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Commit | Line | Data |
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3241b1d3 JT |
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 | ||
1944ce60 | 11 | #include <linux/export.h> |
3241b1d3 JT |
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. */ | |
550929fa | 41 | static int bsearch(struct btree_node *n, uint64_t key, int want_hi) |
3241b1d3 JT |
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 | ||
550929fa | 61 | int lower_bound(struct btree_node *n, uint64_t key) |
3241b1d3 JT |
62 | { |
63 | return bsearch(n, key, 0); | |
64 | } | |
65 | ||
993ceab9 JT |
66 | static int upper_bound(struct btree_node *n, uint64_t key) |
67 | { | |
68 | return bsearch(n, key, 1); | |
69 | } | |
70 | ||
550929fa | 71 | void inc_children(struct dm_transaction_manager *tm, struct btree_node *n, |
3241b1d3 JT |
72 | struct dm_btree_value_type *vt) |
73 | { | |
74 | unsigned i; | |
75 | uint32_t nr_entries = le32_to_cpu(n->header.nr_entries); | |
76 | ||
77 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) | |
78 | for (i = 0; i < nr_entries; i++) | |
79 | dm_tm_inc(tm, value64(n, i)); | |
80 | else if (vt->inc) | |
81 | for (i = 0; i < nr_entries; i++) | |
a3aefb39 | 82 | vt->inc(vt->context, value_ptr(n, i)); |
3241b1d3 JT |
83 | } |
84 | ||
550929fa | 85 | static int insert_at(size_t value_size, struct btree_node *node, unsigned index, |
3241b1d3 JT |
86 | uint64_t key, void *value) |
87 | __dm_written_to_disk(value) | |
88 | { | |
89 | uint32_t nr_entries = le32_to_cpu(node->header.nr_entries); | |
90 | __le64 key_le = cpu_to_le64(key); | |
91 | ||
92 | if (index > nr_entries || | |
93 | index >= le32_to_cpu(node->header.max_entries)) { | |
94 | DMERR("too many entries in btree node for insert"); | |
95 | __dm_unbless_for_disk(value); | |
96 | return -ENOMEM; | |
97 | } | |
98 | ||
99 | __dm_bless_for_disk(&key_le); | |
100 | ||
101 | array_insert(node->keys, sizeof(*node->keys), nr_entries, index, &key_le); | |
102 | array_insert(value_base(node), value_size, nr_entries, index, value); | |
103 | node->header.nr_entries = cpu_to_le32(nr_entries + 1); | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | /*----------------------------------------------------------------*/ | |
109 | ||
110 | /* | |
111 | * We want 3n entries (for some n). This works more nicely for repeated | |
112 | * insert remove loops than (2n + 1). | |
113 | */ | |
114 | static uint32_t calc_max_entries(size_t value_size, size_t block_size) | |
115 | { | |
116 | uint32_t total, n; | |
117 | size_t elt_size = sizeof(uint64_t) + value_size; /* key + value */ | |
118 | ||
119 | block_size -= sizeof(struct node_header); | |
120 | total = block_size / elt_size; | |
121 | n = total / 3; /* rounds down */ | |
122 | ||
123 | return 3 * n; | |
124 | } | |
125 | ||
126 | int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root) | |
127 | { | |
128 | int r; | |
129 | struct dm_block *b; | |
550929fa | 130 | struct btree_node *n; |
3241b1d3 JT |
131 | size_t block_size; |
132 | uint32_t max_entries; | |
133 | ||
134 | r = new_block(info, &b); | |
135 | if (r < 0) | |
136 | return r; | |
137 | ||
138 | block_size = dm_bm_block_size(dm_tm_get_bm(info->tm)); | |
139 | max_entries = calc_max_entries(info->value_type.size, block_size); | |
140 | ||
141 | n = dm_block_data(b); | |
142 | memset(n, 0, block_size); | |
143 | n->header.flags = cpu_to_le32(LEAF_NODE); | |
144 | n->header.nr_entries = cpu_to_le32(0); | |
145 | n->header.max_entries = cpu_to_le32(max_entries); | |
146 | n->header.value_size = cpu_to_le32(info->value_type.size); | |
147 | ||
148 | *root = dm_block_location(b); | |
4c7da06f MP |
149 | unlock_block(info, b); |
150 | ||
151 | return 0; | |
3241b1d3 JT |
152 | } |
153 | EXPORT_SYMBOL_GPL(dm_btree_empty); | |
154 | ||
155 | /*----------------------------------------------------------------*/ | |
156 | ||
157 | /* | |
158 | * Deletion uses a recursive algorithm, since we have limited stack space | |
159 | * we explicitly manage our own stack on the heap. | |
160 | */ | |
161 | #define MAX_SPINE_DEPTH 64 | |
162 | struct frame { | |
163 | struct dm_block *b; | |
550929fa | 164 | struct btree_node *n; |
3241b1d3 JT |
165 | unsigned level; |
166 | unsigned nr_children; | |
167 | unsigned current_child; | |
168 | }; | |
169 | ||
170 | struct del_stack { | |
04f17c80 | 171 | struct dm_btree_info *info; |
3241b1d3 JT |
172 | struct dm_transaction_manager *tm; |
173 | int top; | |
174 | struct frame spine[MAX_SPINE_DEPTH]; | |
175 | }; | |
176 | ||
177 | static int top_frame(struct del_stack *s, struct frame **f) | |
178 | { | |
179 | if (s->top < 0) { | |
180 | DMERR("btree deletion stack empty"); | |
181 | return -EINVAL; | |
182 | } | |
183 | ||
184 | *f = s->spine + s->top; | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | static int unprocessed_frames(struct del_stack *s) | |
190 | { | |
191 | return s->top >= 0; | |
192 | } | |
193 | ||
04f17c80 JT |
194 | static void prefetch_children(struct del_stack *s, struct frame *f) |
195 | { | |
196 | unsigned i; | |
197 | struct dm_block_manager *bm = dm_tm_get_bm(s->tm); | |
198 | ||
199 | for (i = 0; i < f->nr_children; i++) | |
200 | dm_bm_prefetch(bm, value64(f->n, i)); | |
201 | } | |
202 | ||
203 | static bool is_internal_level(struct dm_btree_info *info, struct frame *f) | |
204 | { | |
205 | return f->level < (info->levels - 1); | |
206 | } | |
207 | ||
3241b1d3 JT |
208 | static int push_frame(struct del_stack *s, dm_block_t b, unsigned level) |
209 | { | |
210 | int r; | |
211 | uint32_t ref_count; | |
212 | ||
213 | if (s->top >= MAX_SPINE_DEPTH - 1) { | |
214 | DMERR("btree deletion stack out of memory"); | |
215 | return -ENOMEM; | |
216 | } | |
217 | ||
218 | r = dm_tm_ref(s->tm, b, &ref_count); | |
219 | if (r) | |
220 | return r; | |
221 | ||
222 | if (ref_count > 1) | |
223 | /* | |
224 | * This is a shared node, so we can just decrement it's | |
225 | * reference counter and leave the children. | |
226 | */ | |
227 | dm_tm_dec(s->tm, b); | |
228 | ||
229 | else { | |
04f17c80 | 230 | uint32_t flags; |
3241b1d3 JT |
231 | struct frame *f = s->spine + ++s->top; |
232 | ||
233 | r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b); | |
234 | if (r) { | |
235 | s->top--; | |
236 | return r; | |
237 | } | |
238 | ||
239 | f->n = dm_block_data(f->b); | |
240 | f->level = level; | |
241 | f->nr_children = le32_to_cpu(f->n->header.nr_entries); | |
242 | f->current_child = 0; | |
04f17c80 JT |
243 | |
244 | flags = le32_to_cpu(f->n->header.flags); | |
245 | if (flags & INTERNAL_NODE || is_internal_level(s->info, f)) | |
246 | prefetch_children(s, f); | |
3241b1d3 JT |
247 | } |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | static void pop_frame(struct del_stack *s) | |
253 | { | |
254 | struct frame *f = s->spine + s->top--; | |
255 | ||
256 | dm_tm_dec(s->tm, dm_block_location(f->b)); | |
257 | dm_tm_unlock(s->tm, f->b); | |
258 | } | |
259 | ||
ed8b45a3 JT |
260 | static void unlock_all_frames(struct del_stack *s) |
261 | { | |
262 | struct frame *f; | |
263 | ||
264 | while (unprocessed_frames(s)) { | |
265 | f = s->spine + s->top--; | |
266 | dm_tm_unlock(s->tm, f->b); | |
267 | } | |
268 | } | |
269 | ||
3241b1d3 JT |
270 | int dm_btree_del(struct dm_btree_info *info, dm_block_t root) |
271 | { | |
272 | int r; | |
273 | struct del_stack *s; | |
274 | ||
1c751879 | 275 | s = kmalloc(sizeof(*s), GFP_NOIO); |
3241b1d3 JT |
276 | if (!s) |
277 | return -ENOMEM; | |
04f17c80 | 278 | s->info = info; |
3241b1d3 JT |
279 | s->tm = info->tm; |
280 | s->top = -1; | |
281 | ||
e3cbf945 | 282 | r = push_frame(s, root, 0); |
3241b1d3 JT |
283 | if (r) |
284 | goto out; | |
285 | ||
286 | while (unprocessed_frames(s)) { | |
287 | uint32_t flags; | |
288 | struct frame *f; | |
289 | dm_block_t b; | |
290 | ||
291 | r = top_frame(s, &f); | |
292 | if (r) | |
293 | goto out; | |
294 | ||
295 | if (f->current_child >= f->nr_children) { | |
296 | pop_frame(s); | |
297 | continue; | |
298 | } | |
299 | ||
300 | flags = le32_to_cpu(f->n->header.flags); | |
301 | if (flags & INTERNAL_NODE) { | |
302 | b = value64(f->n, f->current_child); | |
303 | f->current_child++; | |
304 | r = push_frame(s, b, f->level); | |
305 | if (r) | |
306 | goto out; | |
307 | ||
e3cbf945 | 308 | } else if (is_internal_level(info, f)) { |
3241b1d3 JT |
309 | b = value64(f->n, f->current_child); |
310 | f->current_child++; | |
311 | r = push_frame(s, b, f->level + 1); | |
312 | if (r) | |
313 | goto out; | |
314 | ||
315 | } else { | |
316 | if (info->value_type.dec) { | |
317 | unsigned i; | |
318 | ||
319 | for (i = 0; i < f->nr_children; i++) | |
320 | info->value_type.dec(info->value_type.context, | |
a3aefb39 | 321 | value_ptr(f->n, i)); |
3241b1d3 | 322 | } |
cd5acf0b | 323 | pop_frame(s); |
3241b1d3 JT |
324 | } |
325 | } | |
3241b1d3 | 326 | out: |
ed8b45a3 JT |
327 | if (r) { |
328 | /* cleanup all frames of del_stack */ | |
329 | unlock_all_frames(s); | |
330 | } | |
3241b1d3 | 331 | kfree(s); |
ed8b45a3 | 332 | |
3241b1d3 JT |
333 | return r; |
334 | } | |
335 | EXPORT_SYMBOL_GPL(dm_btree_del); | |
336 | ||
337 | /*----------------------------------------------------------------*/ | |
338 | ||
339 | static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key, | |
550929fa | 340 | int (*search_fn)(struct btree_node *, uint64_t), |
3241b1d3 JT |
341 | uint64_t *result_key, void *v, size_t value_size) |
342 | { | |
343 | int i, r; | |
344 | uint32_t flags, nr_entries; | |
345 | ||
346 | do { | |
347 | r = ro_step(s, block); | |
348 | if (r < 0) | |
349 | return r; | |
350 | ||
351 | i = search_fn(ro_node(s), key); | |
352 | ||
353 | flags = le32_to_cpu(ro_node(s)->header.flags); | |
354 | nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries); | |
355 | if (i < 0 || i >= nr_entries) | |
356 | return -ENODATA; | |
357 | ||
358 | if (flags & INTERNAL_NODE) | |
359 | block = value64(ro_node(s), i); | |
360 | ||
361 | } while (!(flags & LEAF_NODE)); | |
362 | ||
363 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); | |
a3aefb39 | 364 | memcpy(v, value_ptr(ro_node(s), i), value_size); |
3241b1d3 JT |
365 | |
366 | return 0; | |
367 | } | |
368 | ||
369 | int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root, | |
370 | uint64_t *keys, void *value_le) | |
371 | { | |
372 | unsigned level, last_level = info->levels - 1; | |
373 | int r = -ENODATA; | |
374 | uint64_t rkey; | |
375 | __le64 internal_value_le; | |
376 | struct ro_spine spine; | |
377 | ||
378 | init_ro_spine(&spine, info); | |
379 | for (level = 0; level < info->levels; level++) { | |
380 | size_t size; | |
381 | void *value_p; | |
382 | ||
383 | if (level == last_level) { | |
384 | value_p = value_le; | |
385 | size = info->value_type.size; | |
386 | ||
387 | } else { | |
388 | value_p = &internal_value_le; | |
389 | size = sizeof(uint64_t); | |
390 | } | |
391 | ||
392 | r = btree_lookup_raw(&spine, root, keys[level], | |
393 | lower_bound, &rkey, | |
394 | value_p, size); | |
395 | ||
396 | if (!r) { | |
397 | if (rkey != keys[level]) { | |
398 | exit_ro_spine(&spine); | |
399 | return -ENODATA; | |
400 | } | |
401 | } else { | |
402 | exit_ro_spine(&spine); | |
403 | return r; | |
404 | } | |
405 | ||
406 | root = le64_to_cpu(internal_value_le); | |
407 | } | |
408 | exit_ro_spine(&spine); | |
409 | ||
410 | return r; | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(dm_btree_lookup); | |
413 | ||
993ceab9 JT |
414 | static int dm_btree_lookup_next_single(struct dm_btree_info *info, dm_block_t root, |
415 | uint64_t key, uint64_t *rkey, void *value_le) | |
416 | { | |
417 | int r, i; | |
418 | uint32_t flags, nr_entries; | |
419 | struct dm_block *node; | |
420 | struct btree_node *n; | |
421 | ||
422 | r = bn_read_lock(info, root, &node); | |
423 | if (r) | |
424 | return r; | |
425 | ||
426 | n = dm_block_data(node); | |
427 | flags = le32_to_cpu(n->header.flags); | |
428 | nr_entries = le32_to_cpu(n->header.nr_entries); | |
429 | ||
430 | if (flags & INTERNAL_NODE) { | |
431 | i = lower_bound(n, key); | |
e7e0f730 JT |
432 | if (i < 0) { |
433 | /* | |
434 | * avoid early -ENODATA return when all entries are | |
435 | * higher than the search @key. | |
436 | */ | |
437 | i = 0; | |
438 | } | |
439 | if (i >= nr_entries) { | |
993ceab9 JT |
440 | r = -ENODATA; |
441 | goto out; | |
442 | } | |
443 | ||
444 | r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le); | |
445 | if (r == -ENODATA && i < (nr_entries - 1)) { | |
446 | i++; | |
447 | r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le); | |
448 | } | |
449 | ||
450 | } else { | |
451 | i = upper_bound(n, key); | |
452 | if (i < 0 || i >= nr_entries) { | |
453 | r = -ENODATA; | |
454 | goto out; | |
455 | } | |
456 | ||
457 | *rkey = le64_to_cpu(n->keys[i]); | |
458 | memcpy(value_le, value_ptr(n, i), info->value_type.size); | |
459 | } | |
460 | out: | |
461 | dm_tm_unlock(info->tm, node); | |
462 | return r; | |
463 | } | |
464 | ||
465 | int dm_btree_lookup_next(struct dm_btree_info *info, dm_block_t root, | |
466 | uint64_t *keys, uint64_t *rkey, void *value_le) | |
467 | { | |
468 | unsigned level; | |
469 | int r = -ENODATA; | |
470 | __le64 internal_value_le; | |
471 | struct ro_spine spine; | |
472 | ||
473 | init_ro_spine(&spine, info); | |
474 | for (level = 0; level < info->levels - 1u; level++) { | |
475 | r = btree_lookup_raw(&spine, root, keys[level], | |
476 | lower_bound, rkey, | |
477 | &internal_value_le, sizeof(uint64_t)); | |
478 | if (r) | |
479 | goto out; | |
480 | ||
481 | if (*rkey != keys[level]) { | |
482 | r = -ENODATA; | |
483 | goto out; | |
484 | } | |
485 | ||
486 | root = le64_to_cpu(internal_value_le); | |
487 | } | |
488 | ||
489 | r = dm_btree_lookup_next_single(info, root, keys[level], rkey, value_le); | |
490 | out: | |
491 | exit_ro_spine(&spine); | |
492 | return r; | |
493 | } | |
494 | ||
495 | EXPORT_SYMBOL_GPL(dm_btree_lookup_next); | |
496 | ||
3241b1d3 JT |
497 | /* |
498 | * Splits a node by creating a sibling node and shifting half the nodes | |
499 | * contents across. Assumes there is a parent node, and it has room for | |
500 | * another child. | |
501 | * | |
502 | * Before: | |
503 | * +--------+ | |
504 | * | Parent | | |
505 | * +--------+ | |
506 | * | | |
507 | * v | |
508 | * +----------+ | |
509 | * | A ++++++ | | |
510 | * +----------+ | |
511 | * | |
512 | * | |
513 | * After: | |
514 | * +--------+ | |
515 | * | Parent | | |
516 | * +--------+ | |
517 | * | | | |
518 | * v +------+ | |
519 | * +---------+ | | |
520 | * | A* +++ | v | |
521 | * +---------+ +-------+ | |
522 | * | B +++ | | |
523 | * +-------+ | |
524 | * | |
525 | * Where A* is a shadow of A. | |
526 | */ | |
0a8d4c3e VG |
527 | static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index, |
528 | uint64_t key) | |
3241b1d3 JT |
529 | { |
530 | int r; | |
531 | size_t size; | |
532 | unsigned nr_left, nr_right; | |
533 | struct dm_block *left, *right, *parent; | |
550929fa | 534 | struct btree_node *ln, *rn, *pn; |
3241b1d3 JT |
535 | __le64 location; |
536 | ||
537 | left = shadow_current(s); | |
538 | ||
539 | r = new_block(s->info, &right); | |
540 | if (r < 0) | |
541 | return r; | |
542 | ||
543 | ln = dm_block_data(left); | |
544 | rn = dm_block_data(right); | |
545 | ||
546 | nr_left = le32_to_cpu(ln->header.nr_entries) / 2; | |
547 | nr_right = le32_to_cpu(ln->header.nr_entries) - nr_left; | |
548 | ||
549 | ln->header.nr_entries = cpu_to_le32(nr_left); | |
550 | ||
551 | rn->header.flags = ln->header.flags; | |
552 | rn->header.nr_entries = cpu_to_le32(nr_right); | |
553 | rn->header.max_entries = ln->header.max_entries; | |
554 | rn->header.value_size = ln->header.value_size; | |
555 | memcpy(rn->keys, ln->keys + nr_left, nr_right * sizeof(rn->keys[0])); | |
556 | ||
557 | size = le32_to_cpu(ln->header.flags) & INTERNAL_NODE ? | |
558 | sizeof(uint64_t) : s->info->value_type.size; | |
a3aefb39 | 559 | memcpy(value_ptr(rn, 0), value_ptr(ln, nr_left), |
3241b1d3 JT |
560 | size * nr_right); |
561 | ||
562 | /* | |
563 | * Patch up the parent | |
564 | */ | |
565 | parent = shadow_parent(s); | |
566 | ||
567 | pn = dm_block_data(parent); | |
568 | location = cpu_to_le64(dm_block_location(left)); | |
569 | __dm_bless_for_disk(&location); | |
a3aefb39 | 570 | memcpy_disk(value_ptr(pn, parent_index), |
3241b1d3 JT |
571 | &location, sizeof(__le64)); |
572 | ||
573 | location = cpu_to_le64(dm_block_location(right)); | |
574 | __dm_bless_for_disk(&location); | |
575 | ||
576 | r = insert_at(sizeof(__le64), pn, parent_index + 1, | |
577 | le64_to_cpu(rn->keys[0]), &location); | |
30ce6e1c MS |
578 | if (r) { |
579 | unlock_block(s->info, right); | |
3241b1d3 | 580 | return r; |
30ce6e1c | 581 | } |
3241b1d3 JT |
582 | |
583 | if (key < le64_to_cpu(rn->keys[0])) { | |
584 | unlock_block(s->info, right); | |
585 | s->nodes[1] = left; | |
586 | } else { | |
587 | unlock_block(s->info, left); | |
588 | s->nodes[1] = right; | |
589 | } | |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | /* | |
595 | * Splits a node by creating two new children beneath the given node. | |
596 | * | |
597 | * Before: | |
598 | * +----------+ | |
599 | * | A ++++++ | | |
600 | * +----------+ | |
601 | * | |
602 | * | |
603 | * After: | |
604 | * +------------+ | |
605 | * | A (shadow) | | |
606 | * +------------+ | |
607 | * | | | |
608 | * +------+ +----+ | |
609 | * | | | |
610 | * v v | |
611 | * +-------+ +-------+ | |
612 | * | B +++ | | C +++ | | |
613 | * +-------+ +-------+ | |
614 | */ | |
615 | static int btree_split_beneath(struct shadow_spine *s, uint64_t key) | |
616 | { | |
617 | int r; | |
618 | size_t size; | |
619 | unsigned nr_left, nr_right; | |
620 | struct dm_block *left, *right, *new_parent; | |
550929fa | 621 | struct btree_node *pn, *ln, *rn; |
3241b1d3 JT |
622 | __le64 val; |
623 | ||
624 | new_parent = shadow_current(s); | |
625 | ||
626 | r = new_block(s->info, &left); | |
627 | if (r < 0) | |
628 | return r; | |
629 | ||
630 | r = new_block(s->info, &right); | |
631 | if (r < 0) { | |
4dcb8b57 | 632 | unlock_block(s->info, left); |
3241b1d3 JT |
633 | return r; |
634 | } | |
635 | ||
636 | pn = dm_block_data(new_parent); | |
637 | ln = dm_block_data(left); | |
638 | rn = dm_block_data(right); | |
639 | ||
640 | nr_left = le32_to_cpu(pn->header.nr_entries) / 2; | |
641 | nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left; | |
642 | ||
643 | ln->header.flags = pn->header.flags; | |
644 | ln->header.nr_entries = cpu_to_le32(nr_left); | |
645 | ln->header.max_entries = pn->header.max_entries; | |
646 | ln->header.value_size = pn->header.value_size; | |
647 | ||
648 | rn->header.flags = pn->header.flags; | |
649 | rn->header.nr_entries = cpu_to_le32(nr_right); | |
650 | rn->header.max_entries = pn->header.max_entries; | |
651 | rn->header.value_size = pn->header.value_size; | |
652 | ||
653 | memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0])); | |
654 | memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0])); | |
655 | ||
656 | size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ? | |
657 | sizeof(__le64) : s->info->value_type.size; | |
a3aefb39 JT |
658 | memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size); |
659 | memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left), | |
3241b1d3 JT |
660 | nr_right * size); |
661 | ||
662 | /* new_parent should just point to l and r now */ | |
663 | pn->header.flags = cpu_to_le32(INTERNAL_NODE); | |
664 | pn->header.nr_entries = cpu_to_le32(2); | |
665 | pn->header.max_entries = cpu_to_le32( | |
666 | calc_max_entries(sizeof(__le64), | |
667 | dm_bm_block_size( | |
668 | dm_tm_get_bm(s->info->tm)))); | |
669 | pn->header.value_size = cpu_to_le32(sizeof(__le64)); | |
670 | ||
671 | val = cpu_to_le64(dm_block_location(left)); | |
672 | __dm_bless_for_disk(&val); | |
673 | pn->keys[0] = ln->keys[0]; | |
a3aefb39 | 674 | memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64)); |
3241b1d3 JT |
675 | |
676 | val = cpu_to_le64(dm_block_location(right)); | |
677 | __dm_bless_for_disk(&val); | |
678 | pn->keys[1] = rn->keys[0]; | |
a3aefb39 | 679 | memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64)); |
3241b1d3 JT |
680 | |
681 | /* | |
682 | * rejig the spine. This is ugly, since it knows too | |
683 | * much about the spine | |
684 | */ | |
685 | if (s->nodes[0] != new_parent) { | |
686 | unlock_block(s->info, s->nodes[0]); | |
687 | s->nodes[0] = new_parent; | |
688 | } | |
689 | if (key < le64_to_cpu(rn->keys[0])) { | |
690 | unlock_block(s->info, right); | |
691 | s->nodes[1] = left; | |
692 | } else { | |
693 | unlock_block(s->info, left); | |
694 | s->nodes[1] = right; | |
695 | } | |
696 | s->count = 2; | |
697 | ||
698 | return 0; | |
699 | } | |
700 | ||
701 | static int btree_insert_raw(struct shadow_spine *s, dm_block_t root, | |
702 | struct dm_btree_value_type *vt, | |
703 | uint64_t key, unsigned *index) | |
704 | { | |
705 | int r, i = *index, top = 1; | |
550929fa | 706 | struct btree_node *node; |
3241b1d3 JT |
707 | |
708 | for (;;) { | |
709 | r = shadow_step(s, root, vt); | |
710 | if (r < 0) | |
711 | return r; | |
712 | ||
713 | node = dm_block_data(shadow_current(s)); | |
714 | ||
715 | /* | |
716 | * We have to patch up the parent node, ugly, but I don't | |
717 | * see a way to do this automatically as part of the spine | |
718 | * op. | |
719 | */ | |
720 | if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */ | |
721 | __le64 location = cpu_to_le64(dm_block_location(shadow_current(s))); | |
722 | ||
723 | __dm_bless_for_disk(&location); | |
a3aefb39 | 724 | memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i), |
3241b1d3 JT |
725 | &location, sizeof(__le64)); |
726 | } | |
727 | ||
728 | node = dm_block_data(shadow_current(s)); | |
729 | ||
730 | if (node->header.nr_entries == node->header.max_entries) { | |
731 | if (top) | |
732 | r = btree_split_beneath(s, key); | |
733 | else | |
0a8d4c3e | 734 | r = btree_split_sibling(s, i, key); |
3241b1d3 JT |
735 | |
736 | if (r < 0) | |
737 | return r; | |
738 | } | |
739 | ||
740 | node = dm_block_data(shadow_current(s)); | |
741 | ||
742 | i = lower_bound(node, key); | |
743 | ||
744 | if (le32_to_cpu(node->header.flags) & LEAF_NODE) | |
745 | break; | |
746 | ||
747 | if (i < 0) { | |
748 | /* change the bounds on the lowest key */ | |
749 | node->keys[0] = cpu_to_le64(key); | |
750 | i = 0; | |
751 | } | |
752 | ||
753 | root = value64(node, i); | |
754 | top = 0; | |
755 | } | |
756 | ||
757 | if (i < 0 || le64_to_cpu(node->keys[i]) != key) | |
758 | i++; | |
759 | ||
760 | *index = i; | |
761 | return 0; | |
762 | } | |
763 | ||
ba503835 MS |
764 | static bool need_insert(struct btree_node *node, uint64_t *keys, |
765 | unsigned level, unsigned index) | |
766 | { | |
767 | return ((index >= le32_to_cpu(node->header.nr_entries)) || | |
768 | (le64_to_cpu(node->keys[index]) != keys[level])); | |
769 | } | |
770 | ||
3241b1d3 JT |
771 | static int insert(struct dm_btree_info *info, dm_block_t root, |
772 | uint64_t *keys, void *value, dm_block_t *new_root, | |
773 | int *inserted) | |
774 | __dm_written_to_disk(value) | |
775 | { | |
ba503835 | 776 | int r; |
3241b1d3 JT |
777 | unsigned level, index = -1, last_level = info->levels - 1; |
778 | dm_block_t block = root; | |
779 | struct shadow_spine spine; | |
550929fa | 780 | struct btree_node *n; |
3241b1d3 JT |
781 | struct dm_btree_value_type le64_type; |
782 | ||
b0dc3c8b | 783 | init_le64_type(info->tm, &le64_type); |
3241b1d3 JT |
784 | init_shadow_spine(&spine, info); |
785 | ||
786 | for (level = 0; level < (info->levels - 1); level++) { | |
787 | r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index); | |
788 | if (r < 0) | |
789 | goto bad; | |
790 | ||
791 | n = dm_block_data(shadow_current(&spine)); | |
3241b1d3 | 792 | |
ba503835 | 793 | if (need_insert(n, keys, level, index)) { |
3241b1d3 JT |
794 | dm_block_t new_tree; |
795 | __le64 new_le; | |
796 | ||
797 | r = dm_btree_empty(info, &new_tree); | |
798 | if (r < 0) | |
799 | goto bad; | |
800 | ||
801 | new_le = cpu_to_le64(new_tree); | |
802 | __dm_bless_for_disk(&new_le); | |
803 | ||
804 | r = insert_at(sizeof(uint64_t), n, index, | |
805 | keys[level], &new_le); | |
806 | if (r) | |
807 | goto bad; | |
808 | } | |
809 | ||
810 | if (level < last_level) | |
811 | block = value64(n, index); | |
812 | } | |
813 | ||
814 | r = btree_insert_raw(&spine, block, &info->value_type, | |
815 | keys[level], &index); | |
816 | if (r < 0) | |
817 | goto bad; | |
818 | ||
819 | n = dm_block_data(shadow_current(&spine)); | |
3241b1d3 | 820 | |
ba503835 | 821 | if (need_insert(n, keys, level, index)) { |
3241b1d3 JT |
822 | if (inserted) |
823 | *inserted = 1; | |
824 | ||
825 | r = insert_at(info->value_type.size, n, index, | |
826 | keys[level], value); | |
827 | if (r) | |
828 | goto bad_unblessed; | |
829 | } else { | |
830 | if (inserted) | |
831 | *inserted = 0; | |
832 | ||
833 | if (info->value_type.dec && | |
834 | (!info->value_type.equal || | |
835 | !info->value_type.equal( | |
836 | info->value_type.context, | |
a3aefb39 | 837 | value_ptr(n, index), |
3241b1d3 JT |
838 | value))) { |
839 | info->value_type.dec(info->value_type.context, | |
a3aefb39 | 840 | value_ptr(n, index)); |
3241b1d3 | 841 | } |
a3aefb39 | 842 | memcpy_disk(value_ptr(n, index), |
3241b1d3 JT |
843 | value, info->value_type.size); |
844 | } | |
845 | ||
846 | *new_root = shadow_root(&spine); | |
847 | exit_shadow_spine(&spine); | |
848 | ||
849 | return 0; | |
850 | ||
851 | bad: | |
852 | __dm_unbless_for_disk(value); | |
853 | bad_unblessed: | |
854 | exit_shadow_spine(&spine); | |
855 | return r; | |
856 | } | |
857 | ||
858 | int dm_btree_insert(struct dm_btree_info *info, dm_block_t root, | |
859 | uint64_t *keys, void *value, dm_block_t *new_root) | |
860 | __dm_written_to_disk(value) | |
861 | { | |
862 | return insert(info, root, keys, value, new_root, NULL); | |
863 | } | |
864 | EXPORT_SYMBOL_GPL(dm_btree_insert); | |
865 | ||
866 | int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, | |
867 | uint64_t *keys, void *value, dm_block_t *new_root, | |
868 | int *inserted) | |
869 | __dm_written_to_disk(value) | |
870 | { | |
871 | return insert(info, root, keys, value, new_root, inserted); | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(dm_btree_insert_notify); | |
874 | ||
875 | /*----------------------------------------------------------------*/ | |
876 | ||
f164e690 JT |
877 | static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest, |
878 | uint64_t *result_key, dm_block_t *next_block) | |
3241b1d3 JT |
879 | { |
880 | int i, r; | |
881 | uint32_t flags; | |
882 | ||
883 | do { | |
884 | r = ro_step(s, block); | |
885 | if (r < 0) | |
886 | return r; | |
887 | ||
888 | flags = le32_to_cpu(ro_node(s)->header.flags); | |
889 | i = le32_to_cpu(ro_node(s)->header.nr_entries); | |
890 | if (!i) | |
891 | return -ENODATA; | |
892 | else | |
893 | i--; | |
894 | ||
f164e690 JT |
895 | if (find_highest) |
896 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); | |
897 | else | |
898 | *result_key = le64_to_cpu(ro_node(s)->keys[0]); | |
899 | ||
3241b1d3 JT |
900 | if (next_block || flags & INTERNAL_NODE) |
901 | block = value64(ro_node(s), i); | |
902 | ||
903 | } while (flags & INTERNAL_NODE); | |
904 | ||
905 | if (next_block) | |
906 | *next_block = block; | |
907 | return 0; | |
908 | } | |
909 | ||
f164e690 JT |
910 | static int dm_btree_find_key(struct dm_btree_info *info, dm_block_t root, |
911 | bool find_highest, uint64_t *result_keys) | |
3241b1d3 JT |
912 | { |
913 | int r = 0, count = 0, level; | |
914 | struct ro_spine spine; | |
915 | ||
916 | init_ro_spine(&spine, info); | |
917 | for (level = 0; level < info->levels; level++) { | |
f164e690 JT |
918 | r = find_key(&spine, root, find_highest, result_keys + level, |
919 | level == info->levels - 1 ? NULL : &root); | |
3241b1d3 JT |
920 | if (r == -ENODATA) { |
921 | r = 0; | |
922 | break; | |
923 | ||
924 | } else if (r) | |
925 | break; | |
926 | ||
927 | count++; | |
928 | } | |
929 | exit_ro_spine(&spine); | |
930 | ||
931 | return r ? r : count; | |
932 | } | |
f164e690 JT |
933 | |
934 | int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root, | |
935 | uint64_t *result_keys) | |
936 | { | |
937 | return dm_btree_find_key(info, root, true, result_keys); | |
938 | } | |
3241b1d3 | 939 | EXPORT_SYMBOL_GPL(dm_btree_find_highest_key); |
4e7f1f90 | 940 | |
f164e690 JT |
941 | int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root, |
942 | uint64_t *result_keys) | |
943 | { | |
944 | return dm_btree_find_key(info, root, false, result_keys); | |
945 | } | |
946 | EXPORT_SYMBOL_GPL(dm_btree_find_lowest_key); | |
947 | ||
948 | /*----------------------------------------------------------------*/ | |
949 | ||
4e7f1f90 JT |
950 | /* |
951 | * FIXME: We shouldn't use a recursive algorithm when we have limited stack | |
952 | * space. Also this only works for single level trees. | |
953 | */ | |
9b460d36 | 954 | static int walk_node(struct dm_btree_info *info, dm_block_t block, |
4e7f1f90 JT |
955 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
956 | void *context) | |
957 | { | |
958 | int r; | |
959 | unsigned i, nr; | |
9b460d36 | 960 | struct dm_block *node; |
4e7f1f90 JT |
961 | struct btree_node *n; |
962 | uint64_t keys; | |
963 | ||
9b460d36 JT |
964 | r = bn_read_lock(info, block, &node); |
965 | if (r) | |
966 | return r; | |
967 | ||
968 | n = dm_block_data(node); | |
4e7f1f90 JT |
969 | |
970 | nr = le32_to_cpu(n->header.nr_entries); | |
971 | for (i = 0; i < nr; i++) { | |
972 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) { | |
9b460d36 | 973 | r = walk_node(info, value64(n, i), fn, context); |
4e7f1f90 JT |
974 | if (r) |
975 | goto out; | |
976 | } else { | |
977 | keys = le64_to_cpu(*key_ptr(n, i)); | |
978 | r = fn(context, &keys, value_ptr(n, i)); | |
979 | if (r) | |
980 | goto out; | |
981 | } | |
982 | } | |
983 | ||
984 | out: | |
9b460d36 | 985 | dm_tm_unlock(info->tm, node); |
4e7f1f90 JT |
986 | return r; |
987 | } | |
988 | ||
989 | int dm_btree_walk(struct dm_btree_info *info, dm_block_t root, | |
990 | int (*fn)(void *context, uint64_t *keys, void *leaf), | |
991 | void *context) | |
992 | { | |
4e7f1f90 | 993 | BUG_ON(info->levels > 1); |
9b460d36 | 994 | return walk_node(info, root, fn, context); |
4e7f1f90 JT |
995 | } |
996 | EXPORT_SYMBOL_GPL(dm_btree_walk); | |
7d111c81 JT |
997 | |
998 | /*----------------------------------------------------------------*/ | |
999 | ||
1000 | static void prefetch_values(struct dm_btree_cursor *c) | |
1001 | { | |
1002 | unsigned i, nr; | |
1003 | __le64 value_le; | |
1004 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1005 | struct btree_node *bn = dm_block_data(n->b); | |
1006 | struct dm_block_manager *bm = dm_tm_get_bm(c->info->tm); | |
1007 | ||
1008 | BUG_ON(c->info->value_type.size != sizeof(value_le)); | |
1009 | ||
1010 | nr = le32_to_cpu(bn->header.nr_entries); | |
1011 | for (i = 0; i < nr; i++) { | |
1012 | memcpy(&value_le, value_ptr(bn, i), sizeof(value_le)); | |
1013 | dm_bm_prefetch(bm, le64_to_cpu(value_le)); | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | static bool leaf_node(struct dm_btree_cursor *c) | |
1018 | { | |
1019 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1020 | struct btree_node *bn = dm_block_data(n->b); | |
1021 | ||
1022 | return le32_to_cpu(bn->header.flags) & LEAF_NODE; | |
1023 | } | |
1024 | ||
1025 | static int push_node(struct dm_btree_cursor *c, dm_block_t b) | |
1026 | { | |
1027 | int r; | |
1028 | struct cursor_node *n = c->nodes + c->depth; | |
1029 | ||
1030 | if (c->depth >= DM_BTREE_CURSOR_MAX_DEPTH - 1) { | |
1031 | DMERR("couldn't push cursor node, stack depth too high"); | |
1032 | return -EINVAL; | |
1033 | } | |
1034 | ||
1035 | r = bn_read_lock(c->info, b, &n->b); | |
1036 | if (r) | |
1037 | return r; | |
1038 | ||
1039 | n->index = 0; | |
1040 | c->depth++; | |
1041 | ||
1042 | if (c->prefetch_leaves || !leaf_node(c)) | |
1043 | prefetch_values(c); | |
1044 | ||
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | static void pop_node(struct dm_btree_cursor *c) | |
1049 | { | |
1050 | c->depth--; | |
1051 | unlock_block(c->info, c->nodes[c->depth].b); | |
1052 | } | |
1053 | ||
1054 | static int inc_or_backtrack(struct dm_btree_cursor *c) | |
1055 | { | |
1056 | struct cursor_node *n; | |
1057 | struct btree_node *bn; | |
1058 | ||
1059 | for (;;) { | |
1060 | if (!c->depth) | |
1061 | return -ENODATA; | |
1062 | ||
1063 | n = c->nodes + c->depth - 1; | |
1064 | bn = dm_block_data(n->b); | |
1065 | ||
1066 | n->index++; | |
1067 | if (n->index < le32_to_cpu(bn->header.nr_entries)) | |
1068 | break; | |
1069 | ||
1070 | pop_node(c); | |
1071 | } | |
1072 | ||
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | static int find_leaf(struct dm_btree_cursor *c) | |
1077 | { | |
1078 | int r = 0; | |
1079 | struct cursor_node *n; | |
1080 | struct btree_node *bn; | |
1081 | __le64 value_le; | |
1082 | ||
1083 | for (;;) { | |
1084 | n = c->nodes + c->depth - 1; | |
1085 | bn = dm_block_data(n->b); | |
1086 | ||
1087 | if (le32_to_cpu(bn->header.flags) & LEAF_NODE) | |
1088 | break; | |
1089 | ||
1090 | memcpy(&value_le, value_ptr(bn, n->index), sizeof(value_le)); | |
1091 | r = push_node(c, le64_to_cpu(value_le)); | |
1092 | if (r) { | |
1093 | DMERR("push_node failed"); | |
1094 | break; | |
1095 | } | |
1096 | } | |
1097 | ||
1098 | if (!r && (le32_to_cpu(bn->header.nr_entries) == 0)) | |
1099 | return -ENODATA; | |
1100 | ||
1101 | return r; | |
1102 | } | |
1103 | ||
1104 | int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root, | |
1105 | bool prefetch_leaves, struct dm_btree_cursor *c) | |
1106 | { | |
1107 | int r; | |
1108 | ||
1109 | c->info = info; | |
1110 | c->root = root; | |
1111 | c->depth = 0; | |
1112 | c->prefetch_leaves = prefetch_leaves; | |
1113 | ||
1114 | r = push_node(c, root); | |
1115 | if (r) | |
1116 | return r; | |
1117 | ||
1118 | return find_leaf(c); | |
1119 | } | |
1120 | EXPORT_SYMBOL_GPL(dm_btree_cursor_begin); | |
1121 | ||
1122 | void dm_btree_cursor_end(struct dm_btree_cursor *c) | |
1123 | { | |
1124 | while (c->depth) | |
1125 | pop_node(c); | |
1126 | } | |
1127 | EXPORT_SYMBOL_GPL(dm_btree_cursor_end); | |
1128 | ||
1129 | int dm_btree_cursor_next(struct dm_btree_cursor *c) | |
1130 | { | |
1131 | int r = inc_or_backtrack(c); | |
1132 | if (!r) { | |
1133 | r = find_leaf(c); | |
1134 | if (r) | |
1135 | DMERR("find_leaf failed"); | |
1136 | } | |
1137 | ||
1138 | return r; | |
1139 | } | |
1140 | EXPORT_SYMBOL_GPL(dm_btree_cursor_next); | |
1141 | ||
1142 | int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le) | |
1143 | { | |
1144 | if (c->depth) { | |
1145 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1146 | struct btree_node *bn = dm_block_data(n->b); | |
1147 | ||
1148 | if (le32_to_cpu(bn->header.flags) & INTERNAL_NODE) | |
1149 | return -EINVAL; | |
1150 | ||
1151 | *key = le64_to_cpu(*key_ptr(bn, n->index)); | |
1152 | memcpy(value_le, value_ptr(bn, n->index), c->info->value_type.size); | |
1153 | return 0; | |
1154 | ||
1155 | } else | |
1156 | return -ENODATA; | |
1157 | } | |
1158 | EXPORT_SYMBOL_GPL(dm_btree_cursor_get_value); |