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Commit | Line | Data |
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be0e5c09 CM |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include "kerncompat.h" | |
eb60ceac CM |
4 | #include "radix-tree.h" |
5 | #include "ctree.h" | |
6 | #include "disk-io.h" | |
5de08d7d | 7 | #include "print-tree.h" |
9a8dd150 | 8 | |
aa5d6bed CM |
9 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
10 | int level); | |
11 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, | |
12 | int data_size); | |
13 | static int push_node_left(struct ctree_root *root, struct ctree_path *path, | |
14 | int level); | |
15 | static int push_node_right(struct ctree_root *root, | |
5de08d7d | 16 | struct ctree_path *path, int level); |
aa5d6bed | 17 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level); |
d97e63b6 | 18 | |
5de08d7d | 19 | inline void init_path(struct ctree_path *p) |
be0e5c09 CM |
20 | { |
21 | memset(p, 0, sizeof(*p)); | |
22 | } | |
23 | ||
5de08d7d | 24 | void release_path(struct ctree_root *root, struct ctree_path *p) |
eb60ceac CM |
25 | { |
26 | int i; | |
27 | for (i = 0; i < MAX_LEVEL; i++) { | |
28 | if (!p->nodes[i]) | |
29 | break; | |
30 | tree_block_release(root, p->nodes[i]); | |
31 | } | |
aa5d6bed | 32 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
33 | } |
34 | ||
74123bd7 CM |
35 | /* |
36 | * The leaf data grows from end-to-front in the node. | |
37 | * this returns the address of the start of the last item, | |
38 | * which is the stop of the leaf data stack | |
39 | */ | |
be0e5c09 CM |
40 | static inline unsigned int leaf_data_end(struct leaf *leaf) |
41 | { | |
42 | unsigned int nr = leaf->header.nritems; | |
43 | if (nr == 0) | |
d97e63b6 | 44 | return sizeof(leaf->data); |
be0e5c09 CM |
45 | return leaf->items[nr-1].offset; |
46 | } | |
47 | ||
74123bd7 CM |
48 | /* |
49 | * The space between the end of the leaf items and | |
50 | * the start of the leaf data. IOW, how much room | |
51 | * the leaf has left for both items and data | |
52 | */ | |
5de08d7d | 53 | int leaf_free_space(struct leaf *leaf) |
be0e5c09 CM |
54 | { |
55 | int data_end = leaf_data_end(leaf); | |
56 | int nritems = leaf->header.nritems; | |
57 | char *items_end = (char *)(leaf->items + nritems + 1); | |
58 | return (char *)(leaf->data + data_end) - (char *)items_end; | |
59 | } | |
60 | ||
74123bd7 CM |
61 | /* |
62 | * compare two keys in a memcmp fashion | |
63 | */ | |
be0e5c09 CM |
64 | int comp_keys(struct key *k1, struct key *k2) |
65 | { | |
66 | if (k1->objectid > k2->objectid) | |
67 | return 1; | |
68 | if (k1->objectid < k2->objectid) | |
69 | return -1; | |
70 | if (k1->flags > k2->flags) | |
71 | return 1; | |
72 | if (k1->flags < k2->flags) | |
73 | return -1; | |
74 | if (k1->offset > k2->offset) | |
75 | return 1; | |
76 | if (k1->offset < k2->offset) | |
77 | return -1; | |
78 | return 0; | |
79 | } | |
74123bd7 | 80 | |
aa5d6bed CM |
81 | int check_node(struct ctree_path *path, int level) |
82 | { | |
83 | int i; | |
84 | struct node *parent = NULL; | |
85 | struct node *node = &path->nodes[level]->node; | |
86 | int parent_slot; | |
87 | ||
88 | if (path->nodes[level + 1]) | |
89 | parent = &path->nodes[level + 1]->node; | |
90 | parent_slot = path->slots[level + 1]; | |
91 | if (parent && node->header.nritems > 0) { | |
92 | struct key *parent_key; | |
93 | parent_key = &parent->keys[parent_slot]; | |
94 | BUG_ON(memcmp(parent_key, node->keys, sizeof(struct key))); | |
95 | BUG_ON(parent->blockptrs[parent_slot] != node->header.blocknr); | |
96 | } | |
97 | BUG_ON(node->header.nritems > NODEPTRS_PER_BLOCK); | |
98 | for (i = 0; i < node->header.nritems - 2; i++) { | |
99 | BUG_ON(comp_keys(&node->keys[i], &node->keys[i+1]) >= 0); | |
100 | } | |
101 | return 0; | |
102 | } | |
103 | ||
104 | int check_leaf(struct ctree_path *path, int level) | |
105 | { | |
106 | int i; | |
107 | struct leaf *leaf = &path->nodes[level]->leaf; | |
108 | struct node *parent = NULL; | |
109 | int parent_slot; | |
110 | ||
111 | if (path->nodes[level + 1]) | |
112 | parent = &path->nodes[level + 1]->node; | |
113 | parent_slot = path->slots[level + 1]; | |
114 | if (parent && leaf->header.nritems > 0) { | |
115 | struct key *parent_key; | |
116 | parent_key = &parent->keys[parent_slot]; | |
117 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, | |
118 | sizeof(struct key))); | |
119 | BUG_ON(parent->blockptrs[parent_slot] != leaf->header.blocknr); | |
120 | } | |
121 | for (i = 0; i < leaf->header.nritems - 2; i++) { | |
122 | BUG_ON(comp_keys(&leaf->items[i].key, | |
123 | &leaf->items[i+1].key) >= 0); | |
124 | BUG_ON(leaf->items[i].offset != leaf->items[i + 1].offset + | |
125 | leaf->items[i + 1].size); | |
126 | if (i == 0) { | |
127 | BUG_ON(leaf->items[i].offset + leaf->items[i].size != | |
128 | LEAF_DATA_SIZE); | |
129 | } | |
130 | } | |
131 | BUG_ON(leaf_free_space(leaf) < 0); | |
132 | return 0; | |
133 | } | |
134 | ||
135 | int check_block(struct ctree_path *path, int level) | |
136 | { | |
137 | if (level == 0) | |
138 | return check_leaf(path, level); | |
139 | return check_node(path, level); | |
140 | } | |
141 | ||
74123bd7 CM |
142 | /* |
143 | * search for key in the array p. items p are item_size apart | |
144 | * and there are 'max' items in p | |
145 | * the slot in the array is returned via slot, and it points to | |
146 | * the place where you would insert key if it is not found in | |
147 | * the array. | |
148 | * | |
149 | * slot may point to max if the key is bigger than all of the keys | |
150 | */ | |
be0e5c09 CM |
151 | int generic_bin_search(char *p, int item_size, struct key *key, |
152 | int max, int *slot) | |
153 | { | |
154 | int low = 0; | |
155 | int high = max; | |
156 | int mid; | |
157 | int ret; | |
158 | struct key *tmp; | |
159 | ||
160 | while(low < high) { | |
161 | mid = (low + high) / 2; | |
162 | tmp = (struct key *)(p + mid * item_size); | |
163 | ret = comp_keys(tmp, key); | |
164 | ||
165 | if (ret < 0) | |
166 | low = mid + 1; | |
167 | else if (ret > 0) | |
168 | high = mid; | |
169 | else { | |
170 | *slot = mid; | |
171 | return 0; | |
172 | } | |
173 | } | |
174 | *slot = low; | |
175 | return 1; | |
176 | } | |
177 | ||
97571fd0 CM |
178 | /* |
179 | * simple bin_search frontend that does the right thing for | |
180 | * leaves vs nodes | |
181 | */ | |
be0e5c09 CM |
182 | int bin_search(struct node *c, struct key *key, int *slot) |
183 | { | |
184 | if (is_leaf(c->header.flags)) { | |
185 | struct leaf *l = (struct leaf *)c; | |
186 | return generic_bin_search((void *)l->items, sizeof(struct item), | |
187 | key, c->header.nritems, slot); | |
188 | } else { | |
189 | return generic_bin_search((void *)c->keys, sizeof(struct key), | |
190 | key, c->header.nritems, slot); | |
191 | } | |
192 | return -1; | |
193 | } | |
194 | ||
74123bd7 CM |
195 | /* |
196 | * look for key in the tree. path is filled in with nodes along the way | |
197 | * if key is found, we return zero and you can find the item in the leaf | |
198 | * level of the path (level 0) | |
199 | * | |
200 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
201 | * be inserted, and 1 is returned. If there are other errors during the |
202 | * search a negative error number is returned. | |
97571fd0 CM |
203 | * |
204 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
205 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
206 | * possible) | |
74123bd7 | 207 | */ |
5de08d7d CM |
208 | int search_slot(struct ctree_root *root, struct key *key, |
209 | struct ctree_path *p, int ins_len) | |
be0e5c09 | 210 | { |
eb60ceac CM |
211 | struct tree_buffer *b = root->node; |
212 | struct node *c; | |
be0e5c09 CM |
213 | int slot; |
214 | int ret; | |
215 | int level; | |
5c680ed6 | 216 | |
eb60ceac CM |
217 | b->count++; |
218 | while (b) { | |
219 | c = &b->node; | |
be0e5c09 | 220 | level = node_level(c->header.flags); |
eb60ceac | 221 | p->nodes[level] = b; |
aa5d6bed CM |
222 | ret = check_block(p, level); |
223 | if (ret) | |
224 | return -1; | |
be0e5c09 CM |
225 | ret = bin_search(c, key, &slot); |
226 | if (!is_leaf(c->header.flags)) { | |
227 | if (ret && slot > 0) | |
228 | slot -= 1; | |
229 | p->slots[level] = slot; | |
5de08d7d CM |
230 | if (ins_len > 0 && |
231 | c->header.nritems == NODEPTRS_PER_BLOCK) { | |
5c680ed6 CM |
232 | int sret = split_node(root, p, level); |
233 | BUG_ON(sret > 0); | |
234 | if (sret) | |
235 | return sret; | |
236 | b = p->nodes[level]; | |
237 | c = &b->node; | |
238 | slot = p->slots[level]; | |
239 | } | |
eb60ceac | 240 | b = read_tree_block(root, c->blockptrs[slot]); |
be0e5c09 CM |
241 | continue; |
242 | } else { | |
5c680ed6 | 243 | struct leaf *l = (struct leaf *)c; |
be0e5c09 | 244 | p->slots[level] = slot; |
5de08d7d CM |
245 | if (ins_len > 0 && leaf_free_space(l) < |
246 | sizeof(struct item) + ins_len) { | |
5c680ed6 CM |
247 | int sret = split_leaf(root, p, ins_len); |
248 | BUG_ON(sret > 0); | |
249 | if (sret) | |
250 | return sret; | |
251 | } | |
be0e5c09 CM |
252 | return ret; |
253 | } | |
254 | } | |
aa5d6bed | 255 | return 1; |
be0e5c09 CM |
256 | } |
257 | ||
74123bd7 CM |
258 | /* |
259 | * adjust the pointers going up the tree, starting at level | |
260 | * making sure the right key of each node is points to 'key'. | |
261 | * This is used after shifting pointers to the left, so it stops | |
262 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
263 | * higher levels | |
aa5d6bed CM |
264 | * |
265 | * If this fails to write a tree block, it returns -1, but continues | |
266 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 267 | */ |
aa5d6bed | 268 | static int fixup_low_keys(struct ctree_root *root, |
eb60ceac CM |
269 | struct ctree_path *path, struct key *key, |
270 | int level) | |
be0e5c09 CM |
271 | { |
272 | int i; | |
aa5d6bed CM |
273 | int ret = 0; |
274 | int wret; | |
be0e5c09 | 275 | for (i = level; i < MAX_LEVEL; i++) { |
eb60ceac | 276 | struct node *t; |
be0e5c09 | 277 | int tslot = path->slots[i]; |
eb60ceac | 278 | if (!path->nodes[i]) |
be0e5c09 | 279 | break; |
eb60ceac | 280 | t = &path->nodes[i]->node; |
be0e5c09 | 281 | memcpy(t->keys + tslot, key, sizeof(*key)); |
aa5d6bed CM |
282 | wret = write_tree_block(root, path->nodes[i]); |
283 | if (wret) | |
284 | ret = wret; | |
be0e5c09 CM |
285 | if (tslot != 0) |
286 | break; | |
287 | } | |
aa5d6bed | 288 | return ret; |
be0e5c09 CM |
289 | } |
290 | ||
74123bd7 CM |
291 | /* |
292 | * try to push data from one node into the next node left in the | |
293 | * tree. The src node is found at specified level in the path. | |
294 | * If some bytes were pushed, return 0, otherwise return 1. | |
295 | * | |
296 | * Lower nodes/leaves in the path are not touched, higher nodes may | |
297 | * be modified to reflect the push. | |
298 | * | |
299 | * The path is altered to reflect the push. | |
aa5d6bed CM |
300 | * |
301 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
302 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 303 | */ |
aa5d6bed CM |
304 | static int push_node_left(struct ctree_root *root, struct ctree_path *path, |
305 | int level) | |
be0e5c09 CM |
306 | { |
307 | int slot; | |
308 | struct node *left; | |
309 | struct node *right; | |
310 | int push_items = 0; | |
311 | int left_nritems; | |
312 | int right_nritems; | |
eb60ceac CM |
313 | struct tree_buffer *t; |
314 | struct tree_buffer *right_buf; | |
aa5d6bed CM |
315 | int ret = 0; |
316 | int wret; | |
be0e5c09 CM |
317 | |
318 | if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0) | |
319 | return 1; | |
320 | slot = path->slots[level + 1]; | |
321 | if (slot == 0) | |
322 | return 1; | |
323 | ||
eb60ceac CM |
324 | t = read_tree_block(root, |
325 | path->nodes[level + 1]->node.blockptrs[slot - 1]); | |
326 | left = &t->node; | |
327 | right_buf = path->nodes[level]; | |
328 | right = &right_buf->node; | |
be0e5c09 CM |
329 | left_nritems = left->header.nritems; |
330 | right_nritems = right->header.nritems; | |
331 | push_items = NODEPTRS_PER_BLOCK - (left_nritems + 1); | |
eb60ceac CM |
332 | if (push_items <= 0) { |
333 | tree_block_release(root, t); | |
be0e5c09 | 334 | return 1; |
eb60ceac | 335 | } |
be0e5c09 CM |
336 | |
337 | if (right_nritems < push_items) | |
338 | push_items = right_nritems; | |
339 | memcpy(left->keys + left_nritems, right->keys, | |
340 | push_items * sizeof(struct key)); | |
341 | memcpy(left->blockptrs + left_nritems, right->blockptrs, | |
342 | push_items * sizeof(u64)); | |
343 | memmove(right->keys, right->keys + push_items, | |
344 | (right_nritems - push_items) * sizeof(struct key)); | |
345 | memmove(right->blockptrs, right->blockptrs + push_items, | |
346 | (right_nritems - push_items) * sizeof(u64)); | |
347 | right->header.nritems -= push_items; | |
348 | left->header.nritems += push_items; | |
349 | ||
350 | /* adjust the pointers going up the tree */ | |
aa5d6bed CM |
351 | wret = fixup_low_keys(root, path, right->keys, level + 1); |
352 | if (wret < 0) | |
353 | ret = wret; | |
eb60ceac | 354 | |
aa5d6bed CM |
355 | wret = write_tree_block(root, t); |
356 | if (wret < 0) | |
357 | ret = wret; | |
358 | ||
359 | wret = write_tree_block(root, right_buf); | |
360 | if (wret < 0) | |
361 | ret = wret; | |
be0e5c09 CM |
362 | |
363 | /* then fixup the leaf pointer in the path */ | |
364 | if (path->slots[level] < push_items) { | |
365 | path->slots[level] += left_nritems; | |
eb60ceac CM |
366 | tree_block_release(root, path->nodes[level]); |
367 | path->nodes[level] = t; | |
be0e5c09 CM |
368 | path->slots[level + 1] -= 1; |
369 | } else { | |
370 | path->slots[level] -= push_items; | |
eb60ceac | 371 | tree_block_release(root, t); |
be0e5c09 | 372 | } |
aa5d6bed | 373 | return ret; |
be0e5c09 CM |
374 | } |
375 | ||
74123bd7 CM |
376 | /* |
377 | * try to push data from one node into the next node right in the | |
378 | * tree. The src node is found at specified level in the path. | |
379 | * If some bytes were pushed, return 0, otherwise return 1. | |
380 | * | |
381 | * Lower nodes/leaves in the path are not touched, higher nodes may | |
382 | * be modified to reflect the push. | |
383 | * | |
384 | * The path is altered to reflect the push. | |
aa5d6bed CM |
385 | * |
386 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
387 | * error, and > 0 if there was no room in the right hand block. | |
74123bd7 | 388 | */ |
aa5d6bed CM |
389 | static int push_node_right(struct ctree_root *root, struct ctree_path *path, |
390 | int level) | |
be0e5c09 CM |
391 | { |
392 | int slot; | |
eb60ceac CM |
393 | struct tree_buffer *t; |
394 | struct tree_buffer *src_buffer; | |
be0e5c09 CM |
395 | struct node *dst; |
396 | struct node *src; | |
397 | int push_items = 0; | |
398 | int dst_nritems; | |
399 | int src_nritems; | |
400 | ||
74123bd7 | 401 | /* can't push from the root */ |
be0e5c09 CM |
402 | if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0) |
403 | return 1; | |
74123bd7 CM |
404 | |
405 | /* only try to push inside the node higher up */ | |
be0e5c09 CM |
406 | slot = path->slots[level + 1]; |
407 | if (slot == NODEPTRS_PER_BLOCK - 1) | |
408 | return 1; | |
409 | ||
eb60ceac | 410 | if (slot >= path->nodes[level + 1]->node.header.nritems -1) |
be0e5c09 CM |
411 | return 1; |
412 | ||
eb60ceac CM |
413 | t = read_tree_block(root, |
414 | path->nodes[level + 1]->node.blockptrs[slot + 1]); | |
415 | dst = &t->node; | |
416 | src_buffer = path->nodes[level]; | |
417 | src = &src_buffer->node; | |
be0e5c09 CM |
418 | dst_nritems = dst->header.nritems; |
419 | src_nritems = src->header.nritems; | |
420 | push_items = NODEPTRS_PER_BLOCK - (dst_nritems + 1); | |
eb60ceac CM |
421 | if (push_items <= 0) { |
422 | tree_block_release(root, t); | |
be0e5c09 | 423 | return 1; |
eb60ceac | 424 | } |
be0e5c09 CM |
425 | |
426 | if (src_nritems < push_items) | |
427 | push_items = src_nritems; | |
428 | memmove(dst->keys + push_items, dst->keys, | |
429 | dst_nritems * sizeof(struct key)); | |
430 | memcpy(dst->keys, src->keys + src_nritems - push_items, | |
431 | push_items * sizeof(struct key)); | |
432 | ||
433 | memmove(dst->blockptrs + push_items, dst->blockptrs, | |
434 | dst_nritems * sizeof(u64)); | |
435 | memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, | |
436 | push_items * sizeof(u64)); | |
437 | ||
438 | src->header.nritems -= push_items; | |
439 | dst->header.nritems += push_items; | |
440 | ||
441 | /* adjust the pointers going up the tree */ | |
eb60ceac | 442 | memcpy(path->nodes[level + 1]->node.keys + path->slots[level + 1] + 1, |
be0e5c09 | 443 | dst->keys, sizeof(struct key)); |
eb60ceac CM |
444 | |
445 | write_tree_block(root, path->nodes[level + 1]); | |
446 | write_tree_block(root, t); | |
447 | write_tree_block(root, src_buffer); | |
448 | ||
74123bd7 | 449 | /* then fixup the pointers in the path */ |
be0e5c09 CM |
450 | if (path->slots[level] >= src->header.nritems) { |
451 | path->slots[level] -= src->header.nritems; | |
eb60ceac CM |
452 | tree_block_release(root, path->nodes[level]); |
453 | path->nodes[level] = t; | |
be0e5c09 | 454 | path->slots[level + 1] += 1; |
eb60ceac CM |
455 | } else { |
456 | tree_block_release(root, t); | |
be0e5c09 CM |
457 | } |
458 | return 0; | |
459 | } | |
460 | ||
97571fd0 CM |
461 | /* |
462 | * helper function to insert a new root level in the tree. | |
463 | * A new node is allocated, and a single item is inserted to | |
464 | * point to the existing root | |
aa5d6bed CM |
465 | * |
466 | * returns zero on success or < 0 on failure. | |
97571fd0 | 467 | */ |
5de08d7d CM |
468 | static int insert_new_root(struct ctree_root *root, |
469 | struct ctree_path *path, int level) | |
5c680ed6 CM |
470 | { |
471 | struct tree_buffer *t; | |
472 | struct node *lower; | |
473 | struct node *c; | |
474 | struct key *lower_key; | |
475 | ||
476 | BUG_ON(path->nodes[level]); | |
477 | BUG_ON(path->nodes[level-1] != root->node); | |
478 | ||
479 | t = alloc_free_block(root); | |
480 | c = &t->node; | |
481 | memset(c, 0, sizeof(c)); | |
482 | c->header.nritems = 1; | |
483 | c->header.flags = node_level(level); | |
484 | c->header.blocknr = t->blocknr; | |
485 | c->header.parentid = root->node->node.header.parentid; | |
486 | lower = &path->nodes[level-1]->node; | |
487 | if (is_leaf(lower->header.flags)) | |
488 | lower_key = &((struct leaf *)lower)->items[0].key; | |
489 | else | |
490 | lower_key = lower->keys; | |
491 | memcpy(c->keys, lower_key, sizeof(struct key)); | |
492 | c->blockptrs[0] = path->nodes[level-1]->blocknr; | |
493 | /* the super has an extra ref to root->node */ | |
494 | tree_block_release(root, root->node); | |
495 | root->node = t; | |
496 | t->count++; | |
497 | write_tree_block(root, t); | |
498 | path->nodes[level] = t; | |
499 | path->slots[level] = 0; | |
500 | return 0; | |
501 | } | |
502 | ||
74123bd7 CM |
503 | /* |
504 | * worker function to insert a single pointer in a node. | |
505 | * the node should have enough room for the pointer already | |
97571fd0 | 506 | * |
74123bd7 CM |
507 | * slot and level indicate where you want the key to go, and |
508 | * blocknr is the block the key points to. | |
aa5d6bed CM |
509 | * |
510 | * returns zero on success and < 0 on any error | |
74123bd7 | 511 | */ |
aa5d6bed | 512 | static int insert_ptr(struct ctree_root *root, |
74123bd7 CM |
513 | struct ctree_path *path, struct key *key, |
514 | u64 blocknr, int slot, int level) | |
515 | { | |
74123bd7 | 516 | struct node *lower; |
74123bd7 | 517 | int nritems; |
5c680ed6 CM |
518 | |
519 | BUG_ON(!path->nodes[level]); | |
74123bd7 CM |
520 | lower = &path->nodes[level]->node; |
521 | nritems = lower->header.nritems; | |
522 | if (slot > nritems) | |
523 | BUG(); | |
524 | if (nritems == NODEPTRS_PER_BLOCK) | |
525 | BUG(); | |
526 | if (slot != nritems) { | |
527 | memmove(lower->keys + slot + 1, lower->keys + slot, | |
528 | (nritems - slot) * sizeof(struct key)); | |
529 | memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, | |
530 | (nritems - slot) * sizeof(u64)); | |
531 | } | |
532 | memcpy(lower->keys + slot, key, sizeof(struct key)); | |
533 | lower->blockptrs[slot] = blocknr; | |
534 | lower->header.nritems++; | |
535 | if (lower->keys[1].objectid == 0) | |
536 | BUG(); | |
537 | write_tree_block(root, path->nodes[level]); | |
538 | return 0; | |
539 | } | |
540 | ||
97571fd0 CM |
541 | /* |
542 | * split the node at the specified level in path in two. | |
543 | * The path is corrected to point to the appropriate node after the split | |
544 | * | |
545 | * Before splitting this tries to make some room in the node by pushing | |
546 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
547 | * |
548 | * returns 0 on success and < 0 on failure | |
97571fd0 | 549 | */ |
aa5d6bed CM |
550 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
551 | int level) | |
be0e5c09 | 552 | { |
5c680ed6 CM |
553 | struct tree_buffer *t; |
554 | struct node *c; | |
555 | struct tree_buffer *split_buffer; | |
556 | struct node *split; | |
be0e5c09 | 557 | int mid; |
5c680ed6 | 558 | int ret; |
aa5d6bed | 559 | int wret; |
eb60ceac | 560 | |
5c680ed6 CM |
561 | ret = push_node_left(root, path, level); |
562 | if (!ret) | |
563 | return 0; | |
aa5d6bed CM |
564 | if (ret < 0) |
565 | return ret; | |
5c680ed6 CM |
566 | ret = push_node_right(root, path, level); |
567 | if (!ret) | |
568 | return 0; | |
aa5d6bed CM |
569 | if (ret < 0) |
570 | return ret; | |
5c680ed6 CM |
571 | t = path->nodes[level]; |
572 | c = &t->node; | |
573 | if (t == root->node) { | |
574 | /* trying to split the root, lets make a new one */ | |
575 | ret = insert_new_root(root, path, level + 1); | |
576 | if (ret) | |
577 | return ret; | |
be0e5c09 | 578 | } |
5c680ed6 CM |
579 | split_buffer = alloc_free_block(root); |
580 | split = &split_buffer->node; | |
581 | split->header.flags = c->header.flags; | |
582 | split->header.blocknr = split_buffer->blocknr; | |
583 | split->header.parentid = root->node->node.header.parentid; | |
584 | mid = (c->header.nritems + 1) / 2; | |
585 | memcpy(split->keys, c->keys + mid, | |
586 | (c->header.nritems - mid) * sizeof(struct key)); | |
587 | memcpy(split->blockptrs, c->blockptrs + mid, | |
588 | (c->header.nritems - mid) * sizeof(u64)); | |
589 | split->header.nritems = c->header.nritems - mid; | |
590 | c->header.nritems = mid; | |
aa5d6bed CM |
591 | ret = 0; |
592 | ||
593 | wret = write_tree_block(root, t); | |
594 | if (wret) | |
595 | ret = wret; | |
596 | wret = write_tree_block(root, split_buffer); | |
597 | if (wret) | |
598 | ret = wret; | |
599 | wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, | |
600 | path->slots[level + 1] + 1, level + 1); | |
601 | if (wret) | |
602 | ret = wret; | |
603 | ||
5de08d7d | 604 | if (path->slots[level] >= mid) { |
5c680ed6 CM |
605 | path->slots[level] -= mid; |
606 | tree_block_release(root, t); | |
607 | path->nodes[level] = split_buffer; | |
608 | path->slots[level + 1] += 1; | |
609 | } else { | |
610 | tree_block_release(root, split_buffer); | |
be0e5c09 | 611 | } |
aa5d6bed | 612 | return ret; |
be0e5c09 CM |
613 | } |
614 | ||
74123bd7 CM |
615 | /* |
616 | * how many bytes are required to store the items in a leaf. start | |
617 | * and nr indicate which items in the leaf to check. This totals up the | |
618 | * space used both by the item structs and the item data | |
619 | */ | |
aa5d6bed | 620 | static int leaf_space_used(struct leaf *l, int start, int nr) |
be0e5c09 CM |
621 | { |
622 | int data_len; | |
623 | int end = start + nr - 1; | |
624 | ||
625 | if (!nr) | |
626 | return 0; | |
627 | data_len = l->items[start].offset + l->items[start].size; | |
628 | data_len = data_len - l->items[end].offset; | |
629 | data_len += sizeof(struct item) * nr; | |
630 | return data_len; | |
631 | } | |
632 | ||
00ec4c51 CM |
633 | /* |
634 | * push some data in the path leaf to the right, trying to free up at | |
635 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
636 | * |
637 | * returns 1 if the push failed because the other node didn't have enough | |
638 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 639 | */ |
aa5d6bed CM |
640 | static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, |
641 | int data_size) | |
00ec4c51 CM |
642 | { |
643 | struct tree_buffer *left_buf = path->nodes[0]; | |
644 | struct leaf *left = &left_buf->leaf; | |
645 | struct leaf *right; | |
646 | struct tree_buffer *right_buf; | |
647 | struct tree_buffer *upper; | |
648 | int slot; | |
649 | int i; | |
650 | int free_space; | |
651 | int push_space = 0; | |
652 | int push_items = 0; | |
653 | struct item *item; | |
654 | ||
655 | slot = path->slots[1]; | |
656 | if (!path->nodes[1]) { | |
657 | return 1; | |
658 | } | |
659 | upper = path->nodes[1]; | |
660 | if (slot >= upper->node.header.nritems - 1) { | |
661 | return 1; | |
662 | } | |
663 | right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]); | |
664 | right = &right_buf->leaf; | |
665 | free_space = leaf_free_space(right); | |
666 | if (free_space < data_size + sizeof(struct item)) { | |
667 | tree_block_release(root, right_buf); | |
668 | return 1; | |
669 | } | |
670 | for (i = left->header.nritems - 1; i >= 0; i--) { | |
671 | item = left->items + i; | |
672 | if (path->slots[0] == i) | |
673 | push_space += data_size + sizeof(*item); | |
674 | if (item->size + sizeof(*item) + push_space > free_space) | |
675 | break; | |
676 | push_items++; | |
677 | push_space += item->size + sizeof(*item); | |
678 | } | |
679 | if (push_items == 0) { | |
680 | tree_block_release(root, right_buf); | |
681 | return 1; | |
682 | } | |
683 | /* push left to right */ | |
684 | push_space = left->items[left->header.nritems - push_items].offset + | |
685 | left->items[left->header.nritems - push_items].size; | |
686 | push_space -= leaf_data_end(left); | |
687 | /* make room in the right data area */ | |
688 | memmove(right->data + leaf_data_end(right) - push_space, | |
689 | right->data + leaf_data_end(right), | |
690 | LEAF_DATA_SIZE - leaf_data_end(right)); | |
691 | /* copy from the left data area */ | |
692 | memcpy(right->data + LEAF_DATA_SIZE - push_space, | |
693 | left->data + leaf_data_end(left), | |
694 | push_space); | |
695 | memmove(right->items + push_items, right->items, | |
696 | right->header.nritems * sizeof(struct item)); | |
697 | /* copy the items from left to right */ | |
698 | memcpy(right->items, left->items + left->header.nritems - push_items, | |
699 | push_items * sizeof(struct item)); | |
700 | ||
701 | /* update the item pointers */ | |
702 | right->header.nritems += push_items; | |
703 | push_space = LEAF_DATA_SIZE; | |
704 | for (i = 0; i < right->header.nritems; i++) { | |
705 | right->items[i].offset = push_space - right->items[i].size; | |
706 | push_space = right->items[i].offset; | |
707 | } | |
708 | left->header.nritems -= push_items; | |
709 | ||
710 | write_tree_block(root, left_buf); | |
711 | write_tree_block(root, right_buf); | |
712 | memcpy(upper->node.keys + slot + 1, | |
713 | &right->items[0].key, sizeof(struct key)); | |
714 | write_tree_block(root, upper); | |
715 | /* then fixup the leaf pointer in the path */ | |
00ec4c51 CM |
716 | if (path->slots[0] >= left->header.nritems) { |
717 | path->slots[0] -= left->header.nritems; | |
718 | tree_block_release(root, path->nodes[0]); | |
719 | path->nodes[0] = right_buf; | |
720 | path->slots[1] += 1; | |
721 | } else { | |
722 | tree_block_release(root, right_buf); | |
723 | } | |
724 | return 0; | |
725 | } | |
74123bd7 CM |
726 | /* |
727 | * push some data in the path leaf to the left, trying to free up at | |
728 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
729 | */ | |
aa5d6bed CM |
730 | static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, |
731 | int data_size) | |
be0e5c09 | 732 | { |
eb60ceac CM |
733 | struct tree_buffer *right_buf = path->nodes[0]; |
734 | struct leaf *right = &right_buf->leaf; | |
735 | struct tree_buffer *t; | |
be0e5c09 CM |
736 | struct leaf *left; |
737 | int slot; | |
738 | int i; | |
739 | int free_space; | |
740 | int push_space = 0; | |
741 | int push_items = 0; | |
742 | struct item *item; | |
743 | int old_left_nritems; | |
aa5d6bed CM |
744 | int ret = 0; |
745 | int wret; | |
be0e5c09 CM |
746 | |
747 | slot = path->slots[1]; | |
748 | if (slot == 0) { | |
749 | return 1; | |
750 | } | |
751 | if (!path->nodes[1]) { | |
752 | return 1; | |
753 | } | |
eb60ceac CM |
754 | t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]); |
755 | left = &t->leaf; | |
be0e5c09 CM |
756 | free_space = leaf_free_space(left); |
757 | if (free_space < data_size + sizeof(struct item)) { | |
eb60ceac | 758 | tree_block_release(root, t); |
be0e5c09 CM |
759 | return 1; |
760 | } | |
761 | for (i = 0; i < right->header.nritems; i++) { | |
762 | item = right->items + i; | |
763 | if (path->slots[0] == i) | |
764 | push_space += data_size + sizeof(*item); | |
765 | if (item->size + sizeof(*item) + push_space > free_space) | |
766 | break; | |
767 | push_items++; | |
768 | push_space += item->size + sizeof(*item); | |
769 | } | |
770 | if (push_items == 0) { | |
eb60ceac | 771 | tree_block_release(root, t); |
be0e5c09 CM |
772 | return 1; |
773 | } | |
774 | /* push data from right to left */ | |
775 | memcpy(left->items + left->header.nritems, | |
776 | right->items, push_items * sizeof(struct item)); | |
777 | push_space = LEAF_DATA_SIZE - right->items[push_items -1].offset; | |
778 | memcpy(left->data + leaf_data_end(left) - push_space, | |
779 | right->data + right->items[push_items - 1].offset, | |
780 | push_space); | |
781 | old_left_nritems = left->header.nritems; | |
eb60ceac CM |
782 | BUG_ON(old_left_nritems < 0); |
783 | ||
be0e5c09 CM |
784 | for(i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
785 | left->items[i].offset -= LEAF_DATA_SIZE - | |
786 | left->items[old_left_nritems -1].offset; | |
787 | } | |
788 | left->header.nritems += push_items; | |
789 | ||
790 | /* fixup right node */ | |
791 | push_space = right->items[push_items-1].offset - leaf_data_end(right); | |
792 | memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + | |
793 | leaf_data_end(right), push_space); | |
794 | memmove(right->items, right->items + push_items, | |
795 | (right->header.nritems - push_items) * sizeof(struct item)); | |
796 | right->header.nritems -= push_items; | |
797 | push_space = LEAF_DATA_SIZE; | |
eb60ceac | 798 | |
be0e5c09 CM |
799 | for (i = 0; i < right->header.nritems; i++) { |
800 | right->items[i].offset = push_space - right->items[i].size; | |
801 | push_space = right->items[i].offset; | |
802 | } | |
eb60ceac | 803 | |
aa5d6bed CM |
804 | wret = write_tree_block(root, t); |
805 | if (wret) | |
806 | ret = wret; | |
807 | wret = write_tree_block(root, right_buf); | |
808 | if (wret) | |
809 | ret = wret; | |
eb60ceac | 810 | |
aa5d6bed CM |
811 | wret = fixup_low_keys(root, path, &right->items[0].key, 1); |
812 | if (wret) | |
813 | ret = wret; | |
be0e5c09 CM |
814 | |
815 | /* then fixup the leaf pointer in the path */ | |
816 | if (path->slots[0] < push_items) { | |
817 | path->slots[0] += old_left_nritems; | |
eb60ceac CM |
818 | tree_block_release(root, path->nodes[0]); |
819 | path->nodes[0] = t; | |
be0e5c09 CM |
820 | path->slots[1] -= 1; |
821 | } else { | |
eb60ceac | 822 | tree_block_release(root, t); |
be0e5c09 CM |
823 | path->slots[0] -= push_items; |
824 | } | |
eb60ceac | 825 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 826 | return ret; |
be0e5c09 CM |
827 | } |
828 | ||
74123bd7 CM |
829 | /* |
830 | * split the path's leaf in two, making sure there is at least data_size | |
831 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
832 | * |
833 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 834 | */ |
aa5d6bed CM |
835 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, |
836 | int data_size) | |
be0e5c09 | 837 | { |
aa5d6bed CM |
838 | struct tree_buffer *l_buf; |
839 | struct leaf *l; | |
eb60ceac CM |
840 | int nritems; |
841 | int mid; | |
842 | int slot; | |
be0e5c09 | 843 | struct leaf *right; |
eb60ceac | 844 | struct tree_buffer *right_buffer; |
be0e5c09 CM |
845 | int space_needed = data_size + sizeof(struct item); |
846 | int data_copy_size; | |
847 | int rt_data_off; | |
848 | int i; | |
849 | int ret; | |
aa5d6bed CM |
850 | int wret; |
851 | ||
852 | wret = push_leaf_left(root, path, data_size); | |
853 | if (wret < 0) | |
854 | return wret; | |
855 | if (wret) { | |
856 | wret = push_leaf_right(root, path, data_size); | |
857 | if (wret < 0) | |
858 | return wret; | |
be0e5c09 | 859 | } |
aa5d6bed CM |
860 | l_buf = path->nodes[0]; |
861 | l = &l_buf->leaf; | |
862 | ||
863 | /* did the pushes work? */ | |
864 | if (leaf_free_space(l) >= sizeof(struct item) + data_size) | |
865 | return 0; | |
866 | ||
5c680ed6 CM |
867 | if (!path->nodes[1]) { |
868 | ret = insert_new_root(root, path, 1); | |
869 | if (ret) | |
870 | return ret; | |
871 | } | |
eb60ceac CM |
872 | slot = path->slots[0]; |
873 | nritems = l->header.nritems; | |
874 | mid = (nritems + 1)/ 2; | |
875 | ||
876 | right_buffer = alloc_free_block(root); | |
877 | BUG_ON(!right_buffer); | |
878 | BUG_ON(mid == nritems); | |
879 | right = &right_buffer->leaf; | |
be0e5c09 CM |
880 | memset(right, 0, sizeof(*right)); |
881 | if (mid <= slot) { | |
97571fd0 | 882 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
883 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
884 | LEAF_DATA_SIZE) | |
885 | BUG(); | |
886 | } else { | |
97571fd0 | 887 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
888 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
889 | LEAF_DATA_SIZE) | |
890 | BUG(); | |
891 | } | |
892 | right->header.nritems = nritems - mid; | |
eb60ceac CM |
893 | right->header.blocknr = right_buffer->blocknr; |
894 | right->header.flags = node_level(0); | |
cfaa7295 | 895 | right->header.parentid = root->node->node.header.parentid; |
be0e5c09 CM |
896 | data_copy_size = l->items[mid].offset + l->items[mid].size - |
897 | leaf_data_end(l); | |
898 | memcpy(right->items, l->items + mid, | |
899 | (nritems - mid) * sizeof(struct item)); | |
900 | memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, | |
901 | l->data + leaf_data_end(l), data_copy_size); | |
902 | rt_data_off = LEAF_DATA_SIZE - | |
903 | (l->items[mid].offset + l->items[mid].size); | |
74123bd7 CM |
904 | |
905 | for (i = 0; i < right->header.nritems; i++) | |
be0e5c09 | 906 | right->items[i].offset += rt_data_off; |
74123bd7 | 907 | |
be0e5c09 | 908 | l->header.nritems = mid; |
aa5d6bed CM |
909 | ret = 0; |
910 | wret = insert_ptr(root, path, &right->items[0].key, | |
5c680ed6 | 911 | right_buffer->blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
912 | if (wret) |
913 | ret = wret; | |
914 | wret = write_tree_block(root, right_buffer); | |
915 | if (wret) | |
916 | ret = wret; | |
917 | wret = write_tree_block(root, l_buf); | |
918 | if (wret) | |
919 | ret = wret; | |
eb60ceac CM |
920 | |
921 | BUG_ON(path->slots[0] != slot); | |
be0e5c09 | 922 | if (mid <= slot) { |
eb60ceac CM |
923 | tree_block_release(root, path->nodes[0]); |
924 | path->nodes[0] = right_buffer; | |
be0e5c09 CM |
925 | path->slots[0] -= mid; |
926 | path->slots[1] += 1; | |
eb60ceac CM |
927 | } else |
928 | tree_block_release(root, right_buffer); | |
929 | BUG_ON(path->slots[0] < 0); | |
be0e5c09 CM |
930 | return ret; |
931 | } | |
932 | ||
74123bd7 CM |
933 | /* |
934 | * Given a key and some data, insert an item into the tree. | |
935 | * This does all the path init required, making room in the tree if needed. | |
936 | */ | |
be0e5c09 CM |
937 | int insert_item(struct ctree_root *root, struct key *key, |
938 | void *data, int data_size) | |
939 | { | |
aa5d6bed CM |
940 | int ret = 0; |
941 | int wret; | |
be0e5c09 | 942 | int slot; |
eb60ceac | 943 | int slot_orig; |
be0e5c09 | 944 | struct leaf *leaf; |
eb60ceac | 945 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
946 | unsigned int nritems; |
947 | unsigned int data_end; | |
948 | struct ctree_path path; | |
949 | ||
74123bd7 | 950 | /* create a root if there isn't one */ |
5c680ed6 | 951 | if (!root->node) |
cfaa7295 | 952 | BUG(); |
be0e5c09 | 953 | init_path(&path); |
5c680ed6 | 954 | ret = search_slot(root, key, &path, data_size); |
eb60ceac CM |
955 | if (ret == 0) { |
956 | release_path(root, &path); | |
be0e5c09 | 957 | return -EEXIST; |
eb60ceac | 958 | } |
aa5d6bed CM |
959 | if (ret < 0) { |
960 | release_path(root, &path); | |
961 | return ret; | |
962 | } | |
be0e5c09 | 963 | |
eb60ceac CM |
964 | slot_orig = path.slots[0]; |
965 | leaf_buf = path.nodes[0]; | |
966 | leaf = &leaf_buf->leaf; | |
74123bd7 | 967 | |
be0e5c09 CM |
968 | nritems = leaf->header.nritems; |
969 | data_end = leaf_data_end(leaf); | |
eb60ceac | 970 | |
be0e5c09 CM |
971 | if (leaf_free_space(leaf) < sizeof(struct item) + data_size) |
972 | BUG(); | |
973 | ||
974 | slot = path.slots[0]; | |
eb60ceac | 975 | BUG_ON(slot < 0); |
be0e5c09 CM |
976 | if (slot != nritems) { |
977 | int i; | |
978 | unsigned int old_data = leaf->items[slot].offset + | |
979 | leaf->items[slot].size; | |
980 | ||
981 | /* | |
982 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
983 | */ | |
984 | /* first correct the data pointers */ | |
985 | for (i = slot; i < nritems; i++) | |
986 | leaf->items[i].offset -= data_size; | |
987 | ||
988 | /* shift the items */ | |
989 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
990 | (nritems - slot) * sizeof(struct item)); | |
991 | ||
992 | /* shift the data */ | |
993 | memmove(leaf->data + data_end - data_size, leaf->data + | |
994 | data_end, old_data - data_end); | |
995 | data_end = old_data; | |
996 | } | |
74123bd7 | 997 | /* copy the new data in */ |
be0e5c09 CM |
998 | memcpy(&leaf->items[slot].key, key, sizeof(struct key)); |
999 | leaf->items[slot].offset = data_end - data_size; | |
1000 | leaf->items[slot].size = data_size; | |
1001 | memcpy(leaf->data + data_end - data_size, data, data_size); | |
1002 | leaf->header.nritems += 1; | |
aa5d6bed CM |
1003 | |
1004 | ret = 0; | |
8e19f2cd | 1005 | if (slot == 0) |
aa5d6bed CM |
1006 | ret = fixup_low_keys(root, &path, key, 1); |
1007 | ||
1008 | wret = write_tree_block(root, leaf_buf); | |
1009 | if (wret) | |
1010 | ret = wret; | |
1011 | ||
be0e5c09 CM |
1012 | if (leaf_free_space(leaf) < 0) |
1013 | BUG(); | |
eb60ceac | 1014 | release_path(root, &path); |
aa5d6bed | 1015 | return ret; |
be0e5c09 CM |
1016 | } |
1017 | ||
74123bd7 | 1018 | /* |
5de08d7d | 1019 | * delete the pointer from a given node. |
74123bd7 CM |
1020 | * |
1021 | * If the delete empties a node, the node is removed from the tree, | |
1022 | * continuing all the way the root if required. The root is converted into | |
1023 | * a leaf if all the nodes are emptied. | |
1024 | */ | |
aa5d6bed | 1025 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level) |
be0e5c09 CM |
1026 | { |
1027 | int slot; | |
eb60ceac | 1028 | struct tree_buffer *t; |
be0e5c09 CM |
1029 | struct node *node; |
1030 | int nritems; | |
9a8dd150 | 1031 | u64 blocknr; |
aa5d6bed CM |
1032 | int wret; |
1033 | int ret = 0; | |
be0e5c09 CM |
1034 | |
1035 | while(1) { | |
eb60ceac CM |
1036 | t = path->nodes[level]; |
1037 | if (!t) | |
be0e5c09 | 1038 | break; |
eb60ceac | 1039 | node = &t->node; |
be0e5c09 CM |
1040 | slot = path->slots[level]; |
1041 | nritems = node->header.nritems; | |
1042 | ||
1043 | if (slot != nritems -1) { | |
1044 | memmove(node->keys + slot, node->keys + slot + 1, | |
1045 | sizeof(struct key) * (nritems - slot - 1)); | |
1046 | memmove(node->blockptrs + slot, | |
1047 | node->blockptrs + slot + 1, | |
1048 | sizeof(u64) * (nritems - slot - 1)); | |
1049 | } | |
1050 | node->header.nritems--; | |
9a8dd150 | 1051 | blocknr = t->blocknr; |
8e19f2cd | 1052 | write_tree_block(root, t); |
be0e5c09 | 1053 | if (node->header.nritems != 0) { |
8e19f2cd | 1054 | int tslot; |
aa5d6bed CM |
1055 | if (slot == 0) { |
1056 | wret = fixup_low_keys(root, path, | |
1057 | node->keys, | |
1058 | level + 1); | |
1059 | if (wret) | |
1060 | ret = wret; | |
1061 | } | |
8e19f2cd CM |
1062 | tslot = path->slots[level + 1]; |
1063 | t->count++; | |
aa5d6bed CM |
1064 | wret = push_node_left(root, path, level); |
1065 | if (wret < 0) { | |
1066 | ret = wret; | |
1067 | break; | |
1068 | } | |
1069 | if (node->header.nritems != 0) { | |
1070 | wret = push_node_right(root, path, level); | |
1071 | if (wret < 0) { | |
1072 | ret = wret; | |
1073 | break; | |
1074 | } | |
1075 | } | |
8e19f2cd CM |
1076 | path->slots[level + 1] = tslot; |
1077 | if (node->header.nritems != 0) { | |
1078 | tree_block_release(root, t); | |
1079 | break; | |
1080 | } | |
1081 | tree_block_release(root, t); | |
be0e5c09 | 1082 | } |
eb60ceac CM |
1083 | if (t == root->node) { |
1084 | /* just turn the root into a leaf and break */ | |
1085 | root->node->node.header.flags = node_level(0); | |
1086 | write_tree_block(root, t); | |
be0e5c09 CM |
1087 | break; |
1088 | } | |
1089 | level++; | |
0f70abe2 CM |
1090 | wret = free_extent(root, blocknr, 1); |
1091 | if (wret) | |
1092 | ret = wret; | |
be0e5c09 CM |
1093 | if (!path->nodes[level]) |
1094 | BUG(); | |
be0e5c09 | 1095 | } |
aa5d6bed | 1096 | return ret; |
be0e5c09 CM |
1097 | } |
1098 | ||
74123bd7 CM |
1099 | /* |
1100 | * delete the item at the leaf level in path. If that empties | |
1101 | * the leaf, remove it from the tree | |
1102 | */ | |
4920c9ac | 1103 | int del_item(struct ctree_root *root, struct ctree_path *path) |
be0e5c09 | 1104 | { |
be0e5c09 CM |
1105 | int slot; |
1106 | struct leaf *leaf; | |
eb60ceac | 1107 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1108 | int doff; |
1109 | int dsize; | |
aa5d6bed CM |
1110 | int ret = 0; |
1111 | int wret; | |
be0e5c09 | 1112 | |
eb60ceac CM |
1113 | leaf_buf = path->nodes[0]; |
1114 | leaf = &leaf_buf->leaf; | |
4920c9ac | 1115 | slot = path->slots[0]; |
be0e5c09 CM |
1116 | doff = leaf->items[slot].offset; |
1117 | dsize = leaf->items[slot].size; | |
1118 | ||
1119 | if (slot != leaf->header.nritems - 1) { | |
1120 | int i; | |
1121 | int data_end = leaf_data_end(leaf); | |
1122 | memmove(leaf->data + data_end + dsize, | |
1123 | leaf->data + data_end, | |
1124 | doff - data_end); | |
1125 | for (i = slot + 1; i < leaf->header.nritems; i++) | |
1126 | leaf->items[i].offset += dsize; | |
1127 | memmove(leaf->items + slot, leaf->items + slot + 1, | |
1128 | sizeof(struct item) * | |
1129 | (leaf->header.nritems - slot - 1)); | |
1130 | } | |
1131 | leaf->header.nritems -= 1; | |
74123bd7 | 1132 | /* delete the leaf if we've emptied it */ |
be0e5c09 | 1133 | if (leaf->header.nritems == 0) { |
eb60ceac CM |
1134 | if (leaf_buf == root->node) { |
1135 | leaf->header.flags = node_level(0); | |
1136 | write_tree_block(root, leaf_buf); | |
9a8dd150 | 1137 | } else { |
aa5d6bed CM |
1138 | wret = del_ptr(root, path, 1); |
1139 | if (wret) | |
1140 | ret = wret; | |
0f70abe2 CM |
1141 | wret = free_extent(root, leaf_buf->blocknr, 1); |
1142 | if (wret) | |
1143 | ret = wret; | |
9a8dd150 | 1144 | } |
be0e5c09 | 1145 | } else { |
5de08d7d | 1146 | int used = leaf_space_used(leaf, 0, leaf->header.nritems); |
aa5d6bed CM |
1147 | if (slot == 0) { |
1148 | wret = fixup_low_keys(root, path, | |
1149 | &leaf->items[0].key, 1); | |
1150 | if (wret) | |
1151 | ret = wret; | |
1152 | } | |
1153 | wret = write_tree_block(root, leaf_buf); | |
1154 | if (wret) | |
1155 | ret = wret; | |
1156 | ||
74123bd7 | 1157 | /* delete the leaf if it is mostly empty */ |
5de08d7d | 1158 | if (used < LEAF_DATA_SIZE / 3) { |
be0e5c09 CM |
1159 | /* push_leaf_left fixes the path. |
1160 | * make sure the path still points to our leaf | |
1161 | * for possible call to del_ptr below | |
1162 | */ | |
4920c9ac | 1163 | slot = path->slots[1]; |
eb60ceac | 1164 | leaf_buf->count++; |
aa5d6bed CM |
1165 | wret = push_leaf_left(root, path, 1); |
1166 | if (wret < 0) | |
1167 | ret = wret; | |
1168 | if (leaf->header.nritems) { | |
1169 | wret = push_leaf_right(root, path, 1); | |
1170 | if (wret < 0) | |
1171 | ret = wret; | |
1172 | } | |
be0e5c09 | 1173 | if (leaf->header.nritems == 0) { |
5de08d7d | 1174 | u64 blocknr = leaf_buf->blocknr; |
4920c9ac | 1175 | path->slots[1] = slot; |
aa5d6bed CM |
1176 | wret = del_ptr(root, path, 1); |
1177 | if (wret) | |
1178 | ret = wret; | |
5de08d7d | 1179 | tree_block_release(root, leaf_buf); |
0f70abe2 CM |
1180 | wret = free_extent(root, blocknr, 1); |
1181 | if (wret) | |
1182 | ret = wret; | |
5de08d7d CM |
1183 | } else { |
1184 | tree_block_release(root, leaf_buf); | |
be0e5c09 CM |
1185 | } |
1186 | } | |
1187 | } | |
aa5d6bed | 1188 | return ret; |
be0e5c09 CM |
1189 | } |
1190 | ||
97571fd0 CM |
1191 | /* |
1192 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1193 | * returns 0 if it found something or 1 if there are no greater leaves. |
1194 | * returns < 0 on io errors. | |
97571fd0 | 1195 | */ |
d97e63b6 CM |
1196 | int next_leaf(struct ctree_root *root, struct ctree_path *path) |
1197 | { | |
1198 | int slot; | |
1199 | int level = 1; | |
1200 | u64 blocknr; | |
1201 | struct tree_buffer *c; | |
cfaa7295 | 1202 | struct tree_buffer *next = NULL; |
d97e63b6 CM |
1203 | |
1204 | while(level < MAX_LEVEL) { | |
1205 | if (!path->nodes[level]) | |
0f70abe2 | 1206 | return 1; |
d97e63b6 CM |
1207 | slot = path->slots[level] + 1; |
1208 | c = path->nodes[level]; | |
1209 | if (slot >= c->node.header.nritems) { | |
1210 | level++; | |
1211 | continue; | |
1212 | } | |
1213 | blocknr = c->node.blockptrs[slot]; | |
cfaa7295 CM |
1214 | if (next) |
1215 | tree_block_release(root, next); | |
d97e63b6 CM |
1216 | next = read_tree_block(root, blocknr); |
1217 | break; | |
1218 | } | |
1219 | path->slots[level] = slot; | |
1220 | while(1) { | |
1221 | level--; | |
1222 | c = path->nodes[level]; | |
1223 | tree_block_release(root, c); | |
1224 | path->nodes[level] = next; | |
1225 | path->slots[level] = 0; | |
1226 | if (!level) | |
1227 | break; | |
1228 | next = read_tree_block(root, next->node.blockptrs[0]); | |
1229 | } | |
1230 | return 0; | |
1231 | } | |
1232 |