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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)); | |
7518a238 | 51 | btrfs_set_header_blocknr(&cow->node.header, cow->blocknr); |
02217ed2 | 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 | { | |
7518a238 | 76 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 77 | if (nr == 0) |
d97e63b6 | 78 | return sizeof(leaf->data); |
0783fcfc | 79 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
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); | |
7518a238 | 90 | int nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 CM |
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 | */ | |
e2fa7227 | 98 | int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 99 | { |
e2fa7227 CM |
100 | struct btrfs_key k1; |
101 | ||
102 | btrfs_disk_key_to_cpu(&k1, disk); | |
103 | ||
104 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 105 | return 1; |
e2fa7227 | 106 | if (k1.objectid < k2->objectid) |
be0e5c09 | 107 | return -1; |
e2fa7227 | 108 | if (k1.flags > k2->flags) |
be0e5c09 | 109 | return 1; |
e2fa7227 | 110 | if (k1.flags < k2->flags) |
be0e5c09 | 111 | return -1; |
e2fa7227 | 112 | if (k1.offset > k2->offset) |
be0e5c09 | 113 | return 1; |
e2fa7227 | 114 | if (k1.offset < k2->offset) |
be0e5c09 CM |
115 | return -1; |
116 | return 0; | |
117 | } | |
74123bd7 | 118 | |
aa5d6bed CM |
119 | int check_node(struct ctree_path *path, int level) |
120 | { | |
121 | int i; | |
122 | struct node *parent = NULL; | |
123 | struct node *node = &path->nodes[level]->node; | |
124 | int parent_slot; | |
7518a238 | 125 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
126 | |
127 | if (path->nodes[level + 1]) | |
128 | parent = &path->nodes[level + 1]->node; | |
129 | parent_slot = path->slots[level + 1]; | |
7518a238 CM |
130 | BUG_ON(nritems == 0); |
131 | if (parent) { | |
e2fa7227 | 132 | struct btrfs_disk_key *parent_key; |
aa5d6bed | 133 | parent_key = &parent->keys[parent_slot]; |
e2fa7227 CM |
134 | BUG_ON(memcmp(parent_key, node->keys, |
135 | sizeof(struct btrfs_disk_key))); | |
7518a238 CM |
136 | BUG_ON(parent->blockptrs[parent_slot] != |
137 | btrfs_header_blocknr(&node->header)); | |
aa5d6bed | 138 | } |
7518a238 CM |
139 | BUG_ON(nritems > NODEPTRS_PER_BLOCK); |
140 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { | |
e2fa7227 CM |
141 | struct btrfs_key cpukey; |
142 | btrfs_disk_key_to_cpu(&cpukey, &node->keys[i + 1]); | |
143 | BUG_ON(comp_keys(&node->keys[i], &cpukey) >= 0); | |
aa5d6bed CM |
144 | } |
145 | return 0; | |
146 | } | |
147 | ||
148 | int check_leaf(struct ctree_path *path, int level) | |
149 | { | |
150 | int i; | |
151 | struct leaf *leaf = &path->nodes[level]->leaf; | |
152 | struct node *parent = NULL; | |
153 | int parent_slot; | |
7518a238 | 154 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
155 | |
156 | if (path->nodes[level + 1]) | |
157 | parent = &path->nodes[level + 1]->node; | |
158 | parent_slot = path->slots[level + 1]; | |
7518a238 CM |
159 | BUG_ON(leaf_free_space(leaf) < 0); |
160 | ||
161 | if (nritems == 0) | |
162 | return 0; | |
163 | ||
164 | if (parent) { | |
e2fa7227 | 165 | struct btrfs_disk_key *parent_key; |
aa5d6bed CM |
166 | parent_key = &parent->keys[parent_slot]; |
167 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, | |
e2fa7227 | 168 | sizeof(struct btrfs_disk_key))); |
7518a238 CM |
169 | BUG_ON(parent->blockptrs[parent_slot] != |
170 | btrfs_header_blocknr(&leaf->header)); | |
aa5d6bed | 171 | } |
7518a238 | 172 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 CM |
173 | struct btrfs_key cpukey; |
174 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key); | |
aa5d6bed | 175 | BUG_ON(comp_keys(&leaf->items[i].key, |
e2fa7227 | 176 | &cpukey) >= 0); |
0783fcfc CM |
177 | BUG_ON(btrfs_item_offset(leaf->items + i) != |
178 | btrfs_item_end(leaf->items + i + 1)); | |
aa5d6bed | 179 | if (i == 0) { |
0783fcfc CM |
180 | BUG_ON(btrfs_item_offset(leaf->items + i) + |
181 | btrfs_item_size(leaf->items + i) != | |
182 | LEAF_DATA_SIZE); | |
aa5d6bed CM |
183 | } |
184 | } | |
aa5d6bed CM |
185 | return 0; |
186 | } | |
187 | ||
188 | int check_block(struct ctree_path *path, int level) | |
189 | { | |
190 | if (level == 0) | |
191 | return check_leaf(path, level); | |
192 | return check_node(path, level); | |
193 | } | |
194 | ||
74123bd7 CM |
195 | /* |
196 | * search for key in the array p. items p are item_size apart | |
197 | * and there are 'max' items in p | |
198 | * the slot in the array is returned via slot, and it points to | |
199 | * the place where you would insert key if it is not found in | |
200 | * the array. | |
201 | * | |
202 | * slot may point to max if the key is bigger than all of the keys | |
203 | */ | |
e2fa7227 | 204 | int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
205 | int max, int *slot) |
206 | { | |
207 | int low = 0; | |
208 | int high = max; | |
209 | int mid; | |
210 | int ret; | |
e2fa7227 | 211 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
212 | |
213 | while(low < high) { | |
214 | mid = (low + high) / 2; | |
e2fa7227 | 215 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
216 | ret = comp_keys(tmp, key); |
217 | ||
218 | if (ret < 0) | |
219 | low = mid + 1; | |
220 | else if (ret > 0) | |
221 | high = mid; | |
222 | else { | |
223 | *slot = mid; | |
224 | return 0; | |
225 | } | |
226 | } | |
227 | *slot = low; | |
228 | return 1; | |
229 | } | |
230 | ||
97571fd0 CM |
231 | /* |
232 | * simple bin_search frontend that does the right thing for | |
233 | * leaves vs nodes | |
234 | */ | |
e2fa7227 | 235 | int bin_search(struct node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 236 | { |
7518a238 | 237 | if (btrfs_is_leaf(c)) { |
be0e5c09 | 238 | struct leaf *l = (struct leaf *)c; |
0783fcfc CM |
239 | return generic_bin_search((void *)l->items, |
240 | sizeof(struct btrfs_item), | |
7518a238 CM |
241 | key, btrfs_header_nritems(&c->header), |
242 | slot); | |
be0e5c09 | 243 | } else { |
e2fa7227 CM |
244 | return generic_bin_search((void *)c->keys, |
245 | sizeof(struct btrfs_disk_key), | |
7518a238 CM |
246 | key, btrfs_header_nritems(&c->header), |
247 | slot); | |
be0e5c09 CM |
248 | } |
249 | return -1; | |
250 | } | |
251 | ||
bb803951 CM |
252 | struct tree_buffer *read_node_slot(struct ctree_root *root, |
253 | struct tree_buffer *parent_buf, | |
254 | int slot) | |
255 | { | |
256 | struct node *node = &parent_buf->node; | |
257 | if (slot < 0) | |
258 | return NULL; | |
7518a238 | 259 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 CM |
260 | return NULL; |
261 | return read_tree_block(root, node->blockptrs[slot]); | |
262 | } | |
263 | ||
264 | static int balance_level(struct ctree_root *root, struct ctree_path *path, | |
265 | int level) | |
266 | { | |
267 | struct tree_buffer *right_buf; | |
268 | struct tree_buffer *mid_buf; | |
269 | struct tree_buffer *left_buf; | |
270 | struct tree_buffer *parent_buf = NULL; | |
271 | struct node *right = NULL; | |
272 | struct node *mid; | |
273 | struct node *left = NULL; | |
274 | struct node *parent = NULL; | |
275 | int ret = 0; | |
276 | int wret; | |
277 | int pslot; | |
bb803951 | 278 | int orig_slot = path->slots[level]; |
79f95c82 | 279 | u64 orig_ptr; |
bb803951 CM |
280 | |
281 | if (level == 0) | |
282 | return 0; | |
283 | ||
284 | mid_buf = path->nodes[level]; | |
285 | mid = &mid_buf->node; | |
79f95c82 CM |
286 | orig_ptr = mid->blockptrs[orig_slot]; |
287 | ||
bb803951 CM |
288 | if (level < MAX_LEVEL - 1) |
289 | parent_buf = path->nodes[level + 1]; | |
290 | pslot = path->slots[level + 1]; | |
291 | ||
292 | if (!parent_buf) { | |
293 | struct tree_buffer *child; | |
294 | u64 blocknr = mid_buf->blocknr; | |
295 | ||
7518a238 | 296 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
297 | return 0; |
298 | ||
299 | /* promote the child to a root */ | |
300 | child = read_node_slot(root, mid_buf, 0); | |
301 | BUG_ON(!child); | |
302 | root->node = child; | |
303 | path->nodes[level] = NULL; | |
304 | /* once for the path */ | |
305 | tree_block_release(root, mid_buf); | |
306 | /* once for the root ptr */ | |
307 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 308 | clean_tree_block(root, mid_buf); |
bb803951 CM |
309 | return free_extent(root, blocknr, 1); |
310 | } | |
311 | parent = &parent_buf->node; | |
312 | ||
7518a238 | 313 | if (btrfs_header_nritems(&mid->header) > NODEPTRS_PER_BLOCK / 4) |
bb803951 CM |
314 | return 0; |
315 | ||
bb803951 CM |
316 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
317 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
318 | |
319 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 320 | if (left_buf) { |
02217ed2 CM |
321 | btrfs_cow_block(root, left_buf, parent_buf, |
322 | pslot - 1, &left_buf); | |
bb803951 | 323 | left = &left_buf->node; |
7518a238 | 324 | orig_slot += btrfs_header_nritems(&left->header); |
79f95c82 CM |
325 | wret = push_node_left(root, left_buf, mid_buf); |
326 | if (wret < 0) | |
327 | ret = wret; | |
bb803951 | 328 | } |
79f95c82 CM |
329 | |
330 | /* | |
331 | * then try to empty the right most buffer into the middle | |
332 | */ | |
bb803951 | 333 | if (right_buf) { |
02217ed2 CM |
334 | btrfs_cow_block(root, right_buf, parent_buf, |
335 | pslot + 1, &right_buf); | |
79f95c82 CM |
336 | right = &right_buf->node; |
337 | wret = push_node_left(root, mid_buf, right_buf); | |
338 | if (wret < 0) | |
339 | ret = wret; | |
7518a238 | 340 | if (btrfs_header_nritems(&right->header) == 0) { |
bb803951 CM |
341 | u64 blocknr = right_buf->blocknr; |
342 | tree_block_release(root, right_buf); | |
ed2ff2cb | 343 | clean_tree_block(root, right_buf); |
bb803951 CM |
344 | right_buf = NULL; |
345 | right = NULL; | |
346 | wret = del_ptr(root, path, level + 1, pslot + 1); | |
347 | if (wret) | |
348 | ret = wret; | |
349 | wret = free_extent(root, blocknr, 1); | |
350 | if (wret) | |
351 | ret = wret; | |
352 | } else { | |
353 | memcpy(parent->keys + pslot + 1, right->keys, | |
e2fa7227 | 354 | sizeof(struct btrfs_disk_key)); |
02217ed2 | 355 | BUG_ON(list_empty(&parent_buf->dirty)); |
bb803951 CM |
356 | } |
357 | } | |
7518a238 | 358 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
359 | /* |
360 | * we're not allowed to leave a node with one item in the | |
361 | * tree during a delete. A deletion from lower in the tree | |
362 | * could try to delete the only pointer in this node. | |
363 | * So, pull some keys from the left. | |
364 | * There has to be a left pointer at this point because | |
365 | * otherwise we would have pulled some pointers from the | |
366 | * right | |
367 | */ | |
368 | BUG_ON(!left_buf); | |
369 | wret = balance_node_right(root, mid_buf, left_buf); | |
370 | if (wret < 0) | |
371 | ret = wret; | |
372 | BUG_ON(wret == 1); | |
373 | } | |
7518a238 | 374 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 375 | /* we've managed to empty the middle node, drop it */ |
bb803951 CM |
376 | u64 blocknr = mid_buf->blocknr; |
377 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 378 | clean_tree_block(root, mid_buf); |
bb803951 CM |
379 | mid_buf = NULL; |
380 | mid = NULL; | |
381 | wret = del_ptr(root, path, level + 1, pslot); | |
382 | if (wret) | |
383 | ret = wret; | |
384 | wret = free_extent(root, blocknr, 1); | |
385 | if (wret) | |
386 | ret = wret; | |
79f95c82 CM |
387 | } else { |
388 | /* update the parent key to reflect our changes */ | |
e2fa7227 CM |
389 | memcpy(parent->keys + pslot, mid->keys, |
390 | sizeof(struct btrfs_disk_key)); | |
02217ed2 | 391 | BUG_ON(list_empty(&parent_buf->dirty)); |
79f95c82 | 392 | } |
bb803951 | 393 | |
79f95c82 | 394 | /* update the path */ |
bb803951 | 395 | if (left_buf) { |
7518a238 | 396 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
bb803951 CM |
397 | left_buf->count++; // released below |
398 | path->nodes[level] = left_buf; | |
399 | path->slots[level + 1] -= 1; | |
400 | path->slots[level] = orig_slot; | |
401 | if (mid_buf) | |
402 | tree_block_release(root, mid_buf); | |
403 | } else { | |
7518a238 | 404 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
405 | path->slots[level] = orig_slot; |
406 | } | |
407 | } | |
79f95c82 CM |
408 | /* double check we haven't messed things up */ |
409 | check_block(path, level); | |
410 | if (orig_ptr != path->nodes[level]->node.blockptrs[path->slots[level]]) | |
411 | BUG(); | |
bb803951 CM |
412 | |
413 | if (right_buf) | |
414 | tree_block_release(root, right_buf); | |
415 | if (left_buf) | |
416 | tree_block_release(root, left_buf); | |
bb803951 CM |
417 | return ret; |
418 | } | |
419 | ||
74123bd7 CM |
420 | /* |
421 | * look for key in the tree. path is filled in with nodes along the way | |
422 | * if key is found, we return zero and you can find the item in the leaf | |
423 | * level of the path (level 0) | |
424 | * | |
425 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
426 | * be inserted, and 1 is returned. If there are other errors during the |
427 | * search a negative error number is returned. | |
97571fd0 CM |
428 | * |
429 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
430 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
431 | * possible) | |
74123bd7 | 432 | */ |
e2fa7227 | 433 | int search_slot(struct ctree_root *root, struct btrfs_key *key, |
02217ed2 | 434 | struct ctree_path *p, int ins_len, int cow) |
be0e5c09 | 435 | { |
bb803951 | 436 | struct tree_buffer *b; |
02217ed2 | 437 | struct tree_buffer *cow_buf; |
eb60ceac | 438 | struct node *c; |
be0e5c09 CM |
439 | int slot; |
440 | int ret; | |
441 | int level; | |
5c680ed6 | 442 | |
bb803951 CM |
443 | again: |
444 | b = root->node; | |
eb60ceac CM |
445 | b->count++; |
446 | while (b) { | |
7518a238 | 447 | level = btrfs_header_level(&b->node.header); |
02217ed2 CM |
448 | if (cow) { |
449 | int wret; | |
450 | wret = btrfs_cow_block(root, b, p->nodes[level + 1], | |
451 | p->slots[level + 1], &cow_buf); | |
452 | b = cow_buf; | |
453 | } | |
454 | BUG_ON(!cow && ins_len); | |
eb60ceac | 455 | c = &b->node; |
eb60ceac | 456 | p->nodes[level] = b; |
aa5d6bed CM |
457 | ret = check_block(p, level); |
458 | if (ret) | |
459 | return -1; | |
be0e5c09 | 460 | ret = bin_search(c, key, &slot); |
7518a238 | 461 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
462 | if (ret && slot > 0) |
463 | slot -= 1; | |
464 | p->slots[level] = slot; | |
7518a238 CM |
465 | if (ins_len > 0 && btrfs_header_nritems(&c->header) == |
466 | NODEPTRS_PER_BLOCK) { | |
5c680ed6 CM |
467 | int sret = split_node(root, p, level); |
468 | BUG_ON(sret > 0); | |
469 | if (sret) | |
470 | return sret; | |
471 | b = p->nodes[level]; | |
472 | c = &b->node; | |
473 | slot = p->slots[level]; | |
bb803951 CM |
474 | } else if (ins_len < 0) { |
475 | int sret = balance_level(root, p, level); | |
476 | if (sret) | |
477 | return sret; | |
478 | b = p->nodes[level]; | |
479 | if (!b) | |
480 | goto again; | |
481 | c = &b->node; | |
482 | slot = p->slots[level]; | |
7518a238 | 483 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 484 | } |
eb60ceac | 485 | b = read_tree_block(root, c->blockptrs[slot]); |
be0e5c09 | 486 | } else { |
5c680ed6 | 487 | struct leaf *l = (struct leaf *)c; |
be0e5c09 | 488 | p->slots[level] = slot; |
5de08d7d | 489 | if (ins_len > 0 && leaf_free_space(l) < |
0783fcfc | 490 | sizeof(struct btrfs_item) + ins_len) { |
5c680ed6 CM |
491 | int sret = split_leaf(root, p, ins_len); |
492 | BUG_ON(sret > 0); | |
493 | if (sret) | |
494 | return sret; | |
495 | } | |
bb803951 | 496 | BUG_ON(root->node->count == 1); |
be0e5c09 CM |
497 | return ret; |
498 | } | |
499 | } | |
bb803951 | 500 | BUG_ON(root->node->count == 1); |
aa5d6bed | 501 | return 1; |
be0e5c09 CM |
502 | } |
503 | ||
74123bd7 CM |
504 | /* |
505 | * adjust the pointers going up the tree, starting at level | |
506 | * making sure the right key of each node is points to 'key'. | |
507 | * This is used after shifting pointers to the left, so it stops | |
508 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
509 | * higher levels | |
aa5d6bed CM |
510 | * |
511 | * If this fails to write a tree block, it returns -1, but continues | |
512 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 513 | */ |
aa5d6bed | 514 | static int fixup_low_keys(struct ctree_root *root, |
e2fa7227 | 515 | struct ctree_path *path, struct btrfs_disk_key *key, |
eb60ceac | 516 | int level) |
be0e5c09 CM |
517 | { |
518 | int i; | |
aa5d6bed | 519 | int ret = 0; |
be0e5c09 | 520 | for (i = level; i < MAX_LEVEL; i++) { |
eb60ceac | 521 | struct node *t; |
be0e5c09 | 522 | int tslot = path->slots[i]; |
eb60ceac | 523 | if (!path->nodes[i]) |
be0e5c09 | 524 | break; |
eb60ceac | 525 | t = &path->nodes[i]->node; |
be0e5c09 | 526 | memcpy(t->keys + tslot, key, sizeof(*key)); |
02217ed2 | 527 | BUG_ON(list_empty(&path->nodes[i]->dirty)); |
be0e5c09 CM |
528 | if (tslot != 0) |
529 | break; | |
530 | } | |
aa5d6bed | 531 | return ret; |
be0e5c09 CM |
532 | } |
533 | ||
74123bd7 CM |
534 | /* |
535 | * try to push data from one node into the next node left in the | |
79f95c82 | 536 | * tree. |
aa5d6bed CM |
537 | * |
538 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
539 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 540 | */ |
bb803951 CM |
541 | static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, |
542 | struct tree_buffer *src_buf) | |
be0e5c09 | 543 | { |
bb803951 CM |
544 | struct node *src = &src_buf->node; |
545 | struct node *dst = &dst_buf->node; | |
be0e5c09 | 546 | int push_items = 0; |
bb803951 CM |
547 | int src_nritems; |
548 | int dst_nritems; | |
aa5d6bed | 549 | int ret = 0; |
be0e5c09 | 550 | |
7518a238 CM |
551 | src_nritems = btrfs_header_nritems(&src->header); |
552 | dst_nritems = btrfs_header_nritems(&dst->header); | |
bb803951 | 553 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; |
eb60ceac | 554 | if (push_items <= 0) { |
be0e5c09 | 555 | return 1; |
eb60ceac | 556 | } |
be0e5c09 | 557 | |
bb803951 | 558 | if (src_nritems < push_items) |
79f95c82 CM |
559 | push_items = src_nritems; |
560 | ||
bb803951 | 561 | memcpy(dst->keys + dst_nritems, src->keys, |
e2fa7227 | 562 | push_items * sizeof(struct btrfs_disk_key)); |
bb803951 | 563 | memcpy(dst->blockptrs + dst_nritems, src->blockptrs, |
be0e5c09 | 564 | push_items * sizeof(u64)); |
bb803951 CM |
565 | if (push_items < src_nritems) { |
566 | memmove(src->keys, src->keys + push_items, | |
e2fa7227 CM |
567 | (src_nritems - push_items) * |
568 | sizeof(struct btrfs_disk_key)); | |
bb803951 CM |
569 | memmove(src->blockptrs, src->blockptrs + push_items, |
570 | (src_nritems - push_items) * sizeof(u64)); | |
571 | } | |
7518a238 CM |
572 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
573 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
02217ed2 CM |
574 | BUG_ON(list_empty(&src_buf->dirty)); |
575 | BUG_ON(list_empty(&dst_buf->dirty)); | |
79f95c82 CM |
576 | return ret; |
577 | } | |
578 | ||
579 | /* | |
580 | * try to push data from one node into the next node right in the | |
581 | * tree. | |
582 | * | |
583 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
584 | * error, and > 0 if there was no room in the right hand block. | |
585 | * | |
586 | * this will only push up to 1/2 the contents of the left node over | |
587 | */ | |
588 | static int balance_node_right(struct ctree_root *root, | |
589 | struct tree_buffer *dst_buf, | |
590 | struct tree_buffer *src_buf) | |
591 | { | |
592 | struct node *src = &src_buf->node; | |
593 | struct node *dst = &dst_buf->node; | |
594 | int push_items = 0; | |
595 | int max_push; | |
596 | int src_nritems; | |
597 | int dst_nritems; | |
598 | int ret = 0; | |
79f95c82 | 599 | |
7518a238 CM |
600 | src_nritems = btrfs_header_nritems(&src->header); |
601 | dst_nritems = btrfs_header_nritems(&dst->header); | |
79f95c82 CM |
602 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; |
603 | if (push_items <= 0) { | |
604 | return 1; | |
605 | } | |
606 | ||
607 | max_push = src_nritems / 2 + 1; | |
608 | /* don't try to empty the node */ | |
609 | if (max_push > src_nritems) | |
610 | return 1; | |
611 | if (max_push < push_items) | |
612 | push_items = max_push; | |
613 | ||
614 | memmove(dst->keys + push_items, dst->keys, | |
e2fa7227 | 615 | dst_nritems * sizeof(struct btrfs_disk_key)); |
79f95c82 CM |
616 | memmove(dst->blockptrs + push_items, dst->blockptrs, |
617 | dst_nritems * sizeof(u64)); | |
618 | memcpy(dst->keys, src->keys + src_nritems - push_items, | |
e2fa7227 | 619 | push_items * sizeof(struct btrfs_disk_key)); |
79f95c82 CM |
620 | memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, |
621 | push_items * sizeof(u64)); | |
622 | ||
7518a238 CM |
623 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
624 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 625 | |
02217ed2 CM |
626 | BUG_ON(list_empty(&src_buf->dirty)); |
627 | BUG_ON(list_empty(&dst_buf->dirty)); | |
aa5d6bed | 628 | return ret; |
be0e5c09 CM |
629 | } |
630 | ||
97571fd0 CM |
631 | /* |
632 | * helper function to insert a new root level in the tree. | |
633 | * A new node is allocated, and a single item is inserted to | |
634 | * point to the existing root | |
aa5d6bed CM |
635 | * |
636 | * returns zero on success or < 0 on failure. | |
97571fd0 | 637 | */ |
5de08d7d CM |
638 | static int insert_new_root(struct ctree_root *root, |
639 | struct ctree_path *path, int level) | |
5c680ed6 CM |
640 | { |
641 | struct tree_buffer *t; | |
642 | struct node *lower; | |
643 | struct node *c; | |
e2fa7227 | 644 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
645 | |
646 | BUG_ON(path->nodes[level]); | |
647 | BUG_ON(path->nodes[level-1] != root->node); | |
648 | ||
649 | t = alloc_free_block(root); | |
650 | c = &t->node; | |
651 | memset(c, 0, sizeof(c)); | |
7518a238 CM |
652 | btrfs_set_header_nritems(&c->header, 1); |
653 | btrfs_set_header_level(&c->header, level); | |
654 | btrfs_set_header_blocknr(&c->header, t->blocknr); | |
655 | btrfs_set_header_parentid(&c->header, | |
656 | btrfs_header_parentid(&root->node->node.header)); | |
5c680ed6 | 657 | lower = &path->nodes[level-1]->node; |
7518a238 | 658 | if (btrfs_is_leaf(lower)) |
5c680ed6 CM |
659 | lower_key = &((struct leaf *)lower)->items[0].key; |
660 | else | |
661 | lower_key = lower->keys; | |
e2fa7227 | 662 | memcpy(c->keys, lower_key, sizeof(struct btrfs_disk_key)); |
5c680ed6 CM |
663 | c->blockptrs[0] = path->nodes[level-1]->blocknr; |
664 | /* the super has an extra ref to root->node */ | |
665 | tree_block_release(root, root->node); | |
666 | root->node = t; | |
667 | t->count++; | |
5c680ed6 CM |
668 | path->nodes[level] = t; |
669 | path->slots[level] = 0; | |
670 | return 0; | |
671 | } | |
672 | ||
74123bd7 CM |
673 | /* |
674 | * worker function to insert a single pointer in a node. | |
675 | * the node should have enough room for the pointer already | |
97571fd0 | 676 | * |
74123bd7 CM |
677 | * slot and level indicate where you want the key to go, and |
678 | * blocknr is the block the key points to. | |
aa5d6bed CM |
679 | * |
680 | * returns zero on success and < 0 on any error | |
74123bd7 | 681 | */ |
aa5d6bed | 682 | static int insert_ptr(struct ctree_root *root, |
e2fa7227 | 683 | struct ctree_path *path, struct btrfs_disk_key *key, |
74123bd7 CM |
684 | u64 blocknr, int slot, int level) |
685 | { | |
74123bd7 | 686 | struct node *lower; |
74123bd7 | 687 | int nritems; |
5c680ed6 CM |
688 | |
689 | BUG_ON(!path->nodes[level]); | |
74123bd7 | 690 | lower = &path->nodes[level]->node; |
7518a238 | 691 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
692 | if (slot > nritems) |
693 | BUG(); | |
694 | if (nritems == NODEPTRS_PER_BLOCK) | |
695 | BUG(); | |
696 | if (slot != nritems) { | |
697 | memmove(lower->keys + slot + 1, lower->keys + slot, | |
e2fa7227 | 698 | (nritems - slot) * sizeof(struct btrfs_disk_key)); |
74123bd7 CM |
699 | memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, |
700 | (nritems - slot) * sizeof(u64)); | |
701 | } | |
e2fa7227 | 702 | memcpy(lower->keys + slot, key, sizeof(struct btrfs_disk_key)); |
74123bd7 | 703 | lower->blockptrs[slot] = blocknr; |
7518a238 | 704 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
74123bd7 CM |
705 | if (lower->keys[1].objectid == 0) |
706 | BUG(); | |
02217ed2 | 707 | BUG_ON(list_empty(&path->nodes[level]->dirty)); |
74123bd7 CM |
708 | return 0; |
709 | } | |
710 | ||
97571fd0 CM |
711 | /* |
712 | * split the node at the specified level in path in two. | |
713 | * The path is corrected to point to the appropriate node after the split | |
714 | * | |
715 | * Before splitting this tries to make some room in the node by pushing | |
716 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
717 | * |
718 | * returns 0 on success and < 0 on failure | |
97571fd0 | 719 | */ |
aa5d6bed CM |
720 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
721 | int level) | |
be0e5c09 | 722 | { |
5c680ed6 CM |
723 | struct tree_buffer *t; |
724 | struct node *c; | |
725 | struct tree_buffer *split_buffer; | |
726 | struct node *split; | |
be0e5c09 | 727 | int mid; |
5c680ed6 | 728 | int ret; |
aa5d6bed | 729 | int wret; |
7518a238 | 730 | u32 c_nritems; |
eb60ceac | 731 | |
5c680ed6 CM |
732 | t = path->nodes[level]; |
733 | c = &t->node; | |
734 | if (t == root->node) { | |
735 | /* trying to split the root, lets make a new one */ | |
736 | ret = insert_new_root(root, path, level + 1); | |
737 | if (ret) | |
738 | return ret; | |
be0e5c09 | 739 | } |
7518a238 | 740 | c_nritems = btrfs_header_nritems(&c->header); |
5c680ed6 CM |
741 | split_buffer = alloc_free_block(root); |
742 | split = &split_buffer->node; | |
7518a238 CM |
743 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
744 | btrfs_set_header_blocknr(&split->header, split_buffer->blocknr); | |
745 | btrfs_set_header_parentid(&split->header, | |
746 | btrfs_header_parentid(&root->node->node.header)); | |
747 | mid = (c_nritems + 1) / 2; | |
5c680ed6 | 748 | memcpy(split->keys, c->keys + mid, |
e2fa7227 | 749 | (c_nritems - mid) * sizeof(struct btrfs_disk_key)); |
5c680ed6 | 750 | memcpy(split->blockptrs, c->blockptrs + mid, |
7518a238 CM |
751 | (c_nritems - mid) * sizeof(u64)); |
752 | btrfs_set_header_nritems(&split->header, c_nritems - mid); | |
753 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
754 | ret = 0; |
755 | ||
02217ed2 | 756 | BUG_ON(list_empty(&t->dirty)); |
aa5d6bed CM |
757 | wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, |
758 | path->slots[level + 1] + 1, level + 1); | |
759 | if (wret) | |
760 | ret = wret; | |
761 | ||
5de08d7d | 762 | if (path->slots[level] >= mid) { |
5c680ed6 CM |
763 | path->slots[level] -= mid; |
764 | tree_block_release(root, t); | |
765 | path->nodes[level] = split_buffer; | |
766 | path->slots[level + 1] += 1; | |
767 | } else { | |
768 | tree_block_release(root, split_buffer); | |
be0e5c09 | 769 | } |
aa5d6bed | 770 | return ret; |
be0e5c09 CM |
771 | } |
772 | ||
74123bd7 CM |
773 | /* |
774 | * how many bytes are required to store the items in a leaf. start | |
775 | * and nr indicate which items in the leaf to check. This totals up the | |
776 | * space used both by the item structs and the item data | |
777 | */ | |
aa5d6bed | 778 | static int leaf_space_used(struct leaf *l, int start, int nr) |
be0e5c09 CM |
779 | { |
780 | int data_len; | |
781 | int end = start + nr - 1; | |
782 | ||
783 | if (!nr) | |
784 | return 0; | |
0783fcfc CM |
785 | data_len = btrfs_item_end(l->items + start); |
786 | data_len = data_len - btrfs_item_offset(l->items + end); | |
787 | data_len += sizeof(struct btrfs_item) * nr; | |
be0e5c09 CM |
788 | return data_len; |
789 | } | |
790 | ||
00ec4c51 CM |
791 | /* |
792 | * push some data in the path leaf to the right, trying to free up at | |
793 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
794 | * |
795 | * returns 1 if the push failed because the other node didn't have enough | |
796 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 797 | */ |
aa5d6bed CM |
798 | static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, |
799 | int data_size) | |
00ec4c51 CM |
800 | { |
801 | struct tree_buffer *left_buf = path->nodes[0]; | |
802 | struct leaf *left = &left_buf->leaf; | |
803 | struct leaf *right; | |
804 | struct tree_buffer *right_buf; | |
805 | struct tree_buffer *upper; | |
806 | int slot; | |
807 | int i; | |
808 | int free_space; | |
809 | int push_space = 0; | |
810 | int push_items = 0; | |
0783fcfc | 811 | struct btrfs_item *item; |
7518a238 CM |
812 | u32 left_nritems; |
813 | u32 right_nritems; | |
00ec4c51 CM |
814 | |
815 | slot = path->slots[1]; | |
816 | if (!path->nodes[1]) { | |
817 | return 1; | |
818 | } | |
819 | upper = path->nodes[1]; | |
7518a238 | 820 | if (slot >= btrfs_header_nritems(&upper->node.header) - 1) { |
00ec4c51 CM |
821 | return 1; |
822 | } | |
823 | right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]); | |
824 | right = &right_buf->leaf; | |
825 | free_space = leaf_free_space(right); | |
0783fcfc | 826 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
00ec4c51 CM |
827 | tree_block_release(root, right_buf); |
828 | return 1; | |
829 | } | |
02217ed2 CM |
830 | /* cow and double check */ |
831 | btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf); | |
832 | right = &right_buf->leaf; | |
833 | free_space = leaf_free_space(right); | |
0783fcfc | 834 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
02217ed2 CM |
835 | tree_block_release(root, right_buf); |
836 | return 1; | |
837 | } | |
838 | ||
7518a238 CM |
839 | left_nritems = btrfs_header_nritems(&left->header); |
840 | for (i = left_nritems - 1; i >= 0; i--) { | |
00ec4c51 CM |
841 | item = left->items + i; |
842 | if (path->slots[0] == i) | |
843 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
844 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
845 | free_space) | |
00ec4c51 CM |
846 | break; |
847 | push_items++; | |
0783fcfc | 848 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
849 | } |
850 | if (push_items == 0) { | |
851 | tree_block_release(root, right_buf); | |
852 | return 1; | |
853 | } | |
7518a238 | 854 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 855 | /* push left to right */ |
0783fcfc | 856 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
00ec4c51 CM |
857 | push_space -= leaf_data_end(left); |
858 | /* make room in the right data area */ | |
859 | memmove(right->data + leaf_data_end(right) - push_space, | |
860 | right->data + leaf_data_end(right), | |
861 | LEAF_DATA_SIZE - leaf_data_end(right)); | |
862 | /* copy from the left data area */ | |
863 | memcpy(right->data + LEAF_DATA_SIZE - push_space, | |
864 | left->data + leaf_data_end(left), | |
865 | push_space); | |
866 | memmove(right->items + push_items, right->items, | |
0783fcfc | 867 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 868 | /* copy the items from left to right */ |
7518a238 | 869 | memcpy(right->items, left->items + left_nritems - push_items, |
0783fcfc | 870 | push_items * sizeof(struct btrfs_item)); |
00ec4c51 CM |
871 | |
872 | /* update the item pointers */ | |
7518a238 CM |
873 | right_nritems += push_items; |
874 | btrfs_set_header_nritems(&right->header, right_nritems); | |
00ec4c51 | 875 | push_space = LEAF_DATA_SIZE; |
7518a238 | 876 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
877 | btrfs_set_item_offset(right->items + i, push_space - |
878 | btrfs_item_size(right->items + i)); | |
879 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 880 | } |
7518a238 CM |
881 | left_nritems -= push_items; |
882 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 883 | |
02217ed2 CM |
884 | BUG_ON(list_empty(&left_buf->dirty)); |
885 | BUG_ON(list_empty(&right_buf->dirty)); | |
00ec4c51 | 886 | memcpy(upper->node.keys + slot + 1, |
e2fa7227 | 887 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
02217ed2 CM |
888 | BUG_ON(list_empty(&upper->dirty)); |
889 | ||
00ec4c51 | 890 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
891 | if (path->slots[0] >= left_nritems) { |
892 | path->slots[0] -= left_nritems; | |
00ec4c51 CM |
893 | tree_block_release(root, path->nodes[0]); |
894 | path->nodes[0] = right_buf; | |
895 | path->slots[1] += 1; | |
896 | } else { | |
897 | tree_block_release(root, right_buf); | |
898 | } | |
899 | return 0; | |
900 | } | |
74123bd7 CM |
901 | /* |
902 | * push some data in the path leaf to the left, trying to free up at | |
903 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
904 | */ | |
aa5d6bed CM |
905 | static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, |
906 | int data_size) | |
be0e5c09 | 907 | { |
eb60ceac CM |
908 | struct tree_buffer *right_buf = path->nodes[0]; |
909 | struct leaf *right = &right_buf->leaf; | |
910 | struct tree_buffer *t; | |
be0e5c09 CM |
911 | struct leaf *left; |
912 | int slot; | |
913 | int i; | |
914 | int free_space; | |
915 | int push_space = 0; | |
916 | int push_items = 0; | |
0783fcfc | 917 | struct btrfs_item *item; |
7518a238 | 918 | u32 old_left_nritems; |
aa5d6bed CM |
919 | int ret = 0; |
920 | int wret; | |
be0e5c09 CM |
921 | |
922 | slot = path->slots[1]; | |
923 | if (slot == 0) { | |
924 | return 1; | |
925 | } | |
926 | if (!path->nodes[1]) { | |
927 | return 1; | |
928 | } | |
eb60ceac CM |
929 | t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]); |
930 | left = &t->leaf; | |
be0e5c09 | 931 | free_space = leaf_free_space(left); |
0783fcfc | 932 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
eb60ceac | 933 | tree_block_release(root, t); |
be0e5c09 CM |
934 | return 1; |
935 | } | |
02217ed2 CM |
936 | |
937 | /* cow and double check */ | |
938 | btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t); | |
939 | left = &t->leaf; | |
940 | free_space = leaf_free_space(left); | |
0783fcfc | 941 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
02217ed2 CM |
942 | tree_block_release(root, t); |
943 | return 1; | |
944 | } | |
945 | ||
7518a238 | 946 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
be0e5c09 CM |
947 | item = right->items + i; |
948 | if (path->slots[0] == i) | |
949 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
950 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
951 | free_space) | |
be0e5c09 CM |
952 | break; |
953 | push_items++; | |
0783fcfc | 954 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
955 | } |
956 | if (push_items == 0) { | |
eb60ceac | 957 | tree_block_release(root, t); |
be0e5c09 CM |
958 | return 1; |
959 | } | |
960 | /* push data from right to left */ | |
7518a238 | 961 | memcpy(left->items + btrfs_header_nritems(&left->header), |
0783fcfc CM |
962 | right->items, push_items * sizeof(struct btrfs_item)); |
963 | push_space = LEAF_DATA_SIZE - | |
964 | btrfs_item_offset(right->items + push_items -1); | |
be0e5c09 | 965 | memcpy(left->data + leaf_data_end(left) - push_space, |
0783fcfc | 966 | right->data + btrfs_item_offset(right->items + push_items - 1), |
be0e5c09 | 967 | push_space); |
7518a238 | 968 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
969 | BUG_ON(old_left_nritems < 0); |
970 | ||
0783fcfc CM |
971 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
972 | u16 ioff = btrfs_item_offset(left->items + i); | |
973 | btrfs_set_item_offset(left->items + i, ioff - (LEAF_DATA_SIZE - | |
974 | btrfs_item_offset(left->items + | |
975 | old_left_nritems - 1))); | |
be0e5c09 | 976 | } |
7518a238 | 977 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
978 | |
979 | /* fixup right node */ | |
0783fcfc CM |
980 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
981 | leaf_data_end(right); | |
be0e5c09 CM |
982 | memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + |
983 | leaf_data_end(right), push_space); | |
984 | memmove(right->items, right->items + push_items, | |
7518a238 | 985 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 986 | sizeof(struct btrfs_item)); |
7518a238 CM |
987 | btrfs_set_header_nritems(&right->header, |
988 | btrfs_header_nritems(&right->header) - | |
989 | push_items); | |
be0e5c09 | 990 | push_space = LEAF_DATA_SIZE; |
eb60ceac | 991 | |
7518a238 | 992 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
993 | btrfs_set_item_offset(right->items + i, push_space - |
994 | btrfs_item_size(right->items + i)); | |
995 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 996 | } |
eb60ceac | 997 | |
02217ed2 CM |
998 | BUG_ON(list_empty(&t->dirty)); |
999 | BUG_ON(list_empty(&right_buf->dirty)); | |
eb60ceac | 1000 | |
aa5d6bed CM |
1001 | wret = fixup_low_keys(root, path, &right->items[0].key, 1); |
1002 | if (wret) | |
1003 | ret = wret; | |
be0e5c09 CM |
1004 | |
1005 | /* then fixup the leaf pointer in the path */ | |
1006 | if (path->slots[0] < push_items) { | |
1007 | path->slots[0] += old_left_nritems; | |
eb60ceac CM |
1008 | tree_block_release(root, path->nodes[0]); |
1009 | path->nodes[0] = t; | |
be0e5c09 CM |
1010 | path->slots[1] -= 1; |
1011 | } else { | |
eb60ceac | 1012 | tree_block_release(root, t); |
be0e5c09 CM |
1013 | path->slots[0] -= push_items; |
1014 | } | |
eb60ceac | 1015 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 1016 | return ret; |
be0e5c09 CM |
1017 | } |
1018 | ||
74123bd7 CM |
1019 | /* |
1020 | * split the path's leaf in two, making sure there is at least data_size | |
1021 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1022 | * |
1023 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1024 | */ |
aa5d6bed CM |
1025 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, |
1026 | int data_size) | |
be0e5c09 | 1027 | { |
aa5d6bed CM |
1028 | struct tree_buffer *l_buf; |
1029 | struct leaf *l; | |
7518a238 | 1030 | u32 nritems; |
eb60ceac CM |
1031 | int mid; |
1032 | int slot; | |
be0e5c09 | 1033 | struct leaf *right; |
eb60ceac | 1034 | struct tree_buffer *right_buffer; |
0783fcfc | 1035 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1036 | int data_copy_size; |
1037 | int rt_data_off; | |
1038 | int i; | |
1039 | int ret; | |
aa5d6bed CM |
1040 | int wret; |
1041 | ||
aa5d6bed CM |
1042 | l_buf = path->nodes[0]; |
1043 | l = &l_buf->leaf; | |
1044 | ||
1045 | /* did the pushes work? */ | |
0783fcfc | 1046 | if (leaf_free_space(l) >= sizeof(struct btrfs_item) + data_size) |
aa5d6bed CM |
1047 | return 0; |
1048 | ||
5c680ed6 CM |
1049 | if (!path->nodes[1]) { |
1050 | ret = insert_new_root(root, path, 1); | |
1051 | if (ret) | |
1052 | return ret; | |
1053 | } | |
eb60ceac | 1054 | slot = path->slots[0]; |
7518a238 | 1055 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1056 | mid = (nritems + 1)/ 2; |
eb60ceac CM |
1057 | right_buffer = alloc_free_block(root); |
1058 | BUG_ON(!right_buffer); | |
1059 | BUG_ON(mid == nritems); | |
1060 | right = &right_buffer->leaf; | |
be0e5c09 CM |
1061 | memset(right, 0, sizeof(*right)); |
1062 | if (mid <= slot) { | |
97571fd0 | 1063 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1064 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
1065 | LEAF_DATA_SIZE) | |
1066 | BUG(); | |
1067 | } else { | |
97571fd0 | 1068 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1069 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
1070 | LEAF_DATA_SIZE) | |
1071 | BUG(); | |
1072 | } | |
7518a238 CM |
1073 | btrfs_set_header_nritems(&right->header, nritems - mid); |
1074 | btrfs_set_header_blocknr(&right->header, right_buffer->blocknr); | |
1075 | btrfs_set_header_level(&right->header, 0); | |
1076 | btrfs_set_header_parentid(&right->header, | |
1077 | btrfs_header_parentid(&root->node->node.header)); | |
0783fcfc | 1078 | data_copy_size = btrfs_item_end(l->items + mid) - leaf_data_end(l); |
be0e5c09 | 1079 | memcpy(right->items, l->items + mid, |
0783fcfc | 1080 | (nritems - mid) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
1081 | memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, |
1082 | l->data + leaf_data_end(l), data_copy_size); | |
0783fcfc | 1083 | rt_data_off = LEAF_DATA_SIZE - btrfs_item_end(l->items + mid); |
74123bd7 | 1084 | |
0783fcfc CM |
1085 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
1086 | u16 ioff = btrfs_item_offset(right->items + i); | |
1087 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); | |
1088 | } | |
74123bd7 | 1089 | |
7518a238 | 1090 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed CM |
1091 | ret = 0; |
1092 | wret = insert_ptr(root, path, &right->items[0].key, | |
5c680ed6 | 1093 | right_buffer->blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1094 | if (wret) |
1095 | ret = wret; | |
02217ed2 CM |
1096 | BUG_ON(list_empty(&right_buffer->dirty)); |
1097 | BUG_ON(list_empty(&l_buf->dirty)); | |
eb60ceac | 1098 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1099 | if (mid <= slot) { |
eb60ceac CM |
1100 | tree_block_release(root, path->nodes[0]); |
1101 | path->nodes[0] = right_buffer; | |
be0e5c09 CM |
1102 | path->slots[0] -= mid; |
1103 | path->slots[1] += 1; | |
eb60ceac CM |
1104 | } else |
1105 | tree_block_release(root, right_buffer); | |
1106 | BUG_ON(path->slots[0] < 0); | |
be0e5c09 CM |
1107 | return ret; |
1108 | } | |
1109 | ||
74123bd7 CM |
1110 | /* |
1111 | * Given a key and some data, insert an item into the tree. | |
1112 | * This does all the path init required, making room in the tree if needed. | |
1113 | */ | |
e2fa7227 | 1114 | int insert_item(struct ctree_root *root, struct btrfs_key *cpu_key, |
be0e5c09 CM |
1115 | void *data, int data_size) |
1116 | { | |
aa5d6bed | 1117 | int ret = 0; |
be0e5c09 | 1118 | int slot; |
eb60ceac | 1119 | int slot_orig; |
be0e5c09 | 1120 | struct leaf *leaf; |
eb60ceac | 1121 | struct tree_buffer *leaf_buf; |
7518a238 | 1122 | u32 nritems; |
be0e5c09 CM |
1123 | unsigned int data_end; |
1124 | struct ctree_path path; | |
e2fa7227 CM |
1125 | struct btrfs_disk_key disk_key; |
1126 | ||
1127 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1128 | |
74123bd7 | 1129 | /* create a root if there isn't one */ |
5c680ed6 | 1130 | if (!root->node) |
cfaa7295 | 1131 | BUG(); |
be0e5c09 | 1132 | init_path(&path); |
e2fa7227 | 1133 | ret = search_slot(root, cpu_key, &path, data_size, 1); |
eb60ceac CM |
1134 | if (ret == 0) { |
1135 | release_path(root, &path); | |
f0930a37 | 1136 | return -EEXIST; |
aa5d6bed | 1137 | } |
ed2ff2cb CM |
1138 | if (ret < 0) |
1139 | goto out; | |
be0e5c09 | 1140 | |
eb60ceac CM |
1141 | slot_orig = path.slots[0]; |
1142 | leaf_buf = path.nodes[0]; | |
1143 | leaf = &leaf_buf->leaf; | |
74123bd7 | 1144 | |
7518a238 | 1145 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1146 | data_end = leaf_data_end(leaf); |
eb60ceac | 1147 | |
0783fcfc | 1148 | if (leaf_free_space(leaf) < sizeof(struct btrfs_item) + data_size) |
be0e5c09 CM |
1149 | BUG(); |
1150 | ||
1151 | slot = path.slots[0]; | |
eb60ceac | 1152 | BUG_ON(slot < 0); |
be0e5c09 CM |
1153 | if (slot != nritems) { |
1154 | int i; | |
0783fcfc | 1155 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1156 | |
1157 | /* | |
1158 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1159 | */ | |
1160 | /* first correct the data pointers */ | |
0783fcfc CM |
1161 | for (i = slot; i < nritems; i++) { |
1162 | u16 ioff = btrfs_item_offset(leaf->items + i); | |
1163 | btrfs_set_item_offset(leaf->items + i, | |
1164 | ioff - data_size); | |
1165 | } | |
be0e5c09 CM |
1166 | |
1167 | /* shift the items */ | |
1168 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
0783fcfc | 1169 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
1170 | |
1171 | /* shift the data */ | |
1172 | memmove(leaf->data + data_end - data_size, leaf->data + | |
1173 | data_end, old_data - data_end); | |
1174 | data_end = old_data; | |
1175 | } | |
74123bd7 | 1176 | /* copy the new data in */ |
e2fa7227 CM |
1177 | memcpy(&leaf->items[slot].key, &disk_key, |
1178 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1179 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1180 | btrfs_set_item_size(leaf->items + slot, data_size); | |
be0e5c09 | 1181 | memcpy(leaf->data + data_end - data_size, data, data_size); |
7518a238 | 1182 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
aa5d6bed CM |
1183 | |
1184 | ret = 0; | |
8e19f2cd | 1185 | if (slot == 0) |
e2fa7227 | 1186 | ret = fixup_low_keys(root, &path, &disk_key, 1); |
aa5d6bed | 1187 | |
02217ed2 | 1188 | BUG_ON(list_empty(&leaf_buf->dirty)); |
be0e5c09 CM |
1189 | if (leaf_free_space(leaf) < 0) |
1190 | BUG(); | |
bb803951 | 1191 | check_leaf(&path, 0); |
ed2ff2cb | 1192 | out: |
eb60ceac | 1193 | release_path(root, &path); |
aa5d6bed | 1194 | return ret; |
be0e5c09 CM |
1195 | } |
1196 | ||
74123bd7 | 1197 | /* |
5de08d7d | 1198 | * delete the pointer from a given node. |
74123bd7 CM |
1199 | * |
1200 | * If the delete empties a node, the node is removed from the tree, | |
1201 | * continuing all the way the root if required. The root is converted into | |
1202 | * a leaf if all the nodes are emptied. | |
1203 | */ | |
bb803951 CM |
1204 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, |
1205 | int slot) | |
be0e5c09 | 1206 | { |
be0e5c09 | 1207 | struct node *node; |
bb803951 | 1208 | struct tree_buffer *parent = path->nodes[level]; |
7518a238 | 1209 | u32 nritems; |
aa5d6bed | 1210 | int ret = 0; |
bb803951 | 1211 | int wret; |
be0e5c09 | 1212 | |
bb803951 | 1213 | node = &parent->node; |
7518a238 | 1214 | nritems = btrfs_header_nritems(&node->header); |
bb803951 CM |
1215 | if (slot != nritems -1) { |
1216 | memmove(node->keys + slot, node->keys + slot + 1, | |
e2fa7227 | 1217 | sizeof(struct btrfs_disk_key) * (nritems - slot - 1)); |
bb803951 CM |
1218 | memmove(node->blockptrs + slot, |
1219 | node->blockptrs + slot + 1, | |
1220 | sizeof(u64) * (nritems - slot - 1)); | |
1221 | } | |
7518a238 CM |
1222 | nritems--; |
1223 | btrfs_set_header_nritems(&node->header, nritems); | |
1224 | if (nritems == 0 && parent == root->node) { | |
1225 | BUG_ON(btrfs_header_level(&root->node->node.header) != 1); | |
bb803951 | 1226 | /* just turn the root into a leaf and break */ |
7518a238 | 1227 | btrfs_set_header_level(&root->node->node.header, 0); |
bb803951 CM |
1228 | } else if (slot == 0) { |
1229 | wret = fixup_low_keys(root, path, node->keys, level + 1); | |
0f70abe2 CM |
1230 | if (wret) |
1231 | ret = wret; | |
be0e5c09 | 1232 | } |
02217ed2 | 1233 | BUG_ON(list_empty(&parent->dirty)); |
aa5d6bed | 1234 | return ret; |
be0e5c09 CM |
1235 | } |
1236 | ||
74123bd7 CM |
1237 | /* |
1238 | * delete the item at the leaf level in path. If that empties | |
1239 | * the leaf, remove it from the tree | |
1240 | */ | |
4920c9ac | 1241 | int del_item(struct ctree_root *root, struct ctree_path *path) |
be0e5c09 | 1242 | { |
be0e5c09 CM |
1243 | int slot; |
1244 | struct leaf *leaf; | |
eb60ceac | 1245 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1246 | int doff; |
1247 | int dsize; | |
aa5d6bed CM |
1248 | int ret = 0; |
1249 | int wret; | |
7518a238 | 1250 | u32 nritems; |
be0e5c09 | 1251 | |
eb60ceac CM |
1252 | leaf_buf = path->nodes[0]; |
1253 | leaf = &leaf_buf->leaf; | |
4920c9ac | 1254 | slot = path->slots[0]; |
0783fcfc CM |
1255 | doff = btrfs_item_offset(leaf->items + slot); |
1256 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1257 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1258 | |
7518a238 | 1259 | if (slot != nritems - 1) { |
be0e5c09 CM |
1260 | int i; |
1261 | int data_end = leaf_data_end(leaf); | |
1262 | memmove(leaf->data + data_end + dsize, | |
1263 | leaf->data + data_end, | |
1264 | doff - data_end); | |
0783fcfc CM |
1265 | for (i = slot + 1; i < nritems; i++) { |
1266 | u16 ioff = btrfs_item_offset(leaf->items + i); | |
1267 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); | |
1268 | } | |
be0e5c09 | 1269 | memmove(leaf->items + slot, leaf->items + slot + 1, |
0783fcfc | 1270 | sizeof(struct btrfs_item) * |
7518a238 | 1271 | (nritems - slot - 1)); |
be0e5c09 | 1272 | } |
7518a238 CM |
1273 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1274 | nritems--; | |
74123bd7 | 1275 | /* delete the leaf if we've emptied it */ |
7518a238 | 1276 | if (nritems == 0) { |
eb60ceac | 1277 | if (leaf_buf == root->node) { |
7518a238 | 1278 | btrfs_set_header_level(&leaf->header, 0); |
02217ed2 | 1279 | BUG_ON(list_empty(&leaf_buf->dirty)); |
9a8dd150 | 1280 | } else { |
ed2ff2cb | 1281 | clean_tree_block(root, leaf_buf); |
bb803951 | 1282 | wret = del_ptr(root, path, 1, path->slots[1]); |
aa5d6bed CM |
1283 | if (wret) |
1284 | ret = wret; | |
0f70abe2 CM |
1285 | wret = free_extent(root, leaf_buf->blocknr, 1); |
1286 | if (wret) | |
1287 | ret = wret; | |
9a8dd150 | 1288 | } |
be0e5c09 | 1289 | } else { |
7518a238 | 1290 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed CM |
1291 | if (slot == 0) { |
1292 | wret = fixup_low_keys(root, path, | |
1293 | &leaf->items[0].key, 1); | |
1294 | if (wret) | |
1295 | ret = wret; | |
1296 | } | |
02217ed2 | 1297 | BUG_ON(list_empty(&leaf_buf->dirty)); |
aa5d6bed | 1298 | |
74123bd7 | 1299 | /* delete the leaf if it is mostly empty */ |
5de08d7d | 1300 | if (used < LEAF_DATA_SIZE / 3) { |
be0e5c09 CM |
1301 | /* push_leaf_left fixes the path. |
1302 | * make sure the path still points to our leaf | |
1303 | * for possible call to del_ptr below | |
1304 | */ | |
4920c9ac | 1305 | slot = path->slots[1]; |
eb60ceac | 1306 | leaf_buf->count++; |
aa5d6bed CM |
1307 | wret = push_leaf_left(root, path, 1); |
1308 | if (wret < 0) | |
1309 | ret = wret; | |
f0930a37 | 1310 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1311 | btrfs_header_nritems(&leaf->header)) { |
aa5d6bed CM |
1312 | wret = push_leaf_right(root, path, 1); |
1313 | if (wret < 0) | |
1314 | ret = wret; | |
1315 | } | |
7518a238 | 1316 | if (btrfs_header_nritems(&leaf->header) == 0) { |
5de08d7d | 1317 | u64 blocknr = leaf_buf->blocknr; |
ed2ff2cb | 1318 | clean_tree_block(root, leaf_buf); |
bb803951 | 1319 | wret = del_ptr(root, path, 1, slot); |
aa5d6bed CM |
1320 | if (wret) |
1321 | ret = wret; | |
5de08d7d | 1322 | tree_block_release(root, leaf_buf); |
0f70abe2 CM |
1323 | wret = free_extent(root, blocknr, 1); |
1324 | if (wret) | |
1325 | ret = wret; | |
5de08d7d CM |
1326 | } else { |
1327 | tree_block_release(root, leaf_buf); | |
be0e5c09 CM |
1328 | } |
1329 | } | |
1330 | } | |
aa5d6bed | 1331 | return ret; |
be0e5c09 CM |
1332 | } |
1333 | ||
97571fd0 CM |
1334 | /* |
1335 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1336 | * returns 0 if it found something or 1 if there are no greater leaves. |
1337 | * returns < 0 on io errors. | |
97571fd0 | 1338 | */ |
d97e63b6 CM |
1339 | int next_leaf(struct ctree_root *root, struct ctree_path *path) |
1340 | { | |
1341 | int slot; | |
1342 | int level = 1; | |
1343 | u64 blocknr; | |
1344 | struct tree_buffer *c; | |
cfaa7295 | 1345 | struct tree_buffer *next = NULL; |
d97e63b6 CM |
1346 | |
1347 | while(level < MAX_LEVEL) { | |
1348 | if (!path->nodes[level]) | |
0f70abe2 | 1349 | return 1; |
d97e63b6 CM |
1350 | slot = path->slots[level] + 1; |
1351 | c = path->nodes[level]; | |
7518a238 | 1352 | if (slot >= btrfs_header_nritems(&c->node.header)) { |
d97e63b6 CM |
1353 | level++; |
1354 | continue; | |
1355 | } | |
1356 | blocknr = c->node.blockptrs[slot]; | |
cfaa7295 CM |
1357 | if (next) |
1358 | tree_block_release(root, next); | |
d97e63b6 CM |
1359 | next = read_tree_block(root, blocknr); |
1360 | break; | |
1361 | } | |
1362 | path->slots[level] = slot; | |
1363 | while(1) { | |
1364 | level--; | |
1365 | c = path->nodes[level]; | |
1366 | tree_block_release(root, c); | |
1367 | path->nodes[level] = next; | |
1368 | path->slots[level] = 0; | |
1369 | if (!level) | |
1370 | break; | |
1371 | next = read_tree_block(root, next->node.blockptrs[0]); | |
1372 | } | |
1373 | return 0; | |
1374 | } | |
1375 | ||
02217ed2 | 1376 |