]>
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 | ||
20 | #define MAX_DEPTH 16 | |
21 | #define NODE_SIZE L1_CACHE_BYTES | |
22 | #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) | |
23 | #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) | |
24 | ||
25 | struct dm_table { | |
1134e5ae | 26 | struct mapped_device *md; |
1da177e4 LT |
27 | atomic_t holders; |
28 | ||
29 | /* btree table */ | |
30 | unsigned int depth; | |
31 | unsigned int counts[MAX_DEPTH]; /* in nodes */ | |
32 | sector_t *index[MAX_DEPTH]; | |
33 | ||
34 | unsigned int num_targets; | |
35 | unsigned int num_allocated; | |
36 | sector_t *highs; | |
37 | struct dm_target *targets; | |
38 | ||
39 | /* | |
40 | * Indicates the rw permissions for the new logical | |
41 | * device. This should be a combination of FMODE_READ | |
42 | * and FMODE_WRITE. | |
43 | */ | |
44 | int mode; | |
45 | ||
46 | /* a list of devices used by this table */ | |
47 | struct list_head devices; | |
48 | ||
49 | /* | |
50 | * These are optimistic limits taken from all the | |
51 | * targets, some targets will need smaller limits. | |
52 | */ | |
53 | struct io_restrictions limits; | |
54 | ||
55 | /* events get handed up using this callback */ | |
56 | void (*event_fn)(void *); | |
57 | void *event_context; | |
58 | }; | |
59 | ||
60 | /* | |
61 | * Similar to ceiling(log_size(n)) | |
62 | */ | |
63 | static unsigned int int_log(unsigned int n, unsigned int base) | |
64 | { | |
65 | int result = 0; | |
66 | ||
67 | while (n > 1) { | |
68 | n = dm_div_up(n, base); | |
69 | result++; | |
70 | } | |
71 | ||
72 | return result; | |
73 | } | |
74 | ||
75 | /* | |
76 | * Returns the minimum that is _not_ zero, unless both are zero. | |
77 | */ | |
78 | #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) | |
79 | ||
80 | /* | |
81 | * Combine two io_restrictions, always taking the lower value. | |
82 | */ | |
83 | static void combine_restrictions_low(struct io_restrictions *lhs, | |
84 | struct io_restrictions *rhs) | |
85 | { | |
86 | lhs->max_sectors = | |
87 | min_not_zero(lhs->max_sectors, rhs->max_sectors); | |
88 | ||
89 | lhs->max_phys_segments = | |
90 | min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments); | |
91 | ||
92 | lhs->max_hw_segments = | |
93 | min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments); | |
94 | ||
95 | lhs->hardsect_size = max(lhs->hardsect_size, rhs->hardsect_size); | |
96 | ||
97 | lhs->max_segment_size = | |
98 | min_not_zero(lhs->max_segment_size, rhs->max_segment_size); | |
99 | ||
100 | lhs->seg_boundary_mask = | |
101 | min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); | |
969429b5 N |
102 | |
103 | lhs->no_cluster |= rhs->no_cluster; | |
1da177e4 LT |
104 | } |
105 | ||
106 | /* | |
107 | * Calculate the index of the child node of the n'th node k'th key. | |
108 | */ | |
109 | static inline unsigned int get_child(unsigned int n, unsigned int k) | |
110 | { | |
111 | return (n * CHILDREN_PER_NODE) + k; | |
112 | } | |
113 | ||
114 | /* | |
115 | * Return the n'th node of level l from table t. | |
116 | */ | |
117 | static inline sector_t *get_node(struct dm_table *t, | |
118 | unsigned int l, unsigned int n) | |
119 | { | |
120 | return t->index[l] + (n * KEYS_PER_NODE); | |
121 | } | |
122 | ||
123 | /* | |
124 | * Return the highest key that you could lookup from the n'th | |
125 | * node on level l of the btree. | |
126 | */ | |
127 | static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) | |
128 | { | |
129 | for (; l < t->depth - 1; l++) | |
130 | n = get_child(n, CHILDREN_PER_NODE - 1); | |
131 | ||
132 | if (n >= t->counts[l]) | |
133 | return (sector_t) - 1; | |
134 | ||
135 | return get_node(t, l, n)[KEYS_PER_NODE - 1]; | |
136 | } | |
137 | ||
138 | /* | |
139 | * Fills in a level of the btree based on the highs of the level | |
140 | * below it. | |
141 | */ | |
142 | static int setup_btree_index(unsigned int l, struct dm_table *t) | |
143 | { | |
144 | unsigned int n, k; | |
145 | sector_t *node; | |
146 | ||
147 | for (n = 0U; n < t->counts[l]; n++) { | |
148 | node = get_node(t, l, n); | |
149 | ||
150 | for (k = 0U; k < KEYS_PER_NODE; k++) | |
151 | node[k] = high(t, l + 1, get_child(n, k)); | |
152 | } | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) | |
158 | { | |
159 | unsigned long size; | |
160 | void *addr; | |
161 | ||
162 | /* | |
163 | * Check that we're not going to overflow. | |
164 | */ | |
165 | if (nmemb > (ULONG_MAX / elem_size)) | |
166 | return NULL; | |
167 | ||
168 | size = nmemb * elem_size; | |
169 | addr = vmalloc(size); | |
170 | if (addr) | |
171 | memset(addr, 0, size); | |
172 | ||
173 | return addr; | |
174 | } | |
175 | ||
176 | /* | |
177 | * highs, and targets are managed as dynamic arrays during a | |
178 | * table load. | |
179 | */ | |
180 | static int alloc_targets(struct dm_table *t, unsigned int num) | |
181 | { | |
182 | sector_t *n_highs; | |
183 | struct dm_target *n_targets; | |
184 | int n = t->num_targets; | |
185 | ||
186 | /* | |
187 | * Allocate both the target array and offset array at once. | |
188 | */ | |
189 | n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) + | |
190 | sizeof(sector_t)); | |
191 | if (!n_highs) | |
192 | return -ENOMEM; | |
193 | ||
194 | n_targets = (struct dm_target *) (n_highs + num); | |
195 | ||
196 | if (n) { | |
197 | memcpy(n_highs, t->highs, sizeof(*n_highs) * n); | |
198 | memcpy(n_targets, t->targets, sizeof(*n_targets) * n); | |
199 | } | |
200 | ||
201 | memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); | |
202 | vfree(t->highs); | |
203 | ||
204 | t->num_allocated = num; | |
205 | t->highs = n_highs; | |
206 | t->targets = n_targets; | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
1134e5ae MA |
211 | int dm_table_create(struct dm_table **result, int mode, |
212 | unsigned num_targets, struct mapped_device *md) | |
1da177e4 LT |
213 | { |
214 | struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL); | |
215 | ||
216 | if (!t) | |
217 | return -ENOMEM; | |
218 | ||
219 | memset(t, 0, sizeof(*t)); | |
220 | INIT_LIST_HEAD(&t->devices); | |
221 | atomic_set(&t->holders, 1); | |
222 | ||
223 | if (!num_targets) | |
224 | num_targets = KEYS_PER_NODE; | |
225 | ||
226 | num_targets = dm_round_up(num_targets, KEYS_PER_NODE); | |
227 | ||
228 | if (alloc_targets(t, num_targets)) { | |
229 | kfree(t); | |
230 | t = NULL; | |
231 | return -ENOMEM; | |
232 | } | |
233 | ||
234 | t->mode = mode; | |
1134e5ae | 235 | t->md = md; |
1da177e4 LT |
236 | *result = t; |
237 | return 0; | |
238 | } | |
239 | ||
240 | static void free_devices(struct list_head *devices) | |
241 | { | |
242 | struct list_head *tmp, *next; | |
243 | ||
244 | for (tmp = devices->next; tmp != devices; tmp = next) { | |
245 | struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); | |
246 | next = tmp->next; | |
247 | kfree(dd); | |
248 | } | |
249 | } | |
250 | ||
5e198d94 | 251 | static void table_destroy(struct dm_table *t) |
1da177e4 LT |
252 | { |
253 | unsigned int i; | |
254 | ||
255 | /* free the indexes (see dm_table_complete) */ | |
256 | if (t->depth >= 2) | |
257 | vfree(t->index[t->depth - 2]); | |
258 | ||
259 | /* free the targets */ | |
260 | for (i = 0; i < t->num_targets; i++) { | |
261 | struct dm_target *tgt = t->targets + i; | |
262 | ||
263 | if (tgt->type->dtr) | |
264 | tgt->type->dtr(tgt); | |
265 | ||
266 | dm_put_target_type(tgt->type); | |
267 | } | |
268 | ||
269 | vfree(t->highs); | |
270 | ||
271 | /* free the device list */ | |
272 | if (t->devices.next != &t->devices) { | |
273 | DMWARN("devices still present during destroy: " | |
274 | "dm_table_remove_device calls missing"); | |
275 | ||
276 | free_devices(&t->devices); | |
277 | } | |
278 | ||
279 | kfree(t); | |
280 | } | |
281 | ||
282 | void dm_table_get(struct dm_table *t) | |
283 | { | |
284 | atomic_inc(&t->holders); | |
285 | } | |
286 | ||
287 | void dm_table_put(struct dm_table *t) | |
288 | { | |
289 | if (!t) | |
290 | return; | |
291 | ||
292 | if (atomic_dec_and_test(&t->holders)) | |
293 | table_destroy(t); | |
294 | } | |
295 | ||
296 | /* | |
297 | * Checks to see if we need to extend highs or targets. | |
298 | */ | |
299 | static inline int check_space(struct dm_table *t) | |
300 | { | |
301 | if (t->num_targets >= t->num_allocated) | |
302 | return alloc_targets(t, t->num_allocated * 2); | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
307 | /* | |
308 | * Convert a device path to a dev_t. | |
309 | */ | |
310 | static int lookup_device(const char *path, dev_t *dev) | |
311 | { | |
312 | int r; | |
313 | struct nameidata nd; | |
314 | struct inode *inode; | |
315 | ||
316 | if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd))) | |
317 | return r; | |
318 | ||
319 | inode = nd.dentry->d_inode; | |
320 | if (!inode) { | |
321 | r = -ENOENT; | |
322 | goto out; | |
323 | } | |
324 | ||
325 | if (!S_ISBLK(inode->i_mode)) { | |
326 | r = -ENOTBLK; | |
327 | goto out; | |
328 | } | |
329 | ||
330 | *dev = inode->i_rdev; | |
331 | ||
332 | out: | |
333 | path_release(&nd); | |
334 | return r; | |
335 | } | |
336 | ||
337 | /* | |
338 | * See if we've already got a device in the list. | |
339 | */ | |
340 | static struct dm_dev *find_device(struct list_head *l, dev_t dev) | |
341 | { | |
342 | struct dm_dev *dd; | |
343 | ||
344 | list_for_each_entry (dd, l, list) | |
345 | if (dd->bdev->bd_dev == dev) | |
346 | return dd; | |
347 | ||
348 | return NULL; | |
349 | } | |
350 | ||
351 | /* | |
352 | * Open a device so we can use it as a map destination. | |
353 | */ | |
f165921d | 354 | static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md) |
1da177e4 LT |
355 | { |
356 | static char *_claim_ptr = "I belong to device-mapper"; | |
357 | struct block_device *bdev; | |
358 | ||
359 | int r; | |
360 | ||
547bc926 | 361 | BUG_ON(d->bdev); |
1da177e4 LT |
362 | |
363 | bdev = open_by_devnum(dev, d->mode); | |
364 | if (IS_ERR(bdev)) | |
365 | return PTR_ERR(bdev); | |
f165921d | 366 | r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
1da177e4 LT |
367 | if (r) |
368 | blkdev_put(bdev); | |
369 | else | |
370 | d->bdev = bdev; | |
371 | return r; | |
372 | } | |
373 | ||
374 | /* | |
375 | * Close a device that we've been using. | |
376 | */ | |
f165921d | 377 | static void close_dev(struct dm_dev *d, struct mapped_device *md) |
1da177e4 LT |
378 | { |
379 | if (!d->bdev) | |
380 | return; | |
381 | ||
f165921d | 382 | bd_release_from_disk(d->bdev, dm_disk(md)); |
1da177e4 LT |
383 | blkdev_put(d->bdev); |
384 | d->bdev = NULL; | |
385 | } | |
386 | ||
387 | /* | |
388 | * If possible (ie. blk_size[major] is set), this checks an area | |
389 | * of a destination device is valid. | |
390 | */ | |
391 | static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) | |
392 | { | |
393 | sector_t dev_size; | |
394 | dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; | |
395 | return ((start < dev_size) && (len <= (dev_size - start))); | |
396 | } | |
397 | ||
398 | /* | |
399 | * This upgrades the mode on an already open dm_dev. Being | |
400 | * careful to leave things as they were if we fail to reopen the | |
401 | * device. | |
402 | */ | |
f165921d | 403 | static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) |
1da177e4 LT |
404 | { |
405 | int r; | |
406 | struct dm_dev dd_copy; | |
407 | dev_t dev = dd->bdev->bd_dev; | |
408 | ||
409 | dd_copy = *dd; | |
410 | ||
411 | dd->mode |= new_mode; | |
412 | dd->bdev = NULL; | |
f165921d | 413 | r = open_dev(dd, dev, md); |
1da177e4 | 414 | if (!r) |
f165921d | 415 | close_dev(&dd_copy, md); |
1da177e4 LT |
416 | else |
417 | *dd = dd_copy; | |
418 | ||
419 | return r; | |
420 | } | |
421 | ||
422 | /* | |
423 | * Add a device to the list, or just increment the usage count if | |
424 | * it's already present. | |
425 | */ | |
426 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
427 | const char *path, sector_t start, sector_t len, | |
428 | int mode, struct dm_dev **result) | |
429 | { | |
430 | int r; | |
431 | dev_t dev; | |
432 | struct dm_dev *dd; | |
433 | unsigned int major, minor; | |
434 | ||
547bc926 | 435 | BUG_ON(!t); |
1da177e4 LT |
436 | |
437 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
438 | /* Extract the major/minor numbers */ | |
439 | dev = MKDEV(major, minor); | |
440 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
441 | return -EOVERFLOW; | |
442 | } else { | |
443 | /* convert the path to a device */ | |
444 | if ((r = lookup_device(path, &dev))) | |
445 | return r; | |
446 | } | |
447 | ||
448 | dd = find_device(&t->devices, dev); | |
449 | if (!dd) { | |
450 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
451 | if (!dd) | |
452 | return -ENOMEM; | |
453 | ||
454 | dd->mode = mode; | |
455 | dd->bdev = NULL; | |
456 | ||
f165921d | 457 | if ((r = open_dev(dd, dev, t->md))) { |
1da177e4 LT |
458 | kfree(dd); |
459 | return r; | |
460 | } | |
461 | ||
462 | format_dev_t(dd->name, dev); | |
463 | ||
464 | atomic_set(&dd->count, 0); | |
465 | list_add(&dd->list, &t->devices); | |
466 | ||
467 | } else if (dd->mode != (mode | dd->mode)) { | |
f165921d | 468 | r = upgrade_mode(dd, mode, t->md); |
1da177e4 LT |
469 | if (r) |
470 | return r; | |
471 | } | |
472 | atomic_inc(&dd->count); | |
473 | ||
474 | if (!check_device_area(dd, start, len)) { | |
475 | DMWARN("device %s too small for target", path); | |
476 | dm_put_device(ti, dd); | |
477 | return -EINVAL; | |
478 | } | |
479 | ||
480 | *result = dd; | |
481 | ||
482 | return 0; | |
483 | } | |
484 | ||
485 | ||
486 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
487 | sector_t len, int mode, struct dm_dev **result) | |
488 | { | |
489 | int r = __table_get_device(ti->table, ti, path, | |
490 | start, len, mode, result); | |
491 | if (!r) { | |
492 | request_queue_t *q = bdev_get_queue((*result)->bdev); | |
493 | struct io_restrictions *rs = &ti->limits; | |
494 | ||
495 | /* | |
496 | * Combine the device limits low. | |
497 | * | |
498 | * FIXME: if we move an io_restriction struct | |
499 | * into q this would just be a call to | |
500 | * combine_restrictions_low() | |
501 | */ | |
502 | rs->max_sectors = | |
503 | min_not_zero(rs->max_sectors, q->max_sectors); | |
504 | ||
505 | /* FIXME: Device-Mapper on top of RAID-0 breaks because DM | |
506 | * currently doesn't honor MD's merge_bvec_fn routine. | |
507 | * In this case, we'll force DM to use PAGE_SIZE or | |
508 | * smaller I/O, just to be safe. A better fix is in the | |
509 | * works, but add this for the time being so it will at | |
510 | * least operate correctly. | |
511 | */ | |
512 | if (q->merge_bvec_fn) | |
513 | rs->max_sectors = | |
514 | min_not_zero(rs->max_sectors, | |
3ee247eb | 515 | (unsigned int) (PAGE_SIZE >> 9)); |
1da177e4 LT |
516 | |
517 | rs->max_phys_segments = | |
518 | min_not_zero(rs->max_phys_segments, | |
519 | q->max_phys_segments); | |
520 | ||
521 | rs->max_hw_segments = | |
522 | min_not_zero(rs->max_hw_segments, q->max_hw_segments); | |
523 | ||
524 | rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); | |
525 | ||
526 | rs->max_segment_size = | |
527 | min_not_zero(rs->max_segment_size, q->max_segment_size); | |
528 | ||
529 | rs->seg_boundary_mask = | |
530 | min_not_zero(rs->seg_boundary_mask, | |
531 | q->seg_boundary_mask); | |
969429b5 N |
532 | |
533 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); | |
1da177e4 LT |
534 | } |
535 | ||
536 | return r; | |
537 | } | |
538 | ||
539 | /* | |
540 | * Decrement a devices use count and remove it if necessary. | |
541 | */ | |
542 | void dm_put_device(struct dm_target *ti, struct dm_dev *dd) | |
543 | { | |
544 | if (atomic_dec_and_test(&dd->count)) { | |
f165921d | 545 | close_dev(dd, ti->table->md); |
1da177e4 LT |
546 | list_del(&dd->list); |
547 | kfree(dd); | |
548 | } | |
549 | } | |
550 | ||
551 | /* | |
552 | * Checks to see if the target joins onto the end of the table. | |
553 | */ | |
554 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
555 | { | |
556 | struct dm_target *prev; | |
557 | ||
558 | if (!table->num_targets) | |
559 | return !ti->begin; | |
560 | ||
561 | prev = &table->targets[table->num_targets - 1]; | |
562 | return (ti->begin == (prev->begin + prev->len)); | |
563 | } | |
564 | ||
565 | /* | |
566 | * Used to dynamically allocate the arg array. | |
567 | */ | |
568 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
569 | { | |
570 | char **argv; | |
571 | unsigned new_size; | |
572 | ||
573 | new_size = *array_size ? *array_size * 2 : 64; | |
574 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
575 | if (argv) { | |
576 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
577 | *array_size = new_size; | |
578 | } | |
579 | ||
580 | kfree(old_argv); | |
581 | return argv; | |
582 | } | |
583 | ||
584 | /* | |
585 | * Destructively splits up the argument list to pass to ctr. | |
586 | */ | |
587 | int dm_split_args(int *argc, char ***argvp, char *input) | |
588 | { | |
589 | char *start, *end = input, *out, **argv = NULL; | |
590 | unsigned array_size = 0; | |
591 | ||
592 | *argc = 0; | |
593 | argv = realloc_argv(&array_size, argv); | |
594 | if (!argv) | |
595 | return -ENOMEM; | |
596 | ||
597 | while (1) { | |
598 | start = end; | |
599 | ||
600 | /* Skip whitespace */ | |
601 | while (*start && isspace(*start)) | |
602 | start++; | |
603 | ||
604 | if (!*start) | |
605 | break; /* success, we hit the end */ | |
606 | ||
607 | /* 'out' is used to remove any back-quotes */ | |
608 | end = out = start; | |
609 | while (*end) { | |
610 | /* Everything apart from '\0' can be quoted */ | |
611 | if (*end == '\\' && *(end + 1)) { | |
612 | *out++ = *(end + 1); | |
613 | end += 2; | |
614 | continue; | |
615 | } | |
616 | ||
617 | if (isspace(*end)) | |
618 | break; /* end of token */ | |
619 | ||
620 | *out++ = *end++; | |
621 | } | |
622 | ||
623 | /* have we already filled the array ? */ | |
624 | if ((*argc + 1) > array_size) { | |
625 | argv = realloc_argv(&array_size, argv); | |
626 | if (!argv) | |
627 | return -ENOMEM; | |
628 | } | |
629 | ||
630 | /* we know this is whitespace */ | |
631 | if (*end) | |
632 | end++; | |
633 | ||
634 | /* terminate the string and put it in the array */ | |
635 | *out = '\0'; | |
636 | argv[*argc] = start; | |
637 | (*argc)++; | |
638 | } | |
639 | ||
640 | *argvp = argv; | |
641 | return 0; | |
642 | } | |
643 | ||
644 | static void check_for_valid_limits(struct io_restrictions *rs) | |
645 | { | |
646 | if (!rs->max_sectors) | |
defd94b7 | 647 | rs->max_sectors = SAFE_MAX_SECTORS; |
1da177e4 LT |
648 | if (!rs->max_phys_segments) |
649 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
650 | if (!rs->max_hw_segments) | |
651 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
652 | if (!rs->hardsect_size) | |
653 | rs->hardsect_size = 1 << SECTOR_SHIFT; | |
654 | if (!rs->max_segment_size) | |
655 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
656 | if (!rs->seg_boundary_mask) | |
657 | rs->seg_boundary_mask = -1; | |
658 | } | |
659 | ||
660 | int dm_table_add_target(struct dm_table *t, const char *type, | |
661 | sector_t start, sector_t len, char *params) | |
662 | { | |
663 | int r = -EINVAL, argc; | |
664 | char **argv; | |
665 | struct dm_target *tgt; | |
666 | ||
667 | if ((r = check_space(t))) | |
668 | return r; | |
669 | ||
670 | tgt = t->targets + t->num_targets; | |
671 | memset(tgt, 0, sizeof(*tgt)); | |
672 | ||
673 | if (!len) { | |
674 | tgt->error = "zero-length target"; | |
675 | DMERR("%s", tgt->error); | |
676 | return -EINVAL; | |
677 | } | |
678 | ||
679 | tgt->type = dm_get_target_type(type); | |
680 | if (!tgt->type) { | |
681 | tgt->error = "unknown target type"; | |
682 | DMERR("%s", tgt->error); | |
683 | return -EINVAL; | |
684 | } | |
685 | ||
686 | tgt->table = t; | |
687 | tgt->begin = start; | |
688 | tgt->len = len; | |
689 | tgt->error = "Unknown error"; | |
690 | ||
691 | /* | |
692 | * Does this target adjoin the previous one ? | |
693 | */ | |
694 | if (!adjoin(t, tgt)) { | |
695 | tgt->error = "Gap in table"; | |
696 | r = -EINVAL; | |
697 | goto bad; | |
698 | } | |
699 | ||
700 | r = dm_split_args(&argc, &argv, params); | |
701 | if (r) { | |
702 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
703 | goto bad; | |
704 | } | |
705 | ||
706 | r = tgt->type->ctr(tgt, argc, argv); | |
707 | kfree(argv); | |
708 | if (r) | |
709 | goto bad; | |
710 | ||
711 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
712 | ||
713 | /* FIXME: the plan is to combine high here and then have | |
714 | * the merge fn apply the target level restrictions. */ | |
715 | combine_restrictions_low(&t->limits, &tgt->limits); | |
716 | return 0; | |
717 | ||
718 | bad: | |
719 | DMERR("%s", tgt->error); | |
720 | dm_put_target_type(tgt->type); | |
721 | return r; | |
722 | } | |
723 | ||
724 | static int setup_indexes(struct dm_table *t) | |
725 | { | |
726 | int i; | |
727 | unsigned int total = 0; | |
728 | sector_t *indexes; | |
729 | ||
730 | /* allocate the space for *all* the indexes */ | |
731 | for (i = t->depth - 2; i >= 0; i--) { | |
732 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
733 | total += t->counts[i]; | |
734 | } | |
735 | ||
736 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
737 | if (!indexes) | |
738 | return -ENOMEM; | |
739 | ||
740 | /* set up internal nodes, bottom-up */ | |
741 | for (i = t->depth - 2, total = 0; i >= 0; i--) { | |
742 | t->index[i] = indexes; | |
743 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
744 | setup_btree_index(i, t); | |
745 | } | |
746 | ||
747 | return 0; | |
748 | } | |
749 | ||
750 | /* | |
751 | * Builds the btree to index the map. | |
752 | */ | |
753 | int dm_table_complete(struct dm_table *t) | |
754 | { | |
755 | int r = 0; | |
756 | unsigned int leaf_nodes; | |
757 | ||
758 | check_for_valid_limits(&t->limits); | |
759 | ||
760 | /* how many indexes will the btree have ? */ | |
761 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
762 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
763 | ||
764 | /* leaf layer has already been set up */ | |
765 | t->counts[t->depth - 1] = leaf_nodes; | |
766 | t->index[t->depth - 1] = t->highs; | |
767 | ||
768 | if (t->depth >= 2) | |
769 | r = setup_indexes(t); | |
770 | ||
771 | return r; | |
772 | } | |
773 | ||
48c9c27b | 774 | static DEFINE_MUTEX(_event_lock); |
1da177e4 LT |
775 | void dm_table_event_callback(struct dm_table *t, |
776 | void (*fn)(void *), void *context) | |
777 | { | |
48c9c27b | 778 | mutex_lock(&_event_lock); |
1da177e4 LT |
779 | t->event_fn = fn; |
780 | t->event_context = context; | |
48c9c27b | 781 | mutex_unlock(&_event_lock); |
1da177e4 LT |
782 | } |
783 | ||
784 | void dm_table_event(struct dm_table *t) | |
785 | { | |
786 | /* | |
787 | * You can no longer call dm_table_event() from interrupt | |
788 | * context, use a bottom half instead. | |
789 | */ | |
790 | BUG_ON(in_interrupt()); | |
791 | ||
48c9c27b | 792 | mutex_lock(&_event_lock); |
1da177e4 LT |
793 | if (t->event_fn) |
794 | t->event_fn(t->event_context); | |
48c9c27b | 795 | mutex_unlock(&_event_lock); |
1da177e4 LT |
796 | } |
797 | ||
798 | sector_t dm_table_get_size(struct dm_table *t) | |
799 | { | |
800 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
801 | } | |
802 | ||
803 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
804 | { | |
805 | if (index > t->num_targets) | |
806 | return NULL; | |
807 | ||
808 | return t->targets + index; | |
809 | } | |
810 | ||
811 | /* | |
812 | * Search the btree for the correct target. | |
813 | */ | |
814 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
815 | { | |
816 | unsigned int l, n = 0, k = 0; | |
817 | sector_t *node; | |
818 | ||
819 | for (l = 0; l < t->depth; l++) { | |
820 | n = get_child(n, k); | |
821 | node = get_node(t, l, n); | |
822 | ||
823 | for (k = 0; k < KEYS_PER_NODE; k++) | |
824 | if (node[k] >= sector) | |
825 | break; | |
826 | } | |
827 | ||
828 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
829 | } | |
830 | ||
831 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) | |
832 | { | |
833 | /* | |
834 | * Make sure we obey the optimistic sub devices | |
835 | * restrictions. | |
836 | */ | |
837 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
838 | q->max_phys_segments = t->limits.max_phys_segments; | |
839 | q->max_hw_segments = t->limits.max_hw_segments; | |
840 | q->hardsect_size = t->limits.hardsect_size; | |
841 | q->max_segment_size = t->limits.max_segment_size; | |
842 | q->seg_boundary_mask = t->limits.seg_boundary_mask; | |
969429b5 N |
843 | if (t->limits.no_cluster) |
844 | q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER); | |
845 | else | |
846 | q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER); | |
847 | ||
1da177e4 LT |
848 | } |
849 | ||
850 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
851 | { | |
852 | return t->num_targets; | |
853 | } | |
854 | ||
855 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
856 | { | |
857 | return &t->devices; | |
858 | } | |
859 | ||
860 | int dm_table_get_mode(struct dm_table *t) | |
861 | { | |
862 | return t->mode; | |
863 | } | |
864 | ||
865 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
866 | { | |
867 | int i = t->num_targets; | |
868 | struct dm_target *ti = t->targets; | |
869 | ||
870 | while (i--) { | |
871 | if (postsuspend) { | |
872 | if (ti->type->postsuspend) | |
873 | ti->type->postsuspend(ti); | |
874 | } else if (ti->type->presuspend) | |
875 | ti->type->presuspend(ti); | |
876 | ||
877 | ti++; | |
878 | } | |
879 | } | |
880 | ||
881 | void dm_table_presuspend_targets(struct dm_table *t) | |
882 | { | |
cf222b37 AK |
883 | if (!t) |
884 | return; | |
885 | ||
1da177e4 LT |
886 | return suspend_targets(t, 0); |
887 | } | |
888 | ||
889 | void dm_table_postsuspend_targets(struct dm_table *t) | |
890 | { | |
cf222b37 AK |
891 | if (!t) |
892 | return; | |
893 | ||
1da177e4 LT |
894 | return suspend_targets(t, 1); |
895 | } | |
896 | ||
897 | void dm_table_resume_targets(struct dm_table *t) | |
898 | { | |
899 | int i; | |
900 | ||
901 | for (i = 0; i < t->num_targets; i++) { | |
902 | struct dm_target *ti = t->targets + i; | |
903 | ||
904 | if (ti->type->resume) | |
905 | ti->type->resume(ti); | |
906 | } | |
907 | } | |
908 | ||
909 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
910 | { | |
911 | struct list_head *d, *devices; | |
912 | int r = 0; | |
913 | ||
914 | devices = dm_table_get_devices(t); | |
915 | for (d = devices->next; d != devices; d = d->next) { | |
916 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
917 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
918 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); | |
919 | } | |
920 | ||
921 | return r; | |
922 | } | |
923 | ||
924 | void dm_table_unplug_all(struct dm_table *t) | |
925 | { | |
926 | struct list_head *d, *devices = dm_table_get_devices(t); | |
927 | ||
928 | for (d = devices->next; d != devices; d = d->next) { | |
929 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
930 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
931 | ||
932 | if (q->unplug_fn) | |
933 | q->unplug_fn(q); | |
934 | } | |
935 | } | |
936 | ||
937 | int dm_table_flush_all(struct dm_table *t) | |
938 | { | |
939 | struct list_head *d, *devices = dm_table_get_devices(t); | |
940 | int ret = 0; | |
941 | ||
942 | for (d = devices->next; d != devices; d = d->next) { | |
943 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
944 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
945 | int err; | |
946 | ||
947 | if (!q->issue_flush_fn) | |
948 | err = -EOPNOTSUPP; | |
949 | else | |
950 | err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL); | |
951 | ||
952 | if (!ret) | |
953 | ret = err; | |
954 | } | |
955 | ||
956 | return ret; | |
957 | } | |
958 | ||
1134e5ae MA |
959 | struct mapped_device *dm_table_get_md(struct dm_table *t) |
960 | { | |
961 | dm_get(t->md); | |
962 | ||
963 | return t->md; | |
964 | } | |
965 | ||
1da177e4 LT |
966 | EXPORT_SYMBOL(dm_vcalloc); |
967 | EXPORT_SYMBOL(dm_get_device); | |
968 | EXPORT_SYMBOL(dm_put_device); | |
969 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 970 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 | 971 | EXPORT_SYMBOL(dm_table_get_mode); |
1134e5ae | 972 | EXPORT_SYMBOL(dm_table_get_md); |
1da177e4 LT |
973 | EXPORT_SYMBOL(dm_table_put); |
974 | EXPORT_SYMBOL(dm_table_get); | |
975 | EXPORT_SYMBOL(dm_table_unplug_all); | |
976 | EXPORT_SYMBOL(dm_table_flush_all); |