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authorJoern Engel <joern@logfs.org>2009-11-20 14:13:39 -0500
committerJoern Engel <joern@logfs.org>2009-11-20 14:13:39 -0500
commit5db53f3e80dee2d9dff5e534f9e9fe1db17c9936 (patch)
tree066f2873eeb7eb86466f6389e45892d957db3de2 /lib
parent66b00a7c93ec782d118d2c03bd599cfd041e80a1 (diff)
[LogFS] add new flash file system
This is a new flash file system. See Documentation/filesystems/logfs.txt Signed-off-by: Joern Engel <joern@logfs.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile1
-rw-r--r--lib/btree.c797
3 files changed, 801 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index bb1326d3839c..277fbfb233b9 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -156,6 +156,9 @@ config TEXTSEARCH_BM
156config TEXTSEARCH_FSM 156config TEXTSEARCH_FSM
157 tristate 157 tristate
158 158
159config BTREE
160 boolean
161
159config HAS_IOMEM 162config HAS_IOMEM
160 boolean 163 boolean
161 depends on !NO_IOMEM 164 depends on !NO_IOMEM
diff --git a/lib/Makefile b/lib/Makefile
index 2e78277eff9d..cff82612e98b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -41,6 +41,7 @@ lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
41obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o 41obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
42obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o 42obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
43obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o 43obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
44obj-$(CONFIG_BTREE) += btree.o
44obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o 45obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
45obj-$(CONFIG_DEBUG_LIST) += list_debug.o 46obj-$(CONFIG_DEBUG_LIST) += list_debug.o
46obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o 47obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
diff --git a/lib/btree.c b/lib/btree.c
new file mode 100644
index 000000000000..41859a820218
--- /dev/null
+++ b/lib/btree.c
@@ -0,0 +1,797 @@
1/*
2 * lib/btree.c - Simple In-memory B+Tree
3 *
4 * As should be obvious for Linux kernel code, license is GPLv2
5 *
6 * Copyright (c) 2007-2008 Joern Engel <joern@logfs.org>
7 * Bits and pieces stolen from Peter Zijlstra's code, which is
8 * Copyright 2007, Red Hat Inc. Peter Zijlstra <pzijlstr@redhat.com>
9 * GPLv2
10 *
11 * see http://programming.kicks-ass.net/kernel-patches/vma_lookup/btree.patch
12 *
13 * A relatively simple B+Tree implementation. I have written it as a learning
14 * excercise to understand how B+Trees work. Turned out to be useful as well.
15 *
16 * B+Trees can be used similar to Linux radix trees (which don't have anything
17 * in common with textbook radix trees, beware). Prerequisite for them working
18 * well is that access to a random tree node is much faster than a large number
19 * of operations within each node.
20 *
21 * Disks have fulfilled the prerequisite for a long time. More recently DRAM
22 * has gained similar properties, as memory access times, when measured in cpu
23 * cycles, have increased. Cacheline sizes have increased as well, which also
24 * helps B+Trees.
25 *
26 * Compared to radix trees, B+Trees are more efficient when dealing with a
27 * sparsely populated address space. Between 25% and 50% of the memory is
28 * occupied with valid pointers. When densely populated, radix trees contain
29 * ~98% pointers - hard to beat. Very sparse radix trees contain only ~2%
30 * pointers.
31 *
32 * This particular implementation stores pointers identified by a long value.
33 * Storing NULL pointers is illegal, lookup will return NULL when no entry
34 * was found.
35 *
36 * A tricks was used that is not commonly found in textbooks. The lowest
37 * values are to the right, not to the left. All used slots within a node
38 * are on the left, all unused slots contain NUL values. Most operations
39 * simply loop once over all slots and terminate on the first NUL.
40 */
41
42#include <linux/btree.h>
43#include <linux/cache.h>
44#include <linux/kernel.h>
45#include <linux/slab.h>
46#include <linux/module.h>
47
48#define MAX(a, b) ((a) > (b) ? (a) : (b))
49#define NODESIZE MAX(L1_CACHE_BYTES, 128)
50
51struct btree_geo {
52 int keylen;
53 int no_pairs;
54 int no_longs;
55};
56
57struct btree_geo btree_geo32 = {
58 .keylen = 1,
59 .no_pairs = NODESIZE / sizeof(long) / 2,
60 .no_longs = NODESIZE / sizeof(long) / 2,
61};
62EXPORT_SYMBOL_GPL(btree_geo32);
63
64#define LONG_PER_U64 (64 / BITS_PER_LONG)
65struct btree_geo btree_geo64 = {
66 .keylen = LONG_PER_U64,
67 .no_pairs = NODESIZE / sizeof(long) / (1 + LONG_PER_U64),
68 .no_longs = LONG_PER_U64 * (NODESIZE / sizeof(long) / (1 + LONG_PER_U64)),
69};
70EXPORT_SYMBOL_GPL(btree_geo64);
71
72struct btree_geo btree_geo128 = {
73 .keylen = 2 * LONG_PER_U64,
74 .no_pairs = NODESIZE / sizeof(long) / (1 + 2 * LONG_PER_U64),
75 .no_longs = 2 * LONG_PER_U64 * (NODESIZE / sizeof(long) / (1 + 2 * LONG_PER_U64)),
76};
77EXPORT_SYMBOL_GPL(btree_geo128);
78
79static struct kmem_cache *btree_cachep;
80
81void *btree_alloc(gfp_t gfp_mask, void *pool_data)
82{
83 return kmem_cache_alloc(btree_cachep, gfp_mask);
84}
85EXPORT_SYMBOL_GPL(btree_alloc);
86
87void btree_free(void *element, void *pool_data)
88{
89 kmem_cache_free(btree_cachep, element);
90}
91EXPORT_SYMBOL_GPL(btree_free);
92
93static unsigned long *btree_node_alloc(struct btree_head *head, gfp_t gfp)
94{
95 unsigned long *node;
96
97 node = mempool_alloc(head->mempool, gfp);
98 memset(node, 0, NODESIZE);
99 return node;
100}
101
102static int longcmp(const unsigned long *l1, const unsigned long *l2, size_t n)
103{
104 size_t i;
105
106 for (i = 0; i < n; i++) {
107 if (l1[i] < l2[i])
108 return -1;
109 if (l1[i] > l2[i])
110 return 1;
111 }
112 return 0;
113}
114
115static unsigned long *longcpy(unsigned long *dest, const unsigned long *src,
116 size_t n)
117{
118 size_t i;
119
120 for (i = 0; i < n; i++)
121 dest[i] = src[i];
122 return dest;
123}
124
125static unsigned long *longset(unsigned long *s, unsigned long c, size_t n)
126{
127 size_t i;
128
129 for (i = 0; i < n; i++)
130 s[i] = c;
131 return s;
132}
133
134static void dec_key(struct btree_geo *geo, unsigned long *key)
135{
136 unsigned long val;
137 int i;
138
139 for (i = geo->keylen - 1; i >= 0; i--) {
140 val = key[i];
141 key[i] = val - 1;
142 if (val)
143 break;
144 }
145}
146
147static unsigned long *bkey(struct btree_geo *geo, unsigned long *node, int n)
148{
149 return &node[n * geo->keylen];
150}
151
152static void *bval(struct btree_geo *geo, unsigned long *node, int n)
153{
154 return (void *)node[geo->no_longs + n];
155}
156
157static void setkey(struct btree_geo *geo, unsigned long *node, int n,
158 unsigned long *key)
159{
160 longcpy(bkey(geo, node, n), key, geo->keylen);
161}
162
163static void setval(struct btree_geo *geo, unsigned long *node, int n,
164 void *val)
165{
166 node[geo->no_longs + n] = (unsigned long) val;
167}
168
169static void clearpair(struct btree_geo *geo, unsigned long *node, int n)
170{
171 longset(bkey(geo, node, n), 0, geo->keylen);
172 node[geo->no_longs + n] = 0;
173}
174
175static inline void __btree_init(struct btree_head *head)
176{
177 head->node = NULL;
178 head->height = 0;
179}
180
181void btree_init_mempool(struct btree_head *head, mempool_t *mempool)
182{
183 __btree_init(head);
184 head->mempool = mempool;
185}
186EXPORT_SYMBOL_GPL(btree_init_mempool);
187
188int btree_init(struct btree_head *head)
189{
190 __btree_init(head);
191 head->mempool = mempool_create(0, btree_alloc, btree_free, NULL);
192 if (!head->mempool)
193 return -ENOMEM;
194 return 0;
195}
196EXPORT_SYMBOL_GPL(btree_init);
197
198void btree_destroy(struct btree_head *head)
199{
200 mempool_destroy(head->mempool);
201 head->mempool = NULL;
202}
203EXPORT_SYMBOL_GPL(btree_destroy);
204
205void *btree_last(struct btree_head *head, struct btree_geo *geo,
206 unsigned long *key)
207{
208 int height = head->height;
209 unsigned long *node = head->node;
210
211 if (height == 0)
212 return NULL;
213
214 for ( ; height > 1; height--)
215 node = bval(geo, node, 0);
216
217 longcpy(key, bkey(geo, node, 0), geo->keylen);
218 return bval(geo, node, 0);
219}
220EXPORT_SYMBOL_GPL(btree_last);
221
222static int keycmp(struct btree_geo *geo, unsigned long *node, int pos,
223 unsigned long *key)
224{
225 return longcmp(bkey(geo, node, pos), key, geo->keylen);
226}
227
228static int keyzero(struct btree_geo *geo, unsigned long *key)
229{
230 int i;
231
232 for (i = 0; i < geo->keylen; i++)
233 if (key[i])
234 return 0;
235
236 return 1;
237}
238
239void *btree_lookup(struct btree_head *head, struct btree_geo *geo,
240 unsigned long *key)
241{
242 int i, height = head->height;
243 unsigned long *node = head->node;
244
245 if (height == 0)
246 return NULL;
247
248 for ( ; height > 1; height--) {
249 for (i = 0; i < geo->no_pairs; i++)
250 if (keycmp(geo, node, i, key) <= 0)
251 break;
252 if (i == geo->no_pairs)
253 return NULL;
254 node = bval(geo, node, i);
255 if (!node)
256 return NULL;
257 }
258
259 if (!node)
260 return NULL;
261
262 for (i = 0; i < geo->no_pairs; i++)
263 if (keycmp(geo, node, i, key) == 0)
264 return bval(geo, node, i);
265 return NULL;
266}
267EXPORT_SYMBOL_GPL(btree_lookup);
268
269int btree_update(struct btree_head *head, struct btree_geo *geo,
270 unsigned long *key, void *val)
271{
272 int i, height = head->height;
273 unsigned long *node = head->node;
274
275 if (height == 0)
276 return -ENOENT;
277
278 for ( ; height > 1; height--) {
279 for (i = 0; i < geo->no_pairs; i++)
280 if (keycmp(geo, node, i, key) <= 0)
281 break;
282 if (i == geo->no_pairs)
283 return -ENOENT;
284 node = bval(geo, node, i);
285 if (!node)
286 return -ENOENT;
287 }
288
289 if (!node)
290 return -ENOENT;
291
292 for (i = 0; i < geo->no_pairs; i++)
293 if (keycmp(geo, node, i, key) == 0) {
294 setval(geo, node, i, val);
295 return 0;
296 }
297 return -ENOENT;
298}
299EXPORT_SYMBOL_GPL(btree_update);
300
301/*
302 * Usually this function is quite similar to normal lookup. But the key of
303 * a parent node may be smaller than the smallest key of all its siblings.
304 * In such a case we cannot just return NULL, as we have only proven that no
305 * key smaller than __key, but larger than this parent key exists.
306 * So we set __key to the parent key and retry. We have to use the smallest
307 * such parent key, which is the last parent key we encountered.
308 */
309void *btree_get_prev(struct btree_head *head, struct btree_geo *geo,
310 unsigned long *__key)
311{
312 int i, height;
313 unsigned long *node, *oldnode;
314 unsigned long *retry_key = NULL, key[geo->keylen];
315
316 if (keyzero(geo, __key))
317 return NULL;
318
319 if (head->height == 0)
320 return NULL;
321retry:
322 longcpy(key, __key, geo->keylen);
323 dec_key(geo, key);
324
325 node = head->node;
326 for (height = head->height ; height > 1; height--) {
327 for (i = 0; i < geo->no_pairs; i++)
328 if (keycmp(geo, node, i, key) <= 0)
329 break;
330 if (i == geo->no_pairs)
331 goto miss;
332 oldnode = node;
333 node = bval(geo, node, i);
334 if (!node)
335 goto miss;
336 retry_key = bkey(geo, oldnode, i);
337 }
338
339 if (!node)
340 goto miss;
341
342 for (i = 0; i < geo->no_pairs; i++) {
343 if (keycmp(geo, node, i, key) <= 0) {
344 if (bval(geo, node, i)) {
345 longcpy(__key, bkey(geo, node, i), geo->keylen);
346 return bval(geo, node, i);
347 } else
348 goto miss;
349 }
350 }
351miss:
352 if (retry_key) {
353 __key = retry_key;
354 retry_key = NULL;
355 goto retry;
356 }
357 return NULL;
358}
359
360static int getpos(struct btree_geo *geo, unsigned long *node,
361 unsigned long *key)
362{
363 int i;
364
365 for (i = 0; i < geo->no_pairs; i++) {
366 if (keycmp(geo, node, i, key) <= 0)
367 break;
368 }
369 return i;
370}
371
372static int getfill(struct btree_geo *geo, unsigned long *node, int start)
373{
374 int i;
375
376 for (i = start; i < geo->no_pairs; i++)
377 if (!bval(geo, node, i))
378 break;
379 return i;
380}
381
382/*
383 * locate the correct leaf node in the btree
384 */
385static unsigned long *find_level(struct btree_head *head, struct btree_geo *geo,
386 unsigned long *key, int level)
387{
388 unsigned long *node = head->node;
389 int i, height;
390
391 for (height = head->height; height > level; height--) {
392 for (i = 0; i < geo->no_pairs; i++)
393 if (keycmp(geo, node, i, key) <= 0)
394 break;
395
396 if ((i == geo->no_pairs) || !bval(geo, node, i)) {
397 /* right-most key is too large, update it */
398 /* FIXME: If the right-most key on higher levels is
399 * always zero, this wouldn't be necessary. */
400 i--;
401 setkey(geo, node, i, key);
402 }
403 BUG_ON(i < 0);
404 node = bval(geo, node, i);
405 }
406 BUG_ON(!node);
407 return node;
408}
409
410static int btree_grow(struct btree_head *head, struct btree_geo *geo,
411 gfp_t gfp)
412{
413 unsigned long *node;
414 int fill;
415
416 node = btree_node_alloc(head, gfp);
417 if (!node)
418 return -ENOMEM;
419 if (head->node) {
420 fill = getfill(geo, head->node, 0);
421 setkey(geo, node, 0, bkey(geo, head->node, fill - 1));
422 setval(geo, node, 0, head->node);
423 }
424 head->node = node;
425 head->height++;
426 return 0;
427}
428
429static void btree_shrink(struct btree_head *head, struct btree_geo *geo)
430{
431 unsigned long *node;
432 int fill;
433
434 if (head->height <= 1)
435 return;
436
437 node = head->node;
438 fill = getfill(geo, node, 0);
439 BUG_ON(fill > 1);
440 head->node = bval(geo, node, 0);
441 head->height--;
442 mempool_free(node, head->mempool);
443}
444
445static int btree_insert_level(struct btree_head *head, struct btree_geo *geo,
446 unsigned long *key, void *val, int level,
447 gfp_t gfp)
448{
449 unsigned long *node;
450 int i, pos, fill, err;
451
452 BUG_ON(!val);
453 if (head->height < level) {
454 err = btree_grow(head, geo, gfp);
455 if (err)
456 return err;
457 }
458
459retry:
460 node = find_level(head, geo, key, level);
461 pos = getpos(geo, node, key);
462 fill = getfill(geo, node, pos);
463 /* two identical keys are not allowed */
464 BUG_ON(pos < fill && keycmp(geo, node, pos, key) == 0);
465
466 if (fill == geo->no_pairs) {
467 /* need to split node */
468 unsigned long *new;
469
470 new = btree_node_alloc(head, gfp);
471 if (!new)
472 return -ENOMEM;
473 err = btree_insert_level(head, geo,
474 bkey(geo, node, fill / 2 - 1),
475 new, level + 1, gfp);
476 if (err) {
477 mempool_free(new, head->mempool);
478 return err;
479 }
480 for (i = 0; i < fill / 2; i++) {
481 setkey(geo, new, i, bkey(geo, node, i));
482 setval(geo, new, i, bval(geo, node, i));
483 setkey(geo, node, i, bkey(geo, node, i + fill / 2));
484 setval(geo, node, i, bval(geo, node, i + fill / 2));
485 clearpair(geo, node, i + fill / 2);
486 }
487 if (fill & 1) {
488 setkey(geo, node, i, bkey(geo, node, fill - 1));
489 setval(geo, node, i, bval(geo, node, fill - 1));
490 clearpair(geo, node, fill - 1);
491 }
492 goto retry;
493 }
494 BUG_ON(fill >= geo->no_pairs);
495
496 /* shift and insert */
497 for (i = fill; i > pos; i--) {
498 setkey(geo, node, i, bkey(geo, node, i - 1));
499 setval(geo, node, i, bval(geo, node, i - 1));
500 }
501 setkey(geo, node, pos, key);
502 setval(geo, node, pos, val);
503
504 return 0;
505}
506
507int btree_insert(struct btree_head *head, struct btree_geo *geo,
508 unsigned long *key, void *val, gfp_t gfp)
509{
510 return btree_insert_level(head, geo, key, val, 1, gfp);
511}
512EXPORT_SYMBOL_GPL(btree_insert);
513
514static void *btree_remove_level(struct btree_head *head, struct btree_geo *geo,
515 unsigned long *key, int level);
516static void merge(struct btree_head *head, struct btree_geo *geo, int level,
517 unsigned long *left, int lfill,
518 unsigned long *right, int rfill,
519 unsigned long *parent, int lpos)
520{
521 int i;
522
523 for (i = 0; i < rfill; i++) {
524 /* Move all keys to the left */
525 setkey(geo, left, lfill + i, bkey(geo, right, i));
526 setval(geo, left, lfill + i, bval(geo, right, i));
527 }
528 /* Exchange left and right child in parent */
529 setval(geo, parent, lpos, right);
530 setval(geo, parent, lpos + 1, left);
531 /* Remove left (formerly right) child from parent */
532 btree_remove_level(head, geo, bkey(geo, parent, lpos), level + 1);
533 mempool_free(right, head->mempool);
534}
535
536static void rebalance(struct btree_head *head, struct btree_geo *geo,
537 unsigned long *key, int level, unsigned long *child, int fill)
538{
539 unsigned long *parent, *left = NULL, *right = NULL;
540 int i, no_left, no_right;
541
542 if (fill == 0) {
543 /* Because we don't steal entries from a neigbour, this case
544 * can happen. Parent node contains a single child, this
545 * node, so merging with a sibling never happens.
546 */
547 btree_remove_level(head, geo, key, level + 1);
548 mempool_free(child, head->mempool);
549 return;
550 }
551
552 parent = find_level(head, geo, key, level + 1);
553 i = getpos(geo, parent, key);
554 BUG_ON(bval(geo, parent, i) != child);
555
556 if (i > 0) {
557 left = bval(geo, parent, i - 1);
558 no_left = getfill(geo, left, 0);
559 if (fill + no_left <= geo->no_pairs) {
560 merge(head, geo, level,
561 left, no_left,
562 child, fill,
563 parent, i - 1);
564 return;
565 }
566 }
567 if (i + 1 < getfill(geo, parent, i)) {
568 right = bval(geo, parent, i + 1);
569 no_right = getfill(geo, right, 0);
570 if (fill + no_right <= geo->no_pairs) {
571 merge(head, geo, level,
572 child, fill,
573 right, no_right,
574 parent, i);
575 return;
576 }
577 }
578 /*
579 * We could also try to steal one entry from the left or right
580 * neighbor. By not doing so we changed the invariant from
581 * "all nodes are at least half full" to "no two neighboring
582 * nodes can be merged". Which means that the average fill of
583 * all nodes is still half or better.
584 */
585}
586
587static void *btree_remove_level(struct btree_head *head, struct btree_geo *geo,
588 unsigned long *key, int level)
589{
590 unsigned long *node;
591 int i, pos, fill;
592 void *ret;
593
594 if (level > head->height) {
595 /* we recursed all the way up */
596 head->height = 0;
597 head->node = NULL;
598 return NULL;
599 }
600
601 node = find_level(head, geo, key, level);
602 pos = getpos(geo, node, key);
603 fill = getfill(geo, node, pos);
604 if ((level == 1) && (keycmp(geo, node, pos, key) != 0))
605 return NULL;
606 ret = bval(geo, node, pos);
607
608 /* remove and shift */
609 for (i = pos; i < fill - 1; i++) {
610 setkey(geo, node, i, bkey(geo, node, i + 1));
611 setval(geo, node, i, bval(geo, node, i + 1));
612 }
613 clearpair(geo, node, fill - 1);
614
615 if (fill - 1 < geo->no_pairs / 2) {
616 if (level < head->height)
617 rebalance(head, geo, key, level, node, fill - 1);
618 else if (fill - 1 == 1)
619 btree_shrink(head, geo);
620 }
621
622 return ret;
623}
624
625void *btree_remove(struct btree_head *head, struct btree_geo *geo,
626 unsigned long *key)
627{
628 if (head->height == 0)
629 return NULL;
630
631 return btree_remove_level(head, geo, key, 1);
632}
633EXPORT_SYMBOL_GPL(btree_remove);
634
635int btree_merge(struct btree_head *target, struct btree_head *victim,
636 struct btree_geo *geo, gfp_t gfp)
637{
638 unsigned long key[geo->keylen];
639 unsigned long dup[geo->keylen];
640 void *val;
641 int err;
642
643 BUG_ON(target == victim);
644
645 if (!(target->node)) {
646 /* target is empty, just copy fields over */
647 target->node = victim->node;
648 target->height = victim->height;
649 __btree_init(victim);
650 return 0;
651 }
652
653 /* TODO: This needs some optimizations. Currently we do three tree
654 * walks to remove a single object from the victim.
655 */
656 for (;;) {
657 if (!btree_last(victim, geo, key))
658 break;
659 val = btree_lookup(victim, geo, key);
660 err = btree_insert(target, geo, key, val, gfp);
661 if (err)
662 return err;
663 /* We must make a copy of the key, as the original will get
664 * mangled inside btree_remove. */
665 longcpy(dup, key, geo->keylen);
666 btree_remove(victim, geo, dup);
667 }
668 return 0;
669}
670EXPORT_SYMBOL_GPL(btree_merge);
671
672static size_t __btree_for_each(struct btree_head *head, struct btree_geo *geo,
673 unsigned long *node, unsigned long opaque,
674 void (*func)(void *elem, unsigned long opaque,
675 unsigned long *key, size_t index,
676 void *func2),
677 void *func2, int reap, int height, size_t count)
678{
679 int i;
680 unsigned long *child;
681
682 for (i = 0; i < geo->no_pairs; i++) {
683 child = bval(geo, node, i);
684 if (!child)
685 break;
686 if (height > 1)
687 count = __btree_for_each(head, geo, child, opaque,
688 func, func2, reap, height - 1, count);
689 else
690 func(child, opaque, bkey(geo, node, i), count++,
691 func2);
692 }
693 if (reap)
694 mempool_free(node, head->mempool);
695 return count;
696}
697
698static void empty(void *elem, unsigned long opaque, unsigned long *key,
699 size_t index, void *func2)
700{
701}
702
703void visitorl(void *elem, unsigned long opaque, unsigned long *key,
704 size_t index, void *__func)
705{
706 visitorl_t func = __func;
707
708 func(elem, opaque, *key, index);
709}
710EXPORT_SYMBOL_GPL(visitorl);
711
712void visitor32(void *elem, unsigned long opaque, unsigned long *__key,
713 size_t index, void *__func)
714{
715 visitor32_t func = __func;
716 u32 *key = (void *)__key;
717
718 func(elem, opaque, *key, index);
719}
720EXPORT_SYMBOL_GPL(visitor32);
721
722void visitor64(void *elem, unsigned long opaque, unsigned long *__key,
723 size_t index, void *__func)
724{
725 visitor64_t func = __func;
726 u64 *key = (void *)__key;
727
728 func(elem, opaque, *key, index);
729}
730EXPORT_SYMBOL_GPL(visitor64);
731
732void visitor128(void *elem, unsigned long opaque, unsigned long *__key,
733 size_t index, void *__func)
734{
735 visitor128_t func = __func;
736 u64 *key = (void *)__key;
737
738 func(elem, opaque, key[0], key[1], index);
739}
740EXPORT_SYMBOL_GPL(visitor128);
741
742size_t btree_visitor(struct btree_head *head, struct btree_geo *geo,
743 unsigned long opaque,
744 void (*func)(void *elem, unsigned long opaque,
745 unsigned long *key,
746 size_t index, void *func2),
747 void *func2)
748{
749 size_t count = 0;
750
751 if (!func2)
752 func = empty;
753 if (head->node)
754 count = __btree_for_each(head, geo, head->node, opaque, func,
755 func2, 0, head->height, 0);
756 return count;
757}
758EXPORT_SYMBOL_GPL(btree_visitor);
759
760size_t btree_grim_visitor(struct btree_head *head, struct btree_geo *geo,
761 unsigned long opaque,
762 void (*func)(void *elem, unsigned long opaque,
763 unsigned long *key,
764 size_t index, void *func2),
765 void *func2)
766{
767 size_t count = 0;
768
769 if (!func2)
770 func = empty;
771 if (head->node)
772 count = __btree_for_each(head, geo, head->node, opaque, func,
773 func2, 1, head->height, 0);
774 __btree_init(head);
775 return count;
776}
777EXPORT_SYMBOL_GPL(btree_grim_visitor);
778
779static int __init btree_module_init(void)
780{
781 btree_cachep = kmem_cache_create("btree_node", NODESIZE, 0,
782 SLAB_HWCACHE_ALIGN, NULL);
783 return 0;
784}
785
786static void __exit btree_module_exit(void)
787{
788 kmem_cache_destroy(btree_cachep);
789}
790
791/* If core code starts using btree, initialization should happen even earlier */
792module_init(btree_module_init);
793module_exit(btree_module_exit);
794
795MODULE_AUTHOR("Joern Engel <joern@logfs.org>");
796MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
797MODULE_LICENSE("GPL");