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); | |
bb803951 CM |
13 | static int push_node_left(struct ctree_root *root, struct tree_buffer *dst, |
14 | struct tree_buffer *src); | |
79f95c82 CM |
15 | static int balance_node_right(struct ctree_root *root, |
16 | struct tree_buffer *dst_buf, | |
17 | struct tree_buffer *src_buf); | |
bb803951 CM |
18 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, |
19 | int slot); | |
d97e63b6 | 20 | |
5de08d7d | 21 | inline void init_path(struct ctree_path *p) |
be0e5c09 CM |
22 | { |
23 | memset(p, 0, sizeof(*p)); | |
24 | } | |
25 | ||
5de08d7d | 26 | void release_path(struct ctree_root *root, struct ctree_path *p) |
eb60ceac CM |
27 | { |
28 | int i; | |
29 | for (i = 0; i < MAX_LEVEL; i++) { | |
30 | if (!p->nodes[i]) | |
31 | break; | |
32 | tree_block_release(root, p->nodes[i]); | |
33 | } | |
aa5d6bed | 34 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
35 | } |
36 | ||
74123bd7 CM |
37 | /* |
38 | * The leaf data grows from end-to-front in the node. | |
39 | * this returns the address of the start of the last item, | |
40 | * which is the stop of the leaf data stack | |
41 | */ | |
be0e5c09 CM |
42 | static inline unsigned int leaf_data_end(struct leaf *leaf) |
43 | { | |
44 | unsigned int nr = leaf->header.nritems; | |
45 | if (nr == 0) | |
d97e63b6 | 46 | return sizeof(leaf->data); |
be0e5c09 CM |
47 | return leaf->items[nr-1].offset; |
48 | } | |
49 | ||
74123bd7 CM |
50 | /* |
51 | * The space between the end of the leaf items and | |
52 | * the start of the leaf data. IOW, how much room | |
53 | * the leaf has left for both items and data | |
54 | */ | |
5de08d7d | 55 | int leaf_free_space(struct leaf *leaf) |
be0e5c09 CM |
56 | { |
57 | int data_end = leaf_data_end(leaf); | |
58 | int nritems = leaf->header.nritems; | |
59 | char *items_end = (char *)(leaf->items + nritems + 1); | |
60 | return (char *)(leaf->data + data_end) - (char *)items_end; | |
61 | } | |
62 | ||
74123bd7 CM |
63 | /* |
64 | * compare two keys in a memcmp fashion | |
65 | */ | |
be0e5c09 CM |
66 | int comp_keys(struct key *k1, struct key *k2) |
67 | { | |
68 | if (k1->objectid > k2->objectid) | |
69 | return 1; | |
70 | if (k1->objectid < k2->objectid) | |
71 | return -1; | |
72 | if (k1->flags > k2->flags) | |
73 | return 1; | |
74 | if (k1->flags < k2->flags) | |
75 | return -1; | |
76 | if (k1->offset > k2->offset) | |
77 | return 1; | |
78 | if (k1->offset < k2->offset) | |
79 | return -1; | |
80 | return 0; | |
81 | } | |
74123bd7 | 82 | |
aa5d6bed CM |
83 | int check_node(struct ctree_path *path, int level) |
84 | { | |
85 | int i; | |
86 | struct node *parent = NULL; | |
87 | struct node *node = &path->nodes[level]->node; | |
88 | int parent_slot; | |
89 | ||
90 | if (path->nodes[level + 1]) | |
91 | parent = &path->nodes[level + 1]->node; | |
92 | parent_slot = path->slots[level + 1]; | |
93 | if (parent && node->header.nritems > 0) { | |
94 | struct key *parent_key; | |
95 | parent_key = &parent->keys[parent_slot]; | |
96 | BUG_ON(memcmp(parent_key, node->keys, sizeof(struct key))); | |
97 | BUG_ON(parent->blockptrs[parent_slot] != node->header.blocknr); | |
98 | } | |
99 | BUG_ON(node->header.nritems > NODEPTRS_PER_BLOCK); | |
100 | for (i = 0; i < node->header.nritems - 2; i++) { | |
101 | BUG_ON(comp_keys(&node->keys[i], &node->keys[i+1]) >= 0); | |
102 | } | |
103 | return 0; | |
104 | } | |
105 | ||
106 | int check_leaf(struct ctree_path *path, int level) | |
107 | { | |
108 | int i; | |
109 | struct leaf *leaf = &path->nodes[level]->leaf; | |
110 | struct node *parent = NULL; | |
111 | int parent_slot; | |
112 | ||
113 | if (path->nodes[level + 1]) | |
114 | parent = &path->nodes[level + 1]->node; | |
115 | parent_slot = path->slots[level + 1]; | |
116 | if (parent && leaf->header.nritems > 0) { | |
117 | struct key *parent_key; | |
118 | parent_key = &parent->keys[parent_slot]; | |
119 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, | |
120 | sizeof(struct key))); | |
121 | BUG_ON(parent->blockptrs[parent_slot] != leaf->header.blocknr); | |
122 | } | |
123 | for (i = 0; i < leaf->header.nritems - 2; i++) { | |
124 | BUG_ON(comp_keys(&leaf->items[i].key, | |
125 | &leaf->items[i+1].key) >= 0); | |
126 | BUG_ON(leaf->items[i].offset != leaf->items[i + 1].offset + | |
127 | leaf->items[i + 1].size); | |
128 | if (i == 0) { | |
129 | BUG_ON(leaf->items[i].offset + leaf->items[i].size != | |
130 | LEAF_DATA_SIZE); | |
131 | } | |
132 | } | |
133 | BUG_ON(leaf_free_space(leaf) < 0); | |
134 | return 0; | |
135 | } | |
136 | ||
137 | int check_block(struct ctree_path *path, int level) | |
138 | { | |
139 | if (level == 0) | |
140 | return check_leaf(path, level); | |
141 | return check_node(path, level); | |
142 | } | |
143 | ||
74123bd7 CM |
144 | /* |
145 | * search for key in the array p. items p are item_size apart | |
146 | * and there are 'max' items in p | |
147 | * the slot in the array is returned via slot, and it points to | |
148 | * the place where you would insert key if it is not found in | |
149 | * the array. | |
150 | * | |
151 | * slot may point to max if the key is bigger than all of the keys | |
152 | */ | |
be0e5c09 CM |
153 | int generic_bin_search(char *p, int item_size, struct key *key, |
154 | int max, int *slot) | |
155 | { | |
156 | int low = 0; | |
157 | int high = max; | |
158 | int mid; | |
159 | int ret; | |
160 | struct key *tmp; | |
161 | ||
162 | while(low < high) { | |
163 | mid = (low + high) / 2; | |
164 | tmp = (struct key *)(p + mid * item_size); | |
165 | ret = comp_keys(tmp, key); | |
166 | ||
167 | if (ret < 0) | |
168 | low = mid + 1; | |
169 | else if (ret > 0) | |
170 | high = mid; | |
171 | else { | |
172 | *slot = mid; | |
173 | return 0; | |
174 | } | |
175 | } | |
176 | *slot = low; | |
177 | return 1; | |
178 | } | |
179 | ||
97571fd0 CM |
180 | /* |
181 | * simple bin_search frontend that does the right thing for | |
182 | * leaves vs nodes | |
183 | */ | |
be0e5c09 CM |
184 | int bin_search(struct node *c, struct key *key, int *slot) |
185 | { | |
186 | if (is_leaf(c->header.flags)) { | |
187 | struct leaf *l = (struct leaf *)c; | |
188 | return generic_bin_search((void *)l->items, sizeof(struct item), | |
189 | key, c->header.nritems, slot); | |
190 | } else { | |
191 | return generic_bin_search((void *)c->keys, sizeof(struct key), | |
192 | key, c->header.nritems, slot); | |
193 | } | |
194 | return -1; | |
195 | } | |
196 | ||
bb803951 CM |
197 | struct tree_buffer *read_node_slot(struct ctree_root *root, |
198 | struct tree_buffer *parent_buf, | |
199 | int slot) | |
200 | { | |
201 | struct node *node = &parent_buf->node; | |
202 | if (slot < 0) | |
203 | return NULL; | |
204 | if (slot >= node->header.nritems) | |
205 | return NULL; | |
206 | return read_tree_block(root, node->blockptrs[slot]); | |
207 | } | |
208 | ||
209 | static int balance_level(struct ctree_root *root, struct ctree_path *path, | |
210 | int level) | |
211 | { | |
212 | struct tree_buffer *right_buf; | |
213 | struct tree_buffer *mid_buf; | |
214 | struct tree_buffer *left_buf; | |
215 | struct tree_buffer *parent_buf = NULL; | |
216 | struct node *right = NULL; | |
217 | struct node *mid; | |
218 | struct node *left = NULL; | |
219 | struct node *parent = NULL; | |
220 | int ret = 0; | |
221 | int wret; | |
222 | int pslot; | |
bb803951 | 223 | int orig_slot = path->slots[level]; |
79f95c82 | 224 | u64 orig_ptr; |
bb803951 CM |
225 | |
226 | if (level == 0) | |
227 | return 0; | |
228 | ||
229 | mid_buf = path->nodes[level]; | |
230 | mid = &mid_buf->node; | |
79f95c82 CM |
231 | orig_ptr = mid->blockptrs[orig_slot]; |
232 | ||
bb803951 CM |
233 | if (level < MAX_LEVEL - 1) |
234 | parent_buf = path->nodes[level + 1]; | |
235 | pslot = path->slots[level + 1]; | |
236 | ||
237 | if (!parent_buf) { | |
238 | struct tree_buffer *child; | |
239 | u64 blocknr = mid_buf->blocknr; | |
240 | ||
241 | if (mid->header.nritems != 1) | |
242 | return 0; | |
243 | ||
244 | /* promote the child to a root */ | |
245 | child = read_node_slot(root, mid_buf, 0); | |
246 | BUG_ON(!child); | |
247 | root->node = child; | |
248 | path->nodes[level] = NULL; | |
249 | /* once for the path */ | |
250 | tree_block_release(root, mid_buf); | |
251 | /* once for the root ptr */ | |
252 | tree_block_release(root, mid_buf); | |
253 | return free_extent(root, blocknr, 1); | |
254 | } | |
255 | parent = &parent_buf->node; | |
256 | ||
257 | if (mid->header.nritems > NODEPTRS_PER_BLOCK / 4) | |
258 | return 0; | |
259 | ||
bb803951 CM |
260 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
261 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
262 | |
263 | /* first, try to make some room in the middle buffer */ | |
bb803951 CM |
264 | if (left_buf) { |
265 | left = &left_buf->node; | |
bb803951 | 266 | orig_slot += left->header.nritems; |
79f95c82 CM |
267 | wret = push_node_left(root, left_buf, mid_buf); |
268 | if (wret < 0) | |
269 | ret = wret; | |
bb803951 | 270 | } |
79f95c82 CM |
271 | |
272 | /* | |
273 | * then try to empty the right most buffer into the middle | |
274 | */ | |
bb803951 | 275 | if (right_buf) { |
79f95c82 CM |
276 | right = &right_buf->node; |
277 | wret = push_node_left(root, mid_buf, right_buf); | |
278 | if (wret < 0) | |
279 | ret = wret; | |
bb803951 CM |
280 | if (right->header.nritems == 0) { |
281 | u64 blocknr = right_buf->blocknr; | |
282 | tree_block_release(root, right_buf); | |
283 | right_buf = NULL; | |
284 | right = NULL; | |
285 | wret = del_ptr(root, path, level + 1, pslot + 1); | |
286 | if (wret) | |
287 | ret = wret; | |
288 | wret = free_extent(root, blocknr, 1); | |
289 | if (wret) | |
290 | ret = wret; | |
291 | } else { | |
292 | memcpy(parent->keys + pslot + 1, right->keys, | |
293 | sizeof(struct key)); | |
79f95c82 CM |
294 | wret = write_tree_block(root, parent_buf); |
295 | if (wret) | |
296 | ret = wret; | |
bb803951 CM |
297 | } |
298 | } | |
79f95c82 CM |
299 | if (mid->header.nritems == 1) { |
300 | /* | |
301 | * we're not allowed to leave a node with one item in the | |
302 | * tree during a delete. A deletion from lower in the tree | |
303 | * could try to delete the only pointer in this node. | |
304 | * So, pull some keys from the left. | |
305 | * There has to be a left pointer at this point because | |
306 | * otherwise we would have pulled some pointers from the | |
307 | * right | |
308 | */ | |
309 | BUG_ON(!left_buf); | |
310 | wret = balance_node_right(root, mid_buf, left_buf); | |
311 | if (wret < 0) | |
312 | ret = wret; | |
313 | BUG_ON(wret == 1); | |
314 | } | |
bb803951 | 315 | if (mid->header.nritems == 0) { |
79f95c82 | 316 | /* we've managed to empty the middle node, drop it */ |
bb803951 CM |
317 | u64 blocknr = mid_buf->blocknr; |
318 | tree_block_release(root, mid_buf); | |
319 | mid_buf = NULL; | |
320 | mid = NULL; | |
321 | wret = del_ptr(root, path, level + 1, pslot); | |
322 | if (wret) | |
323 | ret = wret; | |
324 | wret = free_extent(root, blocknr, 1); | |
325 | if (wret) | |
326 | ret = wret; | |
79f95c82 CM |
327 | } else { |
328 | /* update the parent key to reflect our changes */ | |
bb803951 | 329 | memcpy(parent->keys + pslot, mid->keys, sizeof(struct key)); |
79f95c82 CM |
330 | wret = write_tree_block(root, parent_buf); |
331 | if (wret) | |
332 | ret = wret; | |
333 | } | |
bb803951 | 334 | |
79f95c82 | 335 | /* update the path */ |
bb803951 | 336 | if (left_buf) { |
79f95c82 | 337 | if (left->header.nritems > orig_slot) { |
bb803951 CM |
338 | left_buf->count++; // released below |
339 | path->nodes[level] = left_buf; | |
340 | path->slots[level + 1] -= 1; | |
341 | path->slots[level] = orig_slot; | |
342 | if (mid_buf) | |
343 | tree_block_release(root, mid_buf); | |
344 | } else { | |
345 | orig_slot -= left->header.nritems; | |
346 | path->slots[level] = orig_slot; | |
347 | } | |
348 | } | |
79f95c82 CM |
349 | /* double check we haven't messed things up */ |
350 | check_block(path, level); | |
351 | if (orig_ptr != path->nodes[level]->node.blockptrs[path->slots[level]]) | |
352 | BUG(); | |
bb803951 CM |
353 | |
354 | if (right_buf) | |
355 | tree_block_release(root, right_buf); | |
356 | if (left_buf) | |
357 | tree_block_release(root, left_buf); | |
bb803951 CM |
358 | return ret; |
359 | } | |
360 | ||
74123bd7 CM |
361 | /* |
362 | * look for key in the tree. path is filled in with nodes along the way | |
363 | * if key is found, we return zero and you can find the item in the leaf | |
364 | * level of the path (level 0) | |
365 | * | |
366 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
367 | * be inserted, and 1 is returned. If there are other errors during the |
368 | * search a negative error number is returned. | |
97571fd0 CM |
369 | * |
370 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
371 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
372 | * possible) | |
74123bd7 | 373 | */ |
5de08d7d CM |
374 | int search_slot(struct ctree_root *root, struct key *key, |
375 | struct ctree_path *p, int ins_len) | |
be0e5c09 | 376 | { |
bb803951 | 377 | struct tree_buffer *b; |
eb60ceac | 378 | struct node *c; |
be0e5c09 CM |
379 | int slot; |
380 | int ret; | |
381 | int level; | |
5c680ed6 | 382 | |
bb803951 CM |
383 | again: |
384 | b = root->node; | |
eb60ceac CM |
385 | b->count++; |
386 | while (b) { | |
387 | c = &b->node; | |
be0e5c09 | 388 | level = node_level(c->header.flags); |
eb60ceac | 389 | p->nodes[level] = b; |
aa5d6bed CM |
390 | ret = check_block(p, level); |
391 | if (ret) | |
392 | return -1; | |
be0e5c09 CM |
393 | ret = bin_search(c, key, &slot); |
394 | if (!is_leaf(c->header.flags)) { | |
395 | if (ret && slot > 0) | |
396 | slot -= 1; | |
397 | p->slots[level] = slot; | |
5de08d7d CM |
398 | if (ins_len > 0 && |
399 | c->header.nritems == NODEPTRS_PER_BLOCK) { | |
5c680ed6 CM |
400 | int sret = split_node(root, p, level); |
401 | BUG_ON(sret > 0); | |
402 | if (sret) | |
403 | return sret; | |
404 | b = p->nodes[level]; | |
405 | c = &b->node; | |
406 | slot = p->slots[level]; | |
bb803951 CM |
407 | } else if (ins_len < 0) { |
408 | int sret = balance_level(root, p, level); | |
409 | if (sret) | |
410 | return sret; | |
411 | b = p->nodes[level]; | |
412 | if (!b) | |
413 | goto again; | |
414 | c = &b->node; | |
415 | slot = p->slots[level]; | |
79f95c82 | 416 | BUG_ON(c->header.nritems == 1); |
5c680ed6 | 417 | } |
eb60ceac | 418 | b = read_tree_block(root, c->blockptrs[slot]); |
be0e5c09 | 419 | } else { |
5c680ed6 | 420 | struct leaf *l = (struct leaf *)c; |
be0e5c09 | 421 | p->slots[level] = slot; |
5de08d7d CM |
422 | if (ins_len > 0 && leaf_free_space(l) < |
423 | sizeof(struct item) + ins_len) { | |
5c680ed6 CM |
424 | int sret = split_leaf(root, p, ins_len); |
425 | BUG_ON(sret > 0); | |
426 | if (sret) | |
427 | return sret; | |
428 | } | |
bb803951 | 429 | BUG_ON(root->node->count == 1); |
be0e5c09 CM |
430 | return ret; |
431 | } | |
432 | } | |
bb803951 | 433 | BUG_ON(root->node->count == 1); |
aa5d6bed | 434 | return 1; |
be0e5c09 CM |
435 | } |
436 | ||
74123bd7 CM |
437 | /* |
438 | * adjust the pointers going up the tree, starting at level | |
439 | * making sure the right key of each node is points to 'key'. | |
440 | * This is used after shifting pointers to the left, so it stops | |
441 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
442 | * higher levels | |
aa5d6bed CM |
443 | * |
444 | * If this fails to write a tree block, it returns -1, but continues | |
445 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 446 | */ |
aa5d6bed | 447 | static int fixup_low_keys(struct ctree_root *root, |
eb60ceac CM |
448 | struct ctree_path *path, struct key *key, |
449 | int level) | |
be0e5c09 CM |
450 | { |
451 | int i; | |
aa5d6bed CM |
452 | int ret = 0; |
453 | int wret; | |
be0e5c09 | 454 | for (i = level; i < MAX_LEVEL; i++) { |
eb60ceac | 455 | struct node *t; |
be0e5c09 | 456 | int tslot = path->slots[i]; |
eb60ceac | 457 | if (!path->nodes[i]) |
be0e5c09 | 458 | break; |
eb60ceac | 459 | t = &path->nodes[i]->node; |
be0e5c09 | 460 | memcpy(t->keys + tslot, key, sizeof(*key)); |
aa5d6bed CM |
461 | wret = write_tree_block(root, path->nodes[i]); |
462 | if (wret) | |
463 | ret = wret; | |
be0e5c09 CM |
464 | if (tslot != 0) |
465 | break; | |
466 | } | |
aa5d6bed | 467 | return ret; |
be0e5c09 CM |
468 | } |
469 | ||
74123bd7 CM |
470 | /* |
471 | * try to push data from one node into the next node left in the | |
79f95c82 | 472 | * tree. |
aa5d6bed CM |
473 | * |
474 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
475 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 476 | */ |
bb803951 CM |
477 | static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, |
478 | struct tree_buffer *src_buf) | |
be0e5c09 | 479 | { |
bb803951 CM |
480 | struct node *src = &src_buf->node; |
481 | struct node *dst = &dst_buf->node; | |
be0e5c09 | 482 | int push_items = 0; |
bb803951 CM |
483 | int src_nritems; |
484 | int dst_nritems; | |
aa5d6bed CM |
485 | int ret = 0; |
486 | int wret; | |
be0e5c09 | 487 | |
bb803951 CM |
488 | src_nritems = src->header.nritems; |
489 | dst_nritems = dst->header.nritems; | |
490 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; | |
eb60ceac | 491 | if (push_items <= 0) { |
be0e5c09 | 492 | return 1; |
eb60ceac | 493 | } |
be0e5c09 | 494 | |
bb803951 | 495 | if (src_nritems < push_items) |
79f95c82 CM |
496 | push_items = src_nritems; |
497 | ||
bb803951 | 498 | memcpy(dst->keys + dst_nritems, src->keys, |
be0e5c09 | 499 | push_items * sizeof(struct key)); |
bb803951 | 500 | memcpy(dst->blockptrs + dst_nritems, src->blockptrs, |
be0e5c09 | 501 | push_items * sizeof(u64)); |
bb803951 CM |
502 | if (push_items < src_nritems) { |
503 | memmove(src->keys, src->keys + push_items, | |
504 | (src_nritems - push_items) * sizeof(struct key)); | |
505 | memmove(src->blockptrs, src->blockptrs + push_items, | |
506 | (src_nritems - push_items) * sizeof(u64)); | |
507 | } | |
508 | src->header.nritems -= push_items; | |
509 | dst->header.nritems += push_items; | |
eb60ceac | 510 | |
bb803951 | 511 | wret = write_tree_block(root, src_buf); |
aa5d6bed CM |
512 | if (wret < 0) |
513 | ret = wret; | |
514 | ||
bb803951 | 515 | wret = write_tree_block(root, dst_buf); |
79f95c82 CM |
516 | if (wret < 0) |
517 | ret = wret; | |
518 | return ret; | |
519 | } | |
520 | ||
521 | /* | |
522 | * try to push data from one node into the next node right in the | |
523 | * tree. | |
524 | * | |
525 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
526 | * error, and > 0 if there was no room in the right hand block. | |
527 | * | |
528 | * this will only push up to 1/2 the contents of the left node over | |
529 | */ | |
530 | static int balance_node_right(struct ctree_root *root, | |
531 | struct tree_buffer *dst_buf, | |
532 | struct tree_buffer *src_buf) | |
533 | { | |
534 | struct node *src = &src_buf->node; | |
535 | struct node *dst = &dst_buf->node; | |
536 | int push_items = 0; | |
537 | int max_push; | |
538 | int src_nritems; | |
539 | int dst_nritems; | |
540 | int ret = 0; | |
541 | int wret; | |
542 | ||
543 | src_nritems = src->header.nritems; | |
544 | dst_nritems = dst->header.nritems; | |
545 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; | |
546 | if (push_items <= 0) { | |
547 | return 1; | |
548 | } | |
549 | ||
550 | max_push = src_nritems / 2 + 1; | |
551 | /* don't try to empty the node */ | |
552 | if (max_push > src_nritems) | |
553 | return 1; | |
554 | if (max_push < push_items) | |
555 | push_items = max_push; | |
556 | ||
557 | memmove(dst->keys + push_items, dst->keys, | |
558 | dst_nritems * sizeof(struct key)); | |
559 | memmove(dst->blockptrs + push_items, dst->blockptrs, | |
560 | dst_nritems * sizeof(u64)); | |
561 | memcpy(dst->keys, src->keys + src_nritems - push_items, | |
562 | push_items * sizeof(struct key)); | |
563 | memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, | |
564 | push_items * sizeof(u64)); | |
565 | ||
566 | src->header.nritems -= push_items; | |
567 | dst->header.nritems += push_items; | |
568 | ||
569 | wret = write_tree_block(root, src_buf); | |
570 | if (wret < 0) | |
571 | ret = wret; | |
572 | ||
573 | wret = write_tree_block(root, dst_buf); | |
aa5d6bed CM |
574 | if (wret < 0) |
575 | ret = wret; | |
aa5d6bed | 576 | return ret; |
be0e5c09 CM |
577 | } |
578 | ||
97571fd0 CM |
579 | /* |
580 | * helper function to insert a new root level in the tree. | |
581 | * A new node is allocated, and a single item is inserted to | |
582 | * point to the existing root | |
aa5d6bed CM |
583 | * |
584 | * returns zero on success or < 0 on failure. | |
97571fd0 | 585 | */ |
5de08d7d CM |
586 | static int insert_new_root(struct ctree_root *root, |
587 | struct ctree_path *path, int level) | |
5c680ed6 CM |
588 | { |
589 | struct tree_buffer *t; | |
590 | struct node *lower; | |
591 | struct node *c; | |
592 | struct key *lower_key; | |
593 | ||
594 | BUG_ON(path->nodes[level]); | |
595 | BUG_ON(path->nodes[level-1] != root->node); | |
596 | ||
597 | t = alloc_free_block(root); | |
598 | c = &t->node; | |
599 | memset(c, 0, sizeof(c)); | |
600 | c->header.nritems = 1; | |
601 | c->header.flags = node_level(level); | |
602 | c->header.blocknr = t->blocknr; | |
603 | c->header.parentid = root->node->node.header.parentid; | |
604 | lower = &path->nodes[level-1]->node; | |
605 | if (is_leaf(lower->header.flags)) | |
606 | lower_key = &((struct leaf *)lower)->items[0].key; | |
607 | else | |
608 | lower_key = lower->keys; | |
609 | memcpy(c->keys, lower_key, sizeof(struct key)); | |
610 | c->blockptrs[0] = path->nodes[level-1]->blocknr; | |
611 | /* the super has an extra ref to root->node */ | |
612 | tree_block_release(root, root->node); | |
613 | root->node = t; | |
614 | t->count++; | |
615 | write_tree_block(root, t); | |
616 | path->nodes[level] = t; | |
617 | path->slots[level] = 0; | |
618 | return 0; | |
619 | } | |
620 | ||
74123bd7 CM |
621 | /* |
622 | * worker function to insert a single pointer in a node. | |
623 | * the node should have enough room for the pointer already | |
97571fd0 | 624 | * |
74123bd7 CM |
625 | * slot and level indicate where you want the key to go, and |
626 | * blocknr is the block the key points to. | |
aa5d6bed CM |
627 | * |
628 | * returns zero on success and < 0 on any error | |
74123bd7 | 629 | */ |
aa5d6bed | 630 | static int insert_ptr(struct ctree_root *root, |
74123bd7 CM |
631 | struct ctree_path *path, struct key *key, |
632 | u64 blocknr, int slot, int level) | |
633 | { | |
74123bd7 | 634 | struct node *lower; |
74123bd7 | 635 | int nritems; |
5c680ed6 CM |
636 | |
637 | BUG_ON(!path->nodes[level]); | |
74123bd7 CM |
638 | lower = &path->nodes[level]->node; |
639 | nritems = lower->header.nritems; | |
640 | if (slot > nritems) | |
641 | BUG(); | |
642 | if (nritems == NODEPTRS_PER_BLOCK) | |
643 | BUG(); | |
644 | if (slot != nritems) { | |
645 | memmove(lower->keys + slot + 1, lower->keys + slot, | |
646 | (nritems - slot) * sizeof(struct key)); | |
647 | memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, | |
648 | (nritems - slot) * sizeof(u64)); | |
649 | } | |
650 | memcpy(lower->keys + slot, key, sizeof(struct key)); | |
651 | lower->blockptrs[slot] = blocknr; | |
652 | lower->header.nritems++; | |
653 | if (lower->keys[1].objectid == 0) | |
654 | BUG(); | |
655 | write_tree_block(root, path->nodes[level]); | |
656 | return 0; | |
657 | } | |
658 | ||
97571fd0 CM |
659 | /* |
660 | * split the node at the specified level in path in two. | |
661 | * The path is corrected to point to the appropriate node after the split | |
662 | * | |
663 | * Before splitting this tries to make some room in the node by pushing | |
664 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
665 | * |
666 | * returns 0 on success and < 0 on failure | |
97571fd0 | 667 | */ |
aa5d6bed CM |
668 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
669 | int level) | |
be0e5c09 | 670 | { |
5c680ed6 CM |
671 | struct tree_buffer *t; |
672 | struct node *c; | |
673 | struct tree_buffer *split_buffer; | |
674 | struct node *split; | |
be0e5c09 | 675 | int mid; |
5c680ed6 | 676 | int ret; |
aa5d6bed | 677 | int wret; |
eb60ceac | 678 | |
5c680ed6 CM |
679 | t = path->nodes[level]; |
680 | c = &t->node; | |
681 | if (t == root->node) { | |
682 | /* trying to split the root, lets make a new one */ | |
683 | ret = insert_new_root(root, path, level + 1); | |
684 | if (ret) | |
685 | return ret; | |
be0e5c09 | 686 | } |
5c680ed6 CM |
687 | split_buffer = alloc_free_block(root); |
688 | split = &split_buffer->node; | |
689 | split->header.flags = c->header.flags; | |
690 | split->header.blocknr = split_buffer->blocknr; | |
691 | split->header.parentid = root->node->node.header.parentid; | |
692 | mid = (c->header.nritems + 1) / 2; | |
693 | memcpy(split->keys, c->keys + mid, | |
694 | (c->header.nritems - mid) * sizeof(struct key)); | |
695 | memcpy(split->blockptrs, c->blockptrs + mid, | |
696 | (c->header.nritems - mid) * sizeof(u64)); | |
697 | split->header.nritems = c->header.nritems - mid; | |
698 | c->header.nritems = mid; | |
aa5d6bed CM |
699 | ret = 0; |
700 | ||
701 | wret = write_tree_block(root, t); | |
702 | if (wret) | |
703 | ret = wret; | |
704 | wret = write_tree_block(root, split_buffer); | |
705 | if (wret) | |
706 | ret = wret; | |
707 | wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, | |
708 | path->slots[level + 1] + 1, level + 1); | |
709 | if (wret) | |
710 | ret = wret; | |
711 | ||
5de08d7d | 712 | if (path->slots[level] >= mid) { |
5c680ed6 CM |
713 | path->slots[level] -= mid; |
714 | tree_block_release(root, t); | |
715 | path->nodes[level] = split_buffer; | |
716 | path->slots[level + 1] += 1; | |
717 | } else { | |
718 | tree_block_release(root, split_buffer); | |
be0e5c09 | 719 | } |
aa5d6bed | 720 | return ret; |
be0e5c09 CM |
721 | } |
722 | ||
74123bd7 CM |
723 | /* |
724 | * how many bytes are required to store the items in a leaf. start | |
725 | * and nr indicate which items in the leaf to check. This totals up the | |
726 | * space used both by the item structs and the item data | |
727 | */ | |
aa5d6bed | 728 | static int leaf_space_used(struct leaf *l, int start, int nr) |
be0e5c09 CM |
729 | { |
730 | int data_len; | |
731 | int end = start + nr - 1; | |
732 | ||
733 | if (!nr) | |
734 | return 0; | |
735 | data_len = l->items[start].offset + l->items[start].size; | |
736 | data_len = data_len - l->items[end].offset; | |
737 | data_len += sizeof(struct item) * nr; | |
738 | return data_len; | |
739 | } | |
740 | ||
00ec4c51 CM |
741 | /* |
742 | * push some data in the path leaf to the right, trying to free up at | |
743 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
744 | * |
745 | * returns 1 if the push failed because the other node didn't have enough | |
746 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 747 | */ |
aa5d6bed CM |
748 | static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, |
749 | int data_size) | |
00ec4c51 CM |
750 | { |
751 | struct tree_buffer *left_buf = path->nodes[0]; | |
752 | struct leaf *left = &left_buf->leaf; | |
753 | struct leaf *right; | |
754 | struct tree_buffer *right_buf; | |
755 | struct tree_buffer *upper; | |
756 | int slot; | |
757 | int i; | |
758 | int free_space; | |
759 | int push_space = 0; | |
760 | int push_items = 0; | |
761 | struct item *item; | |
762 | ||
763 | slot = path->slots[1]; | |
764 | if (!path->nodes[1]) { | |
765 | return 1; | |
766 | } | |
767 | upper = path->nodes[1]; | |
768 | if (slot >= upper->node.header.nritems - 1) { | |
769 | return 1; | |
770 | } | |
771 | right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]); | |
772 | right = &right_buf->leaf; | |
773 | free_space = leaf_free_space(right); | |
774 | if (free_space < data_size + sizeof(struct item)) { | |
775 | tree_block_release(root, right_buf); | |
776 | return 1; | |
777 | } | |
778 | for (i = left->header.nritems - 1; i >= 0; i--) { | |
779 | item = left->items + i; | |
780 | if (path->slots[0] == i) | |
781 | push_space += data_size + sizeof(*item); | |
782 | if (item->size + sizeof(*item) + push_space > free_space) | |
783 | break; | |
784 | push_items++; | |
785 | push_space += item->size + sizeof(*item); | |
786 | } | |
787 | if (push_items == 0) { | |
788 | tree_block_release(root, right_buf); | |
789 | return 1; | |
790 | } | |
791 | /* push left to right */ | |
792 | push_space = left->items[left->header.nritems - push_items].offset + | |
793 | left->items[left->header.nritems - push_items].size; | |
794 | push_space -= leaf_data_end(left); | |
795 | /* make room in the right data area */ | |
796 | memmove(right->data + leaf_data_end(right) - push_space, | |
797 | right->data + leaf_data_end(right), | |
798 | LEAF_DATA_SIZE - leaf_data_end(right)); | |
799 | /* copy from the left data area */ | |
800 | memcpy(right->data + LEAF_DATA_SIZE - push_space, | |
801 | left->data + leaf_data_end(left), | |
802 | push_space); | |
803 | memmove(right->items + push_items, right->items, | |
804 | right->header.nritems * sizeof(struct item)); | |
805 | /* copy the items from left to right */ | |
806 | memcpy(right->items, left->items + left->header.nritems - push_items, | |
807 | push_items * sizeof(struct item)); | |
808 | ||
809 | /* update the item pointers */ | |
810 | right->header.nritems += push_items; | |
811 | push_space = LEAF_DATA_SIZE; | |
812 | for (i = 0; i < right->header.nritems; i++) { | |
813 | right->items[i].offset = push_space - right->items[i].size; | |
814 | push_space = right->items[i].offset; | |
815 | } | |
816 | left->header.nritems -= push_items; | |
817 | ||
818 | write_tree_block(root, left_buf); | |
819 | write_tree_block(root, right_buf); | |
820 | memcpy(upper->node.keys + slot + 1, | |
821 | &right->items[0].key, sizeof(struct key)); | |
822 | write_tree_block(root, upper); | |
823 | /* then fixup the leaf pointer in the path */ | |
00ec4c51 CM |
824 | if (path->slots[0] >= left->header.nritems) { |
825 | path->slots[0] -= left->header.nritems; | |
826 | tree_block_release(root, path->nodes[0]); | |
827 | path->nodes[0] = right_buf; | |
828 | path->slots[1] += 1; | |
829 | } else { | |
830 | tree_block_release(root, right_buf); | |
831 | } | |
832 | return 0; | |
833 | } | |
74123bd7 CM |
834 | /* |
835 | * push some data in the path leaf to the left, trying to free up at | |
836 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
837 | */ | |
aa5d6bed CM |
838 | static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, |
839 | int data_size) | |
be0e5c09 | 840 | { |
eb60ceac CM |
841 | struct tree_buffer *right_buf = path->nodes[0]; |
842 | struct leaf *right = &right_buf->leaf; | |
843 | struct tree_buffer *t; | |
be0e5c09 CM |
844 | struct leaf *left; |
845 | int slot; | |
846 | int i; | |
847 | int free_space; | |
848 | int push_space = 0; | |
849 | int push_items = 0; | |
850 | struct item *item; | |
851 | int old_left_nritems; | |
aa5d6bed CM |
852 | int ret = 0; |
853 | int wret; | |
be0e5c09 CM |
854 | |
855 | slot = path->slots[1]; | |
856 | if (slot == 0) { | |
857 | return 1; | |
858 | } | |
859 | if (!path->nodes[1]) { | |
860 | return 1; | |
861 | } | |
eb60ceac CM |
862 | t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]); |
863 | left = &t->leaf; | |
be0e5c09 CM |
864 | free_space = leaf_free_space(left); |
865 | if (free_space < data_size + sizeof(struct item)) { | |
eb60ceac | 866 | tree_block_release(root, t); |
be0e5c09 CM |
867 | return 1; |
868 | } | |
869 | for (i = 0; i < right->header.nritems; i++) { | |
870 | item = right->items + i; | |
871 | if (path->slots[0] == i) | |
872 | push_space += data_size + sizeof(*item); | |
873 | if (item->size + sizeof(*item) + push_space > free_space) | |
874 | break; | |
875 | push_items++; | |
876 | push_space += item->size + sizeof(*item); | |
877 | } | |
878 | if (push_items == 0) { | |
eb60ceac | 879 | tree_block_release(root, t); |
be0e5c09 CM |
880 | return 1; |
881 | } | |
882 | /* push data from right to left */ | |
883 | memcpy(left->items + left->header.nritems, | |
884 | right->items, push_items * sizeof(struct item)); | |
885 | push_space = LEAF_DATA_SIZE - right->items[push_items -1].offset; | |
886 | memcpy(left->data + leaf_data_end(left) - push_space, | |
887 | right->data + right->items[push_items - 1].offset, | |
888 | push_space); | |
889 | old_left_nritems = left->header.nritems; | |
eb60ceac CM |
890 | BUG_ON(old_left_nritems < 0); |
891 | ||
be0e5c09 CM |
892 | for(i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
893 | left->items[i].offset -= LEAF_DATA_SIZE - | |
894 | left->items[old_left_nritems -1].offset; | |
895 | } | |
896 | left->header.nritems += push_items; | |
897 | ||
898 | /* fixup right node */ | |
899 | push_space = right->items[push_items-1].offset - leaf_data_end(right); | |
900 | memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + | |
901 | leaf_data_end(right), push_space); | |
902 | memmove(right->items, right->items + push_items, | |
903 | (right->header.nritems - push_items) * sizeof(struct item)); | |
904 | right->header.nritems -= push_items; | |
905 | push_space = LEAF_DATA_SIZE; | |
eb60ceac | 906 | |
be0e5c09 CM |
907 | for (i = 0; i < right->header.nritems; i++) { |
908 | right->items[i].offset = push_space - right->items[i].size; | |
909 | push_space = right->items[i].offset; | |
910 | } | |
eb60ceac | 911 | |
aa5d6bed CM |
912 | wret = write_tree_block(root, t); |
913 | if (wret) | |
914 | ret = wret; | |
915 | wret = write_tree_block(root, right_buf); | |
916 | if (wret) | |
917 | ret = wret; | |
eb60ceac | 918 | |
aa5d6bed CM |
919 | wret = fixup_low_keys(root, path, &right->items[0].key, 1); |
920 | if (wret) | |
921 | ret = wret; | |
be0e5c09 CM |
922 | |
923 | /* then fixup the leaf pointer in the path */ | |
924 | if (path->slots[0] < push_items) { | |
925 | path->slots[0] += old_left_nritems; | |
eb60ceac CM |
926 | tree_block_release(root, path->nodes[0]); |
927 | path->nodes[0] = t; | |
be0e5c09 CM |
928 | path->slots[1] -= 1; |
929 | } else { | |
eb60ceac | 930 | tree_block_release(root, t); |
be0e5c09 CM |
931 | path->slots[0] -= push_items; |
932 | } | |
eb60ceac | 933 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 934 | return ret; |
be0e5c09 CM |
935 | } |
936 | ||
74123bd7 CM |
937 | /* |
938 | * split the path's leaf in two, making sure there is at least data_size | |
939 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
940 | * |
941 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 942 | */ |
aa5d6bed CM |
943 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, |
944 | int data_size) | |
be0e5c09 | 945 | { |
aa5d6bed CM |
946 | struct tree_buffer *l_buf; |
947 | struct leaf *l; | |
eb60ceac CM |
948 | int nritems; |
949 | int mid; | |
950 | int slot; | |
be0e5c09 | 951 | struct leaf *right; |
eb60ceac | 952 | struct tree_buffer *right_buffer; |
be0e5c09 CM |
953 | int space_needed = data_size + sizeof(struct item); |
954 | int data_copy_size; | |
955 | int rt_data_off; | |
956 | int i; | |
957 | int ret; | |
aa5d6bed CM |
958 | int wret; |
959 | ||
960 | wret = push_leaf_left(root, path, data_size); | |
961 | if (wret < 0) | |
962 | return wret; | |
963 | if (wret) { | |
964 | wret = push_leaf_right(root, path, data_size); | |
965 | if (wret < 0) | |
966 | return wret; | |
be0e5c09 | 967 | } |
aa5d6bed CM |
968 | l_buf = path->nodes[0]; |
969 | l = &l_buf->leaf; | |
970 | ||
971 | /* did the pushes work? */ | |
972 | if (leaf_free_space(l) >= sizeof(struct item) + data_size) | |
973 | return 0; | |
974 | ||
5c680ed6 CM |
975 | if (!path->nodes[1]) { |
976 | ret = insert_new_root(root, path, 1); | |
977 | if (ret) | |
978 | return ret; | |
979 | } | |
eb60ceac CM |
980 | slot = path->slots[0]; |
981 | nritems = l->header.nritems; | |
982 | mid = (nritems + 1)/ 2; | |
983 | ||
984 | right_buffer = alloc_free_block(root); | |
985 | BUG_ON(!right_buffer); | |
986 | BUG_ON(mid == nritems); | |
987 | right = &right_buffer->leaf; | |
be0e5c09 CM |
988 | memset(right, 0, sizeof(*right)); |
989 | if (mid <= slot) { | |
97571fd0 | 990 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
991 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
992 | LEAF_DATA_SIZE) | |
993 | BUG(); | |
994 | } else { | |
97571fd0 | 995 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
996 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
997 | LEAF_DATA_SIZE) | |
998 | BUG(); | |
999 | } | |
1000 | right->header.nritems = nritems - mid; | |
eb60ceac CM |
1001 | right->header.blocknr = right_buffer->blocknr; |
1002 | right->header.flags = node_level(0); | |
cfaa7295 | 1003 | right->header.parentid = root->node->node.header.parentid; |
be0e5c09 CM |
1004 | data_copy_size = l->items[mid].offset + l->items[mid].size - |
1005 | leaf_data_end(l); | |
1006 | memcpy(right->items, l->items + mid, | |
1007 | (nritems - mid) * sizeof(struct item)); | |
1008 | memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, | |
1009 | l->data + leaf_data_end(l), data_copy_size); | |
1010 | rt_data_off = LEAF_DATA_SIZE - | |
1011 | (l->items[mid].offset + l->items[mid].size); | |
74123bd7 CM |
1012 | |
1013 | for (i = 0; i < right->header.nritems; i++) | |
be0e5c09 | 1014 | right->items[i].offset += rt_data_off; |
74123bd7 | 1015 | |
be0e5c09 | 1016 | l->header.nritems = mid; |
aa5d6bed CM |
1017 | ret = 0; |
1018 | wret = insert_ptr(root, path, &right->items[0].key, | |
5c680ed6 | 1019 | right_buffer->blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1020 | if (wret) |
1021 | ret = wret; | |
1022 | wret = write_tree_block(root, right_buffer); | |
1023 | if (wret) | |
1024 | ret = wret; | |
1025 | wret = write_tree_block(root, l_buf); | |
1026 | if (wret) | |
1027 | ret = wret; | |
eb60ceac CM |
1028 | |
1029 | BUG_ON(path->slots[0] != slot); | |
be0e5c09 | 1030 | if (mid <= slot) { |
eb60ceac CM |
1031 | tree_block_release(root, path->nodes[0]); |
1032 | path->nodes[0] = right_buffer; | |
be0e5c09 CM |
1033 | path->slots[0] -= mid; |
1034 | path->slots[1] += 1; | |
eb60ceac CM |
1035 | } else |
1036 | tree_block_release(root, right_buffer); | |
1037 | BUG_ON(path->slots[0] < 0); | |
be0e5c09 CM |
1038 | return ret; |
1039 | } | |
1040 | ||
74123bd7 CM |
1041 | /* |
1042 | * Given a key and some data, insert an item into the tree. | |
1043 | * This does all the path init required, making room in the tree if needed. | |
1044 | */ | |
be0e5c09 CM |
1045 | int insert_item(struct ctree_root *root, struct key *key, |
1046 | void *data, int data_size) | |
1047 | { | |
aa5d6bed CM |
1048 | int ret = 0; |
1049 | int wret; | |
be0e5c09 | 1050 | int slot; |
eb60ceac | 1051 | int slot_orig; |
be0e5c09 | 1052 | struct leaf *leaf; |
eb60ceac | 1053 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1054 | unsigned int nritems; |
1055 | unsigned int data_end; | |
1056 | struct ctree_path path; | |
1057 | ||
74123bd7 | 1058 | /* create a root if there isn't one */ |
5c680ed6 | 1059 | if (!root->node) |
cfaa7295 | 1060 | BUG(); |
be0e5c09 | 1061 | init_path(&path); |
5c680ed6 | 1062 | ret = search_slot(root, key, &path, data_size); |
eb60ceac CM |
1063 | if (ret == 0) { |
1064 | release_path(root, &path); | |
be0e5c09 | 1065 | return -EEXIST; |
eb60ceac | 1066 | } |
aa5d6bed CM |
1067 | if (ret < 0) { |
1068 | release_path(root, &path); | |
1069 | return ret; | |
1070 | } | |
be0e5c09 | 1071 | |
eb60ceac CM |
1072 | slot_orig = path.slots[0]; |
1073 | leaf_buf = path.nodes[0]; | |
1074 | leaf = &leaf_buf->leaf; | |
74123bd7 | 1075 | |
be0e5c09 CM |
1076 | nritems = leaf->header.nritems; |
1077 | data_end = leaf_data_end(leaf); | |
eb60ceac | 1078 | |
be0e5c09 CM |
1079 | if (leaf_free_space(leaf) < sizeof(struct item) + data_size) |
1080 | BUG(); | |
1081 | ||
1082 | slot = path.slots[0]; | |
eb60ceac | 1083 | BUG_ON(slot < 0); |
be0e5c09 CM |
1084 | if (slot != nritems) { |
1085 | int i; | |
1086 | unsigned int old_data = leaf->items[slot].offset + | |
1087 | leaf->items[slot].size; | |
1088 | ||
1089 | /* | |
1090 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1091 | */ | |
1092 | /* first correct the data pointers */ | |
1093 | for (i = slot; i < nritems; i++) | |
1094 | leaf->items[i].offset -= data_size; | |
1095 | ||
1096 | /* shift the items */ | |
1097 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
1098 | (nritems - slot) * sizeof(struct item)); | |
1099 | ||
1100 | /* shift the data */ | |
1101 | memmove(leaf->data + data_end - data_size, leaf->data + | |
1102 | data_end, old_data - data_end); | |
1103 | data_end = old_data; | |
1104 | } | |
74123bd7 | 1105 | /* copy the new data in */ |
be0e5c09 CM |
1106 | memcpy(&leaf->items[slot].key, key, sizeof(struct key)); |
1107 | leaf->items[slot].offset = data_end - data_size; | |
1108 | leaf->items[slot].size = data_size; | |
1109 | memcpy(leaf->data + data_end - data_size, data, data_size); | |
1110 | leaf->header.nritems += 1; | |
aa5d6bed CM |
1111 | |
1112 | ret = 0; | |
8e19f2cd | 1113 | if (slot == 0) |
aa5d6bed CM |
1114 | ret = fixup_low_keys(root, &path, key, 1); |
1115 | ||
1116 | wret = write_tree_block(root, leaf_buf); | |
1117 | if (wret) | |
1118 | ret = wret; | |
1119 | ||
be0e5c09 CM |
1120 | if (leaf_free_space(leaf) < 0) |
1121 | BUG(); | |
bb803951 | 1122 | check_leaf(&path, 0); |
eb60ceac | 1123 | release_path(root, &path); |
aa5d6bed | 1124 | return ret; |
be0e5c09 CM |
1125 | } |
1126 | ||
74123bd7 | 1127 | /* |
5de08d7d | 1128 | * delete the pointer from a given node. |
74123bd7 CM |
1129 | * |
1130 | * If the delete empties a node, the node is removed from the tree, | |
1131 | * continuing all the way the root if required. The root is converted into | |
1132 | * a leaf if all the nodes are emptied. | |
1133 | */ | |
bb803951 CM |
1134 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, |
1135 | int slot) | |
be0e5c09 | 1136 | { |
be0e5c09 | 1137 | struct node *node; |
bb803951 | 1138 | struct tree_buffer *parent = path->nodes[level]; |
be0e5c09 | 1139 | int nritems; |
aa5d6bed | 1140 | int ret = 0; |
bb803951 | 1141 | int wret; |
be0e5c09 | 1142 | |
bb803951 CM |
1143 | node = &parent->node; |
1144 | nritems = node->header.nritems; | |
1145 | ||
1146 | if (slot != nritems -1) { | |
1147 | memmove(node->keys + slot, node->keys + slot + 1, | |
1148 | sizeof(struct key) * (nritems - slot - 1)); | |
1149 | memmove(node->blockptrs + slot, | |
1150 | node->blockptrs + slot + 1, | |
1151 | sizeof(u64) * (nritems - slot - 1)); | |
1152 | } | |
1153 | node->header.nritems--; | |
1154 | if (node->header.nritems == 0 && parent == root->node) { | |
1155 | BUG_ON(node_level(root->node->node.header.flags) != 1); | |
1156 | /* just turn the root into a leaf and break */ | |
1157 | root->node->node.header.flags = node_level(0); | |
1158 | } else if (slot == 0) { | |
1159 | wret = fixup_low_keys(root, path, node->keys, level + 1); | |
0f70abe2 CM |
1160 | if (wret) |
1161 | ret = wret; | |
be0e5c09 | 1162 | } |
bb803951 CM |
1163 | wret = write_tree_block(root, parent); |
1164 | if (wret) | |
1165 | ret = wret; | |
aa5d6bed | 1166 | return ret; |
be0e5c09 CM |
1167 | } |
1168 | ||
74123bd7 CM |
1169 | /* |
1170 | * delete the item at the leaf level in path. If that empties | |
1171 | * the leaf, remove it from the tree | |
1172 | */ | |
4920c9ac | 1173 | int del_item(struct ctree_root *root, struct ctree_path *path) |
be0e5c09 | 1174 | { |
be0e5c09 CM |
1175 | int slot; |
1176 | struct leaf *leaf; | |
eb60ceac | 1177 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1178 | int doff; |
1179 | int dsize; | |
aa5d6bed CM |
1180 | int ret = 0; |
1181 | int wret; | |
be0e5c09 | 1182 | |
eb60ceac CM |
1183 | leaf_buf = path->nodes[0]; |
1184 | leaf = &leaf_buf->leaf; | |
4920c9ac | 1185 | slot = path->slots[0]; |
be0e5c09 CM |
1186 | doff = leaf->items[slot].offset; |
1187 | dsize = leaf->items[slot].size; | |
1188 | ||
1189 | if (slot != leaf->header.nritems - 1) { | |
1190 | int i; | |
1191 | int data_end = leaf_data_end(leaf); | |
1192 | memmove(leaf->data + data_end + dsize, | |
1193 | leaf->data + data_end, | |
1194 | doff - data_end); | |
1195 | for (i = slot + 1; i < leaf->header.nritems; i++) | |
1196 | leaf->items[i].offset += dsize; | |
1197 | memmove(leaf->items + slot, leaf->items + slot + 1, | |
1198 | sizeof(struct item) * | |
1199 | (leaf->header.nritems - slot - 1)); | |
1200 | } | |
1201 | leaf->header.nritems -= 1; | |
74123bd7 | 1202 | /* delete the leaf if we've emptied it */ |
be0e5c09 | 1203 | if (leaf->header.nritems == 0) { |
eb60ceac CM |
1204 | if (leaf_buf == root->node) { |
1205 | leaf->header.flags = node_level(0); | |
1206 | write_tree_block(root, leaf_buf); | |
9a8dd150 | 1207 | } else { |
bb803951 | 1208 | wret = del_ptr(root, path, 1, path->slots[1]); |
aa5d6bed CM |
1209 | if (wret) |
1210 | ret = wret; | |
0f70abe2 CM |
1211 | wret = free_extent(root, leaf_buf->blocknr, 1); |
1212 | if (wret) | |
1213 | ret = wret; | |
9a8dd150 | 1214 | } |
be0e5c09 | 1215 | } else { |
5de08d7d | 1216 | int used = leaf_space_used(leaf, 0, leaf->header.nritems); |
aa5d6bed CM |
1217 | if (slot == 0) { |
1218 | wret = fixup_low_keys(root, path, | |
1219 | &leaf->items[0].key, 1); | |
1220 | if (wret) | |
1221 | ret = wret; | |
1222 | } | |
1223 | wret = write_tree_block(root, leaf_buf); | |
1224 | if (wret) | |
1225 | ret = wret; | |
1226 | ||
74123bd7 | 1227 | /* delete the leaf if it is mostly empty */ |
5de08d7d | 1228 | if (used < LEAF_DATA_SIZE / 3) { |
be0e5c09 CM |
1229 | /* push_leaf_left fixes the path. |
1230 | * make sure the path still points to our leaf | |
1231 | * for possible call to del_ptr below | |
1232 | */ | |
4920c9ac | 1233 | slot = path->slots[1]; |
eb60ceac | 1234 | leaf_buf->count++; |
aa5d6bed CM |
1235 | wret = push_leaf_left(root, path, 1); |
1236 | if (wret < 0) | |
1237 | ret = wret; | |
1238 | if (leaf->header.nritems) { | |
1239 | wret = push_leaf_right(root, path, 1); | |
1240 | if (wret < 0) | |
1241 | ret = wret; | |
1242 | } | |
be0e5c09 | 1243 | if (leaf->header.nritems == 0) { |
5de08d7d | 1244 | u64 blocknr = leaf_buf->blocknr; |
bb803951 | 1245 | wret = del_ptr(root, path, 1, slot); |
aa5d6bed CM |
1246 | if (wret) |
1247 | ret = wret; | |
5de08d7d | 1248 | tree_block_release(root, leaf_buf); |
0f70abe2 CM |
1249 | wret = free_extent(root, blocknr, 1); |
1250 | if (wret) | |
1251 | ret = wret; | |
5de08d7d CM |
1252 | } else { |
1253 | tree_block_release(root, leaf_buf); | |
be0e5c09 CM |
1254 | } |
1255 | } | |
1256 | } | |
aa5d6bed | 1257 | return ret; |
be0e5c09 CM |
1258 | } |
1259 | ||
97571fd0 CM |
1260 | /* |
1261 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1262 | * returns 0 if it found something or 1 if there are no greater leaves. |
1263 | * returns < 0 on io errors. | |
97571fd0 | 1264 | */ |
d97e63b6 CM |
1265 | int next_leaf(struct ctree_root *root, struct ctree_path *path) |
1266 | { | |
1267 | int slot; | |
1268 | int level = 1; | |
1269 | u64 blocknr; | |
1270 | struct tree_buffer *c; | |
cfaa7295 | 1271 | struct tree_buffer *next = NULL; |
d97e63b6 CM |
1272 | |
1273 | while(level < MAX_LEVEL) { | |
1274 | if (!path->nodes[level]) | |
0f70abe2 | 1275 | return 1; |
d97e63b6 CM |
1276 | slot = path->slots[level] + 1; |
1277 | c = path->nodes[level]; | |
1278 | if (slot >= c->node.header.nritems) { | |
1279 | level++; | |
1280 | continue; | |
1281 | } | |
1282 | blocknr = c->node.blockptrs[slot]; | |
cfaa7295 CM |
1283 | if (next) |
1284 | tree_block_release(root, next); | |
d97e63b6 CM |
1285 | next = read_tree_block(root, blocknr); |
1286 | break; | |
1287 | } | |
1288 | path->slots[level] = slot; | |
1289 | while(1) { | |
1290 | level--; | |
1291 | c = path->nodes[level]; | |
1292 | tree_block_release(root, c); | |
1293 | path->nodes[level] = next; | |
1294 | path->slots[level] = 0; | |
1295 | if (!level) | |
1296 | break; | |
1297 | next = read_tree_block(root, next->node.blockptrs[0]); | |
1298 | } | |
1299 | return 0; | |
1300 | } | |
1301 |