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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 | ||
9f9ef065 JT |
275 | /* |
276 | * dm_btree_del() is called via an ioctl, as such should be | |
277 | * considered an FS op. We can't recurse back into the FS, so we | |
278 | * allocate GFP_NOFS. | |
279 | */ | |
280 | s = kmalloc(sizeof(*s), GFP_NOFS); | |
3241b1d3 JT |
281 | if (!s) |
282 | return -ENOMEM; | |
04f17c80 | 283 | s->info = info; |
3241b1d3 JT |
284 | s->tm = info->tm; |
285 | s->top = -1; | |
286 | ||
e3cbf945 | 287 | r = push_frame(s, root, 0); |
3241b1d3 JT |
288 | if (r) |
289 | goto out; | |
290 | ||
291 | while (unprocessed_frames(s)) { | |
292 | uint32_t flags; | |
293 | struct frame *f; | |
294 | dm_block_t b; | |
295 | ||
296 | r = top_frame(s, &f); | |
297 | if (r) | |
298 | goto out; | |
299 | ||
300 | if (f->current_child >= f->nr_children) { | |
301 | pop_frame(s); | |
302 | continue; | |
303 | } | |
304 | ||
305 | flags = le32_to_cpu(f->n->header.flags); | |
306 | if (flags & INTERNAL_NODE) { | |
307 | b = value64(f->n, f->current_child); | |
308 | f->current_child++; | |
309 | r = push_frame(s, b, f->level); | |
310 | if (r) | |
311 | goto out; | |
312 | ||
e3cbf945 | 313 | } else if (is_internal_level(info, f)) { |
3241b1d3 JT |
314 | b = value64(f->n, f->current_child); |
315 | f->current_child++; | |
316 | r = push_frame(s, b, f->level + 1); | |
317 | if (r) | |
318 | goto out; | |
319 | ||
320 | } else { | |
321 | if (info->value_type.dec) { | |
322 | unsigned i; | |
323 | ||
324 | for (i = 0; i < f->nr_children; i++) | |
325 | info->value_type.dec(info->value_type.context, | |
a3aefb39 | 326 | value_ptr(f->n, i)); |
3241b1d3 | 327 | } |
cd5acf0b | 328 | pop_frame(s); |
3241b1d3 JT |
329 | } |
330 | } | |
3241b1d3 | 331 | out: |
ed8b45a3 JT |
332 | if (r) { |
333 | /* cleanup all frames of del_stack */ | |
334 | unlock_all_frames(s); | |
335 | } | |
3241b1d3 | 336 | kfree(s); |
ed8b45a3 | 337 | |
3241b1d3 JT |
338 | return r; |
339 | } | |
340 | EXPORT_SYMBOL_GPL(dm_btree_del); | |
341 | ||
342 | /*----------------------------------------------------------------*/ | |
343 | ||
344 | static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key, | |
550929fa | 345 | int (*search_fn)(struct btree_node *, uint64_t), |
3241b1d3 JT |
346 | uint64_t *result_key, void *v, size_t value_size) |
347 | { | |
348 | int i, r; | |
349 | uint32_t flags, nr_entries; | |
350 | ||
351 | do { | |
352 | r = ro_step(s, block); | |
353 | if (r < 0) | |
354 | return r; | |
355 | ||
356 | i = search_fn(ro_node(s), key); | |
357 | ||
358 | flags = le32_to_cpu(ro_node(s)->header.flags); | |
359 | nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries); | |
360 | if (i < 0 || i >= nr_entries) | |
361 | return -ENODATA; | |
362 | ||
363 | if (flags & INTERNAL_NODE) | |
364 | block = value64(ro_node(s), i); | |
365 | ||
366 | } while (!(flags & LEAF_NODE)); | |
367 | ||
368 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); | |
a3aefb39 | 369 | memcpy(v, value_ptr(ro_node(s), i), value_size); |
3241b1d3 JT |
370 | |
371 | return 0; | |
372 | } | |
373 | ||
374 | int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root, | |
375 | uint64_t *keys, void *value_le) | |
376 | { | |
377 | unsigned level, last_level = info->levels - 1; | |
378 | int r = -ENODATA; | |
379 | uint64_t rkey; | |
380 | __le64 internal_value_le; | |
381 | struct ro_spine spine; | |
382 | ||
383 | init_ro_spine(&spine, info); | |
384 | for (level = 0; level < info->levels; level++) { | |
385 | size_t size; | |
386 | void *value_p; | |
387 | ||
388 | if (level == last_level) { | |
389 | value_p = value_le; | |
390 | size = info->value_type.size; | |
391 | ||
392 | } else { | |
393 | value_p = &internal_value_le; | |
394 | size = sizeof(uint64_t); | |
395 | } | |
396 | ||
397 | r = btree_lookup_raw(&spine, root, keys[level], | |
398 | lower_bound, &rkey, | |
399 | value_p, size); | |
400 | ||
401 | if (!r) { | |
402 | if (rkey != keys[level]) { | |
403 | exit_ro_spine(&spine); | |
404 | return -ENODATA; | |
405 | } | |
406 | } else { | |
407 | exit_ro_spine(&spine); | |
408 | return r; | |
409 | } | |
410 | ||
411 | root = le64_to_cpu(internal_value_le); | |
412 | } | |
413 | exit_ro_spine(&spine); | |
414 | ||
415 | return r; | |
416 | } | |
417 | EXPORT_SYMBOL_GPL(dm_btree_lookup); | |
418 | ||
993ceab9 JT |
419 | static int dm_btree_lookup_next_single(struct dm_btree_info *info, dm_block_t root, |
420 | uint64_t key, uint64_t *rkey, void *value_le) | |
421 | { | |
422 | int r, i; | |
423 | uint32_t flags, nr_entries; | |
424 | struct dm_block *node; | |
425 | struct btree_node *n; | |
426 | ||
427 | r = bn_read_lock(info, root, &node); | |
428 | if (r) | |
429 | return r; | |
430 | ||
431 | n = dm_block_data(node); | |
432 | flags = le32_to_cpu(n->header.flags); | |
433 | nr_entries = le32_to_cpu(n->header.nr_entries); | |
434 | ||
435 | if (flags & INTERNAL_NODE) { | |
436 | i = lower_bound(n, key); | |
e7e0f730 JT |
437 | if (i < 0) { |
438 | /* | |
439 | * avoid early -ENODATA return when all entries are | |
440 | * higher than the search @key. | |
441 | */ | |
442 | i = 0; | |
443 | } | |
444 | if (i >= nr_entries) { | |
993ceab9 JT |
445 | r = -ENODATA; |
446 | goto out; | |
447 | } | |
448 | ||
449 | r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le); | |
450 | if (r == -ENODATA && i < (nr_entries - 1)) { | |
451 | i++; | |
452 | r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le); | |
453 | } | |
454 | ||
455 | } else { | |
456 | i = upper_bound(n, key); | |
457 | if (i < 0 || i >= nr_entries) { | |
458 | r = -ENODATA; | |
459 | goto out; | |
460 | } | |
461 | ||
462 | *rkey = le64_to_cpu(n->keys[i]); | |
463 | memcpy(value_le, value_ptr(n, i), info->value_type.size); | |
464 | } | |
465 | out: | |
466 | dm_tm_unlock(info->tm, node); | |
467 | return r; | |
468 | } | |
469 | ||
470 | int dm_btree_lookup_next(struct dm_btree_info *info, dm_block_t root, | |
471 | uint64_t *keys, uint64_t *rkey, void *value_le) | |
472 | { | |
473 | unsigned level; | |
474 | int r = -ENODATA; | |
475 | __le64 internal_value_le; | |
476 | struct ro_spine spine; | |
477 | ||
478 | init_ro_spine(&spine, info); | |
479 | for (level = 0; level < info->levels - 1u; level++) { | |
480 | r = btree_lookup_raw(&spine, root, keys[level], | |
481 | lower_bound, rkey, | |
482 | &internal_value_le, sizeof(uint64_t)); | |
483 | if (r) | |
484 | goto out; | |
485 | ||
486 | if (*rkey != keys[level]) { | |
487 | r = -ENODATA; | |
488 | goto out; | |
489 | } | |
490 | ||
491 | root = le64_to_cpu(internal_value_le); | |
492 | } | |
493 | ||
494 | r = dm_btree_lookup_next_single(info, root, keys[level], rkey, value_le); | |
495 | out: | |
496 | exit_ro_spine(&spine); | |
497 | return r; | |
498 | } | |
499 | ||
500 | EXPORT_SYMBOL_GPL(dm_btree_lookup_next); | |
501 | ||
3241b1d3 JT |
502 | /* |
503 | * Splits a node by creating a sibling node and shifting half the nodes | |
504 | * contents across. Assumes there is a parent node, and it has room for | |
505 | * another child. | |
506 | * | |
507 | * Before: | |
508 | * +--------+ | |
509 | * | Parent | | |
510 | * +--------+ | |
511 | * | | |
512 | * v | |
513 | * +----------+ | |
514 | * | A ++++++ | | |
515 | * +----------+ | |
516 | * | |
517 | * | |
518 | * After: | |
519 | * +--------+ | |
520 | * | Parent | | |
521 | * +--------+ | |
522 | * | | | |
523 | * v +------+ | |
524 | * +---------+ | | |
525 | * | A* +++ | v | |
526 | * +---------+ +-------+ | |
527 | * | B +++ | | |
528 | * +-------+ | |
529 | * | |
530 | * Where A* is a shadow of A. | |
531 | */ | |
0a8d4c3e VG |
532 | static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index, |
533 | uint64_t key) | |
3241b1d3 JT |
534 | { |
535 | int r; | |
536 | size_t size; | |
537 | unsigned nr_left, nr_right; | |
538 | struct dm_block *left, *right, *parent; | |
550929fa | 539 | struct btree_node *ln, *rn, *pn; |
3241b1d3 JT |
540 | __le64 location; |
541 | ||
542 | left = shadow_current(s); | |
543 | ||
544 | r = new_block(s->info, &right); | |
545 | if (r < 0) | |
546 | return r; | |
547 | ||
548 | ln = dm_block_data(left); | |
549 | rn = dm_block_data(right); | |
550 | ||
551 | nr_left = le32_to_cpu(ln->header.nr_entries) / 2; | |
552 | nr_right = le32_to_cpu(ln->header.nr_entries) - nr_left; | |
553 | ||
554 | ln->header.nr_entries = cpu_to_le32(nr_left); | |
555 | ||
556 | rn->header.flags = ln->header.flags; | |
557 | rn->header.nr_entries = cpu_to_le32(nr_right); | |
558 | rn->header.max_entries = ln->header.max_entries; | |
559 | rn->header.value_size = ln->header.value_size; | |
560 | memcpy(rn->keys, ln->keys + nr_left, nr_right * sizeof(rn->keys[0])); | |
561 | ||
562 | size = le32_to_cpu(ln->header.flags) & INTERNAL_NODE ? | |
563 | sizeof(uint64_t) : s->info->value_type.size; | |
a3aefb39 | 564 | memcpy(value_ptr(rn, 0), value_ptr(ln, nr_left), |
3241b1d3 JT |
565 | size * nr_right); |
566 | ||
567 | /* | |
568 | * Patch up the parent | |
569 | */ | |
570 | parent = shadow_parent(s); | |
571 | ||
572 | pn = dm_block_data(parent); | |
573 | location = cpu_to_le64(dm_block_location(left)); | |
574 | __dm_bless_for_disk(&location); | |
a3aefb39 | 575 | memcpy_disk(value_ptr(pn, parent_index), |
3241b1d3 JT |
576 | &location, sizeof(__le64)); |
577 | ||
578 | location = cpu_to_le64(dm_block_location(right)); | |
579 | __dm_bless_for_disk(&location); | |
580 | ||
581 | r = insert_at(sizeof(__le64), pn, parent_index + 1, | |
582 | le64_to_cpu(rn->keys[0]), &location); | |
30ce6e1c MS |
583 | if (r) { |
584 | unlock_block(s->info, right); | |
3241b1d3 | 585 | return r; |
30ce6e1c | 586 | } |
3241b1d3 JT |
587 | |
588 | if (key < le64_to_cpu(rn->keys[0])) { | |
589 | unlock_block(s->info, right); | |
590 | s->nodes[1] = left; | |
591 | } else { | |
592 | unlock_block(s->info, left); | |
593 | s->nodes[1] = right; | |
594 | } | |
595 | ||
596 | return 0; | |
597 | } | |
598 | ||
599 | /* | |
600 | * Splits a node by creating two new children beneath the given node. | |
601 | * | |
602 | * Before: | |
603 | * +----------+ | |
604 | * | A ++++++ | | |
605 | * +----------+ | |
606 | * | |
607 | * | |
608 | * After: | |
609 | * +------------+ | |
610 | * | A (shadow) | | |
611 | * +------------+ | |
612 | * | | | |
613 | * +------+ +----+ | |
614 | * | | | |
615 | * v v | |
616 | * +-------+ +-------+ | |
617 | * | B +++ | | C +++ | | |
618 | * +-------+ +-------+ | |
619 | */ | |
620 | static int btree_split_beneath(struct shadow_spine *s, uint64_t key) | |
621 | { | |
622 | int r; | |
623 | size_t size; | |
624 | unsigned nr_left, nr_right; | |
625 | struct dm_block *left, *right, *new_parent; | |
550929fa | 626 | struct btree_node *pn, *ln, *rn; |
3241b1d3 JT |
627 | __le64 val; |
628 | ||
629 | new_parent = shadow_current(s); | |
630 | ||
631 | r = new_block(s->info, &left); | |
632 | if (r < 0) | |
633 | return r; | |
634 | ||
635 | r = new_block(s->info, &right); | |
636 | if (r < 0) { | |
4dcb8b57 | 637 | unlock_block(s->info, left); |
3241b1d3 JT |
638 | return r; |
639 | } | |
640 | ||
641 | pn = dm_block_data(new_parent); | |
642 | ln = dm_block_data(left); | |
643 | rn = dm_block_data(right); | |
644 | ||
645 | nr_left = le32_to_cpu(pn->header.nr_entries) / 2; | |
646 | nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left; | |
647 | ||
648 | ln->header.flags = pn->header.flags; | |
649 | ln->header.nr_entries = cpu_to_le32(nr_left); | |
650 | ln->header.max_entries = pn->header.max_entries; | |
651 | ln->header.value_size = pn->header.value_size; | |
652 | ||
653 | rn->header.flags = pn->header.flags; | |
654 | rn->header.nr_entries = cpu_to_le32(nr_right); | |
655 | rn->header.max_entries = pn->header.max_entries; | |
656 | rn->header.value_size = pn->header.value_size; | |
657 | ||
658 | memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0])); | |
659 | memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0])); | |
660 | ||
661 | size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ? | |
662 | sizeof(__le64) : s->info->value_type.size; | |
a3aefb39 JT |
663 | memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size); |
664 | memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left), | |
3241b1d3 JT |
665 | nr_right * size); |
666 | ||
667 | /* new_parent should just point to l and r now */ | |
668 | pn->header.flags = cpu_to_le32(INTERNAL_NODE); | |
669 | pn->header.nr_entries = cpu_to_le32(2); | |
670 | pn->header.max_entries = cpu_to_le32( | |
671 | calc_max_entries(sizeof(__le64), | |
672 | dm_bm_block_size( | |
673 | dm_tm_get_bm(s->info->tm)))); | |
674 | pn->header.value_size = cpu_to_le32(sizeof(__le64)); | |
675 | ||
676 | val = cpu_to_le64(dm_block_location(left)); | |
677 | __dm_bless_for_disk(&val); | |
678 | pn->keys[0] = ln->keys[0]; | |
a3aefb39 | 679 | memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64)); |
3241b1d3 JT |
680 | |
681 | val = cpu_to_le64(dm_block_location(right)); | |
682 | __dm_bless_for_disk(&val); | |
683 | pn->keys[1] = rn->keys[0]; | |
a3aefb39 | 684 | memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64)); |
3241b1d3 JT |
685 | |
686 | /* | |
687 | * rejig the spine. This is ugly, since it knows too | |
688 | * much about the spine | |
689 | */ | |
690 | if (s->nodes[0] != new_parent) { | |
691 | unlock_block(s->info, s->nodes[0]); | |
692 | s->nodes[0] = new_parent; | |
693 | } | |
694 | if (key < le64_to_cpu(rn->keys[0])) { | |
695 | unlock_block(s->info, right); | |
696 | s->nodes[1] = left; | |
697 | } else { | |
698 | unlock_block(s->info, left); | |
699 | s->nodes[1] = right; | |
700 | } | |
701 | s->count = 2; | |
702 | ||
703 | return 0; | |
704 | } | |
705 | ||
706 | static int btree_insert_raw(struct shadow_spine *s, dm_block_t root, | |
707 | struct dm_btree_value_type *vt, | |
708 | uint64_t key, unsigned *index) | |
709 | { | |
710 | int r, i = *index, top = 1; | |
550929fa | 711 | struct btree_node *node; |
3241b1d3 JT |
712 | |
713 | for (;;) { | |
714 | r = shadow_step(s, root, vt); | |
715 | if (r < 0) | |
716 | return r; | |
717 | ||
718 | node = dm_block_data(shadow_current(s)); | |
719 | ||
720 | /* | |
721 | * We have to patch up the parent node, ugly, but I don't | |
722 | * see a way to do this automatically as part of the spine | |
723 | * op. | |
724 | */ | |
725 | if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */ | |
726 | __le64 location = cpu_to_le64(dm_block_location(shadow_current(s))); | |
727 | ||
728 | __dm_bless_for_disk(&location); | |
a3aefb39 | 729 | memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i), |
3241b1d3 JT |
730 | &location, sizeof(__le64)); |
731 | } | |
732 | ||
733 | node = dm_block_data(shadow_current(s)); | |
734 | ||
735 | if (node->header.nr_entries == node->header.max_entries) { | |
736 | if (top) | |
737 | r = btree_split_beneath(s, key); | |
738 | else | |
0a8d4c3e | 739 | r = btree_split_sibling(s, i, key); |
3241b1d3 JT |
740 | |
741 | if (r < 0) | |
742 | return r; | |
743 | } | |
744 | ||
745 | node = dm_block_data(shadow_current(s)); | |
746 | ||
747 | i = lower_bound(node, key); | |
748 | ||
749 | if (le32_to_cpu(node->header.flags) & LEAF_NODE) | |
750 | break; | |
751 | ||
752 | if (i < 0) { | |
753 | /* change the bounds on the lowest key */ | |
754 | node->keys[0] = cpu_to_le64(key); | |
755 | i = 0; | |
756 | } | |
757 | ||
758 | root = value64(node, i); | |
759 | top = 0; | |
760 | } | |
761 | ||
762 | if (i < 0 || le64_to_cpu(node->keys[i]) != key) | |
763 | i++; | |
764 | ||
765 | *index = i; | |
766 | return 0; | |
767 | } | |
768 | ||
ba503835 MS |
769 | static bool need_insert(struct btree_node *node, uint64_t *keys, |
770 | unsigned level, unsigned index) | |
771 | { | |
772 | return ((index >= le32_to_cpu(node->header.nr_entries)) || | |
773 | (le64_to_cpu(node->keys[index]) != keys[level])); | |
774 | } | |
775 | ||
3241b1d3 JT |
776 | static int insert(struct dm_btree_info *info, dm_block_t root, |
777 | uint64_t *keys, void *value, dm_block_t *new_root, | |
778 | int *inserted) | |
779 | __dm_written_to_disk(value) | |
780 | { | |
ba503835 | 781 | int r; |
3241b1d3 JT |
782 | unsigned level, index = -1, last_level = info->levels - 1; |
783 | dm_block_t block = root; | |
784 | struct shadow_spine spine; | |
550929fa | 785 | struct btree_node *n; |
3241b1d3 JT |
786 | struct dm_btree_value_type le64_type; |
787 | ||
b0dc3c8b | 788 | init_le64_type(info->tm, &le64_type); |
3241b1d3 JT |
789 | init_shadow_spine(&spine, info); |
790 | ||
791 | for (level = 0; level < (info->levels - 1); level++) { | |
792 | r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index); | |
793 | if (r < 0) | |
794 | goto bad; | |
795 | ||
796 | n = dm_block_data(shadow_current(&spine)); | |
3241b1d3 | 797 | |
ba503835 | 798 | if (need_insert(n, keys, level, index)) { |
3241b1d3 JT |
799 | dm_block_t new_tree; |
800 | __le64 new_le; | |
801 | ||
802 | r = dm_btree_empty(info, &new_tree); | |
803 | if (r < 0) | |
804 | goto bad; | |
805 | ||
806 | new_le = cpu_to_le64(new_tree); | |
807 | __dm_bless_for_disk(&new_le); | |
808 | ||
809 | r = insert_at(sizeof(uint64_t), n, index, | |
810 | keys[level], &new_le); | |
811 | if (r) | |
812 | goto bad; | |
813 | } | |
814 | ||
815 | if (level < last_level) | |
816 | block = value64(n, index); | |
817 | } | |
818 | ||
819 | r = btree_insert_raw(&spine, block, &info->value_type, | |
820 | keys[level], &index); | |
821 | if (r < 0) | |
822 | goto bad; | |
823 | ||
824 | n = dm_block_data(shadow_current(&spine)); | |
3241b1d3 | 825 | |
ba503835 | 826 | if (need_insert(n, keys, level, index)) { |
3241b1d3 JT |
827 | if (inserted) |
828 | *inserted = 1; | |
829 | ||
830 | r = insert_at(info->value_type.size, n, index, | |
831 | keys[level], value); | |
832 | if (r) | |
833 | goto bad_unblessed; | |
834 | } else { | |
835 | if (inserted) | |
836 | *inserted = 0; | |
837 | ||
838 | if (info->value_type.dec && | |
839 | (!info->value_type.equal || | |
840 | !info->value_type.equal( | |
841 | info->value_type.context, | |
a3aefb39 | 842 | value_ptr(n, index), |
3241b1d3 JT |
843 | value))) { |
844 | info->value_type.dec(info->value_type.context, | |
a3aefb39 | 845 | value_ptr(n, index)); |
3241b1d3 | 846 | } |
a3aefb39 | 847 | memcpy_disk(value_ptr(n, index), |
3241b1d3 JT |
848 | value, info->value_type.size); |
849 | } | |
850 | ||
851 | *new_root = shadow_root(&spine); | |
852 | exit_shadow_spine(&spine); | |
853 | ||
854 | return 0; | |
855 | ||
856 | bad: | |
857 | __dm_unbless_for_disk(value); | |
858 | bad_unblessed: | |
859 | exit_shadow_spine(&spine); | |
860 | return r; | |
861 | } | |
862 | ||
863 | int dm_btree_insert(struct dm_btree_info *info, dm_block_t root, | |
864 | uint64_t *keys, void *value, dm_block_t *new_root) | |
865 | __dm_written_to_disk(value) | |
866 | { | |
867 | return insert(info, root, keys, value, new_root, NULL); | |
868 | } | |
869 | EXPORT_SYMBOL_GPL(dm_btree_insert); | |
870 | ||
871 | int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, | |
872 | uint64_t *keys, void *value, dm_block_t *new_root, | |
873 | int *inserted) | |
874 | __dm_written_to_disk(value) | |
875 | { | |
876 | return insert(info, root, keys, value, new_root, inserted); | |
877 | } | |
878 | EXPORT_SYMBOL_GPL(dm_btree_insert_notify); | |
879 | ||
880 | /*----------------------------------------------------------------*/ | |
881 | ||
f164e690 JT |
882 | static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest, |
883 | uint64_t *result_key, dm_block_t *next_block) | |
3241b1d3 JT |
884 | { |
885 | int i, r; | |
886 | uint32_t flags; | |
887 | ||
888 | do { | |
889 | r = ro_step(s, block); | |
890 | if (r < 0) | |
891 | return r; | |
892 | ||
893 | flags = le32_to_cpu(ro_node(s)->header.flags); | |
894 | i = le32_to_cpu(ro_node(s)->header.nr_entries); | |
895 | if (!i) | |
896 | return -ENODATA; | |
897 | else | |
898 | i--; | |
899 | ||
f164e690 JT |
900 | if (find_highest) |
901 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); | |
902 | else | |
903 | *result_key = le64_to_cpu(ro_node(s)->keys[0]); | |
904 | ||
7d1fedb6 VR |
905 | if (next_block || flags & INTERNAL_NODE) { |
906 | if (find_highest) | |
907 | block = value64(ro_node(s), i); | |
908 | else | |
909 | block = value64(ro_node(s), 0); | |
910 | } | |
3241b1d3 JT |
911 | |
912 | } while (flags & INTERNAL_NODE); | |
913 | ||
914 | if (next_block) | |
915 | *next_block = block; | |
916 | return 0; | |
917 | } | |
918 | ||
f164e690 JT |
919 | static int dm_btree_find_key(struct dm_btree_info *info, dm_block_t root, |
920 | bool find_highest, uint64_t *result_keys) | |
3241b1d3 JT |
921 | { |
922 | int r = 0, count = 0, level; | |
923 | struct ro_spine spine; | |
924 | ||
925 | init_ro_spine(&spine, info); | |
926 | for (level = 0; level < info->levels; level++) { | |
f164e690 JT |
927 | r = find_key(&spine, root, find_highest, result_keys + level, |
928 | level == info->levels - 1 ? NULL : &root); | |
3241b1d3 JT |
929 | if (r == -ENODATA) { |
930 | r = 0; | |
931 | break; | |
932 | ||
933 | } else if (r) | |
934 | break; | |
935 | ||
936 | count++; | |
937 | } | |
938 | exit_ro_spine(&spine); | |
939 | ||
940 | return r ? r : count; | |
941 | } | |
f164e690 JT |
942 | |
943 | int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root, | |
944 | uint64_t *result_keys) | |
945 | { | |
946 | return dm_btree_find_key(info, root, true, result_keys); | |
947 | } | |
3241b1d3 | 948 | EXPORT_SYMBOL_GPL(dm_btree_find_highest_key); |
4e7f1f90 | 949 | |
f164e690 JT |
950 | int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root, |
951 | uint64_t *result_keys) | |
952 | { | |
953 | return dm_btree_find_key(info, root, false, result_keys); | |
954 | } | |
955 | EXPORT_SYMBOL_GPL(dm_btree_find_lowest_key); | |
956 | ||
957 | /*----------------------------------------------------------------*/ | |
958 | ||
4e7f1f90 JT |
959 | /* |
960 | * FIXME: We shouldn't use a recursive algorithm when we have limited stack | |
961 | * space. Also this only works for single level trees. | |
962 | */ | |
9b460d36 | 963 | static int walk_node(struct dm_btree_info *info, dm_block_t block, |
4e7f1f90 JT |
964 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
965 | void *context) | |
966 | { | |
967 | int r; | |
968 | unsigned i, nr; | |
9b460d36 | 969 | struct dm_block *node; |
4e7f1f90 JT |
970 | struct btree_node *n; |
971 | uint64_t keys; | |
972 | ||
9b460d36 JT |
973 | r = bn_read_lock(info, block, &node); |
974 | if (r) | |
975 | return r; | |
976 | ||
977 | n = dm_block_data(node); | |
4e7f1f90 JT |
978 | |
979 | nr = le32_to_cpu(n->header.nr_entries); | |
980 | for (i = 0; i < nr; i++) { | |
981 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) { | |
9b460d36 | 982 | r = walk_node(info, value64(n, i), fn, context); |
4e7f1f90 JT |
983 | if (r) |
984 | goto out; | |
985 | } else { | |
986 | keys = le64_to_cpu(*key_ptr(n, i)); | |
987 | r = fn(context, &keys, value_ptr(n, i)); | |
988 | if (r) | |
989 | goto out; | |
990 | } | |
991 | } | |
992 | ||
993 | out: | |
9b460d36 | 994 | dm_tm_unlock(info->tm, node); |
4e7f1f90 JT |
995 | return r; |
996 | } | |
997 | ||
998 | int dm_btree_walk(struct dm_btree_info *info, dm_block_t root, | |
999 | int (*fn)(void *context, uint64_t *keys, void *leaf), | |
1000 | void *context) | |
1001 | { | |
4e7f1f90 | 1002 | BUG_ON(info->levels > 1); |
9b460d36 | 1003 | return walk_node(info, root, fn, context); |
4e7f1f90 JT |
1004 | } |
1005 | EXPORT_SYMBOL_GPL(dm_btree_walk); | |
7d111c81 JT |
1006 | |
1007 | /*----------------------------------------------------------------*/ | |
1008 | ||
1009 | static void prefetch_values(struct dm_btree_cursor *c) | |
1010 | { | |
1011 | unsigned i, nr; | |
1012 | __le64 value_le; | |
1013 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1014 | struct btree_node *bn = dm_block_data(n->b); | |
1015 | struct dm_block_manager *bm = dm_tm_get_bm(c->info->tm); | |
1016 | ||
1017 | BUG_ON(c->info->value_type.size != sizeof(value_le)); | |
1018 | ||
1019 | nr = le32_to_cpu(bn->header.nr_entries); | |
1020 | for (i = 0; i < nr; i++) { | |
1021 | memcpy(&value_le, value_ptr(bn, i), sizeof(value_le)); | |
1022 | dm_bm_prefetch(bm, le64_to_cpu(value_le)); | |
1023 | } | |
1024 | } | |
1025 | ||
1026 | static bool leaf_node(struct dm_btree_cursor *c) | |
1027 | { | |
1028 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1029 | struct btree_node *bn = dm_block_data(n->b); | |
1030 | ||
1031 | return le32_to_cpu(bn->header.flags) & LEAF_NODE; | |
1032 | } | |
1033 | ||
1034 | static int push_node(struct dm_btree_cursor *c, dm_block_t b) | |
1035 | { | |
1036 | int r; | |
1037 | struct cursor_node *n = c->nodes + c->depth; | |
1038 | ||
1039 | if (c->depth >= DM_BTREE_CURSOR_MAX_DEPTH - 1) { | |
1040 | DMERR("couldn't push cursor node, stack depth too high"); | |
1041 | return -EINVAL; | |
1042 | } | |
1043 | ||
1044 | r = bn_read_lock(c->info, b, &n->b); | |
1045 | if (r) | |
1046 | return r; | |
1047 | ||
1048 | n->index = 0; | |
1049 | c->depth++; | |
1050 | ||
1051 | if (c->prefetch_leaves || !leaf_node(c)) | |
1052 | prefetch_values(c); | |
1053 | ||
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | static void pop_node(struct dm_btree_cursor *c) | |
1058 | { | |
1059 | c->depth--; | |
1060 | unlock_block(c->info, c->nodes[c->depth].b); | |
1061 | } | |
1062 | ||
1063 | static int inc_or_backtrack(struct dm_btree_cursor *c) | |
1064 | { | |
1065 | struct cursor_node *n; | |
1066 | struct btree_node *bn; | |
1067 | ||
1068 | for (;;) { | |
1069 | if (!c->depth) | |
1070 | return -ENODATA; | |
1071 | ||
1072 | n = c->nodes + c->depth - 1; | |
1073 | bn = dm_block_data(n->b); | |
1074 | ||
1075 | n->index++; | |
1076 | if (n->index < le32_to_cpu(bn->header.nr_entries)) | |
1077 | break; | |
1078 | ||
1079 | pop_node(c); | |
1080 | } | |
1081 | ||
1082 | return 0; | |
1083 | } | |
1084 | ||
1085 | static int find_leaf(struct dm_btree_cursor *c) | |
1086 | { | |
1087 | int r = 0; | |
1088 | struct cursor_node *n; | |
1089 | struct btree_node *bn; | |
1090 | __le64 value_le; | |
1091 | ||
1092 | for (;;) { | |
1093 | n = c->nodes + c->depth - 1; | |
1094 | bn = dm_block_data(n->b); | |
1095 | ||
1096 | if (le32_to_cpu(bn->header.flags) & LEAF_NODE) | |
1097 | break; | |
1098 | ||
1099 | memcpy(&value_le, value_ptr(bn, n->index), sizeof(value_le)); | |
1100 | r = push_node(c, le64_to_cpu(value_le)); | |
1101 | if (r) { | |
1102 | DMERR("push_node failed"); | |
1103 | break; | |
1104 | } | |
1105 | } | |
1106 | ||
1107 | if (!r && (le32_to_cpu(bn->header.nr_entries) == 0)) | |
1108 | return -ENODATA; | |
1109 | ||
1110 | return r; | |
1111 | } | |
1112 | ||
1113 | int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root, | |
1114 | bool prefetch_leaves, struct dm_btree_cursor *c) | |
1115 | { | |
1116 | int r; | |
1117 | ||
1118 | c->info = info; | |
1119 | c->root = root; | |
1120 | c->depth = 0; | |
1121 | c->prefetch_leaves = prefetch_leaves; | |
1122 | ||
1123 | r = push_node(c, root); | |
1124 | if (r) | |
1125 | return r; | |
1126 | ||
1127 | return find_leaf(c); | |
1128 | } | |
1129 | EXPORT_SYMBOL_GPL(dm_btree_cursor_begin); | |
1130 | ||
1131 | void dm_btree_cursor_end(struct dm_btree_cursor *c) | |
1132 | { | |
1133 | while (c->depth) | |
1134 | pop_node(c); | |
1135 | } | |
1136 | EXPORT_SYMBOL_GPL(dm_btree_cursor_end); | |
1137 | ||
1138 | int dm_btree_cursor_next(struct dm_btree_cursor *c) | |
1139 | { | |
1140 | int r = inc_or_backtrack(c); | |
1141 | if (!r) { | |
1142 | r = find_leaf(c); | |
1143 | if (r) | |
1144 | DMERR("find_leaf failed"); | |
1145 | } | |
1146 | ||
1147 | return r; | |
1148 | } | |
1149 | EXPORT_SYMBOL_GPL(dm_btree_cursor_next); | |
1150 | ||
9b696229 JT |
1151 | int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count) |
1152 | { | |
1153 | int r = 0; | |
1154 | ||
1155 | while (count-- && !r) | |
1156 | r = dm_btree_cursor_next(c); | |
1157 | ||
1158 | return r; | |
1159 | } | |
1160 | EXPORT_SYMBOL_GPL(dm_btree_cursor_skip); | |
1161 | ||
7d111c81 JT |
1162 | int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le) |
1163 | { | |
1164 | if (c->depth) { | |
1165 | struct cursor_node *n = c->nodes + c->depth - 1; | |
1166 | struct btree_node *bn = dm_block_data(n->b); | |
1167 | ||
1168 | if (le32_to_cpu(bn->header.flags) & INTERNAL_NODE) | |
1169 | return -EINVAL; | |
1170 | ||
1171 | *key = le64_to_cpu(*key_ptr(bn, n->index)); | |
1172 | memcpy(value_le, value_ptr(bn, n->index), c->info->value_type.size); | |
1173 | return 0; | |
1174 | ||
1175 | } else | |
1176 | return -ENODATA; | |
1177 | } | |
1178 | EXPORT_SYMBOL_GPL(dm_btree_cursor_get_value); |