blob: 8f56a54cf0ce5eefe2a742f79a65e49dd21f0fbc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Arjan van de Ven48c9c272006-03-27 01:18:20 -080017#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#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
25struct dm_table {
Mike Anderson1134e5a2006-03-27 01:17:54 -080026 struct mapped_device *md;
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 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 */
63static 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 */
83static 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);
NeilBrown969429b2006-03-27 01:17:49 -0800102
103 lhs->no_cluster |= rhs->no_cluster;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104}
105
106/*
107 * Calculate the index of the child node of the n'th node k'th key.
108 */
109static 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 */
117static 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 */
127static 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 */
142static 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
157void *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 */
180static 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
Mike Anderson1134e5a2006-03-27 01:17:54 -0800211int dm_table_create(struct dm_table **result, int mode,
212 unsigned num_targets, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
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;
Mike Anderson1134e5a2006-03-27 01:17:54 -0800235 t->md = md;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 *result = t;
237 return 0;
238}
239
240static 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
Alasdair G Kergon5e198d92005-05-05 16:16:09 -0700251static void table_destroy(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
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
282void dm_table_get(struct dm_table *t)
283{
284 atomic_inc(&t->holders);
285}
286
287void 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 */
299static 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 */
310static 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 */
340static 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 */
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800354static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355{
356 static char *_claim_ptr = "I belong to device-mapper";
357 struct block_device *bdev;
358
359 int r;
360
Eric Sesterhenn547bc922006-03-26 18:22:50 +0200361 BUG_ON(d->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 bdev = open_by_devnum(dev, d->mode);
364 if (IS_ERR(bdev))
365 return PTR_ERR(bdev);
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800366 r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 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 */
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800377static void close_dev(struct dm_dev *d, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378{
379 if (!d->bdev)
380 return;
381
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800382 bd_release_from_disk(d->bdev, dm_disk(md));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 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 */
391static 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 */
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800403static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404{
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;
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800413 r = open_dev(dd, dev, md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 if (!r)
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800415 close_dev(&dd_copy, md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 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 */
426static 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
Eric Sesterhenn547bc922006-03-26 18:22:50 +0200435 BUG_ON(!t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
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
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800457 if ((r = open_dev(dd, dev, t->md))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 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)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800468 r = upgrade_mode(dd, mode, t->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 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
486int 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,
Alasdair G Kergon3ee247e2006-02-01 03:04:55 -0800515 (unsigned int) (PAGE_SIZE >> 9));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
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);
NeilBrown969429b2006-03-27 01:17:49 -0800532
533 rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 }
535
536 return r;
537}
538
539/*
540 * Decrement a devices use count and remove it if necessary.
541 */
542void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
543{
544 if (atomic_dec_and_test(&dd->count)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800545 close_dev(dd, ti->table->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 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 */
554static 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 */
568static 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 */
587int 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
644static void check_for_valid_limits(struct io_restrictions *rs)
645{
646 if (!rs->max_sectors)
Mike Christiedefd94b2005-12-05 02:37:06 -0600647 rs->max_sectors = SAFE_MAX_SECTORS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 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
660int 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
724static 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 */
753int 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
Arjan van de Ven48c9c272006-03-27 01:18:20 -0800774static DEFINE_MUTEX(_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775void dm_table_event_callback(struct dm_table *t,
776 void (*fn)(void *), void *context)
777{
Arjan van de Ven48c9c272006-03-27 01:18:20 -0800778 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 t->event_fn = fn;
780 t->event_context = context;
Arjan van de Ven48c9c272006-03-27 01:18:20 -0800781 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782}
783
784void 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
Arjan van de Ven48c9c272006-03-27 01:18:20 -0800792 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 if (t->event_fn)
794 t->event_fn(t->event_context);
Arjan van de Ven48c9c272006-03-27 01:18:20 -0800795 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796}
797
798sector_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
803struct 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 */
814struct 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
831void 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;
NeilBrown969429b2006-03-27 01:17:49 -0800843 if (t->limits.no_cluster)
844 q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER);
845 else
846 q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER);
847
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848}
849
850unsigned int dm_table_get_num_targets(struct dm_table *t)
851{
852 return t->num_targets;
853}
854
855struct list_head *dm_table_get_devices(struct dm_table *t)
856{
857 return &t->devices;
858}
859
860int dm_table_get_mode(struct dm_table *t)
861{
862 return t->mode;
863}
864
865static 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
881void dm_table_presuspend_targets(struct dm_table *t)
882{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -0700883 if (!t)
884 return;
885
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 return suspend_targets(t, 0);
887}
888
889void dm_table_postsuspend_targets(struct dm_table *t)
890{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -0700891 if (!t)
892 return;
893
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 return suspend_targets(t, 1);
895}
896
897void 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
909int 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
924void 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
937int 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
Mike Anderson1134e5a2006-03-27 01:17:54 -0800959struct mapped_device *dm_table_get_md(struct dm_table *t)
960{
961 dm_get(t->md);
962
963 return t->md;
964}
965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966EXPORT_SYMBOL(dm_vcalloc);
967EXPORT_SYMBOL(dm_get_device);
968EXPORT_SYMBOL(dm_put_device);
969EXPORT_SYMBOL(dm_table_event);
Alasdair G Kergond5e404c2005-07-12 15:53:05 -0700970EXPORT_SYMBOL(dm_table_get_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971EXPORT_SYMBOL(dm_table_get_mode);
Mike Anderson1134e5a2006-03-27 01:17:54 -0800972EXPORT_SYMBOL(dm_table_get_md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973EXPORT_SYMBOL(dm_table_put);
974EXPORT_SYMBOL(dm_table_get);
975EXPORT_SYMBOL(dm_table_unplug_all);
976EXPORT_SYMBOL(dm_table_flush_all);