Commit | Line | Data |
---|---|---|
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) { |
82b1519b MP |
253 | struct dm_dev_internal *dd = |
254 | list_entry(tmp, struct dm_dev_internal, list); | |
1da177e4 LT |
255 | kfree(dd); |
256 | } | |
257 | } | |
258 | ||
5e198d94 | 259 | static void table_destroy(struct dm_table *t) |
1da177e4 LT |
260 | { |
261 | unsigned int i; | |
262 | ||
263 | /* free the indexes (see dm_table_complete) */ | |
264 | if (t->depth >= 2) | |
265 | vfree(t->index[t->depth - 2]); | |
266 | ||
267 | /* free the targets */ | |
268 | for (i = 0; i < t->num_targets; i++) { | |
269 | struct dm_target *tgt = t->targets + i; | |
270 | ||
271 | if (tgt->type->dtr) | |
272 | tgt->type->dtr(tgt); | |
273 | ||
274 | dm_put_target_type(tgt->type); | |
275 | } | |
276 | ||
277 | vfree(t->highs); | |
278 | ||
279 | /* free the device list */ | |
280 | if (t->devices.next != &t->devices) { | |
281 | DMWARN("devices still present during destroy: " | |
282 | "dm_table_remove_device calls missing"); | |
283 | ||
284 | free_devices(&t->devices); | |
285 | } | |
286 | ||
287 | kfree(t); | |
288 | } | |
289 | ||
290 | void dm_table_get(struct dm_table *t) | |
291 | { | |
292 | atomic_inc(&t->holders); | |
293 | } | |
294 | ||
295 | void dm_table_put(struct dm_table *t) | |
296 | { | |
297 | if (!t) | |
298 | return; | |
299 | ||
300 | if (atomic_dec_and_test(&t->holders)) | |
301 | table_destroy(t); | |
302 | } | |
303 | ||
304 | /* | |
305 | * Checks to see if we need to extend highs or targets. | |
306 | */ | |
307 | static inline int check_space(struct dm_table *t) | |
308 | { | |
309 | if (t->num_targets >= t->num_allocated) | |
310 | return alloc_targets(t, t->num_allocated * 2); | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
1da177e4 LT |
315 | /* |
316 | * See if we've already got a device in the list. | |
317 | */ | |
82b1519b | 318 | static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev) |
1da177e4 | 319 | { |
82b1519b | 320 | struct dm_dev_internal *dd; |
1da177e4 LT |
321 | |
322 | list_for_each_entry (dd, l, list) | |
82b1519b | 323 | if (dd->dm_dev.bdev->bd_dev == dev) |
1da177e4 LT |
324 | return dd; |
325 | ||
326 | return NULL; | |
327 | } | |
328 | ||
329 | /* | |
330 | * Open a device so we can use it as a map destination. | |
331 | */ | |
82b1519b MP |
332 | static int open_dev(struct dm_dev_internal *d, dev_t dev, |
333 | struct mapped_device *md) | |
1da177e4 LT |
334 | { |
335 | static char *_claim_ptr = "I belong to device-mapper"; | |
336 | struct block_device *bdev; | |
337 | ||
338 | int r; | |
339 | ||
82b1519b | 340 | BUG_ON(d->dm_dev.bdev); |
1da177e4 | 341 | |
82b1519b | 342 | bdev = open_by_devnum(dev, d->dm_dev.mode); |
1da177e4 LT |
343 | if (IS_ERR(bdev)) |
344 | return PTR_ERR(bdev); | |
f165921d | 345 | r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
1da177e4 LT |
346 | if (r) |
347 | blkdev_put(bdev); | |
348 | else | |
82b1519b | 349 | d->dm_dev.bdev = bdev; |
1da177e4 LT |
350 | return r; |
351 | } | |
352 | ||
353 | /* | |
354 | * Close a device that we've been using. | |
355 | */ | |
82b1519b | 356 | static void close_dev(struct dm_dev_internal *d, struct mapped_device *md) |
1da177e4 | 357 | { |
82b1519b | 358 | if (!d->dm_dev.bdev) |
1da177e4 LT |
359 | return; |
360 | ||
82b1519b MP |
361 | bd_release_from_disk(d->dm_dev.bdev, dm_disk(md)); |
362 | blkdev_put(d->dm_dev.bdev); | |
363 | d->dm_dev.bdev = NULL; | |
1da177e4 LT |
364 | } |
365 | ||
366 | /* | |
2cd54d9b | 367 | * If possible, this checks an area of a destination device is valid. |
1da177e4 | 368 | */ |
82b1519b MP |
369 | static int check_device_area(struct dm_dev_internal *dd, sector_t start, |
370 | sector_t len) | |
1da177e4 | 371 | { |
82b1519b | 372 | sector_t dev_size = dd->dm_dev.bdev->bd_inode->i_size >> SECTOR_SHIFT; |
2cd54d9b MA |
373 | |
374 | if (!dev_size) | |
375 | return 1; | |
376 | ||
1da177e4 LT |
377 | return ((start < dev_size) && (len <= (dev_size - start))); |
378 | } | |
379 | ||
380 | /* | |
381 | * This upgrades the mode on an already open dm_dev. Being | |
382 | * careful to leave things as they were if we fail to reopen the | |
383 | * device. | |
384 | */ | |
82b1519b MP |
385 | static int upgrade_mode(struct dm_dev_internal *dd, int new_mode, |
386 | struct mapped_device *md) | |
1da177e4 LT |
387 | { |
388 | int r; | |
82b1519b MP |
389 | struct dm_dev_internal dd_copy; |
390 | dev_t dev = dd->dm_dev.bdev->bd_dev; | |
1da177e4 LT |
391 | |
392 | dd_copy = *dd; | |
393 | ||
82b1519b MP |
394 | dd->dm_dev.mode |= new_mode; |
395 | dd->dm_dev.bdev = NULL; | |
f165921d | 396 | r = open_dev(dd, dev, md); |
1da177e4 | 397 | if (!r) |
f165921d | 398 | close_dev(&dd_copy, md); |
1da177e4 LT |
399 | else |
400 | *dd = dd_copy; | |
401 | ||
402 | return r; | |
403 | } | |
404 | ||
405 | /* | |
406 | * Add a device to the list, or just increment the usage count if | |
407 | * it's already present. | |
408 | */ | |
409 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
410 | const char *path, sector_t start, sector_t len, | |
411 | int mode, struct dm_dev **result) | |
412 | { | |
413 | int r; | |
69a2ce72 | 414 | dev_t uninitialized_var(dev); |
82b1519b | 415 | struct dm_dev_internal *dd; |
1da177e4 LT |
416 | unsigned int major, minor; |
417 | ||
547bc926 | 418 | BUG_ON(!t); |
1da177e4 LT |
419 | |
420 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
421 | /* Extract the major/minor numbers */ | |
422 | dev = MKDEV(major, minor); | |
423 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
424 | return -EOVERFLOW; | |
425 | } else { | |
426 | /* convert the path to a device */ | |
72e8264e CH |
427 | struct block_device *bdev = lookup_bdev(path); |
428 | ||
429 | if (IS_ERR(bdev)) | |
430 | return PTR_ERR(bdev); | |
431 | dev = bdev->bd_dev; | |
432 | bdput(bdev); | |
1da177e4 LT |
433 | } |
434 | ||
435 | dd = find_device(&t->devices, dev); | |
436 | if (!dd) { | |
437 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
438 | if (!dd) | |
439 | return -ENOMEM; | |
440 | ||
82b1519b MP |
441 | dd->dm_dev.mode = mode; |
442 | dd->dm_dev.bdev = NULL; | |
1da177e4 | 443 | |
f165921d | 444 | if ((r = open_dev(dd, dev, t->md))) { |
1da177e4 LT |
445 | kfree(dd); |
446 | return r; | |
447 | } | |
448 | ||
82b1519b | 449 | format_dev_t(dd->dm_dev.name, dev); |
1da177e4 LT |
450 | |
451 | atomic_set(&dd->count, 0); | |
452 | list_add(&dd->list, &t->devices); | |
453 | ||
82b1519b | 454 | } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) { |
f165921d | 455 | r = upgrade_mode(dd, mode, t->md); |
1da177e4 LT |
456 | if (r) |
457 | return r; | |
458 | } | |
459 | atomic_inc(&dd->count); | |
460 | ||
461 | if (!check_device_area(dd, start, len)) { | |
462 | DMWARN("device %s too small for target", path); | |
82b1519b | 463 | dm_put_device(ti, &dd->dm_dev); |
1da177e4 LT |
464 | return -EINVAL; |
465 | } | |
466 | ||
82b1519b | 467 | *result = &dd->dm_dev; |
1da177e4 LT |
468 | |
469 | return 0; | |
470 | } | |
471 | ||
3cb40214 | 472 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) |
1da177e4 | 473 | { |
165125e1 | 474 | struct request_queue *q = bdev_get_queue(bdev); |
3cb40214 | 475 | struct io_restrictions *rs = &ti->limits; |
0c2322e4 AK |
476 | char b[BDEVNAME_SIZE]; |
477 | ||
478 | if (unlikely(!q)) { | |
479 | DMWARN("%s: Cannot set limits for nonexistent device %s", | |
480 | dm_device_name(ti->table->md), bdevname(bdev, b)); | |
481 | return; | |
482 | } | |
3cb40214 BR |
483 | |
484 | /* | |
485 | * Combine the device limits low. | |
486 | * | |
487 | * FIXME: if we move an io_restriction struct | |
488 | * into q this would just be a call to | |
489 | * combine_restrictions_low() | |
490 | */ | |
491 | rs->max_sectors = | |
492 | min_not_zero(rs->max_sectors, q->max_sectors); | |
493 | ||
9980c638 MB |
494 | /* |
495 | * Check if merge fn is supported. | |
496 | * If not we'll force DM to use PAGE_SIZE or | |
497 | * smaller I/O, just to be safe. | |
3cb40214 | 498 | */ |
9980c638 MB |
499 | |
500 | if (q->merge_bvec_fn && !ti->type->merge) | |
1da177e4 | 501 | rs->max_sectors = |
3cb40214 BR |
502 | min_not_zero(rs->max_sectors, |
503 | (unsigned int) (PAGE_SIZE >> 9)); | |
1da177e4 | 504 | |
3cb40214 BR |
505 | rs->max_phys_segments = |
506 | min_not_zero(rs->max_phys_segments, | |
507 | q->max_phys_segments); | |
1da177e4 | 508 | |
3cb40214 BR |
509 | rs->max_hw_segments = |
510 | min_not_zero(rs->max_hw_segments, q->max_hw_segments); | |
1da177e4 | 511 | |
3cb40214 | 512 | rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); |
1da177e4 | 513 | |
3cb40214 BR |
514 | rs->max_segment_size = |
515 | min_not_zero(rs->max_segment_size, q->max_segment_size); | |
1da177e4 | 516 | |
91212507 NB |
517 | rs->max_hw_sectors = |
518 | min_not_zero(rs->max_hw_sectors, q->max_hw_sectors); | |
519 | ||
3cb40214 BR |
520 | rs->seg_boundary_mask = |
521 | min_not_zero(rs->seg_boundary_mask, | |
522 | q->seg_boundary_mask); | |
1da177e4 | 523 | |
5ec140e6 VA |
524 | rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn); |
525 | ||
3cb40214 BR |
526 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
527 | } | |
528 | EXPORT_SYMBOL_GPL(dm_set_device_limits); | |
969429b5 | 529 | |
3cb40214 BR |
530 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, |
531 | sector_t len, int mode, struct dm_dev **result) | |
532 | { | |
533 | int r = __table_get_device(ti->table, ti, path, | |
534 | start, len, mode, result); | |
535 | ||
536 | if (!r) | |
537 | dm_set_device_limits(ti, (*result)->bdev); | |
1da177e4 LT |
538 | |
539 | return r; | |
540 | } | |
541 | ||
542 | /* | |
543 | * Decrement a devices use count and remove it if necessary. | |
544 | */ | |
82b1519b | 545 | void dm_put_device(struct dm_target *ti, struct dm_dev *d) |
1da177e4 | 546 | { |
82b1519b MP |
547 | struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal, |
548 | dm_dev); | |
549 | ||
1da177e4 | 550 | if (atomic_dec_and_test(&dd->count)) { |
f165921d | 551 | close_dev(dd, ti->table->md); |
1da177e4 LT |
552 | list_del(&dd->list); |
553 | kfree(dd); | |
554 | } | |
555 | } | |
556 | ||
557 | /* | |
558 | * Checks to see if the target joins onto the end of the table. | |
559 | */ | |
560 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
561 | { | |
562 | struct dm_target *prev; | |
563 | ||
564 | if (!table->num_targets) | |
565 | return !ti->begin; | |
566 | ||
567 | prev = &table->targets[table->num_targets - 1]; | |
568 | return (ti->begin == (prev->begin + prev->len)); | |
569 | } | |
570 | ||
571 | /* | |
572 | * Used to dynamically allocate the arg array. | |
573 | */ | |
574 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
575 | { | |
576 | char **argv; | |
577 | unsigned new_size; | |
578 | ||
579 | new_size = *array_size ? *array_size * 2 : 64; | |
580 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
581 | if (argv) { | |
582 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
583 | *array_size = new_size; | |
584 | } | |
585 | ||
586 | kfree(old_argv); | |
587 | return argv; | |
588 | } | |
589 | ||
590 | /* | |
591 | * Destructively splits up the argument list to pass to ctr. | |
592 | */ | |
593 | int dm_split_args(int *argc, char ***argvp, char *input) | |
594 | { | |
595 | char *start, *end = input, *out, **argv = NULL; | |
596 | unsigned array_size = 0; | |
597 | ||
598 | *argc = 0; | |
814d6862 DT |
599 | |
600 | if (!input) { | |
601 | *argvp = NULL; | |
602 | return 0; | |
603 | } | |
604 | ||
1da177e4 LT |
605 | argv = realloc_argv(&array_size, argv); |
606 | if (!argv) | |
607 | return -ENOMEM; | |
608 | ||
609 | while (1) { | |
610 | start = end; | |
611 | ||
612 | /* Skip whitespace */ | |
613 | while (*start && isspace(*start)) | |
614 | start++; | |
615 | ||
616 | if (!*start) | |
617 | break; /* success, we hit the end */ | |
618 | ||
619 | /* 'out' is used to remove any back-quotes */ | |
620 | end = out = start; | |
621 | while (*end) { | |
622 | /* Everything apart from '\0' can be quoted */ | |
623 | if (*end == '\\' && *(end + 1)) { | |
624 | *out++ = *(end + 1); | |
625 | end += 2; | |
626 | continue; | |
627 | } | |
628 | ||
629 | if (isspace(*end)) | |
630 | break; /* end of token */ | |
631 | ||
632 | *out++ = *end++; | |
633 | } | |
634 | ||
635 | /* have we already filled the array ? */ | |
636 | if ((*argc + 1) > array_size) { | |
637 | argv = realloc_argv(&array_size, argv); | |
638 | if (!argv) | |
639 | return -ENOMEM; | |
640 | } | |
641 | ||
642 | /* we know this is whitespace */ | |
643 | if (*end) | |
644 | end++; | |
645 | ||
646 | /* terminate the string and put it in the array */ | |
647 | *out = '\0'; | |
648 | argv[*argc] = start; | |
649 | (*argc)++; | |
650 | } | |
651 | ||
652 | *argvp = argv; | |
653 | return 0; | |
654 | } | |
655 | ||
656 | static void check_for_valid_limits(struct io_restrictions *rs) | |
657 | { | |
658 | if (!rs->max_sectors) | |
defd94b7 | 659 | rs->max_sectors = SAFE_MAX_SECTORS; |
91212507 NB |
660 | if (!rs->max_hw_sectors) |
661 | rs->max_hw_sectors = SAFE_MAX_SECTORS; | |
1da177e4 LT |
662 | if (!rs->max_phys_segments) |
663 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
664 | if (!rs->max_hw_segments) | |
665 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
666 | if (!rs->hardsect_size) | |
667 | rs->hardsect_size = 1 << SECTOR_SHIFT; | |
668 | if (!rs->max_segment_size) | |
669 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
670 | if (!rs->seg_boundary_mask) | |
671 | rs->seg_boundary_mask = -1; | |
5ec140e6 VA |
672 | if (!rs->bounce_pfn) |
673 | rs->bounce_pfn = -1; | |
1da177e4 LT |
674 | } |
675 | ||
676 | int dm_table_add_target(struct dm_table *t, const char *type, | |
677 | sector_t start, sector_t len, char *params) | |
678 | { | |
679 | int r = -EINVAL, argc; | |
680 | char **argv; | |
681 | struct dm_target *tgt; | |
682 | ||
683 | if ((r = check_space(t))) | |
684 | return r; | |
685 | ||
686 | tgt = t->targets + t->num_targets; | |
687 | memset(tgt, 0, sizeof(*tgt)); | |
688 | ||
689 | if (!len) { | |
72d94861 | 690 | DMERR("%s: zero-length target", dm_device_name(t->md)); |
1da177e4 LT |
691 | return -EINVAL; |
692 | } | |
693 | ||
694 | tgt->type = dm_get_target_type(type); | |
695 | if (!tgt->type) { | |
72d94861 AK |
696 | DMERR("%s: %s: unknown target type", dm_device_name(t->md), |
697 | type); | |
1da177e4 LT |
698 | return -EINVAL; |
699 | } | |
700 | ||
701 | tgt->table = t; | |
702 | tgt->begin = start; | |
703 | tgt->len = len; | |
704 | tgt->error = "Unknown error"; | |
705 | ||
706 | /* | |
707 | * Does this target adjoin the previous one ? | |
708 | */ | |
709 | if (!adjoin(t, tgt)) { | |
710 | tgt->error = "Gap in table"; | |
711 | r = -EINVAL; | |
712 | goto bad; | |
713 | } | |
714 | ||
715 | r = dm_split_args(&argc, &argv, params); | |
716 | if (r) { | |
717 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
718 | goto bad; | |
719 | } | |
720 | ||
721 | r = tgt->type->ctr(tgt, argc, argv); | |
722 | kfree(argv); | |
723 | if (r) | |
724 | goto bad; | |
725 | ||
726 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
727 | ||
728 | /* FIXME: the plan is to combine high here and then have | |
729 | * the merge fn apply the target level restrictions. */ | |
730 | combine_restrictions_low(&t->limits, &tgt->limits); | |
731 | return 0; | |
732 | ||
733 | bad: | |
72d94861 | 734 | DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); |
1da177e4 LT |
735 | dm_put_target_type(tgt->type); |
736 | return r; | |
737 | } | |
738 | ||
739 | static int setup_indexes(struct dm_table *t) | |
740 | { | |
741 | int i; | |
742 | unsigned int total = 0; | |
743 | sector_t *indexes; | |
744 | ||
745 | /* allocate the space for *all* the indexes */ | |
746 | for (i = t->depth - 2; i >= 0; i--) { | |
747 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
748 | total += t->counts[i]; | |
749 | } | |
750 | ||
751 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
752 | if (!indexes) | |
753 | return -ENOMEM; | |
754 | ||
755 | /* set up internal nodes, bottom-up */ | |
82d601dc | 756 | for (i = t->depth - 2; i >= 0; i--) { |
1da177e4 LT |
757 | t->index[i] = indexes; |
758 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
759 | setup_btree_index(i, t); | |
760 | } | |
761 | ||
762 | return 0; | |
763 | } | |
764 | ||
765 | /* | |
766 | * Builds the btree to index the map. | |
767 | */ | |
768 | int dm_table_complete(struct dm_table *t) | |
769 | { | |
770 | int r = 0; | |
771 | unsigned int leaf_nodes; | |
772 | ||
773 | check_for_valid_limits(&t->limits); | |
774 | ||
775 | /* how many indexes will the btree have ? */ | |
776 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
777 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
778 | ||
779 | /* leaf layer has already been set up */ | |
780 | t->counts[t->depth - 1] = leaf_nodes; | |
781 | t->index[t->depth - 1] = t->highs; | |
782 | ||
783 | if (t->depth >= 2) | |
784 | r = setup_indexes(t); | |
785 | ||
786 | return r; | |
787 | } | |
788 | ||
48c9c27b | 789 | static DEFINE_MUTEX(_event_lock); |
1da177e4 LT |
790 | void dm_table_event_callback(struct dm_table *t, |
791 | void (*fn)(void *), void *context) | |
792 | { | |
48c9c27b | 793 | mutex_lock(&_event_lock); |
1da177e4 LT |
794 | t->event_fn = fn; |
795 | t->event_context = context; | |
48c9c27b | 796 | mutex_unlock(&_event_lock); |
1da177e4 LT |
797 | } |
798 | ||
799 | void dm_table_event(struct dm_table *t) | |
800 | { | |
801 | /* | |
802 | * You can no longer call dm_table_event() from interrupt | |
803 | * context, use a bottom half instead. | |
804 | */ | |
805 | BUG_ON(in_interrupt()); | |
806 | ||
48c9c27b | 807 | mutex_lock(&_event_lock); |
1da177e4 LT |
808 | if (t->event_fn) |
809 | t->event_fn(t->event_context); | |
48c9c27b | 810 | mutex_unlock(&_event_lock); |
1da177e4 LT |
811 | } |
812 | ||
813 | sector_t dm_table_get_size(struct dm_table *t) | |
814 | { | |
815 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
816 | } | |
817 | ||
818 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
819 | { | |
14353539 | 820 | if (index >= t->num_targets) |
1da177e4 LT |
821 | return NULL; |
822 | ||
823 | return t->targets + index; | |
824 | } | |
825 | ||
826 | /* | |
827 | * Search the btree for the correct target. | |
512875bd JN |
828 | * |
829 | * Caller should check returned pointer with dm_target_is_valid() | |
830 | * to trap I/O beyond end of device. | |
1da177e4 LT |
831 | */ |
832 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
833 | { | |
834 | unsigned int l, n = 0, k = 0; | |
835 | sector_t *node; | |
836 | ||
837 | for (l = 0; l < t->depth; l++) { | |
838 | n = get_child(n, k); | |
839 | node = get_node(t, l, n); | |
840 | ||
841 | for (k = 0; k < KEYS_PER_NODE; k++) | |
842 | if (node[k] >= sector) | |
843 | break; | |
844 | } | |
845 | ||
846 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
847 | } | |
848 | ||
849 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) | |
850 | { | |
851 | /* | |
852 | * Make sure we obey the optimistic sub devices | |
853 | * restrictions. | |
854 | */ | |
855 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
856 | q->max_phys_segments = t->limits.max_phys_segments; | |
857 | q->max_hw_segments = t->limits.max_hw_segments; | |
858 | q->hardsect_size = t->limits.hardsect_size; | |
859 | q->max_segment_size = t->limits.max_segment_size; | |
91212507 | 860 | q->max_hw_sectors = t->limits.max_hw_sectors; |
1da177e4 | 861 | q->seg_boundary_mask = t->limits.seg_boundary_mask; |
5ec140e6 | 862 | q->bounce_pfn = t->limits.bounce_pfn; |
c9a3f6d6 | 863 | |
969429b5 | 864 | if (t->limits.no_cluster) |
c9a3f6d6 | 865 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 866 | else |
c9a3f6d6 | 867 | queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); |
969429b5 | 868 | |
1da177e4 LT |
869 | } |
870 | ||
871 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
872 | { | |
873 | return t->num_targets; | |
874 | } | |
875 | ||
876 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
877 | { | |
878 | return &t->devices; | |
879 | } | |
880 | ||
881 | int dm_table_get_mode(struct dm_table *t) | |
882 | { | |
883 | return t->mode; | |
884 | } | |
885 | ||
886 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
887 | { | |
888 | int i = t->num_targets; | |
889 | struct dm_target *ti = t->targets; | |
890 | ||
891 | while (i--) { | |
892 | if (postsuspend) { | |
893 | if (ti->type->postsuspend) | |
894 | ti->type->postsuspend(ti); | |
895 | } else if (ti->type->presuspend) | |
896 | ti->type->presuspend(ti); | |
897 | ||
898 | ti++; | |
899 | } | |
900 | } | |
901 | ||
902 | void dm_table_presuspend_targets(struct dm_table *t) | |
903 | { | |
cf222b37 AK |
904 | if (!t) |
905 | return; | |
906 | ||
e8488d08 | 907 | suspend_targets(t, 0); |
1da177e4 LT |
908 | } |
909 | ||
910 | void dm_table_postsuspend_targets(struct dm_table *t) | |
911 | { | |
cf222b37 AK |
912 | if (!t) |
913 | return; | |
914 | ||
e8488d08 | 915 | suspend_targets(t, 1); |
1da177e4 LT |
916 | } |
917 | ||
8757b776 | 918 | int dm_table_resume_targets(struct dm_table *t) |
1da177e4 | 919 | { |
8757b776 MB |
920 | int i, r = 0; |
921 | ||
922 | for (i = 0; i < t->num_targets; i++) { | |
923 | struct dm_target *ti = t->targets + i; | |
924 | ||
925 | if (!ti->type->preresume) | |
926 | continue; | |
927 | ||
928 | r = ti->type->preresume(ti); | |
929 | if (r) | |
930 | return r; | |
931 | } | |
1da177e4 LT |
932 | |
933 | for (i = 0; i < t->num_targets; i++) { | |
934 | struct dm_target *ti = t->targets + i; | |
935 | ||
936 | if (ti->type->resume) | |
937 | ti->type->resume(ti); | |
938 | } | |
8757b776 MB |
939 | |
940 | return 0; | |
1da177e4 LT |
941 | } |
942 | ||
943 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
944 | { | |
82b1519b | 945 | struct dm_dev_internal *dd; |
afb24528 | 946 | struct list_head *devices = dm_table_get_devices(t); |
1da177e4 LT |
947 | int r = 0; |
948 | ||
afb24528 | 949 | list_for_each_entry(dd, devices, list) { |
82b1519b | 950 | struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); |
0c2322e4 AK |
951 | char b[BDEVNAME_SIZE]; |
952 | ||
953 | if (likely(q)) | |
954 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); | |
955 | else | |
956 | DMWARN_LIMIT("%s: any_congested: nonexistent device %s", | |
957 | dm_device_name(t->md), | |
958 | bdevname(dd->dm_dev.bdev, b)); | |
1da177e4 LT |
959 | } |
960 | ||
961 | return r; | |
962 | } | |
963 | ||
964 | void dm_table_unplug_all(struct dm_table *t) | |
965 | { | |
82b1519b | 966 | struct dm_dev_internal *dd; |
afb24528 | 967 | struct list_head *devices = dm_table_get_devices(t); |
1da177e4 | 968 | |
afb24528 | 969 | list_for_each_entry(dd, devices, list) { |
82b1519b | 970 | struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); |
0c2322e4 AK |
971 | char b[BDEVNAME_SIZE]; |
972 | ||
973 | if (likely(q)) | |
974 | blk_unplug(q); | |
975 | else | |
976 | DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s", | |
977 | dm_device_name(t->md), | |
978 | bdevname(dd->dm_dev.bdev, b)); | |
1da177e4 LT |
979 | } |
980 | } | |
981 | ||
1134e5ae MA |
982 | struct mapped_device *dm_table_get_md(struct dm_table *t) |
983 | { | |
984 | dm_get(t->md); | |
985 | ||
986 | return t->md; | |
987 | } | |
988 | ||
1da177e4 LT |
989 | EXPORT_SYMBOL(dm_vcalloc); |
990 | EXPORT_SYMBOL(dm_get_device); | |
991 | EXPORT_SYMBOL(dm_put_device); | |
992 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 993 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 | 994 | EXPORT_SYMBOL(dm_table_get_mode); |
1134e5ae | 995 | EXPORT_SYMBOL(dm_table_get_md); |
1da177e4 LT |
996 | EXPORT_SYMBOL(dm_table_put); |
997 | EXPORT_SYMBOL(dm_table_get); | |
998 | EXPORT_SYMBOL(dm_table_unplug_all); |