Root/
1 | /* |
2 | * Copyright (C) 2011 Red Hat, Inc. |
3 | * |
4 | * This file is released under the GPL. |
5 | */ |
6 | |
7 | #include "dm-btree-internal.h" |
8 | #include "dm-space-map.h" |
9 | #include "dm-transaction-manager.h" |
10 | |
11 | #include <linux/export.h> |
12 | #include <linux/device-mapper.h> |
13 | |
14 | #define DM_MSG_PREFIX "btree" |
15 | |
16 | /*---------------------------------------------------------------- |
17 | * Array manipulation |
18 | *--------------------------------------------------------------*/ |
19 | static void memcpy_disk(void *dest, const void *src, size_t len) |
20 | __dm_written_to_disk(src) |
21 | { |
22 | memcpy(dest, src, len); |
23 | __dm_unbless_for_disk(src); |
24 | } |
25 | |
26 | static void array_insert(void *base, size_t elt_size, unsigned nr_elts, |
27 | unsigned index, void *elt) |
28 | __dm_written_to_disk(elt) |
29 | { |
30 | if (index < nr_elts) |
31 | memmove(base + (elt_size * (index + 1)), |
32 | base + (elt_size * index), |
33 | (nr_elts - index) * elt_size); |
34 | |
35 | memcpy_disk(base + (elt_size * index), elt, elt_size); |
36 | } |
37 | |
38 | /*----------------------------------------------------------------*/ |
39 | |
40 | /* makes the assumption that no two keys are the same. */ |
41 | static int bsearch(struct btree_node *n, uint64_t key, int want_hi) |
42 | { |
43 | int lo = -1, hi = le32_to_cpu(n->header.nr_entries); |
44 | |
45 | while (hi - lo > 1) { |
46 | int mid = lo + ((hi - lo) / 2); |
47 | uint64_t mid_key = le64_to_cpu(n->keys[mid]); |
48 | |
49 | if (mid_key == key) |
50 | return mid; |
51 | |
52 | if (mid_key < key) |
53 | lo = mid; |
54 | else |
55 | hi = mid; |
56 | } |
57 | |
58 | return want_hi ? hi : lo; |
59 | } |
60 | |
61 | int lower_bound(struct btree_node *n, uint64_t key) |
62 | { |
63 | return bsearch(n, key, 0); |
64 | } |
65 | |
66 | void inc_children(struct dm_transaction_manager *tm, struct btree_node *n, |
67 | struct dm_btree_value_type *vt) |
68 | { |
69 | unsigned i; |
70 | uint32_t nr_entries = le32_to_cpu(n->header.nr_entries); |
71 | |
72 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) |
73 | for (i = 0; i < nr_entries; i++) |
74 | dm_tm_inc(tm, value64(n, i)); |
75 | else if (vt->inc) |
76 | for (i = 0; i < nr_entries; i++) |
77 | vt->inc(vt->context, value_ptr(n, i)); |
78 | } |
79 | |
80 | static int insert_at(size_t value_size, struct btree_node *node, unsigned index, |
81 | uint64_t key, void *value) |
82 | __dm_written_to_disk(value) |
83 | { |
84 | uint32_t nr_entries = le32_to_cpu(node->header.nr_entries); |
85 | __le64 key_le = cpu_to_le64(key); |
86 | |
87 | if (index > nr_entries || |
88 | index >= le32_to_cpu(node->header.max_entries)) { |
89 | DMERR("too many entries in btree node for insert"); |
90 | __dm_unbless_for_disk(value); |
91 | return -ENOMEM; |
92 | } |
93 | |
94 | __dm_bless_for_disk(&key_le); |
95 | |
96 | array_insert(node->keys, sizeof(*node->keys), nr_entries, index, &key_le); |
97 | array_insert(value_base(node), value_size, nr_entries, index, value); |
98 | node->header.nr_entries = cpu_to_le32(nr_entries + 1); |
99 | |
100 | return 0; |
101 | } |
102 | |
103 | /*----------------------------------------------------------------*/ |
104 | |
105 | /* |
106 | * We want 3n entries (for some n). This works more nicely for repeated |
107 | * insert remove loops than (2n + 1). |
108 | */ |
109 | static uint32_t calc_max_entries(size_t value_size, size_t block_size) |
110 | { |
111 | uint32_t total, n; |
112 | size_t elt_size = sizeof(uint64_t) + value_size; /* key + value */ |
113 | |
114 | block_size -= sizeof(struct node_header); |
115 | total = block_size / elt_size; |
116 | n = total / 3; /* rounds down */ |
117 | |
118 | return 3 * n; |
119 | } |
120 | |
121 | int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root) |
122 | { |
123 | int r; |
124 | struct dm_block *b; |
125 | struct btree_node *n; |
126 | size_t block_size; |
127 | uint32_t max_entries; |
128 | |
129 | r = new_block(info, &b); |
130 | if (r < 0) |
131 | return r; |
132 | |
133 | block_size = dm_bm_block_size(dm_tm_get_bm(info->tm)); |
134 | max_entries = calc_max_entries(info->value_type.size, block_size); |
135 | |
136 | n = dm_block_data(b); |
137 | memset(n, 0, block_size); |
138 | n->header.flags = cpu_to_le32(LEAF_NODE); |
139 | n->header.nr_entries = cpu_to_le32(0); |
140 | n->header.max_entries = cpu_to_le32(max_entries); |
141 | n->header.value_size = cpu_to_le32(info->value_type.size); |
142 | |
143 | *root = dm_block_location(b); |
144 | return unlock_block(info, b); |
145 | } |
146 | EXPORT_SYMBOL_GPL(dm_btree_empty); |
147 | |
148 | /*----------------------------------------------------------------*/ |
149 | |
150 | /* |
151 | * Deletion uses a recursive algorithm, since we have limited stack space |
152 | * we explicitly manage our own stack on the heap. |
153 | */ |
154 | #define MAX_SPINE_DEPTH 64 |
155 | struct frame { |
156 | struct dm_block *b; |
157 | struct btree_node *n; |
158 | unsigned level; |
159 | unsigned nr_children; |
160 | unsigned current_child; |
161 | }; |
162 | |
163 | struct del_stack { |
164 | struct dm_transaction_manager *tm; |
165 | int top; |
166 | struct frame spine[MAX_SPINE_DEPTH]; |
167 | }; |
168 | |
169 | static int top_frame(struct del_stack *s, struct frame **f) |
170 | { |
171 | if (s->top < 0) { |
172 | DMERR("btree deletion stack empty"); |
173 | return -EINVAL; |
174 | } |
175 | |
176 | *f = s->spine + s->top; |
177 | |
178 | return 0; |
179 | } |
180 | |
181 | static int unprocessed_frames(struct del_stack *s) |
182 | { |
183 | return s->top >= 0; |
184 | } |
185 | |
186 | static int push_frame(struct del_stack *s, dm_block_t b, unsigned level) |
187 | { |
188 | int r; |
189 | uint32_t ref_count; |
190 | |
191 | if (s->top >= MAX_SPINE_DEPTH - 1) { |
192 | DMERR("btree deletion stack out of memory"); |
193 | return -ENOMEM; |
194 | } |
195 | |
196 | r = dm_tm_ref(s->tm, b, &ref_count); |
197 | if (r) |
198 | return r; |
199 | |
200 | if (ref_count > 1) |
201 | /* |
202 | * This is a shared node, so we can just decrement it's |
203 | * reference counter and leave the children. |
204 | */ |
205 | dm_tm_dec(s->tm, b); |
206 | |
207 | else { |
208 | struct frame *f = s->spine + ++s->top; |
209 | |
210 | r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b); |
211 | if (r) { |
212 | s->top--; |
213 | return r; |
214 | } |
215 | |
216 | f->n = dm_block_data(f->b); |
217 | f->level = level; |
218 | f->nr_children = le32_to_cpu(f->n->header.nr_entries); |
219 | f->current_child = 0; |
220 | } |
221 | |
222 | return 0; |
223 | } |
224 | |
225 | static void pop_frame(struct del_stack *s) |
226 | { |
227 | struct frame *f = s->spine + s->top--; |
228 | |
229 | dm_tm_dec(s->tm, dm_block_location(f->b)); |
230 | dm_tm_unlock(s->tm, f->b); |
231 | } |
232 | |
233 | static bool is_internal_level(struct dm_btree_info *info, struct frame *f) |
234 | { |
235 | return f->level < (info->levels - 1); |
236 | } |
237 | |
238 | int dm_btree_del(struct dm_btree_info *info, dm_block_t root) |
239 | { |
240 | int r; |
241 | struct del_stack *s; |
242 | |
243 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
244 | if (!s) |
245 | return -ENOMEM; |
246 | s->tm = info->tm; |
247 | s->top = -1; |
248 | |
249 | r = push_frame(s, root, 0); |
250 | if (r) |
251 | goto out; |
252 | |
253 | while (unprocessed_frames(s)) { |
254 | uint32_t flags; |
255 | struct frame *f; |
256 | dm_block_t b; |
257 | |
258 | r = top_frame(s, &f); |
259 | if (r) |
260 | goto out; |
261 | |
262 | if (f->current_child >= f->nr_children) { |
263 | pop_frame(s); |
264 | continue; |
265 | } |
266 | |
267 | flags = le32_to_cpu(f->n->header.flags); |
268 | if (flags & INTERNAL_NODE) { |
269 | b = value64(f->n, f->current_child); |
270 | f->current_child++; |
271 | r = push_frame(s, b, f->level); |
272 | if (r) |
273 | goto out; |
274 | |
275 | } else if (is_internal_level(info, f)) { |
276 | b = value64(f->n, f->current_child); |
277 | f->current_child++; |
278 | r = push_frame(s, b, f->level + 1); |
279 | if (r) |
280 | goto out; |
281 | |
282 | } else { |
283 | if (info->value_type.dec) { |
284 | unsigned i; |
285 | |
286 | for (i = 0; i < f->nr_children; i++) |
287 | info->value_type.dec(info->value_type.context, |
288 | value_ptr(f->n, i)); |
289 | } |
290 | f->current_child = f->nr_children; |
291 | } |
292 | } |
293 | |
294 | out: |
295 | kfree(s); |
296 | return r; |
297 | } |
298 | EXPORT_SYMBOL_GPL(dm_btree_del); |
299 | |
300 | /*----------------------------------------------------------------*/ |
301 | |
302 | static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key, |
303 | int (*search_fn)(struct btree_node *, uint64_t), |
304 | uint64_t *result_key, void *v, size_t value_size) |
305 | { |
306 | int i, r; |
307 | uint32_t flags, nr_entries; |
308 | |
309 | do { |
310 | r = ro_step(s, block); |
311 | if (r < 0) |
312 | return r; |
313 | |
314 | i = search_fn(ro_node(s), key); |
315 | |
316 | flags = le32_to_cpu(ro_node(s)->header.flags); |
317 | nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries); |
318 | if (i < 0 || i >= nr_entries) |
319 | return -ENODATA; |
320 | |
321 | if (flags & INTERNAL_NODE) |
322 | block = value64(ro_node(s), i); |
323 | |
324 | } while (!(flags & LEAF_NODE)); |
325 | |
326 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); |
327 | memcpy(v, value_ptr(ro_node(s), i), value_size); |
328 | |
329 | return 0; |
330 | } |
331 | |
332 | int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root, |
333 | uint64_t *keys, void *value_le) |
334 | { |
335 | unsigned level, last_level = info->levels - 1; |
336 | int r = -ENODATA; |
337 | uint64_t rkey; |
338 | __le64 internal_value_le; |
339 | struct ro_spine spine; |
340 | |
341 | init_ro_spine(&spine, info); |
342 | for (level = 0; level < info->levels; level++) { |
343 | size_t size; |
344 | void *value_p; |
345 | |
346 | if (level == last_level) { |
347 | value_p = value_le; |
348 | size = info->value_type.size; |
349 | |
350 | } else { |
351 | value_p = &internal_value_le; |
352 | size = sizeof(uint64_t); |
353 | } |
354 | |
355 | r = btree_lookup_raw(&spine, root, keys[level], |
356 | lower_bound, &rkey, |
357 | value_p, size); |
358 | |
359 | if (!r) { |
360 | if (rkey != keys[level]) { |
361 | exit_ro_spine(&spine); |
362 | return -ENODATA; |
363 | } |
364 | } else { |
365 | exit_ro_spine(&spine); |
366 | return r; |
367 | } |
368 | |
369 | root = le64_to_cpu(internal_value_le); |
370 | } |
371 | exit_ro_spine(&spine); |
372 | |
373 | return r; |
374 | } |
375 | EXPORT_SYMBOL_GPL(dm_btree_lookup); |
376 | |
377 | /* |
378 | * Splits a node by creating a sibling node and shifting half the nodes |
379 | * contents across. Assumes there is a parent node, and it has room for |
380 | * another child. |
381 | * |
382 | * Before: |
383 | * +--------+ |
384 | * | Parent | |
385 | * +--------+ |
386 | * | |
387 | * v |
388 | * +----------+ |
389 | * | A ++++++ | |
390 | * +----------+ |
391 | * |
392 | * |
393 | * After: |
394 | * +--------+ |
395 | * | Parent | |
396 | * +--------+ |
397 | * | | |
398 | * v +------+ |
399 | * +---------+ | |
400 | * | A* +++ | v |
401 | * +---------+ +-------+ |
402 | * | B +++ | |
403 | * +-------+ |
404 | * |
405 | * Where A* is a shadow of A. |
406 | */ |
407 | static int btree_split_sibling(struct shadow_spine *s, dm_block_t root, |
408 | unsigned parent_index, uint64_t key) |
409 | { |
410 | int r; |
411 | size_t size; |
412 | unsigned nr_left, nr_right; |
413 | struct dm_block *left, *right, *parent; |
414 | struct btree_node *ln, *rn, *pn; |
415 | __le64 location; |
416 | |
417 | left = shadow_current(s); |
418 | |
419 | r = new_block(s->info, &right); |
420 | if (r < 0) |
421 | return r; |
422 | |
423 | ln = dm_block_data(left); |
424 | rn = dm_block_data(right); |
425 | |
426 | nr_left = le32_to_cpu(ln->header.nr_entries) / 2; |
427 | nr_right = le32_to_cpu(ln->header.nr_entries) - nr_left; |
428 | |
429 | ln->header.nr_entries = cpu_to_le32(nr_left); |
430 | |
431 | rn->header.flags = ln->header.flags; |
432 | rn->header.nr_entries = cpu_to_le32(nr_right); |
433 | rn->header.max_entries = ln->header.max_entries; |
434 | rn->header.value_size = ln->header.value_size; |
435 | memcpy(rn->keys, ln->keys + nr_left, nr_right * sizeof(rn->keys[0])); |
436 | |
437 | size = le32_to_cpu(ln->header.flags) & INTERNAL_NODE ? |
438 | sizeof(uint64_t) : s->info->value_type.size; |
439 | memcpy(value_ptr(rn, 0), value_ptr(ln, nr_left), |
440 | size * nr_right); |
441 | |
442 | /* |
443 | * Patch up the parent |
444 | */ |
445 | parent = shadow_parent(s); |
446 | |
447 | pn = dm_block_data(parent); |
448 | location = cpu_to_le64(dm_block_location(left)); |
449 | __dm_bless_for_disk(&location); |
450 | memcpy_disk(value_ptr(pn, parent_index), |
451 | &location, sizeof(__le64)); |
452 | |
453 | location = cpu_to_le64(dm_block_location(right)); |
454 | __dm_bless_for_disk(&location); |
455 | |
456 | r = insert_at(sizeof(__le64), pn, parent_index + 1, |
457 | le64_to_cpu(rn->keys[0]), &location); |
458 | if (r) |
459 | return r; |
460 | |
461 | if (key < le64_to_cpu(rn->keys[0])) { |
462 | unlock_block(s->info, right); |
463 | s->nodes[1] = left; |
464 | } else { |
465 | unlock_block(s->info, left); |
466 | s->nodes[1] = right; |
467 | } |
468 | |
469 | return 0; |
470 | } |
471 | |
472 | /* |
473 | * Splits a node by creating two new children beneath the given node. |
474 | * |
475 | * Before: |
476 | * +----------+ |
477 | * | A ++++++ | |
478 | * +----------+ |
479 | * |
480 | * |
481 | * After: |
482 | * +------------+ |
483 | * | A (shadow) | |
484 | * +------------+ |
485 | * | | |
486 | * +------+ +----+ |
487 | * | | |
488 | * v v |
489 | * +-------+ +-------+ |
490 | * | B +++ | | C +++ | |
491 | * +-------+ +-------+ |
492 | */ |
493 | static int btree_split_beneath(struct shadow_spine *s, uint64_t key) |
494 | { |
495 | int r; |
496 | size_t size; |
497 | unsigned nr_left, nr_right; |
498 | struct dm_block *left, *right, *new_parent; |
499 | struct btree_node *pn, *ln, *rn; |
500 | __le64 val; |
501 | |
502 | new_parent = shadow_current(s); |
503 | |
504 | r = new_block(s->info, &left); |
505 | if (r < 0) |
506 | return r; |
507 | |
508 | r = new_block(s->info, &right); |
509 | if (r < 0) { |
510 | /* FIXME: put left */ |
511 | return r; |
512 | } |
513 | |
514 | pn = dm_block_data(new_parent); |
515 | ln = dm_block_data(left); |
516 | rn = dm_block_data(right); |
517 | |
518 | nr_left = le32_to_cpu(pn->header.nr_entries) / 2; |
519 | nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left; |
520 | |
521 | ln->header.flags = pn->header.flags; |
522 | ln->header.nr_entries = cpu_to_le32(nr_left); |
523 | ln->header.max_entries = pn->header.max_entries; |
524 | ln->header.value_size = pn->header.value_size; |
525 | |
526 | rn->header.flags = pn->header.flags; |
527 | rn->header.nr_entries = cpu_to_le32(nr_right); |
528 | rn->header.max_entries = pn->header.max_entries; |
529 | rn->header.value_size = pn->header.value_size; |
530 | |
531 | memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0])); |
532 | memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0])); |
533 | |
534 | size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ? |
535 | sizeof(__le64) : s->info->value_type.size; |
536 | memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size); |
537 | memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left), |
538 | nr_right * size); |
539 | |
540 | /* new_parent should just point to l and r now */ |
541 | pn->header.flags = cpu_to_le32(INTERNAL_NODE); |
542 | pn->header.nr_entries = cpu_to_le32(2); |
543 | pn->header.max_entries = cpu_to_le32( |
544 | calc_max_entries(sizeof(__le64), |
545 | dm_bm_block_size( |
546 | dm_tm_get_bm(s->info->tm)))); |
547 | pn->header.value_size = cpu_to_le32(sizeof(__le64)); |
548 | |
549 | val = cpu_to_le64(dm_block_location(left)); |
550 | __dm_bless_for_disk(&val); |
551 | pn->keys[0] = ln->keys[0]; |
552 | memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64)); |
553 | |
554 | val = cpu_to_le64(dm_block_location(right)); |
555 | __dm_bless_for_disk(&val); |
556 | pn->keys[1] = rn->keys[0]; |
557 | memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64)); |
558 | |
559 | /* |
560 | * rejig the spine. This is ugly, since it knows too |
561 | * much about the spine |
562 | */ |
563 | if (s->nodes[0] != new_parent) { |
564 | unlock_block(s->info, s->nodes[0]); |
565 | s->nodes[0] = new_parent; |
566 | } |
567 | if (key < le64_to_cpu(rn->keys[0])) { |
568 | unlock_block(s->info, right); |
569 | s->nodes[1] = left; |
570 | } else { |
571 | unlock_block(s->info, left); |
572 | s->nodes[1] = right; |
573 | } |
574 | s->count = 2; |
575 | |
576 | return 0; |
577 | } |
578 | |
579 | static int btree_insert_raw(struct shadow_spine *s, dm_block_t root, |
580 | struct dm_btree_value_type *vt, |
581 | uint64_t key, unsigned *index) |
582 | { |
583 | int r, i = *index, top = 1; |
584 | struct btree_node *node; |
585 | |
586 | for (;;) { |
587 | r = shadow_step(s, root, vt); |
588 | if (r < 0) |
589 | return r; |
590 | |
591 | node = dm_block_data(shadow_current(s)); |
592 | |
593 | /* |
594 | * We have to patch up the parent node, ugly, but I don't |
595 | * see a way to do this automatically as part of the spine |
596 | * op. |
597 | */ |
598 | if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */ |
599 | __le64 location = cpu_to_le64(dm_block_location(shadow_current(s))); |
600 | |
601 | __dm_bless_for_disk(&location); |
602 | memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i), |
603 | &location, sizeof(__le64)); |
604 | } |
605 | |
606 | node = dm_block_data(shadow_current(s)); |
607 | |
608 | if (node->header.nr_entries == node->header.max_entries) { |
609 | if (top) |
610 | r = btree_split_beneath(s, key); |
611 | else |
612 | r = btree_split_sibling(s, root, i, key); |
613 | |
614 | if (r < 0) |
615 | return r; |
616 | } |
617 | |
618 | node = dm_block_data(shadow_current(s)); |
619 | |
620 | i = lower_bound(node, key); |
621 | |
622 | if (le32_to_cpu(node->header.flags) & LEAF_NODE) |
623 | break; |
624 | |
625 | if (i < 0) { |
626 | /* change the bounds on the lowest key */ |
627 | node->keys[0] = cpu_to_le64(key); |
628 | i = 0; |
629 | } |
630 | |
631 | root = value64(node, i); |
632 | top = 0; |
633 | } |
634 | |
635 | if (i < 0 || le64_to_cpu(node->keys[i]) != key) |
636 | i++; |
637 | |
638 | *index = i; |
639 | return 0; |
640 | } |
641 | |
642 | static int insert(struct dm_btree_info *info, dm_block_t root, |
643 | uint64_t *keys, void *value, dm_block_t *new_root, |
644 | int *inserted) |
645 | __dm_written_to_disk(value) |
646 | { |
647 | int r, need_insert; |
648 | unsigned level, index = -1, last_level = info->levels - 1; |
649 | dm_block_t block = root; |
650 | struct shadow_spine spine; |
651 | struct btree_node *n; |
652 | struct dm_btree_value_type le64_type; |
653 | |
654 | le64_type.context = NULL; |
655 | le64_type.size = sizeof(__le64); |
656 | le64_type.inc = NULL; |
657 | le64_type.dec = NULL; |
658 | le64_type.equal = NULL; |
659 | |
660 | init_shadow_spine(&spine, info); |
661 | |
662 | for (level = 0; level < (info->levels - 1); level++) { |
663 | r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index); |
664 | if (r < 0) |
665 | goto bad; |
666 | |
667 | n = dm_block_data(shadow_current(&spine)); |
668 | need_insert = ((index >= le32_to_cpu(n->header.nr_entries)) || |
669 | (le64_to_cpu(n->keys[index]) != keys[level])); |
670 | |
671 | if (need_insert) { |
672 | dm_block_t new_tree; |
673 | __le64 new_le; |
674 | |
675 | r = dm_btree_empty(info, &new_tree); |
676 | if (r < 0) |
677 | goto bad; |
678 | |
679 | new_le = cpu_to_le64(new_tree); |
680 | __dm_bless_for_disk(&new_le); |
681 | |
682 | r = insert_at(sizeof(uint64_t), n, index, |
683 | keys[level], &new_le); |
684 | if (r) |
685 | goto bad; |
686 | } |
687 | |
688 | if (level < last_level) |
689 | block = value64(n, index); |
690 | } |
691 | |
692 | r = btree_insert_raw(&spine, block, &info->value_type, |
693 | keys[level], &index); |
694 | if (r < 0) |
695 | goto bad; |
696 | |
697 | n = dm_block_data(shadow_current(&spine)); |
698 | need_insert = ((index >= le32_to_cpu(n->header.nr_entries)) || |
699 | (le64_to_cpu(n->keys[index]) != keys[level])); |
700 | |
701 | if (need_insert) { |
702 | if (inserted) |
703 | *inserted = 1; |
704 | |
705 | r = insert_at(info->value_type.size, n, index, |
706 | keys[level], value); |
707 | if (r) |
708 | goto bad_unblessed; |
709 | } else { |
710 | if (inserted) |
711 | *inserted = 0; |
712 | |
713 | if (info->value_type.dec && |
714 | (!info->value_type.equal || |
715 | !info->value_type.equal( |
716 | info->value_type.context, |
717 | value_ptr(n, index), |
718 | value))) { |
719 | info->value_type.dec(info->value_type.context, |
720 | value_ptr(n, index)); |
721 | } |
722 | memcpy_disk(value_ptr(n, index), |
723 | value, info->value_type.size); |
724 | } |
725 | |
726 | *new_root = shadow_root(&spine); |
727 | exit_shadow_spine(&spine); |
728 | |
729 | return 0; |
730 | |
731 | bad: |
732 | __dm_unbless_for_disk(value); |
733 | bad_unblessed: |
734 | exit_shadow_spine(&spine); |
735 | return r; |
736 | } |
737 | |
738 | int dm_btree_insert(struct dm_btree_info *info, dm_block_t root, |
739 | uint64_t *keys, void *value, dm_block_t *new_root) |
740 | __dm_written_to_disk(value) |
741 | { |
742 | return insert(info, root, keys, value, new_root, NULL); |
743 | } |
744 | EXPORT_SYMBOL_GPL(dm_btree_insert); |
745 | |
746 | int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, |
747 | uint64_t *keys, void *value, dm_block_t *new_root, |
748 | int *inserted) |
749 | __dm_written_to_disk(value) |
750 | { |
751 | return insert(info, root, keys, value, new_root, inserted); |
752 | } |
753 | EXPORT_SYMBOL_GPL(dm_btree_insert_notify); |
754 | |
755 | /*----------------------------------------------------------------*/ |
756 | |
757 | static int find_highest_key(struct ro_spine *s, dm_block_t block, |
758 | uint64_t *result_key, dm_block_t *next_block) |
759 | { |
760 | int i, r; |
761 | uint32_t flags; |
762 | |
763 | do { |
764 | r = ro_step(s, block); |
765 | if (r < 0) |
766 | return r; |
767 | |
768 | flags = le32_to_cpu(ro_node(s)->header.flags); |
769 | i = le32_to_cpu(ro_node(s)->header.nr_entries); |
770 | if (!i) |
771 | return -ENODATA; |
772 | else |
773 | i--; |
774 | |
775 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); |
776 | if (next_block || flags & INTERNAL_NODE) |
777 | block = value64(ro_node(s), i); |
778 | |
779 | } while (flags & INTERNAL_NODE); |
780 | |
781 | if (next_block) |
782 | *next_block = block; |
783 | return 0; |
784 | } |
785 | |
786 | int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root, |
787 | uint64_t *result_keys) |
788 | { |
789 | int r = 0, count = 0, level; |
790 | struct ro_spine spine; |
791 | |
792 | init_ro_spine(&spine, info); |
793 | for (level = 0; level < info->levels; level++) { |
794 | r = find_highest_key(&spine, root, result_keys + level, |
795 | level == info->levels - 1 ? NULL : &root); |
796 | if (r == -ENODATA) { |
797 | r = 0; |
798 | break; |
799 | |
800 | } else if (r) |
801 | break; |
802 | |
803 | count++; |
804 | } |
805 | exit_ro_spine(&spine); |
806 | |
807 | return r ? r : count; |
808 | } |
809 | EXPORT_SYMBOL_GPL(dm_btree_find_highest_key); |
810 | |
811 | /* |
812 | * FIXME: We shouldn't use a recursive algorithm when we have limited stack |
813 | * space. Also this only works for single level trees. |
814 | */ |
815 | static int walk_node(struct ro_spine *s, dm_block_t block, |
816 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
817 | void *context) |
818 | { |
819 | int r; |
820 | unsigned i, nr; |
821 | struct btree_node *n; |
822 | uint64_t keys; |
823 | |
824 | r = ro_step(s, block); |
825 | n = ro_node(s); |
826 | |
827 | nr = le32_to_cpu(n->header.nr_entries); |
828 | for (i = 0; i < nr; i++) { |
829 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) { |
830 | r = walk_node(s, value64(n, i), fn, context); |
831 | if (r) |
832 | goto out; |
833 | } else { |
834 | keys = le64_to_cpu(*key_ptr(n, i)); |
835 | r = fn(context, &keys, value_ptr(n, i)); |
836 | if (r) |
837 | goto out; |
838 | } |
839 | } |
840 | |
841 | out: |
842 | ro_pop(s); |
843 | return r; |
844 | } |
845 | |
846 | int dm_btree_walk(struct dm_btree_info *info, dm_block_t root, |
847 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
848 | void *context) |
849 | { |
850 | int r; |
851 | struct ro_spine spine; |
852 | |
853 | BUG_ON(info->levels > 1); |
854 | |
855 | init_ro_spine(&spine, info); |
856 | r = walk_node(&spine, root, fn, context); |
857 | exit_ro_spine(&spine); |
858 | |
859 | return r; |
860 | } |
861 | EXPORT_SYMBOL_GPL(dm_btree_walk); |
862 |
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