4 LT |
1021 | EXPORT_SYMBOL(dm_table_put); |
1022 | EXPORT_SYMBOL(dm_table_get); | |
1023 | EXPORT_SYMBOL(dm_table_unplug_all); |