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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); | |
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 | ||
02217ed2 CM |
37 | int btrfs_cow_block(struct ctree_root *root, |
38 | struct tree_buffer *buf, | |
39 | struct tree_buffer *parent, | |
40 | int parent_slot, | |
41 | struct tree_buffer **cow_ret) | |
42 | { | |
43 | struct tree_buffer *cow; | |
44 | ||
45 | if (!list_empty(&buf->dirty)) { | |
46 | *cow_ret = buf; | |
47 | return 0; | |
48 | } | |
49 | cow = alloc_free_block(root); | |
50 | memcpy(&cow->node, &buf->node, sizeof(buf->node)); | |
51 | cow->node.header.blocknr = cow->blocknr; | |
52 | *cow_ret = cow; | |
a28ec197 | 53 | btrfs_inc_ref(root, buf); |
02217ed2 CM |
54 | if (buf == root->node) { |
55 | root->node = cow; | |
56 | cow->count++; | |
a28ec197 CM |
57 | if (buf != root->commit_root) |
58 | free_extent(root, buf->blocknr, 1); | |
02217ed2 CM |
59 | tree_block_release(root, buf); |
60 | } else { | |
61 | parent->node.blockptrs[parent_slot] = cow->blocknr; | |
62 | BUG_ON(list_empty(&parent->dirty)); | |
a28ec197 | 63 | free_extent(root, buf->blocknr, 1); |
02217ed2 CM |
64 | } |
65 | tree_block_release(root, buf); | |
66 | return 0; | |
67 | } | |
68 | ||
74123bd7 CM |
69 | /* |
70 | * The leaf data grows from end-to-front in the node. | |
71 | * this returns the address of the start of the last item, | |
72 | * which is the stop of the leaf data stack | |
73 | */ | |
be0e5c09 CM |
74 | static inline unsigned int leaf_data_end(struct leaf *leaf) |
75 | { | |
76 | unsigned int nr = leaf->header.nritems; | |
77 | if (nr == 0) | |
d97e63b6 | 78 | return sizeof(leaf->data); |
be0e5c09 CM |
79 | return leaf->items[nr-1].offset; |
80 | } | |
81 | ||
74123bd7 CM |
82 | /* |
83 | * The space between the end of the leaf items and | |
84 | * the start of the leaf data. IOW, how much room | |
85 | * the leaf has left for both items and data | |
86 | */ | |
5de08d7d | 87 | int leaf_free_space(struct leaf *leaf) |
be0e5c09 CM |
88 | { |
89 | int data_end = leaf_data_end(leaf); | |
90 | int nritems = leaf->header.nritems; | |
91 | char *items_end = (char *)(leaf->items + nritems + 1); | |
92 | return (char *)(leaf->data + data_end) - (char *)items_end; | |
93 | } | |
94 | ||
74123bd7 CM |
95 | /* |
96 | * compare two keys in a memcmp fashion | |
97 | */ | |
be0e5c09 CM |
98 | int comp_keys(struct key *k1, struct key *k2) |
99 | { | |
100 | if (k1->objectid > k2->objectid) | |
101 | return 1; | |
102 | if (k1->objectid < k2->objectid) | |
103 | return -1; | |
104 | if (k1->flags > k2->flags) | |
105 | return 1; | |
106 | if (k1->flags < k2->flags) | |
107 | return -1; | |
108 | if (k1->offset > k2->offset) | |
109 | return 1; | |
110 | if (k1->offset < k2->offset) | |
111 | return -1; | |
112 | return 0; | |
113 | } | |
74123bd7 | 114 | |
aa5d6bed CM |
115 | int check_node(struct ctree_path *path, int level) |
116 | { | |
117 | int i; | |
118 | struct node *parent = NULL; | |
119 | struct node *node = &path->nodes[level]->node; | |
120 | int parent_slot; | |
121 | ||
122 | if (path->nodes[level + 1]) | |
123 | parent = &path->nodes[level + 1]->node; | |
124 | parent_slot = path->slots[level + 1]; | |
125 | if (parent && node->header.nritems > 0) { | |
126 | struct key *parent_key; | |
127 | parent_key = &parent->keys[parent_slot]; | |
128 | BUG_ON(memcmp(parent_key, node->keys, sizeof(struct key))); | |
129 | BUG_ON(parent->blockptrs[parent_slot] != node->header.blocknr); | |
130 | } | |
131 | BUG_ON(node->header.nritems > NODEPTRS_PER_BLOCK); | |
132 | for (i = 0; i < node->header.nritems - 2; i++) { | |
133 | BUG_ON(comp_keys(&node->keys[i], &node->keys[i+1]) >= 0); | |
134 | } | |
135 | return 0; | |
136 | } | |
137 | ||
138 | int check_leaf(struct ctree_path *path, int level) | |
139 | { | |
140 | int i; | |
141 | struct leaf *leaf = &path->nodes[level]->leaf; | |
142 | struct node *parent = NULL; | |
143 | int parent_slot; | |
144 | ||
145 | if (path->nodes[level + 1]) | |
146 | parent = &path->nodes[level + 1]->node; | |
147 | parent_slot = path->slots[level + 1]; | |
148 | if (parent && leaf->header.nritems > 0) { | |
149 | struct key *parent_key; | |
150 | parent_key = &parent->keys[parent_slot]; | |
151 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, | |
152 | sizeof(struct key))); | |
153 | BUG_ON(parent->blockptrs[parent_slot] != leaf->header.blocknr); | |
154 | } | |
155 | for (i = 0; i < leaf->header.nritems - 2; i++) { | |
156 | BUG_ON(comp_keys(&leaf->items[i].key, | |
157 | &leaf->items[i+1].key) >= 0); | |
158 | BUG_ON(leaf->items[i].offset != leaf->items[i + 1].offset + | |
159 | leaf->items[i + 1].size); | |
160 | if (i == 0) { | |
161 | BUG_ON(leaf->items[i].offset + leaf->items[i].size != | |
162 | LEAF_DATA_SIZE); | |
163 | } | |
164 | } | |
165 | BUG_ON(leaf_free_space(leaf) < 0); | |
166 | return 0; | |
167 | } | |
168 | ||
169 | int check_block(struct ctree_path *path, int level) | |
170 | { | |
171 | if (level == 0) | |
172 | return check_leaf(path, level); | |
173 | return check_node(path, level); | |
174 | } | |
175 | ||
74123bd7 CM |
176 | /* |
177 | * search for key in the array p. items p are item_size apart | |
178 | * and there are 'max' items in p | |
179 | * the slot in the array is returned via slot, and it points to | |
180 | * the place where you would insert key if it is not found in | |
181 | * the array. | |
182 | * | |
183 | * slot may point to max if the key is bigger than all of the keys | |
184 | */ | |
be0e5c09 CM |
185 | int generic_bin_search(char *p, int item_size, struct key *key, |
186 | int max, int *slot) | |
187 | { | |
188 | int low = 0; | |
189 | int high = max; | |
190 | int mid; | |
191 | int ret; | |
192 | struct key *tmp; | |
193 | ||
194 | while(low < high) { | |
195 | mid = (low + high) / 2; | |
196 | tmp = (struct key *)(p + mid * item_size); | |
197 | ret = comp_keys(tmp, key); | |
198 | ||
199 | if (ret < 0) | |
200 | low = mid + 1; | |
201 | else if (ret > 0) | |
202 | high = mid; | |
203 | else { | |
204 | *slot = mid; | |
205 | return 0; | |
206 | } | |
207 | } | |
208 | *slot = low; | |
209 | return 1; | |
210 | } | |
211 | ||
97571fd0 CM |
212 | /* |
213 | * simple bin_search frontend that does the right thing for | |
214 | * leaves vs nodes | |
215 | */ | |
be0e5c09 CM |
216 | int bin_search(struct node *c, struct key *key, int *slot) |
217 | { | |
218 | if (is_leaf(c->header.flags)) { | |
219 | struct leaf *l = (struct leaf *)c; | |
220 | return generic_bin_search((void *)l->items, sizeof(struct item), | |
221 | key, c->header.nritems, slot); | |
222 | } else { | |
223 | return generic_bin_search((void *)c->keys, sizeof(struct key), | |
224 | key, c->header.nritems, slot); | |
225 | } | |
226 | return -1; | |
227 | } | |
228 | ||
bb803951 CM |
229 | struct tree_buffer *read_node_slot(struct ctree_root *root, |
230 | struct tree_buffer *parent_buf, | |
231 | int slot) | |
232 | { | |
233 | struct node *node = &parent_buf->node; | |
234 | if (slot < 0) | |
235 | return NULL; | |
236 | if (slot >= node->header.nritems) | |
237 | return NULL; | |
238 | return read_tree_block(root, node->blockptrs[slot]); | |
239 | } | |
240 | ||
241 | static int balance_level(struct ctree_root *root, struct ctree_path *path, | |
242 | int level) | |
243 | { | |
244 | struct tree_buffer *right_buf; | |
245 | struct tree_buffer *mid_buf; | |
246 | struct tree_buffer *left_buf; | |
247 | struct tree_buffer *parent_buf = NULL; | |
248 | struct node *right = NULL; | |
249 | struct node *mid; | |
250 | struct node *left = NULL; | |
251 | struct node *parent = NULL; | |
252 | int ret = 0; | |
253 | int wret; | |
254 | int pslot; | |
bb803951 | 255 | int orig_slot = path->slots[level]; |
79f95c82 | 256 | u64 orig_ptr; |
bb803951 CM |
257 | |
258 | if (level == 0) | |
259 | return 0; | |
260 | ||
261 | mid_buf = path->nodes[level]; | |
262 | mid = &mid_buf->node; | |
79f95c82 CM |
263 | orig_ptr = mid->blockptrs[orig_slot]; |
264 | ||
bb803951 CM |
265 | if (level < MAX_LEVEL - 1) |
266 | parent_buf = path->nodes[level + 1]; | |
267 | pslot = path->slots[level + 1]; | |
268 | ||
269 | if (!parent_buf) { | |
270 | struct tree_buffer *child; | |
271 | u64 blocknr = mid_buf->blocknr; | |
272 | ||
273 | if (mid->header.nritems != 1) | |
274 | return 0; | |
275 | ||
276 | /* promote the child to a root */ | |
277 | child = read_node_slot(root, mid_buf, 0); | |
278 | BUG_ON(!child); | |
279 | root->node = child; | |
280 | path->nodes[level] = NULL; | |
281 | /* once for the path */ | |
282 | tree_block_release(root, mid_buf); | |
283 | /* once for the root ptr */ | |
284 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 285 | clean_tree_block(root, mid_buf); |
bb803951 CM |
286 | return free_extent(root, blocknr, 1); |
287 | } | |
288 | parent = &parent_buf->node; | |
289 | ||
290 | if (mid->header.nritems > NODEPTRS_PER_BLOCK / 4) | |
291 | return 0; | |
292 | ||
bb803951 CM |
293 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
294 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
295 | |
296 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 297 | if (left_buf) { |
02217ed2 CM |
298 | btrfs_cow_block(root, left_buf, parent_buf, |
299 | pslot - 1, &left_buf); | |
bb803951 | 300 | left = &left_buf->node; |
bb803951 | 301 | orig_slot += left->header.nritems; |
79f95c82 CM |
302 | wret = push_node_left(root, left_buf, mid_buf); |
303 | if (wret < 0) | |
304 | ret = wret; | |
bb803951 | 305 | } |
79f95c82 CM |
306 | |
307 | /* | |
308 | * then try to empty the right most buffer into the middle | |
309 | */ | |
bb803951 | 310 | if (right_buf) { |
02217ed2 CM |
311 | btrfs_cow_block(root, right_buf, parent_buf, |
312 | pslot + 1, &right_buf); | |
79f95c82 CM |
313 | right = &right_buf->node; |
314 | wret = push_node_left(root, mid_buf, right_buf); | |
315 | if (wret < 0) | |
316 | ret = wret; | |
bb803951 CM |
317 | if (right->header.nritems == 0) { |
318 | u64 blocknr = right_buf->blocknr; | |
319 | tree_block_release(root, right_buf); | |
ed2ff2cb | 320 | clean_tree_block(root, right_buf); |
bb803951 CM |
321 | right_buf = NULL; |
322 | right = NULL; | |
323 | wret = del_ptr(root, path, level + 1, pslot + 1); | |
324 | if (wret) | |
325 | ret = wret; | |
326 | wret = free_extent(root, blocknr, 1); | |
327 | if (wret) | |
328 | ret = wret; | |
329 | } else { | |
330 | memcpy(parent->keys + pslot + 1, right->keys, | |
331 | sizeof(struct key)); | |
02217ed2 | 332 | BUG_ON(list_empty(&parent_buf->dirty)); |
bb803951 CM |
333 | } |
334 | } | |
79f95c82 CM |
335 | if (mid->header.nritems == 1) { |
336 | /* | |
337 | * we're not allowed to leave a node with one item in the | |
338 | * tree during a delete. A deletion from lower in the tree | |
339 | * could try to delete the only pointer in this node. | |
340 | * So, pull some keys from the left. | |
341 | * There has to be a left pointer at this point because | |
342 | * otherwise we would have pulled some pointers from the | |
343 | * right | |
344 | */ | |
345 | BUG_ON(!left_buf); | |
346 | wret = balance_node_right(root, mid_buf, left_buf); | |
347 | if (wret < 0) | |
348 | ret = wret; | |
349 | BUG_ON(wret == 1); | |
350 | } | |
bb803951 | 351 | if (mid->header.nritems == 0) { |
79f95c82 | 352 | /* we've managed to empty the middle node, drop it */ |
bb803951 CM |
353 | u64 blocknr = mid_buf->blocknr; |
354 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 355 | clean_tree_block(root, mid_buf); |
bb803951 CM |
356 | mid_buf = NULL; |
357 | mid = NULL; | |
358 | wret = del_ptr(root, path, level + 1, pslot); | |
359 | if (wret) | |
360 | ret = wret; | |
361 | wret = free_extent(root, blocknr, 1); | |
362 | if (wret) | |
363 | ret = wret; | |
79f95c82 CM |
364 | } else { |
365 | /* update the parent key to reflect our changes */ | |
bb803951 | 366 | memcpy(parent->keys + pslot, mid->keys, sizeof(struct key)); |
02217ed2 | 367 | BUG_ON(list_empty(&parent_buf->dirty)); |
79f95c82 | 368 | } |
bb803951 | 369 | |
79f95c82 | 370 | /* update the path */ |
bb803951 | 371 | if (left_buf) { |
79f95c82 | 372 | if (left->header.nritems > orig_slot) { |
bb803951 CM |
373 | left_buf->count++; // released below |
374 | path->nodes[level] = left_buf; | |
375 | path->slots[level + 1] -= 1; | |
376 | path->slots[level] = orig_slot; | |
377 | if (mid_buf) | |
378 | tree_block_release(root, mid_buf); | |
379 | } else { | |
380 | orig_slot -= left->header.nritems; | |
381 | path->slots[level] = orig_slot; | |
382 | } | |
383 | } | |
79f95c82 CM |
384 | /* double check we haven't messed things up */ |
385 | check_block(path, level); | |
386 | if (orig_ptr != path->nodes[level]->node.blockptrs[path->slots[level]]) | |
387 | BUG(); | |
bb803951 CM |
388 | |
389 | if (right_buf) | |
390 | tree_block_release(root, right_buf); | |
391 | if (left_buf) | |
392 | tree_block_release(root, left_buf); | |
bb803951 CM |
393 | return ret; |
394 | } | |
395 | ||
74123bd7 CM |
396 | /* |
397 | * look for key in the tree. path is filled in with nodes along the way | |
398 | * if key is found, we return zero and you can find the item in the leaf | |
399 | * level of the path (level 0) | |
400 | * | |
401 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
402 | * be inserted, and 1 is returned. If there are other errors during the |
403 | * search a negative error number is returned. | |
97571fd0 CM |
404 | * |
405 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
406 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
407 | * possible) | |
74123bd7 | 408 | */ |
5de08d7d | 409 | int search_slot(struct ctree_root *root, struct key *key, |
02217ed2 | 410 | struct ctree_path *p, int ins_len, int cow) |
be0e5c09 | 411 | { |
bb803951 | 412 | struct tree_buffer *b; |
02217ed2 | 413 | struct tree_buffer *cow_buf; |
eb60ceac | 414 | struct node *c; |
be0e5c09 CM |
415 | int slot; |
416 | int ret; | |
417 | int level; | |
5c680ed6 | 418 | |
bb803951 CM |
419 | again: |
420 | b = root->node; | |
eb60ceac CM |
421 | b->count++; |
422 | while (b) { | |
02217ed2 CM |
423 | level = node_level(b->node.header.flags); |
424 | if (cow) { | |
425 | int wret; | |
426 | wret = btrfs_cow_block(root, b, p->nodes[level + 1], | |
427 | p->slots[level + 1], &cow_buf); | |
428 | b = cow_buf; | |
429 | } | |
430 | BUG_ON(!cow && ins_len); | |
eb60ceac | 431 | c = &b->node; |
eb60ceac | 432 | p->nodes[level] = b; |
aa5d6bed CM |
433 | ret = check_block(p, level); |
434 | if (ret) | |
435 | return -1; | |
be0e5c09 CM |
436 | ret = bin_search(c, key, &slot); |
437 | if (!is_leaf(c->header.flags)) { | |
438 | if (ret && slot > 0) | |
439 | slot -= 1; | |
440 | p->slots[level] = slot; | |
5de08d7d CM |
441 | if (ins_len > 0 && |
442 | c->header.nritems == NODEPTRS_PER_BLOCK) { | |
5c680ed6 CM |
443 | int sret = split_node(root, p, level); |
444 | BUG_ON(sret > 0); | |
445 | if (sret) | |
446 | return sret; | |
447 | b = p->nodes[level]; | |
448 | c = &b->node; | |
449 | slot = p->slots[level]; | |
bb803951 CM |
450 | } else if (ins_len < 0) { |
451 | int sret = balance_level(root, p, level); | |
452 | if (sret) | |
453 | return sret; | |
454 | b = p->nodes[level]; | |
455 | if (!b) | |
456 | goto again; | |
457 | c = &b->node; | |
458 | slot = p->slots[level]; | |
79f95c82 | 459 | BUG_ON(c->header.nritems == 1); |
5c680ed6 | 460 | } |
eb60ceac | 461 | b = read_tree_block(root, c->blockptrs[slot]); |
be0e5c09 | 462 | } else { |
5c680ed6 | 463 | struct leaf *l = (struct leaf *)c; |
be0e5c09 | 464 | p->slots[level] = slot; |
5de08d7d CM |
465 | if (ins_len > 0 && leaf_free_space(l) < |
466 | sizeof(struct item) + ins_len) { | |
5c680ed6 CM |
467 | int sret = split_leaf(root, p, ins_len); |
468 | BUG_ON(sret > 0); | |
469 | if (sret) | |
470 | return sret; | |
471 | } | |
bb803951 | 472 | BUG_ON(root->node->count == 1); |
be0e5c09 CM |
473 | return ret; |
474 | } | |
475 | } | |
bb803951 | 476 | BUG_ON(root->node->count == 1); |
aa5d6bed | 477 | return 1; |
be0e5c09 CM |
478 | } |
479 | ||
74123bd7 CM |
480 | /* |
481 | * adjust the pointers going up the tree, starting at level | |
482 | * making sure the right key of each node is points to 'key'. | |
483 | * This is used after shifting pointers to the left, so it stops | |
484 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
485 | * higher levels | |
aa5d6bed CM |
486 | * |
487 | * If this fails to write a tree block, it returns -1, but continues | |
488 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 489 | */ |
aa5d6bed | 490 | static int fixup_low_keys(struct ctree_root *root, |
eb60ceac CM |
491 | struct ctree_path *path, struct key *key, |
492 | int level) | |
be0e5c09 CM |
493 | { |
494 | int i; | |
aa5d6bed | 495 | int ret = 0; |
be0e5c09 | 496 | for (i = level; i < MAX_LEVEL; i++) { |
eb60ceac | 497 | struct node *t; |
be0e5c09 | 498 | int tslot = path->slots[i]; |
eb60ceac | 499 | if (!path->nodes[i]) |
be0e5c09 | 500 | break; |
eb60ceac | 501 | t = &path->nodes[i]->node; |
be0e5c09 | 502 | memcpy(t->keys + tslot, key, sizeof(*key)); |
02217ed2 | 503 | BUG_ON(list_empty(&path->nodes[i]->dirty)); |
be0e5c09 CM |
504 | if (tslot != 0) |
505 | break; | |
506 | } | |
aa5d6bed | 507 | return ret; |
be0e5c09 CM |
508 | } |
509 | ||
74123bd7 CM |
510 | /* |
511 | * try to push data from one node into the next node left in the | |
79f95c82 | 512 | * tree. |
aa5d6bed CM |
513 | * |
514 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
515 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 516 | */ |
bb803951 CM |
517 | static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, |
518 | struct tree_buffer *src_buf) | |
be0e5c09 | 519 | { |
bb803951 CM |
520 | struct node *src = &src_buf->node; |
521 | struct node *dst = &dst_buf->node; | |
be0e5c09 | 522 | int push_items = 0; |
bb803951 CM |
523 | int src_nritems; |
524 | int dst_nritems; | |
aa5d6bed | 525 | int ret = 0; |
be0e5c09 | 526 | |
bb803951 CM |
527 | src_nritems = src->header.nritems; |
528 | dst_nritems = dst->header.nritems; | |
529 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; | |
eb60ceac | 530 | if (push_items <= 0) { |
be0e5c09 | 531 | return 1; |
eb60ceac | 532 | } |
be0e5c09 | 533 | |
bb803951 | 534 | if (src_nritems < push_items) |
79f95c82 CM |
535 | push_items = src_nritems; |
536 | ||
bb803951 | 537 | memcpy(dst->keys + dst_nritems, src->keys, |
be0e5c09 | 538 | push_items * sizeof(struct key)); |
bb803951 | 539 | memcpy(dst->blockptrs + dst_nritems, src->blockptrs, |
be0e5c09 | 540 | push_items * sizeof(u64)); |
bb803951 CM |
541 | if (push_items < src_nritems) { |
542 | memmove(src->keys, src->keys + push_items, | |
543 | (src_nritems - push_items) * sizeof(struct key)); | |
544 | memmove(src->blockptrs, src->blockptrs + push_items, | |
545 | (src_nritems - push_items) * sizeof(u64)); | |
546 | } | |
547 | src->header.nritems -= push_items; | |
548 | dst->header.nritems += push_items; | |
eb60ceac | 549 | |
02217ed2 CM |
550 | BUG_ON(list_empty(&src_buf->dirty)); |
551 | BUG_ON(list_empty(&dst_buf->dirty)); | |
79f95c82 CM |
552 | return ret; |
553 | } | |
554 | ||
555 | /* | |
556 | * try to push data from one node into the next node right in the | |
557 | * tree. | |
558 | * | |
559 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
560 | * error, and > 0 if there was no room in the right hand block. | |
561 | * | |
562 | * this will only push up to 1/2 the contents of the left node over | |
563 | */ | |
564 | static int balance_node_right(struct ctree_root *root, | |
565 | struct tree_buffer *dst_buf, | |
566 | struct tree_buffer *src_buf) | |
567 | { | |
568 | struct node *src = &src_buf->node; | |
569 | struct node *dst = &dst_buf->node; | |
570 | int push_items = 0; | |
571 | int max_push; | |
572 | int src_nritems; | |
573 | int dst_nritems; | |
574 | int ret = 0; | |
79f95c82 CM |
575 | |
576 | src_nritems = src->header.nritems; | |
577 | dst_nritems = dst->header.nritems; | |
578 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; | |
579 | if (push_items <= 0) { | |
580 | return 1; | |
581 | } | |
582 | ||
583 | max_push = src_nritems / 2 + 1; | |
584 | /* don't try to empty the node */ | |
585 | if (max_push > src_nritems) | |
586 | return 1; | |
587 | if (max_push < push_items) | |
588 | push_items = max_push; | |
589 | ||
590 | memmove(dst->keys + push_items, dst->keys, | |
591 | dst_nritems * sizeof(struct key)); | |
592 | memmove(dst->blockptrs + push_items, dst->blockptrs, | |
593 | dst_nritems * sizeof(u64)); | |
594 | memcpy(dst->keys, src->keys + src_nritems - push_items, | |
595 | push_items * sizeof(struct key)); | |
596 | memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, | |
597 | push_items * sizeof(u64)); | |
598 | ||
599 | src->header.nritems -= push_items; | |
600 | dst->header.nritems += push_items; | |
601 | ||
02217ed2 CM |
602 | BUG_ON(list_empty(&src_buf->dirty)); |
603 | BUG_ON(list_empty(&dst_buf->dirty)); | |
aa5d6bed | 604 | return ret; |
be0e5c09 CM |
605 | } |
606 | ||
97571fd0 CM |
607 | /* |
608 | * helper function to insert a new root level in the tree. | |
609 | * A new node is allocated, and a single item is inserted to | |
610 | * point to the existing root | |
aa5d6bed CM |
611 | * |
612 | * returns zero on success or < 0 on failure. | |
97571fd0 | 613 | */ |
5de08d7d CM |
614 | static int insert_new_root(struct ctree_root *root, |
615 | struct ctree_path *path, int level) | |
5c680ed6 CM |
616 | { |
617 | struct tree_buffer *t; | |
618 | struct node *lower; | |
619 | struct node *c; | |
620 | struct key *lower_key; | |
621 | ||
622 | BUG_ON(path->nodes[level]); | |
623 | BUG_ON(path->nodes[level-1] != root->node); | |
624 | ||
625 | t = alloc_free_block(root); | |
626 | c = &t->node; | |
627 | memset(c, 0, sizeof(c)); | |
628 | c->header.nritems = 1; | |
629 | c->header.flags = node_level(level); | |
630 | c->header.blocknr = t->blocknr; | |
631 | c->header.parentid = root->node->node.header.parentid; | |
632 | lower = &path->nodes[level-1]->node; | |
633 | if (is_leaf(lower->header.flags)) | |
634 | lower_key = &((struct leaf *)lower)->items[0].key; | |
635 | else | |
636 | lower_key = lower->keys; | |
637 | memcpy(c->keys, lower_key, sizeof(struct key)); | |
638 | c->blockptrs[0] = path->nodes[level-1]->blocknr; | |
639 | /* the super has an extra ref to root->node */ | |
640 | tree_block_release(root, root->node); | |
641 | root->node = t; | |
642 | t->count++; | |
5c680ed6 CM |
643 | path->nodes[level] = t; |
644 | path->slots[level] = 0; | |
645 | return 0; | |
646 | } | |
647 | ||
74123bd7 CM |
648 | /* |
649 | * worker function to insert a single pointer in a node. | |
650 | * the node should have enough room for the pointer already | |
97571fd0 | 651 | * |
74123bd7 CM |
652 | * slot and level indicate where you want the key to go, and |
653 | * blocknr is the block the key points to. | |
aa5d6bed CM |
654 | * |
655 | * returns zero on success and < 0 on any error | |
74123bd7 | 656 | */ |
aa5d6bed | 657 | static int insert_ptr(struct ctree_root *root, |
74123bd7 CM |
658 | struct ctree_path *path, struct key *key, |
659 | u64 blocknr, int slot, int level) | |
660 | { | |
74123bd7 | 661 | struct node *lower; |
74123bd7 | 662 | int nritems; |
5c680ed6 CM |
663 | |
664 | BUG_ON(!path->nodes[level]); | |
74123bd7 CM |
665 | lower = &path->nodes[level]->node; |
666 | nritems = lower->header.nritems; | |
667 | if (slot > nritems) | |
668 | BUG(); | |
669 | if (nritems == NODEPTRS_PER_BLOCK) | |
670 | BUG(); | |
671 | if (slot != nritems) { | |
672 | memmove(lower->keys + slot + 1, lower->keys + slot, | |
673 | (nritems - slot) * sizeof(struct key)); | |
674 | memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, | |
675 | (nritems - slot) * sizeof(u64)); | |
676 | } | |
677 | memcpy(lower->keys + slot, key, sizeof(struct key)); | |
678 | lower->blockptrs[slot] = blocknr; | |
679 | lower->header.nritems++; | |
680 | if (lower->keys[1].objectid == 0) | |
681 | BUG(); | |
02217ed2 | 682 | BUG_ON(list_empty(&path->nodes[level]->dirty)); |
74123bd7 CM |
683 | return 0; |
684 | } | |
685 | ||
97571fd0 CM |
686 | /* |
687 | * split the node at the specified level in path in two. | |
688 | * The path is corrected to point to the appropriate node after the split | |
689 | * | |
690 | * Before splitting this tries to make some room in the node by pushing | |
691 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
692 | * |
693 | * returns 0 on success and < 0 on failure | |
97571fd0 | 694 | */ |
aa5d6bed CM |
695 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
696 | int level) | |
be0e5c09 | 697 | { |
5c680ed6 CM |
698 | struct tree_buffer *t; |
699 | struct node *c; | |
700 | struct tree_buffer *split_buffer; | |
701 | struct node *split; | |
be0e5c09 | 702 | int mid; |
5c680ed6 | 703 | int ret; |
aa5d6bed | 704 | int wret; |
eb60ceac | 705 | |
5c680ed6 CM |
706 | t = path->nodes[level]; |
707 | c = &t->node; | |
708 | if (t == root->node) { | |
709 | /* trying to split the root, lets make a new one */ | |
710 | ret = insert_new_root(root, path, level + 1); | |
711 | if (ret) | |
712 | return ret; | |
be0e5c09 | 713 | } |
5c680ed6 CM |
714 | split_buffer = alloc_free_block(root); |
715 | split = &split_buffer->node; | |
716 | split->header.flags = c->header.flags; | |
717 | split->header.blocknr = split_buffer->blocknr; | |
718 | split->header.parentid = root->node->node.header.parentid; | |
719 | mid = (c->header.nritems + 1) / 2; | |
720 | memcpy(split->keys, c->keys + mid, | |
721 | (c->header.nritems - mid) * sizeof(struct key)); | |
722 | memcpy(split->blockptrs, c->blockptrs + mid, | |
723 | (c->header.nritems - mid) * sizeof(u64)); | |
724 | split->header.nritems = c->header.nritems - mid; | |
725 | c->header.nritems = mid; | |
aa5d6bed CM |
726 | ret = 0; |
727 | ||
02217ed2 | 728 | BUG_ON(list_empty(&t->dirty)); |
aa5d6bed CM |
729 | wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, |
730 | path->slots[level + 1] + 1, level + 1); | |
731 | if (wret) | |
732 | ret = wret; | |
733 | ||
5de08d7d | 734 | if (path->slots[level] >= mid) { |
5c680ed6 CM |
735 | path->slots[level] -= mid; |
736 | tree_block_release(root, t); | |
737 | path->nodes[level] = split_buffer; | |
738 | path->slots[level + 1] += 1; | |
739 | } else { | |
740 | tree_block_release(root, split_buffer); | |
be0e5c09 | 741 | } |
aa5d6bed | 742 | return ret; |
be0e5c09 CM |
743 | } |
744 | ||
74123bd7 CM |
745 | /* |
746 | * how many bytes are required to store the items in a leaf. start | |
747 | * and nr indicate which items in the leaf to check. This totals up the | |
748 | * space used both by the item structs and the item data | |
749 | */ | |
aa5d6bed | 750 | static int leaf_space_used(struct leaf *l, int start, int nr) |
be0e5c09 CM |
751 | { |
752 | int data_len; | |
753 | int end = start + nr - 1; | |
754 | ||
755 | if (!nr) | |
756 | return 0; | |
757 | data_len = l->items[start].offset + l->items[start].size; | |
758 | data_len = data_len - l->items[end].offset; | |
759 | data_len += sizeof(struct item) * nr; | |
760 | return data_len; | |
761 | } | |
762 | ||
00ec4c51 CM |
763 | /* |
764 | * push some data in the path leaf to the right, trying to free up at | |
765 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
766 | * |
767 | * returns 1 if the push failed because the other node didn't have enough | |
768 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 769 | */ |
aa5d6bed CM |
770 | static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, |
771 | int data_size) | |
00ec4c51 CM |
772 | { |
773 | struct tree_buffer *left_buf = path->nodes[0]; | |
774 | struct leaf *left = &left_buf->leaf; | |
775 | struct leaf *right; | |
776 | struct tree_buffer *right_buf; | |
777 | struct tree_buffer *upper; | |
778 | int slot; | |
779 | int i; | |
780 | int free_space; | |
781 | int push_space = 0; | |
782 | int push_items = 0; | |
783 | struct item *item; | |
784 | ||
785 | slot = path->slots[1]; | |
786 | if (!path->nodes[1]) { | |
787 | return 1; | |
788 | } | |
789 | upper = path->nodes[1]; | |
790 | if (slot >= upper->node.header.nritems - 1) { | |
791 | return 1; | |
792 | } | |
793 | right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]); | |
794 | right = &right_buf->leaf; | |
795 | free_space = leaf_free_space(right); | |
796 | if (free_space < data_size + sizeof(struct item)) { | |
797 | tree_block_release(root, right_buf); | |
798 | return 1; | |
799 | } | |
02217ed2 CM |
800 | /* cow and double check */ |
801 | btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf); | |
802 | right = &right_buf->leaf; | |
803 | free_space = leaf_free_space(right); | |
804 | if (free_space < data_size + sizeof(struct item)) { | |
805 | tree_block_release(root, right_buf); | |
806 | return 1; | |
807 | } | |
808 | ||
00ec4c51 CM |
809 | for (i = left->header.nritems - 1; i >= 0; i--) { |
810 | item = left->items + i; | |
811 | if (path->slots[0] == i) | |
812 | push_space += data_size + sizeof(*item); | |
813 | if (item->size + sizeof(*item) + push_space > free_space) | |
814 | break; | |
815 | push_items++; | |
816 | push_space += item->size + sizeof(*item); | |
817 | } | |
818 | if (push_items == 0) { | |
819 | tree_block_release(root, right_buf); | |
820 | return 1; | |
821 | } | |
822 | /* push left to right */ | |
823 | push_space = left->items[left->header.nritems - push_items].offset + | |
824 | left->items[left->header.nritems - push_items].size; | |
825 | push_space -= leaf_data_end(left); | |
826 | /* make room in the right data area */ | |
827 | memmove(right->data + leaf_data_end(right) - push_space, | |
828 | right->data + leaf_data_end(right), | |
829 | LEAF_DATA_SIZE - leaf_data_end(right)); | |
830 | /* copy from the left data area */ | |
831 | memcpy(right->data + LEAF_DATA_SIZE - push_space, | |
832 | left->data + leaf_data_end(left), | |
833 | push_space); | |
834 | memmove(right->items + push_items, right->items, | |
835 | right->header.nritems * sizeof(struct item)); | |
836 | /* copy the items from left to right */ | |
837 | memcpy(right->items, left->items + left->header.nritems - push_items, | |
838 | push_items * sizeof(struct item)); | |
839 | ||
840 | /* update the item pointers */ | |
841 | right->header.nritems += push_items; | |
842 | push_space = LEAF_DATA_SIZE; | |
843 | for (i = 0; i < right->header.nritems; i++) { | |
844 | right->items[i].offset = push_space - right->items[i].size; | |
845 | push_space = right->items[i].offset; | |
846 | } | |
847 | left->header.nritems -= push_items; | |
848 | ||
02217ed2 CM |
849 | BUG_ON(list_empty(&left_buf->dirty)); |
850 | BUG_ON(list_empty(&right_buf->dirty)); | |
00ec4c51 CM |
851 | memcpy(upper->node.keys + slot + 1, |
852 | &right->items[0].key, sizeof(struct key)); | |
02217ed2 CM |
853 | BUG_ON(list_empty(&upper->dirty)); |
854 | ||
00ec4c51 | 855 | /* then fixup the leaf pointer in the path */ |
00ec4c51 CM |
856 | if (path->slots[0] >= left->header.nritems) { |
857 | path->slots[0] -= left->header.nritems; | |
858 | tree_block_release(root, path->nodes[0]); | |
859 | path->nodes[0] = right_buf; | |
860 | path->slots[1] += 1; | |
861 | } else { | |
862 | tree_block_release(root, right_buf); | |
863 | } | |
864 | return 0; | |
865 | } | |
74123bd7 CM |
866 | /* |
867 | * push some data in the path leaf to the left, trying to free up at | |
868 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
869 | */ | |
aa5d6bed CM |
870 | static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, |
871 | int data_size) | |
be0e5c09 | 872 | { |
eb60ceac CM |
873 | struct tree_buffer *right_buf = path->nodes[0]; |
874 | struct leaf *right = &right_buf->leaf; | |
875 | struct tree_buffer *t; | |
be0e5c09 CM |
876 | struct leaf *left; |
877 | int slot; | |
878 | int i; | |
879 | int free_space; | |
880 | int push_space = 0; | |
881 | int push_items = 0; | |
882 | struct item *item; | |
883 | int old_left_nritems; | |
aa5d6bed CM |
884 | int ret = 0; |
885 | int wret; | |
be0e5c09 CM |
886 | |
887 | slot = path->slots[1]; | |
888 | if (slot == 0) { | |
889 | return 1; | |
890 | } | |
891 | if (!path->nodes[1]) { | |
892 | return 1; | |
893 | } | |
eb60ceac CM |
894 | t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]); |
895 | left = &t->leaf; | |
be0e5c09 CM |
896 | free_space = leaf_free_space(left); |
897 | if (free_space < data_size + sizeof(struct item)) { | |
eb60ceac | 898 | tree_block_release(root, t); |
be0e5c09 CM |
899 | return 1; |
900 | } | |
02217ed2 CM |
901 | |
902 | /* cow and double check */ | |
903 | btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t); | |
904 | left = &t->leaf; | |
905 | free_space = leaf_free_space(left); | |
906 | if (free_space < data_size + sizeof(struct item)) { | |
907 | tree_block_release(root, t); | |
908 | return 1; | |
909 | } | |
910 | ||
be0e5c09 CM |
911 | for (i = 0; i < right->header.nritems; i++) { |
912 | item = right->items + i; | |
913 | if (path->slots[0] == i) | |
914 | push_space += data_size + sizeof(*item); | |
915 | if (item->size + sizeof(*item) + push_space > free_space) | |
916 | break; | |
917 | push_items++; | |
918 | push_space += item->size + sizeof(*item); | |
919 | } | |
920 | if (push_items == 0) { | |
eb60ceac | 921 | tree_block_release(root, t); |
be0e5c09 CM |
922 | return 1; |
923 | } | |
924 | /* push data from right to left */ | |
925 | memcpy(left->items + left->header.nritems, | |
926 | right->items, push_items * sizeof(struct item)); | |
927 | push_space = LEAF_DATA_SIZE - right->items[push_items -1].offset; | |
928 | memcpy(left->data + leaf_data_end(left) - push_space, | |
929 | right->data + right->items[push_items - 1].offset, | |
930 | push_space); | |
931 | old_left_nritems = left->header.nritems; | |
eb60ceac CM |
932 | BUG_ON(old_left_nritems < 0); |
933 | ||
be0e5c09 CM |
934 | for(i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
935 | left->items[i].offset -= LEAF_DATA_SIZE - | |
936 | left->items[old_left_nritems -1].offset; | |
937 | } | |
938 | left->header.nritems += push_items; | |
939 | ||
940 | /* fixup right node */ | |
941 | push_space = right->items[push_items-1].offset - leaf_data_end(right); | |
942 | memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + | |
943 | leaf_data_end(right), push_space); | |
944 | memmove(right->items, right->items + push_items, | |
945 | (right->header.nritems - push_items) * sizeof(struct item)); | |
946 | right->header.nritems -= push_items; | |
947 | push_space = LEAF_DATA_SIZE; | |
eb60ceac | 948 | |
be0e5c09 CM |
949 | for (i = 0; i < right->header.nritems; i++) { |
950 | right->items[i].offset = push_space - right->items[i].size; | |
951 | push_space = right->items[i].offset; | |
952 | } | |
eb60ceac | 953 | |
02217ed2 CM |
954 | BUG_ON(list_empty(&t->dirty)); |
955 | BUG_ON(list_empty(&right_buf->dirty)); | |
eb60ceac | 956 | |
aa5d6bed CM |
957 | wret = fixup_low_keys(root, path, &right->items[0].key, 1); |
958 | if (wret) | |
959 | ret = wret; | |
be0e5c09 CM |
960 | |
961 | /* then fixup the leaf pointer in the path */ | |
962 | if (path->slots[0] < push_items) { | |
963 | path->slots[0] += old_left_nritems; | |
eb60ceac CM |
964 | tree_block_release(root, path->nodes[0]); |
965 | path->nodes[0] = t; | |
be0e5c09 CM |
966 | path->slots[1] -= 1; |
967 | } else { | |
eb60ceac | 968 | tree_block_release(root, t); |
be0e5c09 CM |
969 | path->slots[0] -= push_items; |
970 | } | |
eb60ceac | 971 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 972 | return ret; |
be0e5c09 CM |
973 | } |
974 | ||
74123bd7 CM |
975 | /* |
976 | * split the path's leaf in two, making sure there is at least data_size | |
977 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
978 | * |
979 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 980 | */ |
aa5d6bed CM |
981 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, |
982 | int data_size) | |
be0e5c09 | 983 | { |
aa5d6bed CM |
984 | struct tree_buffer *l_buf; |
985 | struct leaf *l; | |
eb60ceac CM |
986 | int nritems; |
987 | int mid; | |
988 | int slot; | |
be0e5c09 | 989 | struct leaf *right; |
eb60ceac | 990 | struct tree_buffer *right_buffer; |
be0e5c09 CM |
991 | int space_needed = data_size + sizeof(struct item); |
992 | int data_copy_size; | |
993 | int rt_data_off; | |
994 | int i; | |
995 | int ret; | |
aa5d6bed CM |
996 | int wret; |
997 | ||
aa5d6bed CM |
998 | l_buf = path->nodes[0]; |
999 | l = &l_buf->leaf; | |
1000 | ||
1001 | /* did the pushes work? */ | |
1002 | if (leaf_free_space(l) >= sizeof(struct item) + data_size) | |
1003 | return 0; | |
1004 | ||
5c680ed6 CM |
1005 | if (!path->nodes[1]) { |
1006 | ret = insert_new_root(root, path, 1); | |
1007 | if (ret) | |
1008 | return ret; | |
1009 | } | |
eb60ceac CM |
1010 | slot = path->slots[0]; |
1011 | nritems = l->header.nritems; | |
1012 | mid = (nritems + 1)/ 2; | |
eb60ceac CM |
1013 | right_buffer = alloc_free_block(root); |
1014 | BUG_ON(!right_buffer); | |
1015 | BUG_ON(mid == nritems); | |
1016 | right = &right_buffer->leaf; | |
be0e5c09 CM |
1017 | memset(right, 0, sizeof(*right)); |
1018 | if (mid <= slot) { | |
97571fd0 | 1019 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1020 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
1021 | LEAF_DATA_SIZE) | |
1022 | BUG(); | |
1023 | } else { | |
97571fd0 | 1024 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1025 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
1026 | LEAF_DATA_SIZE) | |
1027 | BUG(); | |
1028 | } | |
1029 | right->header.nritems = nritems - mid; | |
eb60ceac CM |
1030 | right->header.blocknr = right_buffer->blocknr; |
1031 | right->header.flags = node_level(0); | |
cfaa7295 | 1032 | right->header.parentid = root->node->node.header.parentid; |
be0e5c09 CM |
1033 | data_copy_size = l->items[mid].offset + l->items[mid].size - |
1034 | leaf_data_end(l); | |
1035 | memcpy(right->items, l->items + mid, | |
1036 | (nritems - mid) * sizeof(struct item)); | |
1037 | memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, | |
1038 | l->data + leaf_data_end(l), data_copy_size); | |
1039 | rt_data_off = LEAF_DATA_SIZE - | |
1040 | (l->items[mid].offset + l->items[mid].size); | |
74123bd7 CM |
1041 | |
1042 | for (i = 0; i < right->header.nritems; i++) | |
be0e5c09 | 1043 | right->items[i].offset += rt_data_off; |
74123bd7 | 1044 | |
be0e5c09 | 1045 | l->header.nritems = mid; |
aa5d6bed CM |
1046 | ret = 0; |
1047 | wret = insert_ptr(root, path, &right->items[0].key, | |
5c680ed6 | 1048 | right_buffer->blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1049 | if (wret) |
1050 | ret = wret; | |
02217ed2 CM |
1051 | BUG_ON(list_empty(&right_buffer->dirty)); |
1052 | BUG_ON(list_empty(&l_buf->dirty)); | |
eb60ceac | 1053 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1054 | if (mid <= slot) { |
eb60ceac CM |
1055 | tree_block_release(root, path->nodes[0]); |
1056 | path->nodes[0] = right_buffer; | |
be0e5c09 CM |
1057 | path->slots[0] -= mid; |
1058 | path->slots[1] += 1; | |
eb60ceac CM |
1059 | } else |
1060 | tree_block_release(root, right_buffer); | |
1061 | BUG_ON(path->slots[0] < 0); | |
be0e5c09 CM |
1062 | return ret; |
1063 | } | |
1064 | ||
74123bd7 CM |
1065 | /* |
1066 | * Given a key and some data, insert an item into the tree. | |
1067 | * This does all the path init required, making room in the tree if needed. | |
1068 | */ | |
be0e5c09 CM |
1069 | int insert_item(struct ctree_root *root, struct key *key, |
1070 | void *data, int data_size) | |
1071 | { | |
aa5d6bed | 1072 | int ret = 0; |
be0e5c09 | 1073 | int slot; |
eb60ceac | 1074 | int slot_orig; |
be0e5c09 | 1075 | struct leaf *leaf; |
eb60ceac | 1076 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1077 | unsigned int nritems; |
1078 | unsigned int data_end; | |
1079 | struct ctree_path path; | |
1080 | ||
74123bd7 | 1081 | /* create a root if there isn't one */ |
5c680ed6 | 1082 | if (!root->node) |
cfaa7295 | 1083 | BUG(); |
be0e5c09 | 1084 | init_path(&path); |
02217ed2 | 1085 | ret = search_slot(root, key, &path, data_size, 1); |
eb60ceac CM |
1086 | if (ret == 0) { |
1087 | release_path(root, &path); | |
f0930a37 | 1088 | return -EEXIST; |
aa5d6bed | 1089 | } |
ed2ff2cb CM |
1090 | if (ret < 0) |
1091 | goto out; | |
be0e5c09 | 1092 | |
eb60ceac CM |
1093 | slot_orig = path.slots[0]; |
1094 | leaf_buf = path.nodes[0]; | |
1095 | leaf = &leaf_buf->leaf; | |
74123bd7 | 1096 | |
be0e5c09 CM |
1097 | nritems = leaf->header.nritems; |
1098 | data_end = leaf_data_end(leaf); | |
eb60ceac | 1099 | |
be0e5c09 CM |
1100 | if (leaf_free_space(leaf) < sizeof(struct item) + data_size) |
1101 | BUG(); | |
1102 | ||
1103 | slot = path.slots[0]; | |
eb60ceac | 1104 | BUG_ON(slot < 0); |
be0e5c09 CM |
1105 | if (slot != nritems) { |
1106 | int i; | |
1107 | unsigned int old_data = leaf->items[slot].offset + | |
1108 | leaf->items[slot].size; | |
1109 | ||
1110 | /* | |
1111 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1112 | */ | |
1113 | /* first correct the data pointers */ | |
1114 | for (i = slot; i < nritems; i++) | |
1115 | leaf->items[i].offset -= data_size; | |
1116 | ||
1117 | /* shift the items */ | |
1118 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
1119 | (nritems - slot) * sizeof(struct item)); | |
1120 | ||
1121 | /* shift the data */ | |
1122 | memmove(leaf->data + data_end - data_size, leaf->data + | |
1123 | data_end, old_data - data_end); | |
1124 | data_end = old_data; | |
1125 | } | |
74123bd7 | 1126 | /* copy the new data in */ |
be0e5c09 CM |
1127 | memcpy(&leaf->items[slot].key, key, sizeof(struct key)); |
1128 | leaf->items[slot].offset = data_end - data_size; | |
1129 | leaf->items[slot].size = data_size; | |
1130 | memcpy(leaf->data + data_end - data_size, data, data_size); | |
1131 | leaf->header.nritems += 1; | |
aa5d6bed CM |
1132 | |
1133 | ret = 0; | |
8e19f2cd | 1134 | if (slot == 0) |
aa5d6bed CM |
1135 | ret = fixup_low_keys(root, &path, key, 1); |
1136 | ||
02217ed2 | 1137 | BUG_ON(list_empty(&leaf_buf->dirty)); |
be0e5c09 CM |
1138 | if (leaf_free_space(leaf) < 0) |
1139 | BUG(); | |
bb803951 | 1140 | check_leaf(&path, 0); |
ed2ff2cb | 1141 | out: |
eb60ceac | 1142 | release_path(root, &path); |
aa5d6bed | 1143 | return ret; |
be0e5c09 CM |
1144 | } |
1145 | ||
74123bd7 | 1146 | /* |
5de08d7d | 1147 | * delete the pointer from a given node. |
74123bd7 CM |
1148 | * |
1149 | * If the delete empties a node, the node is removed from the tree, | |
1150 | * continuing all the way the root if required. The root is converted into | |
1151 | * a leaf if all the nodes are emptied. | |
1152 | */ | |
bb803951 CM |
1153 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, |
1154 | int slot) | |
be0e5c09 | 1155 | { |
be0e5c09 | 1156 | struct node *node; |
bb803951 | 1157 | struct tree_buffer *parent = path->nodes[level]; |
be0e5c09 | 1158 | int nritems; |
aa5d6bed | 1159 | int ret = 0; |
bb803951 | 1160 | int wret; |
be0e5c09 | 1161 | |
bb803951 CM |
1162 | node = &parent->node; |
1163 | nritems = node->header.nritems; | |
bb803951 CM |
1164 | if (slot != nritems -1) { |
1165 | memmove(node->keys + slot, node->keys + slot + 1, | |
1166 | sizeof(struct key) * (nritems - slot - 1)); | |
1167 | memmove(node->blockptrs + slot, | |
1168 | node->blockptrs + slot + 1, | |
1169 | sizeof(u64) * (nritems - slot - 1)); | |
1170 | } | |
1171 | node->header.nritems--; | |
1172 | if (node->header.nritems == 0 && parent == root->node) { | |
1173 | BUG_ON(node_level(root->node->node.header.flags) != 1); | |
1174 | /* just turn the root into a leaf and break */ | |
1175 | root->node->node.header.flags = node_level(0); | |
1176 | } else if (slot == 0) { | |
1177 | wret = fixup_low_keys(root, path, node->keys, level + 1); | |
0f70abe2 CM |
1178 | if (wret) |
1179 | ret = wret; | |
be0e5c09 | 1180 | } |
02217ed2 | 1181 | BUG_ON(list_empty(&parent->dirty)); |
aa5d6bed | 1182 | return ret; |
be0e5c09 CM |
1183 | } |
1184 | ||
74123bd7 CM |
1185 | /* |
1186 | * delete the item at the leaf level in path. If that empties | |
1187 | * the leaf, remove it from the tree | |
1188 | */ | |
4920c9ac | 1189 | int del_item(struct ctree_root *root, struct ctree_path *path) |
be0e5c09 | 1190 | { |
be0e5c09 CM |
1191 | int slot; |
1192 | struct leaf *leaf; | |
eb60ceac | 1193 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1194 | int doff; |
1195 | int dsize; | |
aa5d6bed CM |
1196 | int ret = 0; |
1197 | int wret; | |
be0e5c09 | 1198 | |
eb60ceac CM |
1199 | leaf_buf = path->nodes[0]; |
1200 | leaf = &leaf_buf->leaf; | |
4920c9ac | 1201 | slot = path->slots[0]; |
be0e5c09 CM |
1202 | doff = leaf->items[slot].offset; |
1203 | dsize = leaf->items[slot].size; | |
1204 | ||
1205 | if (slot != leaf->header.nritems - 1) { | |
1206 | int i; | |
1207 | int data_end = leaf_data_end(leaf); | |
1208 | memmove(leaf->data + data_end + dsize, | |
1209 | leaf->data + data_end, | |
1210 | doff - data_end); | |
1211 | for (i = slot + 1; i < leaf->header.nritems; i++) | |
1212 | leaf->items[i].offset += dsize; | |
1213 | memmove(leaf->items + slot, leaf->items + slot + 1, | |
1214 | sizeof(struct item) * | |
1215 | (leaf->header.nritems - slot - 1)); | |
1216 | } | |
1217 | leaf->header.nritems -= 1; | |
74123bd7 | 1218 | /* delete the leaf if we've emptied it */ |
be0e5c09 | 1219 | if (leaf->header.nritems == 0) { |
eb60ceac CM |
1220 | if (leaf_buf == root->node) { |
1221 | leaf->header.flags = node_level(0); | |
02217ed2 | 1222 | BUG_ON(list_empty(&leaf_buf->dirty)); |
9a8dd150 | 1223 | } else { |
ed2ff2cb | 1224 | clean_tree_block(root, leaf_buf); |
bb803951 | 1225 | wret = del_ptr(root, path, 1, path->slots[1]); |
aa5d6bed CM |
1226 | if (wret) |
1227 | ret = wret; | |
0f70abe2 CM |
1228 | wret = free_extent(root, leaf_buf->blocknr, 1); |
1229 | if (wret) | |
1230 | ret = wret; | |
9a8dd150 | 1231 | } |
be0e5c09 | 1232 | } else { |
5de08d7d | 1233 | int used = leaf_space_used(leaf, 0, leaf->header.nritems); |
aa5d6bed CM |
1234 | if (slot == 0) { |
1235 | wret = fixup_low_keys(root, path, | |
1236 | &leaf->items[0].key, 1); | |
1237 | if (wret) | |
1238 | ret = wret; | |
1239 | } | |
02217ed2 | 1240 | BUG_ON(list_empty(&leaf_buf->dirty)); |
aa5d6bed | 1241 | |
74123bd7 | 1242 | /* delete the leaf if it is mostly empty */ |
5de08d7d | 1243 | if (used < LEAF_DATA_SIZE / 3) { |
be0e5c09 CM |
1244 | /* push_leaf_left fixes the path. |
1245 | * make sure the path still points to our leaf | |
1246 | * for possible call to del_ptr below | |
1247 | */ | |
4920c9ac | 1248 | slot = path->slots[1]; |
eb60ceac | 1249 | leaf_buf->count++; |
aa5d6bed CM |
1250 | wret = push_leaf_left(root, path, 1); |
1251 | if (wret < 0) | |
1252 | ret = wret; | |
f0930a37 CM |
1253 | if (path->nodes[0] == leaf_buf && |
1254 | leaf->header.nritems) { | |
aa5d6bed CM |
1255 | wret = push_leaf_right(root, path, 1); |
1256 | if (wret < 0) | |
1257 | ret = wret; | |
1258 | } | |
be0e5c09 | 1259 | if (leaf->header.nritems == 0) { |
5de08d7d | 1260 | u64 blocknr = leaf_buf->blocknr; |
ed2ff2cb | 1261 | clean_tree_block(root, leaf_buf); |
bb803951 | 1262 | wret = del_ptr(root, path, 1, slot); |
aa5d6bed CM |
1263 | if (wret) |
1264 | ret = wret; | |
5de08d7d | 1265 | tree_block_release(root, leaf_buf); |
0f70abe2 CM |
1266 | wret = free_extent(root, blocknr, 1); |
1267 | if (wret) | |
1268 | ret = wret; | |
5de08d7d CM |
1269 | } else { |
1270 | tree_block_release(root, leaf_buf); | |
be0e5c09 CM |
1271 | } |
1272 | } | |
1273 | } | |
aa5d6bed | 1274 | return ret; |
be0e5c09 CM |
1275 | } |
1276 | ||
97571fd0 CM |
1277 | /* |
1278 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1279 | * returns 0 if it found something or 1 if there are no greater leaves. |
1280 | * returns < 0 on io errors. | |
97571fd0 | 1281 | */ |
d97e63b6 CM |
1282 | int next_leaf(struct ctree_root *root, struct ctree_path *path) |
1283 | { | |
1284 | int slot; | |
1285 | int level = 1; | |
1286 | u64 blocknr; | |
1287 | struct tree_buffer *c; | |
cfaa7295 | 1288 | struct tree_buffer *next = NULL; |
d97e63b6 CM |
1289 | |
1290 | while(level < MAX_LEVEL) { | |
1291 | if (!path->nodes[level]) | |
0f70abe2 | 1292 | return 1; |
d97e63b6 CM |
1293 | slot = path->slots[level] + 1; |
1294 | c = path->nodes[level]; | |
1295 | if (slot >= c->node.header.nritems) { | |
1296 | level++; | |
1297 | continue; | |
1298 | } | |
1299 | blocknr = c->node.blockptrs[slot]; | |
cfaa7295 CM |
1300 | if (next) |
1301 | tree_block_release(root, next); | |
d97e63b6 CM |
1302 | next = read_tree_block(root, blocknr); |
1303 | break; | |
1304 | } | |
1305 | path->slots[level] = slot; | |
1306 | while(1) { | |
1307 | level--; | |
1308 | c = path->nodes[level]; | |
1309 | tree_block_release(root, c); | |
1310 | path->nodes[level] = next; | |
1311 | path->slots[level] = 0; | |
1312 | if (!level) | |
1313 | break; | |
1314 | next = read_tree_block(root, next->node.blockptrs[0]); | |
1315 | } | |
1316 | return 0; | |
1317 | } | |
1318 | ||
02217ed2 | 1319 |