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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> | |
17 | #include <asm/atomic.h> | |
18 | ||
19 | #define MAX_DEPTH 16 | |
20 | #define NODE_SIZE L1_CACHE_BYTES | |
21 | #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) | |
22 | #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) | |
23 | ||
24 | struct dm_table { | |
25 | atomic_t holders; | |
26 | ||
27 | /* btree table */ | |
28 | unsigned int depth; | |
29 | unsigned int counts[MAX_DEPTH]; /* in nodes */ | |
30 | sector_t *index[MAX_DEPTH]; | |
31 | ||
32 | unsigned int num_targets; | |
33 | unsigned int num_allocated; | |
34 | sector_t *highs; | |
35 | struct dm_target *targets; | |
36 | ||
37 | /* | |
38 | * Indicates the rw permissions for the new logical | |
39 | * device. This should be a combination of FMODE_READ | |
40 | * and FMODE_WRITE. | |
41 | */ | |
42 | int mode; | |
43 | ||
44 | /* a list of devices used by this table */ | |
45 | struct list_head devices; | |
46 | ||
47 | /* | |
48 | * These are optimistic limits taken from all the | |
49 | * targets, some targets will need smaller limits. | |
50 | */ | |
51 | struct io_restrictions limits; | |
52 | ||
53 | /* events get handed up using this callback */ | |
54 | void (*event_fn)(void *); | |
55 | void *event_context; | |
56 | }; | |
57 | ||
58 | /* | |
59 | * Similar to ceiling(log_size(n)) | |
60 | */ | |
61 | static unsigned int int_log(unsigned int n, unsigned int base) | |
62 | { | |
63 | int result = 0; | |
64 | ||
65 | while (n > 1) { | |
66 | n = dm_div_up(n, base); | |
67 | result++; | |
68 | } | |
69 | ||
70 | return result; | |
71 | } | |
72 | ||
73 | /* | |
74 | * Returns the minimum that is _not_ zero, unless both are zero. | |
75 | */ | |
76 | #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) | |
77 | ||
78 | /* | |
79 | * Combine two io_restrictions, always taking the lower value. | |
80 | */ | |
81 | static void combine_restrictions_low(struct io_restrictions *lhs, | |
82 | struct io_restrictions *rhs) | |
83 | { | |
84 | lhs->max_sectors = | |
85 | min_not_zero(lhs->max_sectors, rhs->max_sectors); | |
86 | ||
87 | lhs->max_phys_segments = | |
88 | min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments); | |
89 | ||
90 | lhs->max_hw_segments = | |
91 | min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments); | |
92 | ||
93 | lhs->hardsect_size = max(lhs->hardsect_size, rhs->hardsect_size); | |
94 | ||
95 | lhs->max_segment_size = | |
96 | min_not_zero(lhs->max_segment_size, rhs->max_segment_size); | |
97 | ||
98 | lhs->seg_boundary_mask = | |
99 | min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); | |
969429b5 N |
100 | |
101 | lhs->no_cluster |= rhs->no_cluster; | |
1da177e4 LT |
102 | } |
103 | ||
104 | /* | |
105 | * Calculate the index of the child node of the n'th node k'th key. | |
106 | */ | |
107 | static inline unsigned int get_child(unsigned int n, unsigned int k) | |
108 | { | |
109 | return (n * CHILDREN_PER_NODE) + k; | |
110 | } | |
111 | ||
112 | /* | |
113 | * Return the n'th node of level l from table t. | |
114 | */ | |
115 | static inline sector_t *get_node(struct dm_table *t, | |
116 | unsigned int l, unsigned int n) | |
117 | { | |
118 | return t->index[l] + (n * KEYS_PER_NODE); | |
119 | } | |
120 | ||
121 | /* | |
122 | * Return the highest key that you could lookup from the n'th | |
123 | * node on level l of the btree. | |
124 | */ | |
125 | static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) | |
126 | { | |
127 | for (; l < t->depth - 1; l++) | |
128 | n = get_child(n, CHILDREN_PER_NODE - 1); | |
129 | ||
130 | if (n >= t->counts[l]) | |
131 | return (sector_t) - 1; | |
132 | ||
133 | return get_node(t, l, n)[KEYS_PER_NODE - 1]; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Fills in a level of the btree based on the highs of the level | |
138 | * below it. | |
139 | */ | |
140 | static int setup_btree_index(unsigned int l, struct dm_table *t) | |
141 | { | |
142 | unsigned int n, k; | |
143 | sector_t *node; | |
144 | ||
145 | for (n = 0U; n < t->counts[l]; n++) { | |
146 | node = get_node(t, l, n); | |
147 | ||
148 | for (k = 0U; k < KEYS_PER_NODE; k++) | |
149 | node[k] = high(t, l + 1, get_child(n, k)); | |
150 | } | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) | |
156 | { | |
157 | unsigned long size; | |
158 | void *addr; | |
159 | ||
160 | /* | |
161 | * Check that we're not going to overflow. | |
162 | */ | |
163 | if (nmemb > (ULONG_MAX / elem_size)) | |
164 | return NULL; | |
165 | ||
166 | size = nmemb * elem_size; | |
167 | addr = vmalloc(size); | |
168 | if (addr) | |
169 | memset(addr, 0, size); | |
170 | ||
171 | return addr; | |
172 | } | |
173 | ||
174 | /* | |
175 | * highs, and targets are managed as dynamic arrays during a | |
176 | * table load. | |
177 | */ | |
178 | static int alloc_targets(struct dm_table *t, unsigned int num) | |
179 | { | |
180 | sector_t *n_highs; | |
181 | struct dm_target *n_targets; | |
182 | int n = t->num_targets; | |
183 | ||
184 | /* | |
185 | * Allocate both the target array and offset array at once. | |
186 | */ | |
187 | n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) + | |
188 | sizeof(sector_t)); | |
189 | if (!n_highs) | |
190 | return -ENOMEM; | |
191 | ||
192 | n_targets = (struct dm_target *) (n_highs + num); | |
193 | ||
194 | if (n) { | |
195 | memcpy(n_highs, t->highs, sizeof(*n_highs) * n); | |
196 | memcpy(n_targets, t->targets, sizeof(*n_targets) * n); | |
197 | } | |
198 | ||
199 | memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); | |
200 | vfree(t->highs); | |
201 | ||
202 | t->num_allocated = num; | |
203 | t->highs = n_highs; | |
204 | t->targets = n_targets; | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | int dm_table_create(struct dm_table **result, int mode, unsigned num_targets) | |
210 | { | |
211 | struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL); | |
212 | ||
213 | if (!t) | |
214 | return -ENOMEM; | |
215 | ||
216 | memset(t, 0, sizeof(*t)); | |
217 | INIT_LIST_HEAD(&t->devices); | |
218 | atomic_set(&t->holders, 1); | |
219 | ||
220 | if (!num_targets) | |
221 | num_targets = KEYS_PER_NODE; | |
222 | ||
223 | num_targets = dm_round_up(num_targets, KEYS_PER_NODE); | |
224 | ||
225 | if (alloc_targets(t, num_targets)) { | |
226 | kfree(t); | |
227 | t = NULL; | |
228 | return -ENOMEM; | |
229 | } | |
230 | ||
231 | t->mode = mode; | |
232 | *result = t; | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static void free_devices(struct list_head *devices) | |
237 | { | |
238 | struct list_head *tmp, *next; | |
239 | ||
240 | for (tmp = devices->next; tmp != devices; tmp = next) { | |
241 | struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); | |
242 | next = tmp->next; | |
243 | kfree(dd); | |
244 | } | |
245 | } | |
246 | ||
5e198d94 | 247 | static void table_destroy(struct dm_table *t) |
1da177e4 LT |
248 | { |
249 | unsigned int i; | |
250 | ||
251 | /* free the indexes (see dm_table_complete) */ | |
252 | if (t->depth >= 2) | |
253 | vfree(t->index[t->depth - 2]); | |
254 | ||
255 | /* free the targets */ | |
256 | for (i = 0; i < t->num_targets; i++) { | |
257 | struct dm_target *tgt = t->targets + i; | |
258 | ||
259 | if (tgt->type->dtr) | |
260 | tgt->type->dtr(tgt); | |
261 | ||
262 | dm_put_target_type(tgt->type); | |
263 | } | |
264 | ||
265 | vfree(t->highs); | |
266 | ||
267 | /* free the device list */ | |
268 | if (t->devices.next != &t->devices) { | |
269 | DMWARN("devices still present during destroy: " | |
270 | "dm_table_remove_device calls missing"); | |
271 | ||
272 | free_devices(&t->devices); | |
273 | } | |
274 | ||
275 | kfree(t); | |
276 | } | |
277 | ||
278 | void dm_table_get(struct dm_table *t) | |
279 | { | |
280 | atomic_inc(&t->holders); | |
281 | } | |
282 | ||
283 | void dm_table_put(struct dm_table *t) | |
284 | { | |
285 | if (!t) | |
286 | return; | |
287 | ||
288 | if (atomic_dec_and_test(&t->holders)) | |
289 | table_destroy(t); | |
290 | } | |
291 | ||
292 | /* | |
293 | * Checks to see if we need to extend highs or targets. | |
294 | */ | |
295 | static inline int check_space(struct dm_table *t) | |
296 | { | |
297 | if (t->num_targets >= t->num_allocated) | |
298 | return alloc_targets(t, t->num_allocated * 2); | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | /* | |
304 | * Convert a device path to a dev_t. | |
305 | */ | |
306 | static int lookup_device(const char *path, dev_t *dev) | |
307 | { | |
308 | int r; | |
309 | struct nameidata nd; | |
310 | struct inode *inode; | |
311 | ||
312 | if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd))) | |
313 | return r; | |
314 | ||
315 | inode = nd.dentry->d_inode; | |
316 | if (!inode) { | |
317 | r = -ENOENT; | |
318 | goto out; | |
319 | } | |
320 | ||
321 | if (!S_ISBLK(inode->i_mode)) { | |
322 | r = -ENOTBLK; | |
323 | goto out; | |
324 | } | |
325 | ||
326 | *dev = inode->i_rdev; | |
327 | ||
328 | out: | |
329 | path_release(&nd); | |
330 | return r; | |
331 | } | |
332 | ||
333 | /* | |
334 | * See if we've already got a device in the list. | |
335 | */ | |
336 | static struct dm_dev *find_device(struct list_head *l, dev_t dev) | |
337 | { | |
338 | struct dm_dev *dd; | |
339 | ||
340 | list_for_each_entry (dd, l, list) | |
341 | if (dd->bdev->bd_dev == dev) | |
342 | return dd; | |
343 | ||
344 | return NULL; | |
345 | } | |
346 | ||
347 | /* | |
348 | * Open a device so we can use it as a map destination. | |
349 | */ | |
350 | static int open_dev(struct dm_dev *d, dev_t dev) | |
351 | { | |
352 | static char *_claim_ptr = "I belong to device-mapper"; | |
353 | struct block_device *bdev; | |
354 | ||
355 | int r; | |
356 | ||
547bc926 | 357 | BUG_ON(d->bdev); |
1da177e4 LT |
358 | |
359 | bdev = open_by_devnum(dev, d->mode); | |
360 | if (IS_ERR(bdev)) | |
361 | return PTR_ERR(bdev); | |
362 | r = bd_claim(bdev, _claim_ptr); | |
363 | if (r) | |
364 | blkdev_put(bdev); | |
365 | else | |
366 | d->bdev = bdev; | |
367 | return r; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Close a device that we've been using. | |
372 | */ | |
373 | static void close_dev(struct dm_dev *d) | |
374 | { | |
375 | if (!d->bdev) | |
376 | return; | |
377 | ||
378 | bd_release(d->bdev); | |
379 | blkdev_put(d->bdev); | |
380 | d->bdev = NULL; | |
381 | } | |
382 | ||
383 | /* | |
384 | * If possible (ie. blk_size[major] is set), this checks an area | |
385 | * of a destination device is valid. | |
386 | */ | |
387 | static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) | |
388 | { | |
389 | sector_t dev_size; | |
390 | dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; | |
391 | return ((start < dev_size) && (len <= (dev_size - start))); | |
392 | } | |
393 | ||
394 | /* | |
395 | * This upgrades the mode on an already open dm_dev. Being | |
396 | * careful to leave things as they were if we fail to reopen the | |
397 | * device. | |
398 | */ | |
399 | static int upgrade_mode(struct dm_dev *dd, int new_mode) | |
400 | { | |
401 | int r; | |
402 | struct dm_dev dd_copy; | |
403 | dev_t dev = dd->bdev->bd_dev; | |
404 | ||
405 | dd_copy = *dd; | |
406 | ||
407 | dd->mode |= new_mode; | |
408 | dd->bdev = NULL; | |
409 | r = open_dev(dd, dev); | |
410 | if (!r) | |
411 | close_dev(&dd_copy); | |
412 | else | |
413 | *dd = dd_copy; | |
414 | ||
415 | return r; | |
416 | } | |
417 | ||
418 | /* | |
419 | * Add a device to the list, or just increment the usage count if | |
420 | * it's already present. | |
421 | */ | |
422 | static int __table_get_device(struct dm_table *t, struct dm_target *ti, | |
423 | const char *path, sector_t start, sector_t len, | |
424 | int mode, struct dm_dev **result) | |
425 | { | |
426 | int r; | |
427 | dev_t dev; | |
428 | struct dm_dev *dd; | |
429 | unsigned int major, minor; | |
430 | ||
547bc926 | 431 | BUG_ON(!t); |
1da177e4 LT |
432 | |
433 | if (sscanf(path, "%u:%u", &major, &minor) == 2) { | |
434 | /* Extract the major/minor numbers */ | |
435 | dev = MKDEV(major, minor); | |
436 | if (MAJOR(dev) != major || MINOR(dev) != minor) | |
437 | return -EOVERFLOW; | |
438 | } else { | |
439 | /* convert the path to a device */ | |
440 | if ((r = lookup_device(path, &dev))) | |
441 | return r; | |
442 | } | |
443 | ||
444 | dd = find_device(&t->devices, dev); | |
445 | if (!dd) { | |
446 | dd = kmalloc(sizeof(*dd), GFP_KERNEL); | |
447 | if (!dd) | |
448 | return -ENOMEM; | |
449 | ||
450 | dd->mode = mode; | |
451 | dd->bdev = NULL; | |
452 | ||
453 | if ((r = open_dev(dd, dev))) { | |
454 | kfree(dd); | |
455 | return r; | |
456 | } | |
457 | ||
458 | format_dev_t(dd->name, dev); | |
459 | ||
460 | atomic_set(&dd->count, 0); | |
461 | list_add(&dd->list, &t->devices); | |
462 | ||
463 | } else if (dd->mode != (mode | dd->mode)) { | |
464 | r = upgrade_mode(dd, mode); | |
465 | if (r) | |
466 | return r; | |
467 | } | |
468 | atomic_inc(&dd->count); | |
469 | ||
470 | if (!check_device_area(dd, start, len)) { | |
471 | DMWARN("device %s too small for target", path); | |
472 | dm_put_device(ti, dd); | |
473 | return -EINVAL; | |
474 | } | |
475 | ||
476 | *result = dd; | |
477 | ||
478 | return 0; | |
479 | } | |
480 | ||
481 | ||
482 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
483 | sector_t len, int mode, struct dm_dev **result) | |
484 | { | |
485 | int r = __table_get_device(ti->table, ti, path, | |
486 | start, len, mode, result); | |
487 | if (!r) { | |
488 | request_queue_t *q = bdev_get_queue((*result)->bdev); | |
489 | struct io_restrictions *rs = &ti->limits; | |
490 | ||
491 | /* | |
492 | * Combine the device limits low. | |
493 | * | |
494 | * FIXME: if we move an io_restriction struct | |
495 | * into q this would just be a call to | |
496 | * combine_restrictions_low() | |
497 | */ | |
498 | rs->max_sectors = | |
499 | min_not_zero(rs->max_sectors, q->max_sectors); | |
500 | ||
501 | /* FIXME: Device-Mapper on top of RAID-0 breaks because DM | |
502 | * currently doesn't honor MD's merge_bvec_fn routine. | |
503 | * In this case, we'll force DM to use PAGE_SIZE or | |
504 | * smaller I/O, just to be safe. A better fix is in the | |
505 | * works, but add this for the time being so it will at | |
506 | * least operate correctly. | |
507 | */ | |
508 | if (q->merge_bvec_fn) | |
509 | rs->max_sectors = | |
510 | min_not_zero(rs->max_sectors, | |
3ee247eb | 511 | (unsigned int) (PAGE_SIZE >> 9)); |
1da177e4 LT |
512 | |
513 | rs->max_phys_segments = | |
514 | min_not_zero(rs->max_phys_segments, | |
515 | q->max_phys_segments); | |
516 | ||
517 | rs->max_hw_segments = | |
518 | min_not_zero(rs->max_hw_segments, q->max_hw_segments); | |
519 | ||
520 | rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); | |
521 | ||
522 | rs->max_segment_size = | |
523 | min_not_zero(rs->max_segment_size, q->max_segment_size); | |
524 | ||
525 | rs->seg_boundary_mask = | |
526 | min_not_zero(rs->seg_boundary_mask, | |
527 | q->seg_boundary_mask); | |
969429b5 N |
528 | |
529 | rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); | |
1da177e4 LT |
530 | } |
531 | ||
532 | return r; | |
533 | } | |
534 | ||
535 | /* | |
536 | * Decrement a devices use count and remove it if necessary. | |
537 | */ | |
538 | void dm_put_device(struct dm_target *ti, struct dm_dev *dd) | |
539 | { | |
540 | if (atomic_dec_and_test(&dd->count)) { | |
541 | close_dev(dd); | |
542 | list_del(&dd->list); | |
543 | kfree(dd); | |
544 | } | |
545 | } | |
546 | ||
547 | /* | |
548 | * Checks to see if the target joins onto the end of the table. | |
549 | */ | |
550 | static int adjoin(struct dm_table *table, struct dm_target *ti) | |
551 | { | |
552 | struct dm_target *prev; | |
553 | ||
554 | if (!table->num_targets) | |
555 | return !ti->begin; | |
556 | ||
557 | prev = &table->targets[table->num_targets - 1]; | |
558 | return (ti->begin == (prev->begin + prev->len)); | |
559 | } | |
560 | ||
561 | /* | |
562 | * Used to dynamically allocate the arg array. | |
563 | */ | |
564 | static char **realloc_argv(unsigned *array_size, char **old_argv) | |
565 | { | |
566 | char **argv; | |
567 | unsigned new_size; | |
568 | ||
569 | new_size = *array_size ? *array_size * 2 : 64; | |
570 | argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); | |
571 | if (argv) { | |
572 | memcpy(argv, old_argv, *array_size * sizeof(*argv)); | |
573 | *array_size = new_size; | |
574 | } | |
575 | ||
576 | kfree(old_argv); | |
577 | return argv; | |
578 | } | |
579 | ||
580 | /* | |
581 | * Destructively splits up the argument list to pass to ctr. | |
582 | */ | |
583 | int dm_split_args(int *argc, char ***argvp, char *input) | |
584 | { | |
585 | char *start, *end = input, *out, **argv = NULL; | |
586 | unsigned array_size = 0; | |
587 | ||
588 | *argc = 0; | |
589 | argv = realloc_argv(&array_size, argv); | |
590 | if (!argv) | |
591 | return -ENOMEM; | |
592 | ||
593 | while (1) { | |
594 | start = end; | |
595 | ||
596 | /* Skip whitespace */ | |
597 | while (*start && isspace(*start)) | |
598 | start++; | |
599 | ||
600 | if (!*start) | |
601 | break; /* success, we hit the end */ | |
602 | ||
603 | /* 'out' is used to remove any back-quotes */ | |
604 | end = out = start; | |
605 | while (*end) { | |
606 | /* Everything apart from '\0' can be quoted */ | |
607 | if (*end == '\\' && *(end + 1)) { | |
608 | *out++ = *(end + 1); | |
609 | end += 2; | |
610 | continue; | |
611 | } | |
612 | ||
613 | if (isspace(*end)) | |
614 | break; /* end of token */ | |
615 | ||
616 | *out++ = *end++; | |
617 | } | |
618 | ||
619 | /* have we already filled the array ? */ | |
620 | if ((*argc + 1) > array_size) { | |
621 | argv = realloc_argv(&array_size, argv); | |
622 | if (!argv) | |
623 | return -ENOMEM; | |
624 | } | |
625 | ||
626 | /* we know this is whitespace */ | |
627 | if (*end) | |
628 | end++; | |
629 | ||
630 | /* terminate the string and put it in the array */ | |
631 | *out = '\0'; | |
632 | argv[*argc] = start; | |
633 | (*argc)++; | |
634 | } | |
635 | ||
636 | *argvp = argv; | |
637 | return 0; | |
638 | } | |
639 | ||
640 | static void check_for_valid_limits(struct io_restrictions *rs) | |
641 | { | |
642 | if (!rs->max_sectors) | |
defd94b7 | 643 | rs->max_sectors = SAFE_MAX_SECTORS; |
1da177e4 LT |
644 | if (!rs->max_phys_segments) |
645 | rs->max_phys_segments = MAX_PHYS_SEGMENTS; | |
646 | if (!rs->max_hw_segments) | |
647 | rs->max_hw_segments = MAX_HW_SEGMENTS; | |
648 | if (!rs->hardsect_size) | |
649 | rs->hardsect_size = 1 << SECTOR_SHIFT; | |
650 | if (!rs->max_segment_size) | |
651 | rs->max_segment_size = MAX_SEGMENT_SIZE; | |
652 | if (!rs->seg_boundary_mask) | |
653 | rs->seg_boundary_mask = -1; | |
654 | } | |
655 | ||
656 | int dm_table_add_target(struct dm_table *t, const char *type, | |
657 | sector_t start, sector_t len, char *params) | |
658 | { | |
659 | int r = -EINVAL, argc; | |
660 | char **argv; | |
661 | struct dm_target *tgt; | |
662 | ||
663 | if ((r = check_space(t))) | |
664 | return r; | |
665 | ||
666 | tgt = t->targets + t->num_targets; | |
667 | memset(tgt, 0, sizeof(*tgt)); | |
668 | ||
669 | if (!len) { | |
670 | tgt->error = "zero-length target"; | |
671 | DMERR("%s", tgt->error); | |
672 | return -EINVAL; | |
673 | } | |
674 | ||
675 | tgt->type = dm_get_target_type(type); | |
676 | if (!tgt->type) { | |
677 | tgt->error = "unknown target type"; | |
678 | DMERR("%s", tgt->error); | |
679 | return -EINVAL; | |
680 | } | |
681 | ||
682 | tgt->table = t; | |
683 | tgt->begin = start; | |
684 | tgt->len = len; | |
685 | tgt->error = "Unknown error"; | |
686 | ||
687 | /* | |
688 | * Does this target adjoin the previous one ? | |
689 | */ | |
690 | if (!adjoin(t, tgt)) { | |
691 | tgt->error = "Gap in table"; | |
692 | r = -EINVAL; | |
693 | goto bad; | |
694 | } | |
695 | ||
696 | r = dm_split_args(&argc, &argv, params); | |
697 | if (r) { | |
698 | tgt->error = "couldn't split parameters (insufficient memory)"; | |
699 | goto bad; | |
700 | } | |
701 | ||
702 | r = tgt->type->ctr(tgt, argc, argv); | |
703 | kfree(argv); | |
704 | if (r) | |
705 | goto bad; | |
706 | ||
707 | t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; | |
708 | ||
709 | /* FIXME: the plan is to combine high here and then have | |
710 | * the merge fn apply the target level restrictions. */ | |
711 | combine_restrictions_low(&t->limits, &tgt->limits); | |
712 | return 0; | |
713 | ||
714 | bad: | |
715 | DMERR("%s", tgt->error); | |
716 | dm_put_target_type(tgt->type); | |
717 | return r; | |
718 | } | |
719 | ||
720 | static int setup_indexes(struct dm_table *t) | |
721 | { | |
722 | int i; | |
723 | unsigned int total = 0; | |
724 | sector_t *indexes; | |
725 | ||
726 | /* allocate the space for *all* the indexes */ | |
727 | for (i = t->depth - 2; i >= 0; i--) { | |
728 | t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); | |
729 | total += t->counts[i]; | |
730 | } | |
731 | ||
732 | indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); | |
733 | if (!indexes) | |
734 | return -ENOMEM; | |
735 | ||
736 | /* set up internal nodes, bottom-up */ | |
737 | for (i = t->depth - 2, total = 0; i >= 0; i--) { | |
738 | t->index[i] = indexes; | |
739 | indexes += (KEYS_PER_NODE * t->counts[i]); | |
740 | setup_btree_index(i, t); | |
741 | } | |
742 | ||
743 | return 0; | |
744 | } | |
745 | ||
746 | /* | |
747 | * Builds the btree to index the map. | |
748 | */ | |
749 | int dm_table_complete(struct dm_table *t) | |
750 | { | |
751 | int r = 0; | |
752 | unsigned int leaf_nodes; | |
753 | ||
754 | check_for_valid_limits(&t->limits); | |
755 | ||
756 | /* how many indexes will the btree have ? */ | |
757 | leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); | |
758 | t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); | |
759 | ||
760 | /* leaf layer has already been set up */ | |
761 | t->counts[t->depth - 1] = leaf_nodes; | |
762 | t->index[t->depth - 1] = t->highs; | |
763 | ||
764 | if (t->depth >= 2) | |
765 | r = setup_indexes(t); | |
766 | ||
767 | return r; | |
768 | } | |
769 | ||
770 | static DECLARE_MUTEX(_event_lock); | |
771 | void dm_table_event_callback(struct dm_table *t, | |
772 | void (*fn)(void *), void *context) | |
773 | { | |
774 | down(&_event_lock); | |
775 | t->event_fn = fn; | |
776 | t->event_context = context; | |
777 | up(&_event_lock); | |
778 | } | |
779 | ||
780 | void dm_table_event(struct dm_table *t) | |
781 | { | |
782 | /* | |
783 | * You can no longer call dm_table_event() from interrupt | |
784 | * context, use a bottom half instead. | |
785 | */ | |
786 | BUG_ON(in_interrupt()); | |
787 | ||
788 | down(&_event_lock); | |
789 | if (t->event_fn) | |
790 | t->event_fn(t->event_context); | |
791 | up(&_event_lock); | |
792 | } | |
793 | ||
794 | sector_t dm_table_get_size(struct dm_table *t) | |
795 | { | |
796 | return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; | |
797 | } | |
798 | ||
799 | struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) | |
800 | { | |
801 | if (index > t->num_targets) | |
802 | return NULL; | |
803 | ||
804 | return t->targets + index; | |
805 | } | |
806 | ||
807 | /* | |
808 | * Search the btree for the correct target. | |
809 | */ | |
810 | struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) | |
811 | { | |
812 | unsigned int l, n = 0, k = 0; | |
813 | sector_t *node; | |
814 | ||
815 | for (l = 0; l < t->depth; l++) { | |
816 | n = get_child(n, k); | |
817 | node = get_node(t, l, n); | |
818 | ||
819 | for (k = 0; k < KEYS_PER_NODE; k++) | |
820 | if (node[k] >= sector) | |
821 | break; | |
822 | } | |
823 | ||
824 | return &t->targets[(KEYS_PER_NODE * n) + k]; | |
825 | } | |
826 | ||
827 | void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) | |
828 | { | |
829 | /* | |
830 | * Make sure we obey the optimistic sub devices | |
831 | * restrictions. | |
832 | */ | |
833 | blk_queue_max_sectors(q, t->limits.max_sectors); | |
834 | q->max_phys_segments = t->limits.max_phys_segments; | |
835 | q->max_hw_segments = t->limits.max_hw_segments; | |
836 | q->hardsect_size = t->limits.hardsect_size; | |
837 | q->max_segment_size = t->limits.max_segment_size; | |
838 | q->seg_boundary_mask = t->limits.seg_boundary_mask; | |
969429b5 N |
839 | if (t->limits.no_cluster) |
840 | q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER); | |
841 | else | |
842 | q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER); | |
843 | ||
1da177e4 LT |
844 | } |
845 | ||
846 | unsigned int dm_table_get_num_targets(struct dm_table *t) | |
847 | { | |
848 | return t->num_targets; | |
849 | } | |
850 | ||
851 | struct list_head *dm_table_get_devices(struct dm_table *t) | |
852 | { | |
853 | return &t->devices; | |
854 | } | |
855 | ||
856 | int dm_table_get_mode(struct dm_table *t) | |
857 | { | |
858 | return t->mode; | |
859 | } | |
860 | ||
861 | static void suspend_targets(struct dm_table *t, unsigned postsuspend) | |
862 | { | |
863 | int i = t->num_targets; | |
864 | struct dm_target *ti = t->targets; | |
865 | ||
866 | while (i--) { | |
867 | if (postsuspend) { | |
868 | if (ti->type->postsuspend) | |
869 | ti->type->postsuspend(ti); | |
870 | } else if (ti->type->presuspend) | |
871 | ti->type->presuspend(ti); | |
872 | ||
873 | ti++; | |
874 | } | |
875 | } | |
876 | ||
877 | void dm_table_presuspend_targets(struct dm_table *t) | |
878 | { | |
cf222b37 AK |
879 | if (!t) |
880 | return; | |
881 | ||
1da177e4 LT |
882 | return suspend_targets(t, 0); |
883 | } | |
884 | ||
885 | void dm_table_postsuspend_targets(struct dm_table *t) | |
886 | { | |
cf222b37 AK |
887 | if (!t) |
888 | return; | |
889 | ||
1da177e4 LT |
890 | return suspend_targets(t, 1); |
891 | } | |
892 | ||
893 | void dm_table_resume_targets(struct dm_table *t) | |
894 | { | |
895 | int i; | |
896 | ||
897 | for (i = 0; i < t->num_targets; i++) { | |
898 | struct dm_target *ti = t->targets + i; | |
899 | ||
900 | if (ti->type->resume) | |
901 | ti->type->resume(ti); | |
902 | } | |
903 | } | |
904 | ||
905 | int dm_table_any_congested(struct dm_table *t, int bdi_bits) | |
906 | { | |
907 | struct list_head *d, *devices; | |
908 | int r = 0; | |
909 | ||
910 | devices = dm_table_get_devices(t); | |
911 | for (d = devices->next; d != devices; d = d->next) { | |
912 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
913 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
914 | r |= bdi_congested(&q->backing_dev_info, bdi_bits); | |
915 | } | |
916 | ||
917 | return r; | |
918 | } | |
919 | ||
920 | void dm_table_unplug_all(struct dm_table *t) | |
921 | { | |
922 | struct list_head *d, *devices = dm_table_get_devices(t); | |
923 | ||
924 | for (d = devices->next; d != devices; d = d->next) { | |
925 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
926 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
927 | ||
928 | if (q->unplug_fn) | |
929 | q->unplug_fn(q); | |
930 | } | |
931 | } | |
932 | ||
933 | int dm_table_flush_all(struct dm_table *t) | |
934 | { | |
935 | struct list_head *d, *devices = dm_table_get_devices(t); | |
936 | int ret = 0; | |
937 | ||
938 | for (d = devices->next; d != devices; d = d->next) { | |
939 | struct dm_dev *dd = list_entry(d, struct dm_dev, list); | |
940 | request_queue_t *q = bdev_get_queue(dd->bdev); | |
941 | int err; | |
942 | ||
943 | if (!q->issue_flush_fn) | |
944 | err = -EOPNOTSUPP; | |
945 | else | |
946 | err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL); | |
947 | ||
948 | if (!ret) | |
949 | ret = err; | |
950 | } | |
951 | ||
952 | return ret; | |
953 | } | |
954 | ||
955 | EXPORT_SYMBOL(dm_vcalloc); | |
956 | EXPORT_SYMBOL(dm_get_device); | |
957 | EXPORT_SYMBOL(dm_put_device); | |
958 | EXPORT_SYMBOL(dm_table_event); | |
d5e404c1 | 959 | EXPORT_SYMBOL(dm_table_get_size); |
1da177e4 LT |
960 | EXPORT_SYMBOL(dm_table_get_mode); |
961 | EXPORT_SYMBOL(dm_table_put); | |
962 | EXPORT_SYMBOL(dm_table_get); | |
963 | EXPORT_SYMBOL(dm_table_unplug_all); | |
964 | EXPORT_SYMBOL(dm_table_flush_all); |