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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 { | |
1d4f8a0c CM |
61 | btrfs_set_node_blockptr(&parent->node, parent_slot, |
62 | cow->blocknr); | |
02217ed2 | 63 | BUG_ON(list_empty(&parent->dirty)); |
a28ec197 | 64 | free_extent(root, buf->blocknr, 1); |
02217ed2 CM |
65 | } |
66 | tree_block_release(root, buf); | |
67 | return 0; | |
68 | } | |
69 | ||
74123bd7 CM |
70 | /* |
71 | * The leaf data grows from end-to-front in the node. | |
72 | * this returns the address of the start of the last item, | |
73 | * which is the stop of the leaf data stack | |
74 | */ | |
be0e5c09 CM |
75 | static inline unsigned int leaf_data_end(struct leaf *leaf) |
76 | { | |
7518a238 | 77 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 78 | if (nr == 0) |
d97e63b6 | 79 | return sizeof(leaf->data); |
0783fcfc | 80 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
81 | } |
82 | ||
74123bd7 CM |
83 | /* |
84 | * The space between the end of the leaf items and | |
85 | * the start of the leaf data. IOW, how much room | |
86 | * the leaf has left for both items and data | |
87 | */ | |
5de08d7d | 88 | int leaf_free_space(struct leaf *leaf) |
be0e5c09 CM |
89 | { |
90 | int data_end = leaf_data_end(leaf); | |
7518a238 | 91 | int nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 CM |
92 | char *items_end = (char *)(leaf->items + nritems + 1); |
93 | return (char *)(leaf->data + data_end) - (char *)items_end; | |
94 | } | |
95 | ||
74123bd7 CM |
96 | /* |
97 | * compare two keys in a memcmp fashion | |
98 | */ | |
e2fa7227 | 99 | int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 100 | { |
e2fa7227 CM |
101 | struct btrfs_key k1; |
102 | ||
103 | btrfs_disk_key_to_cpu(&k1, disk); | |
104 | ||
105 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 106 | return 1; |
e2fa7227 | 107 | if (k1.objectid < k2->objectid) |
be0e5c09 | 108 | return -1; |
e2fa7227 | 109 | if (k1.flags > k2->flags) |
be0e5c09 | 110 | return 1; |
e2fa7227 | 111 | if (k1.flags < k2->flags) |
be0e5c09 | 112 | return -1; |
e2fa7227 | 113 | if (k1.offset > k2->offset) |
be0e5c09 | 114 | return 1; |
e2fa7227 | 115 | if (k1.offset < k2->offset) |
be0e5c09 CM |
116 | return -1; |
117 | return 0; | |
118 | } | |
74123bd7 | 119 | |
aa5d6bed CM |
120 | int check_node(struct ctree_path *path, int level) |
121 | { | |
122 | int i; | |
123 | struct node *parent = NULL; | |
124 | struct node *node = &path->nodes[level]->node; | |
125 | int parent_slot; | |
7518a238 | 126 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
127 | |
128 | if (path->nodes[level + 1]) | |
129 | parent = &path->nodes[level + 1]->node; | |
130 | parent_slot = path->slots[level + 1]; | |
7518a238 CM |
131 | BUG_ON(nritems == 0); |
132 | if (parent) { | |
e2fa7227 | 133 | struct btrfs_disk_key *parent_key; |
aa5d6bed | 134 | parent_key = &parent->keys[parent_slot]; |
e2fa7227 CM |
135 | BUG_ON(memcmp(parent_key, node->keys, |
136 | sizeof(struct btrfs_disk_key))); | |
1d4f8a0c | 137 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 138 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 139 | } |
7518a238 CM |
140 | BUG_ON(nritems > NODEPTRS_PER_BLOCK); |
141 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { | |
e2fa7227 CM |
142 | struct btrfs_key cpukey; |
143 | btrfs_disk_key_to_cpu(&cpukey, &node->keys[i + 1]); | |
144 | BUG_ON(comp_keys(&node->keys[i], &cpukey) >= 0); | |
aa5d6bed CM |
145 | } |
146 | return 0; | |
147 | } | |
148 | ||
149 | int check_leaf(struct ctree_path *path, int level) | |
150 | { | |
151 | int i; | |
152 | struct leaf *leaf = &path->nodes[level]->leaf; | |
153 | struct node *parent = NULL; | |
154 | int parent_slot; | |
7518a238 | 155 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
156 | |
157 | if (path->nodes[level + 1]) | |
158 | parent = &path->nodes[level + 1]->node; | |
159 | parent_slot = path->slots[level + 1]; | |
7518a238 CM |
160 | BUG_ON(leaf_free_space(leaf) < 0); |
161 | ||
162 | if (nritems == 0) | |
163 | return 0; | |
164 | ||
165 | if (parent) { | |
e2fa7227 | 166 | struct btrfs_disk_key *parent_key; |
aa5d6bed CM |
167 | parent_key = &parent->keys[parent_slot]; |
168 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, | |
e2fa7227 | 169 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 170 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 171 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 172 | } |
7518a238 | 173 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 CM |
174 | struct btrfs_key cpukey; |
175 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key); | |
aa5d6bed | 176 | BUG_ON(comp_keys(&leaf->items[i].key, |
e2fa7227 | 177 | &cpukey) >= 0); |
0783fcfc CM |
178 | BUG_ON(btrfs_item_offset(leaf->items + i) != |
179 | btrfs_item_end(leaf->items + i + 1)); | |
aa5d6bed | 180 | if (i == 0) { |
0783fcfc CM |
181 | BUG_ON(btrfs_item_offset(leaf->items + i) + |
182 | btrfs_item_size(leaf->items + i) != | |
183 | LEAF_DATA_SIZE); | |
aa5d6bed CM |
184 | } |
185 | } | |
aa5d6bed CM |
186 | return 0; |
187 | } | |
188 | ||
189 | int check_block(struct ctree_path *path, int level) | |
190 | { | |
191 | if (level == 0) | |
192 | return check_leaf(path, level); | |
193 | return check_node(path, level); | |
194 | } | |
195 | ||
74123bd7 CM |
196 | /* |
197 | * search for key in the array p. items p are item_size apart | |
198 | * and there are 'max' items in p | |
199 | * the slot in the array is returned via slot, and it points to | |
200 | * the place where you would insert key if it is not found in | |
201 | * the array. | |
202 | * | |
203 | * slot may point to max if the key is bigger than all of the keys | |
204 | */ | |
e2fa7227 | 205 | int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
206 | int max, int *slot) |
207 | { | |
208 | int low = 0; | |
209 | int high = max; | |
210 | int mid; | |
211 | int ret; | |
e2fa7227 | 212 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
213 | |
214 | while(low < high) { | |
215 | mid = (low + high) / 2; | |
e2fa7227 | 216 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
217 | ret = comp_keys(tmp, key); |
218 | ||
219 | if (ret < 0) | |
220 | low = mid + 1; | |
221 | else if (ret > 0) | |
222 | high = mid; | |
223 | else { | |
224 | *slot = mid; | |
225 | return 0; | |
226 | } | |
227 | } | |
228 | *slot = low; | |
229 | return 1; | |
230 | } | |
231 | ||
97571fd0 CM |
232 | /* |
233 | * simple bin_search frontend that does the right thing for | |
234 | * leaves vs nodes | |
235 | */ | |
e2fa7227 | 236 | int bin_search(struct node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 237 | { |
7518a238 | 238 | if (btrfs_is_leaf(c)) { |
be0e5c09 | 239 | struct leaf *l = (struct leaf *)c; |
0783fcfc CM |
240 | return generic_bin_search((void *)l->items, |
241 | sizeof(struct btrfs_item), | |
7518a238 CM |
242 | key, btrfs_header_nritems(&c->header), |
243 | slot); | |
be0e5c09 | 244 | } else { |
e2fa7227 CM |
245 | return generic_bin_search((void *)c->keys, |
246 | sizeof(struct btrfs_disk_key), | |
7518a238 CM |
247 | key, btrfs_header_nritems(&c->header), |
248 | slot); | |
be0e5c09 CM |
249 | } |
250 | return -1; | |
251 | } | |
252 | ||
bb803951 CM |
253 | struct tree_buffer *read_node_slot(struct ctree_root *root, |
254 | struct tree_buffer *parent_buf, | |
255 | int slot) | |
256 | { | |
257 | struct node *node = &parent_buf->node; | |
258 | if (slot < 0) | |
259 | return NULL; | |
7518a238 | 260 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 261 | return NULL; |
1d4f8a0c | 262 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
263 | } |
264 | ||
265 | static int balance_level(struct ctree_root *root, struct ctree_path *path, | |
266 | int level) | |
267 | { | |
268 | struct tree_buffer *right_buf; | |
269 | struct tree_buffer *mid_buf; | |
270 | struct tree_buffer *left_buf; | |
271 | struct tree_buffer *parent_buf = NULL; | |
272 | struct node *right = NULL; | |
273 | struct node *mid; | |
274 | struct node *left = NULL; | |
275 | struct node *parent = NULL; | |
276 | int ret = 0; | |
277 | int wret; | |
278 | int pslot; | |
bb803951 | 279 | int orig_slot = path->slots[level]; |
79f95c82 | 280 | u64 orig_ptr; |
bb803951 CM |
281 | |
282 | if (level == 0) | |
283 | return 0; | |
284 | ||
285 | mid_buf = path->nodes[level]; | |
286 | mid = &mid_buf->node; | |
1d4f8a0c | 287 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 288 | |
bb803951 CM |
289 | if (level < MAX_LEVEL - 1) |
290 | parent_buf = path->nodes[level + 1]; | |
291 | pslot = path->slots[level + 1]; | |
292 | ||
293 | if (!parent_buf) { | |
294 | struct tree_buffer *child; | |
295 | u64 blocknr = mid_buf->blocknr; | |
296 | ||
7518a238 | 297 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
298 | return 0; |
299 | ||
300 | /* promote the child to a root */ | |
301 | child = read_node_slot(root, mid_buf, 0); | |
302 | BUG_ON(!child); | |
303 | root->node = child; | |
304 | path->nodes[level] = NULL; | |
305 | /* once for the path */ | |
306 | tree_block_release(root, mid_buf); | |
307 | /* once for the root ptr */ | |
308 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 309 | clean_tree_block(root, mid_buf); |
bb803951 CM |
310 | return free_extent(root, blocknr, 1); |
311 | } | |
312 | parent = &parent_buf->node; | |
313 | ||
7518a238 | 314 | if (btrfs_header_nritems(&mid->header) > NODEPTRS_PER_BLOCK / 4) |
bb803951 CM |
315 | return 0; |
316 | ||
bb803951 CM |
317 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
318 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
319 | |
320 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 321 | if (left_buf) { |
02217ed2 CM |
322 | btrfs_cow_block(root, left_buf, parent_buf, |
323 | pslot - 1, &left_buf); | |
bb803951 | 324 | left = &left_buf->node; |
7518a238 | 325 | orig_slot += btrfs_header_nritems(&left->header); |
79f95c82 CM |
326 | wret = push_node_left(root, left_buf, mid_buf); |
327 | if (wret < 0) | |
328 | ret = wret; | |
bb803951 | 329 | } |
79f95c82 CM |
330 | |
331 | /* | |
332 | * then try to empty the right most buffer into the middle | |
333 | */ | |
bb803951 | 334 | if (right_buf) { |
02217ed2 CM |
335 | btrfs_cow_block(root, right_buf, parent_buf, |
336 | pslot + 1, &right_buf); | |
79f95c82 CM |
337 | right = &right_buf->node; |
338 | wret = push_node_left(root, mid_buf, right_buf); | |
339 | if (wret < 0) | |
340 | ret = wret; | |
7518a238 | 341 | if (btrfs_header_nritems(&right->header) == 0) { |
bb803951 CM |
342 | u64 blocknr = right_buf->blocknr; |
343 | tree_block_release(root, right_buf); | |
ed2ff2cb | 344 | clean_tree_block(root, right_buf); |
bb803951 CM |
345 | right_buf = NULL; |
346 | right = NULL; | |
347 | wret = del_ptr(root, path, level + 1, pslot + 1); | |
348 | if (wret) | |
349 | ret = wret; | |
350 | wret = free_extent(root, blocknr, 1); | |
351 | if (wret) | |
352 | ret = wret; | |
353 | } else { | |
354 | memcpy(parent->keys + pslot + 1, right->keys, | |
e2fa7227 | 355 | sizeof(struct btrfs_disk_key)); |
02217ed2 | 356 | BUG_ON(list_empty(&parent_buf->dirty)); |
bb803951 CM |
357 | } |
358 | } | |
7518a238 | 359 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
360 | /* |
361 | * we're not allowed to leave a node with one item in the | |
362 | * tree during a delete. A deletion from lower in the tree | |
363 | * could try to delete the only pointer in this node. | |
364 | * So, pull some keys from the left. | |
365 | * There has to be a left pointer at this point because | |
366 | * otherwise we would have pulled some pointers from the | |
367 | * right | |
368 | */ | |
369 | BUG_ON(!left_buf); | |
370 | wret = balance_node_right(root, mid_buf, left_buf); | |
371 | if (wret < 0) | |
372 | ret = wret; | |
373 | BUG_ON(wret == 1); | |
374 | } | |
7518a238 | 375 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 376 | /* we've managed to empty the middle node, drop it */ |
bb803951 CM |
377 | u64 blocknr = mid_buf->blocknr; |
378 | tree_block_release(root, mid_buf); | |
ed2ff2cb | 379 | clean_tree_block(root, mid_buf); |
bb803951 CM |
380 | mid_buf = NULL; |
381 | mid = NULL; | |
382 | wret = del_ptr(root, path, level + 1, pslot); | |
383 | if (wret) | |
384 | ret = wret; | |
385 | wret = free_extent(root, blocknr, 1); | |
386 | if (wret) | |
387 | ret = wret; | |
79f95c82 CM |
388 | } else { |
389 | /* update the parent key to reflect our changes */ | |
e2fa7227 CM |
390 | memcpy(parent->keys + pslot, mid->keys, |
391 | sizeof(struct btrfs_disk_key)); | |
02217ed2 | 392 | BUG_ON(list_empty(&parent_buf->dirty)); |
79f95c82 | 393 | } |
bb803951 | 394 | |
79f95c82 | 395 | /* update the path */ |
bb803951 | 396 | if (left_buf) { |
7518a238 | 397 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
bb803951 CM |
398 | left_buf->count++; // released below |
399 | path->nodes[level] = left_buf; | |
400 | path->slots[level + 1] -= 1; | |
401 | path->slots[level] = orig_slot; | |
402 | if (mid_buf) | |
403 | tree_block_release(root, mid_buf); | |
404 | } else { | |
7518a238 | 405 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
406 | path->slots[level] = orig_slot; |
407 | } | |
408 | } | |
79f95c82 CM |
409 | /* double check we haven't messed things up */ |
410 | check_block(path, level); | |
1d4f8a0c CM |
411 | if (orig_ptr != btrfs_node_blockptr(&path->nodes[level]->node, |
412 | path->slots[level])) | |
79f95c82 | 413 | BUG(); |
bb803951 CM |
414 | |
415 | if (right_buf) | |
416 | tree_block_release(root, right_buf); | |
417 | if (left_buf) | |
418 | tree_block_release(root, left_buf); | |
bb803951 CM |
419 | return ret; |
420 | } | |
421 | ||
74123bd7 CM |
422 | /* |
423 | * look for key in the tree. path is filled in with nodes along the way | |
424 | * if key is found, we return zero and you can find the item in the leaf | |
425 | * level of the path (level 0) | |
426 | * | |
427 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
428 | * be inserted, and 1 is returned. If there are other errors during the |
429 | * search a negative error number is returned. | |
97571fd0 CM |
430 | * |
431 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
432 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
433 | * possible) | |
74123bd7 | 434 | */ |
e2fa7227 | 435 | int search_slot(struct ctree_root *root, struct btrfs_key *key, |
02217ed2 | 436 | struct ctree_path *p, int ins_len, int cow) |
be0e5c09 | 437 | { |
bb803951 | 438 | struct tree_buffer *b; |
02217ed2 | 439 | struct tree_buffer *cow_buf; |
eb60ceac | 440 | struct node *c; |
be0e5c09 CM |
441 | int slot; |
442 | int ret; | |
443 | int level; | |
5c680ed6 | 444 | |
bb803951 CM |
445 | again: |
446 | b = root->node; | |
eb60ceac CM |
447 | b->count++; |
448 | while (b) { | |
7518a238 | 449 | level = btrfs_header_level(&b->node.header); |
02217ed2 CM |
450 | if (cow) { |
451 | int wret; | |
452 | wret = btrfs_cow_block(root, b, p->nodes[level + 1], | |
453 | p->slots[level + 1], &cow_buf); | |
454 | b = cow_buf; | |
455 | } | |
456 | BUG_ON(!cow && ins_len); | |
eb60ceac | 457 | c = &b->node; |
eb60ceac | 458 | p->nodes[level] = b; |
aa5d6bed CM |
459 | ret = check_block(p, level); |
460 | if (ret) | |
461 | return -1; | |
be0e5c09 | 462 | ret = bin_search(c, key, &slot); |
7518a238 | 463 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
464 | if (ret && slot > 0) |
465 | slot -= 1; | |
466 | p->slots[level] = slot; | |
7518a238 CM |
467 | if (ins_len > 0 && btrfs_header_nritems(&c->header) == |
468 | NODEPTRS_PER_BLOCK) { | |
5c680ed6 CM |
469 | int sret = split_node(root, p, level); |
470 | BUG_ON(sret > 0); | |
471 | if (sret) | |
472 | return sret; | |
473 | b = p->nodes[level]; | |
474 | c = &b->node; | |
475 | slot = p->slots[level]; | |
bb803951 CM |
476 | } else if (ins_len < 0) { |
477 | int sret = balance_level(root, p, level); | |
478 | if (sret) | |
479 | return sret; | |
480 | b = p->nodes[level]; | |
481 | if (!b) | |
482 | goto again; | |
483 | c = &b->node; | |
484 | slot = p->slots[level]; | |
7518a238 | 485 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 486 | } |
1d4f8a0c | 487 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
be0e5c09 | 488 | } else { |
5c680ed6 | 489 | struct leaf *l = (struct leaf *)c; |
be0e5c09 | 490 | p->slots[level] = slot; |
5de08d7d | 491 | if (ins_len > 0 && leaf_free_space(l) < |
0783fcfc | 492 | sizeof(struct btrfs_item) + ins_len) { |
5c680ed6 CM |
493 | int sret = split_leaf(root, p, ins_len); |
494 | BUG_ON(sret > 0); | |
495 | if (sret) | |
496 | return sret; | |
497 | } | |
bb803951 | 498 | BUG_ON(root->node->count == 1); |
be0e5c09 CM |
499 | return ret; |
500 | } | |
501 | } | |
bb803951 | 502 | BUG_ON(root->node->count == 1); |
aa5d6bed | 503 | return 1; |
be0e5c09 CM |
504 | } |
505 | ||
74123bd7 CM |
506 | /* |
507 | * adjust the pointers going up the tree, starting at level | |
508 | * making sure the right key of each node is points to 'key'. | |
509 | * This is used after shifting pointers to the left, so it stops | |
510 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
511 | * higher levels | |
aa5d6bed CM |
512 | * |
513 | * If this fails to write a tree block, it returns -1, but continues | |
514 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 515 | */ |
aa5d6bed | 516 | static int fixup_low_keys(struct ctree_root *root, |
e2fa7227 | 517 | struct ctree_path *path, struct btrfs_disk_key *key, |
eb60ceac | 518 | int level) |
be0e5c09 CM |
519 | { |
520 | int i; | |
aa5d6bed | 521 | int ret = 0; |
be0e5c09 | 522 | for (i = level; i < MAX_LEVEL; i++) { |
eb60ceac | 523 | struct node *t; |
be0e5c09 | 524 | int tslot = path->slots[i]; |
eb60ceac | 525 | if (!path->nodes[i]) |
be0e5c09 | 526 | break; |
eb60ceac | 527 | t = &path->nodes[i]->node; |
be0e5c09 | 528 | memcpy(t->keys + tslot, key, sizeof(*key)); |
02217ed2 | 529 | BUG_ON(list_empty(&path->nodes[i]->dirty)); |
be0e5c09 CM |
530 | if (tslot != 0) |
531 | break; | |
532 | } | |
aa5d6bed | 533 | return ret; |
be0e5c09 CM |
534 | } |
535 | ||
74123bd7 CM |
536 | /* |
537 | * try to push data from one node into the next node left in the | |
79f95c82 | 538 | * tree. |
aa5d6bed CM |
539 | * |
540 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
541 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 542 | */ |
bb803951 CM |
543 | static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, |
544 | struct tree_buffer *src_buf) | |
be0e5c09 | 545 | { |
bb803951 CM |
546 | struct node *src = &src_buf->node; |
547 | struct node *dst = &dst_buf->node; | |
be0e5c09 | 548 | int push_items = 0; |
bb803951 CM |
549 | int src_nritems; |
550 | int dst_nritems; | |
aa5d6bed | 551 | int ret = 0; |
be0e5c09 | 552 | |
7518a238 CM |
553 | src_nritems = btrfs_header_nritems(&src->header); |
554 | dst_nritems = btrfs_header_nritems(&dst->header); | |
bb803951 | 555 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; |
eb60ceac | 556 | if (push_items <= 0) { |
be0e5c09 | 557 | return 1; |
eb60ceac | 558 | } |
be0e5c09 | 559 | |
bb803951 | 560 | if (src_nritems < push_items) |
79f95c82 CM |
561 | push_items = src_nritems; |
562 | ||
bb803951 | 563 | memcpy(dst->keys + dst_nritems, src->keys, |
e2fa7227 | 564 | push_items * sizeof(struct btrfs_disk_key)); |
bb803951 | 565 | memcpy(dst->blockptrs + dst_nritems, src->blockptrs, |
be0e5c09 | 566 | push_items * sizeof(u64)); |
bb803951 CM |
567 | if (push_items < src_nritems) { |
568 | memmove(src->keys, src->keys + push_items, | |
e2fa7227 CM |
569 | (src_nritems - push_items) * |
570 | sizeof(struct btrfs_disk_key)); | |
bb803951 CM |
571 | memmove(src->blockptrs, src->blockptrs + push_items, |
572 | (src_nritems - push_items) * sizeof(u64)); | |
573 | } | |
7518a238 CM |
574 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
575 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
02217ed2 CM |
576 | BUG_ON(list_empty(&src_buf->dirty)); |
577 | BUG_ON(list_empty(&dst_buf->dirty)); | |
79f95c82 CM |
578 | return ret; |
579 | } | |
580 | ||
581 | /* | |
582 | * try to push data from one node into the next node right in the | |
583 | * tree. | |
584 | * | |
585 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
586 | * error, and > 0 if there was no room in the right hand block. | |
587 | * | |
588 | * this will only push up to 1/2 the contents of the left node over | |
589 | */ | |
590 | static int balance_node_right(struct ctree_root *root, | |
591 | struct tree_buffer *dst_buf, | |
592 | struct tree_buffer *src_buf) | |
593 | { | |
594 | struct node *src = &src_buf->node; | |
595 | struct node *dst = &dst_buf->node; | |
596 | int push_items = 0; | |
597 | int max_push; | |
598 | int src_nritems; | |
599 | int dst_nritems; | |
600 | int ret = 0; | |
79f95c82 | 601 | |
7518a238 CM |
602 | src_nritems = btrfs_header_nritems(&src->header); |
603 | dst_nritems = btrfs_header_nritems(&dst->header); | |
79f95c82 CM |
604 | push_items = NODEPTRS_PER_BLOCK - dst_nritems; |
605 | if (push_items <= 0) { | |
606 | return 1; | |
607 | } | |
608 | ||
609 | max_push = src_nritems / 2 + 1; | |
610 | /* don't try to empty the node */ | |
611 | if (max_push > src_nritems) | |
612 | return 1; | |
613 | if (max_push < push_items) | |
614 | push_items = max_push; | |
615 | ||
616 | memmove(dst->keys + push_items, dst->keys, | |
e2fa7227 | 617 | dst_nritems * sizeof(struct btrfs_disk_key)); |
79f95c82 CM |
618 | memmove(dst->blockptrs + push_items, dst->blockptrs, |
619 | dst_nritems * sizeof(u64)); | |
620 | memcpy(dst->keys, src->keys + src_nritems - push_items, | |
e2fa7227 | 621 | push_items * sizeof(struct btrfs_disk_key)); |
79f95c82 CM |
622 | memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, |
623 | push_items * sizeof(u64)); | |
624 | ||
7518a238 CM |
625 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
626 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 627 | |
02217ed2 CM |
628 | BUG_ON(list_empty(&src_buf->dirty)); |
629 | BUG_ON(list_empty(&dst_buf->dirty)); | |
aa5d6bed | 630 | return ret; |
be0e5c09 CM |
631 | } |
632 | ||
97571fd0 CM |
633 | /* |
634 | * helper function to insert a new root level in the tree. | |
635 | * A new node is allocated, and a single item is inserted to | |
636 | * point to the existing root | |
aa5d6bed CM |
637 | * |
638 | * returns zero on success or < 0 on failure. | |
97571fd0 | 639 | */ |
5de08d7d CM |
640 | static int insert_new_root(struct ctree_root *root, |
641 | struct ctree_path *path, int level) | |
5c680ed6 CM |
642 | { |
643 | struct tree_buffer *t; | |
644 | struct node *lower; | |
645 | struct node *c; | |
e2fa7227 | 646 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
647 | |
648 | BUG_ON(path->nodes[level]); | |
649 | BUG_ON(path->nodes[level-1] != root->node); | |
650 | ||
651 | t = alloc_free_block(root); | |
652 | c = &t->node; | |
653 | memset(c, 0, sizeof(c)); | |
7518a238 CM |
654 | btrfs_set_header_nritems(&c->header, 1); |
655 | btrfs_set_header_level(&c->header, level); | |
656 | btrfs_set_header_blocknr(&c->header, t->blocknr); | |
657 | btrfs_set_header_parentid(&c->header, | |
658 | btrfs_header_parentid(&root->node->node.header)); | |
5c680ed6 | 659 | lower = &path->nodes[level-1]->node; |
7518a238 | 660 | if (btrfs_is_leaf(lower)) |
5c680ed6 CM |
661 | lower_key = &((struct leaf *)lower)->items[0].key; |
662 | else | |
663 | lower_key = lower->keys; | |
e2fa7227 | 664 | memcpy(c->keys, lower_key, sizeof(struct btrfs_disk_key)); |
1d4f8a0c | 665 | btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->blocknr); |
5c680ed6 CM |
666 | /* the super has an extra ref to root->node */ |
667 | tree_block_release(root, root->node); | |
668 | root->node = t; | |
669 | t->count++; | |
5c680ed6 CM |
670 | path->nodes[level] = t; |
671 | path->slots[level] = 0; | |
672 | return 0; | |
673 | } | |
674 | ||
74123bd7 CM |
675 | /* |
676 | * worker function to insert a single pointer in a node. | |
677 | * the node should have enough room for the pointer already | |
97571fd0 | 678 | * |
74123bd7 CM |
679 | * slot and level indicate where you want the key to go, and |
680 | * blocknr is the block the key points to. | |
aa5d6bed CM |
681 | * |
682 | * returns zero on success and < 0 on any error | |
74123bd7 | 683 | */ |
aa5d6bed | 684 | static int insert_ptr(struct ctree_root *root, |
e2fa7227 | 685 | struct ctree_path *path, struct btrfs_disk_key *key, |
74123bd7 CM |
686 | u64 blocknr, int slot, int level) |
687 | { | |
74123bd7 | 688 | struct node *lower; |
74123bd7 | 689 | int nritems; |
5c680ed6 CM |
690 | |
691 | BUG_ON(!path->nodes[level]); | |
74123bd7 | 692 | lower = &path->nodes[level]->node; |
7518a238 | 693 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
694 | if (slot > nritems) |
695 | BUG(); | |
696 | if (nritems == NODEPTRS_PER_BLOCK) | |
697 | BUG(); | |
698 | if (slot != nritems) { | |
699 | memmove(lower->keys + slot + 1, lower->keys + slot, | |
e2fa7227 | 700 | (nritems - slot) * sizeof(struct btrfs_disk_key)); |
74123bd7 CM |
701 | memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, |
702 | (nritems - slot) * sizeof(u64)); | |
703 | } | |
e2fa7227 | 704 | memcpy(lower->keys + slot, key, sizeof(struct btrfs_disk_key)); |
1d4f8a0c | 705 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 706 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
74123bd7 CM |
707 | if (lower->keys[1].objectid == 0) |
708 | BUG(); | |
02217ed2 | 709 | BUG_ON(list_empty(&path->nodes[level]->dirty)); |
74123bd7 CM |
710 | return 0; |
711 | } | |
712 | ||
97571fd0 CM |
713 | /* |
714 | * split the node at the specified level in path in two. | |
715 | * The path is corrected to point to the appropriate node after the split | |
716 | * | |
717 | * Before splitting this tries to make some room in the node by pushing | |
718 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
719 | * |
720 | * returns 0 on success and < 0 on failure | |
97571fd0 | 721 | */ |
aa5d6bed CM |
722 | static int split_node(struct ctree_root *root, struct ctree_path *path, |
723 | int level) | |
be0e5c09 | 724 | { |
5c680ed6 CM |
725 | struct tree_buffer *t; |
726 | struct node *c; | |
727 | struct tree_buffer *split_buffer; | |
728 | struct node *split; | |
be0e5c09 | 729 | int mid; |
5c680ed6 | 730 | int ret; |
aa5d6bed | 731 | int wret; |
7518a238 | 732 | u32 c_nritems; |
eb60ceac | 733 | |
5c680ed6 CM |
734 | t = path->nodes[level]; |
735 | c = &t->node; | |
736 | if (t == root->node) { | |
737 | /* trying to split the root, lets make a new one */ | |
738 | ret = insert_new_root(root, path, level + 1); | |
739 | if (ret) | |
740 | return ret; | |
be0e5c09 | 741 | } |
7518a238 | 742 | c_nritems = btrfs_header_nritems(&c->header); |
5c680ed6 CM |
743 | split_buffer = alloc_free_block(root); |
744 | split = &split_buffer->node; | |
7518a238 CM |
745 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
746 | btrfs_set_header_blocknr(&split->header, split_buffer->blocknr); | |
747 | btrfs_set_header_parentid(&split->header, | |
748 | btrfs_header_parentid(&root->node->node.header)); | |
749 | mid = (c_nritems + 1) / 2; | |
5c680ed6 | 750 | memcpy(split->keys, c->keys + mid, |
e2fa7227 | 751 | (c_nritems - mid) * sizeof(struct btrfs_disk_key)); |
5c680ed6 | 752 | memcpy(split->blockptrs, c->blockptrs + mid, |
7518a238 CM |
753 | (c_nritems - mid) * sizeof(u64)); |
754 | btrfs_set_header_nritems(&split->header, c_nritems - mid); | |
755 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
756 | ret = 0; |
757 | ||
02217ed2 | 758 | BUG_ON(list_empty(&t->dirty)); |
aa5d6bed CM |
759 | wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, |
760 | path->slots[level + 1] + 1, level + 1); | |
761 | if (wret) | |
762 | ret = wret; | |
763 | ||
5de08d7d | 764 | if (path->slots[level] >= mid) { |
5c680ed6 CM |
765 | path->slots[level] -= mid; |
766 | tree_block_release(root, t); | |
767 | path->nodes[level] = split_buffer; | |
768 | path->slots[level + 1] += 1; | |
769 | } else { | |
770 | tree_block_release(root, split_buffer); | |
be0e5c09 | 771 | } |
aa5d6bed | 772 | return ret; |
be0e5c09 CM |
773 | } |
774 | ||
74123bd7 CM |
775 | /* |
776 | * how many bytes are required to store the items in a leaf. start | |
777 | * and nr indicate which items in the leaf to check. This totals up the | |
778 | * space used both by the item structs and the item data | |
779 | */ | |
aa5d6bed | 780 | static int leaf_space_used(struct leaf *l, int start, int nr) |
be0e5c09 CM |
781 | { |
782 | int data_len; | |
783 | int end = start + nr - 1; | |
784 | ||
785 | if (!nr) | |
786 | return 0; | |
0783fcfc CM |
787 | data_len = btrfs_item_end(l->items + start); |
788 | data_len = data_len - btrfs_item_offset(l->items + end); | |
789 | data_len += sizeof(struct btrfs_item) * nr; | |
be0e5c09 CM |
790 | return data_len; |
791 | } | |
792 | ||
00ec4c51 CM |
793 | /* |
794 | * push some data in the path leaf to the right, trying to free up at | |
795 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
796 | * |
797 | * returns 1 if the push failed because the other node didn't have enough | |
798 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 799 | */ |
aa5d6bed CM |
800 | static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, |
801 | int data_size) | |
00ec4c51 CM |
802 | { |
803 | struct tree_buffer *left_buf = path->nodes[0]; | |
804 | struct leaf *left = &left_buf->leaf; | |
805 | struct leaf *right; | |
806 | struct tree_buffer *right_buf; | |
807 | struct tree_buffer *upper; | |
808 | int slot; | |
809 | int i; | |
810 | int free_space; | |
811 | int push_space = 0; | |
812 | int push_items = 0; | |
0783fcfc | 813 | struct btrfs_item *item; |
7518a238 CM |
814 | u32 left_nritems; |
815 | u32 right_nritems; | |
00ec4c51 CM |
816 | |
817 | slot = path->slots[1]; | |
818 | if (!path->nodes[1]) { | |
819 | return 1; | |
820 | } | |
821 | upper = path->nodes[1]; | |
7518a238 | 822 | if (slot >= btrfs_header_nritems(&upper->node.header) - 1) { |
00ec4c51 CM |
823 | return 1; |
824 | } | |
1d4f8a0c CM |
825 | right_buf = read_tree_block(root, btrfs_node_blockptr(&upper->node, |
826 | slot + 1)); | |
00ec4c51 CM |
827 | right = &right_buf->leaf; |
828 | free_space = leaf_free_space(right); | |
0783fcfc | 829 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
00ec4c51 CM |
830 | tree_block_release(root, right_buf); |
831 | return 1; | |
832 | } | |
02217ed2 CM |
833 | /* cow and double check */ |
834 | btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf); | |
835 | right = &right_buf->leaf; | |
836 | free_space = leaf_free_space(right); | |
0783fcfc | 837 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
02217ed2 CM |
838 | tree_block_release(root, right_buf); |
839 | return 1; | |
840 | } | |
841 | ||
7518a238 CM |
842 | left_nritems = btrfs_header_nritems(&left->header); |
843 | for (i = left_nritems - 1; i >= 0; i--) { | |
00ec4c51 CM |
844 | item = left->items + i; |
845 | if (path->slots[0] == i) | |
846 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
847 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
848 | free_space) | |
00ec4c51 CM |
849 | break; |
850 | push_items++; | |
0783fcfc | 851 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
852 | } |
853 | if (push_items == 0) { | |
854 | tree_block_release(root, right_buf); | |
855 | return 1; | |
856 | } | |
7518a238 | 857 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 858 | /* push left to right */ |
0783fcfc | 859 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
00ec4c51 CM |
860 | push_space -= leaf_data_end(left); |
861 | /* make room in the right data area */ | |
862 | memmove(right->data + leaf_data_end(right) - push_space, | |
863 | right->data + leaf_data_end(right), | |
864 | LEAF_DATA_SIZE - leaf_data_end(right)); | |
865 | /* copy from the left data area */ | |
866 | memcpy(right->data + LEAF_DATA_SIZE - push_space, | |
867 | left->data + leaf_data_end(left), | |
868 | push_space); | |
869 | memmove(right->items + push_items, right->items, | |
0783fcfc | 870 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 871 | /* copy the items from left to right */ |
7518a238 | 872 | memcpy(right->items, left->items + left_nritems - push_items, |
0783fcfc | 873 | push_items * sizeof(struct btrfs_item)); |
00ec4c51 CM |
874 | |
875 | /* update the item pointers */ | |
7518a238 CM |
876 | right_nritems += push_items; |
877 | btrfs_set_header_nritems(&right->header, right_nritems); | |
00ec4c51 | 878 | push_space = LEAF_DATA_SIZE; |
7518a238 | 879 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
880 | btrfs_set_item_offset(right->items + i, push_space - |
881 | btrfs_item_size(right->items + i)); | |
882 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 883 | } |
7518a238 CM |
884 | left_nritems -= push_items; |
885 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 886 | |
02217ed2 CM |
887 | BUG_ON(list_empty(&left_buf->dirty)); |
888 | BUG_ON(list_empty(&right_buf->dirty)); | |
00ec4c51 | 889 | memcpy(upper->node.keys + slot + 1, |
e2fa7227 | 890 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
02217ed2 CM |
891 | BUG_ON(list_empty(&upper->dirty)); |
892 | ||
00ec4c51 | 893 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
894 | if (path->slots[0] >= left_nritems) { |
895 | path->slots[0] -= left_nritems; | |
00ec4c51 CM |
896 | tree_block_release(root, path->nodes[0]); |
897 | path->nodes[0] = right_buf; | |
898 | path->slots[1] += 1; | |
899 | } else { | |
900 | tree_block_release(root, right_buf); | |
901 | } | |
902 | return 0; | |
903 | } | |
74123bd7 CM |
904 | /* |
905 | * push some data in the path leaf to the left, trying to free up at | |
906 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
907 | */ | |
aa5d6bed CM |
908 | static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, |
909 | int data_size) | |
be0e5c09 | 910 | { |
eb60ceac CM |
911 | struct tree_buffer *right_buf = path->nodes[0]; |
912 | struct leaf *right = &right_buf->leaf; | |
913 | struct tree_buffer *t; | |
be0e5c09 CM |
914 | struct leaf *left; |
915 | int slot; | |
916 | int i; | |
917 | int free_space; | |
918 | int push_space = 0; | |
919 | int push_items = 0; | |
0783fcfc | 920 | struct btrfs_item *item; |
7518a238 | 921 | u32 old_left_nritems; |
aa5d6bed CM |
922 | int ret = 0; |
923 | int wret; | |
be0e5c09 CM |
924 | |
925 | slot = path->slots[1]; | |
926 | if (slot == 0) { | |
927 | return 1; | |
928 | } | |
929 | if (!path->nodes[1]) { | |
930 | return 1; | |
931 | } | |
1d4f8a0c CM |
932 | t = read_tree_block(root, btrfs_node_blockptr(&path->nodes[1]->node, |
933 | slot - 1)); | |
eb60ceac | 934 | left = &t->leaf; |
be0e5c09 | 935 | free_space = leaf_free_space(left); |
0783fcfc | 936 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
eb60ceac | 937 | tree_block_release(root, t); |
be0e5c09 CM |
938 | return 1; |
939 | } | |
02217ed2 CM |
940 | |
941 | /* cow and double check */ | |
942 | btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t); | |
943 | left = &t->leaf; | |
944 | free_space = leaf_free_space(left); | |
0783fcfc | 945 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
02217ed2 CM |
946 | tree_block_release(root, t); |
947 | return 1; | |
948 | } | |
949 | ||
7518a238 | 950 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
be0e5c09 CM |
951 | item = right->items + i; |
952 | if (path->slots[0] == i) | |
953 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
954 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
955 | free_space) | |
be0e5c09 CM |
956 | break; |
957 | push_items++; | |
0783fcfc | 958 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
959 | } |
960 | if (push_items == 0) { | |
eb60ceac | 961 | tree_block_release(root, t); |
be0e5c09 CM |
962 | return 1; |
963 | } | |
964 | /* push data from right to left */ | |
7518a238 | 965 | memcpy(left->items + btrfs_header_nritems(&left->header), |
0783fcfc CM |
966 | right->items, push_items * sizeof(struct btrfs_item)); |
967 | push_space = LEAF_DATA_SIZE - | |
968 | btrfs_item_offset(right->items + push_items -1); | |
be0e5c09 | 969 | memcpy(left->data + leaf_data_end(left) - push_space, |
0783fcfc | 970 | right->data + btrfs_item_offset(right->items + push_items - 1), |
be0e5c09 | 971 | push_space); |
7518a238 | 972 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
973 | BUG_ON(old_left_nritems < 0); |
974 | ||
0783fcfc CM |
975 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
976 | u16 ioff = btrfs_item_offset(left->items + i); | |
977 | btrfs_set_item_offset(left->items + i, ioff - (LEAF_DATA_SIZE - | |
978 | btrfs_item_offset(left->items + | |
979 | old_left_nritems - 1))); | |
be0e5c09 | 980 | } |
7518a238 | 981 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
982 | |
983 | /* fixup right node */ | |
0783fcfc CM |
984 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
985 | leaf_data_end(right); | |
be0e5c09 CM |
986 | memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + |
987 | leaf_data_end(right), push_space); | |
988 | memmove(right->items, right->items + push_items, | |
7518a238 | 989 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 990 | sizeof(struct btrfs_item)); |
7518a238 CM |
991 | btrfs_set_header_nritems(&right->header, |
992 | btrfs_header_nritems(&right->header) - | |
993 | push_items); | |
be0e5c09 | 994 | push_space = LEAF_DATA_SIZE; |
eb60ceac | 995 | |
7518a238 | 996 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
997 | btrfs_set_item_offset(right->items + i, push_space - |
998 | btrfs_item_size(right->items + i)); | |
999 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1000 | } |
eb60ceac | 1001 | |
02217ed2 CM |
1002 | BUG_ON(list_empty(&t->dirty)); |
1003 | BUG_ON(list_empty(&right_buf->dirty)); | |
eb60ceac | 1004 | |
aa5d6bed CM |
1005 | wret = fixup_low_keys(root, path, &right->items[0].key, 1); |
1006 | if (wret) | |
1007 | ret = wret; | |
be0e5c09 CM |
1008 | |
1009 | /* then fixup the leaf pointer in the path */ | |
1010 | if (path->slots[0] < push_items) { | |
1011 | path->slots[0] += old_left_nritems; | |
eb60ceac CM |
1012 | tree_block_release(root, path->nodes[0]); |
1013 | path->nodes[0] = t; | |
be0e5c09 CM |
1014 | path->slots[1] -= 1; |
1015 | } else { | |
eb60ceac | 1016 | tree_block_release(root, t); |
be0e5c09 CM |
1017 | path->slots[0] -= push_items; |
1018 | } | |
eb60ceac | 1019 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 1020 | return ret; |
be0e5c09 CM |
1021 | } |
1022 | ||
74123bd7 CM |
1023 | /* |
1024 | * split the path's leaf in two, making sure there is at least data_size | |
1025 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1026 | * |
1027 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1028 | */ |
aa5d6bed CM |
1029 | static int split_leaf(struct ctree_root *root, struct ctree_path *path, |
1030 | int data_size) | |
be0e5c09 | 1031 | { |
aa5d6bed CM |
1032 | struct tree_buffer *l_buf; |
1033 | struct leaf *l; | |
7518a238 | 1034 | u32 nritems; |
eb60ceac CM |
1035 | int mid; |
1036 | int slot; | |
be0e5c09 | 1037 | struct leaf *right; |
eb60ceac | 1038 | struct tree_buffer *right_buffer; |
0783fcfc | 1039 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1040 | int data_copy_size; |
1041 | int rt_data_off; | |
1042 | int i; | |
1043 | int ret; | |
aa5d6bed CM |
1044 | int wret; |
1045 | ||
aa5d6bed CM |
1046 | l_buf = path->nodes[0]; |
1047 | l = &l_buf->leaf; | |
1048 | ||
1049 | /* did the pushes work? */ | |
0783fcfc | 1050 | if (leaf_free_space(l) >= sizeof(struct btrfs_item) + data_size) |
aa5d6bed CM |
1051 | return 0; |
1052 | ||
5c680ed6 CM |
1053 | if (!path->nodes[1]) { |
1054 | ret = insert_new_root(root, path, 1); | |
1055 | if (ret) | |
1056 | return ret; | |
1057 | } | |
eb60ceac | 1058 | slot = path->slots[0]; |
7518a238 | 1059 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1060 | mid = (nritems + 1)/ 2; |
eb60ceac CM |
1061 | right_buffer = alloc_free_block(root); |
1062 | BUG_ON(!right_buffer); | |
1063 | BUG_ON(mid == nritems); | |
1064 | right = &right_buffer->leaf; | |
be0e5c09 CM |
1065 | memset(right, 0, sizeof(*right)); |
1066 | if (mid <= slot) { | |
97571fd0 | 1067 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1068 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
1069 | LEAF_DATA_SIZE) | |
1070 | BUG(); | |
1071 | } else { | |
97571fd0 | 1072 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 CM |
1073 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
1074 | LEAF_DATA_SIZE) | |
1075 | BUG(); | |
1076 | } | |
7518a238 CM |
1077 | btrfs_set_header_nritems(&right->header, nritems - mid); |
1078 | btrfs_set_header_blocknr(&right->header, right_buffer->blocknr); | |
1079 | btrfs_set_header_level(&right->header, 0); | |
1080 | btrfs_set_header_parentid(&right->header, | |
1081 | btrfs_header_parentid(&root->node->node.header)); | |
0783fcfc | 1082 | data_copy_size = btrfs_item_end(l->items + mid) - leaf_data_end(l); |
be0e5c09 | 1083 | memcpy(right->items, l->items + mid, |
0783fcfc | 1084 | (nritems - mid) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
1085 | memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, |
1086 | l->data + leaf_data_end(l), data_copy_size); | |
0783fcfc | 1087 | rt_data_off = LEAF_DATA_SIZE - btrfs_item_end(l->items + mid); |
74123bd7 | 1088 | |
0783fcfc CM |
1089 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
1090 | u16 ioff = btrfs_item_offset(right->items + i); | |
1091 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); | |
1092 | } | |
74123bd7 | 1093 | |
7518a238 | 1094 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed CM |
1095 | ret = 0; |
1096 | wret = insert_ptr(root, path, &right->items[0].key, | |
5c680ed6 | 1097 | right_buffer->blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1098 | if (wret) |
1099 | ret = wret; | |
02217ed2 CM |
1100 | BUG_ON(list_empty(&right_buffer->dirty)); |
1101 | BUG_ON(list_empty(&l_buf->dirty)); | |
eb60ceac | 1102 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1103 | if (mid <= slot) { |
eb60ceac CM |
1104 | tree_block_release(root, path->nodes[0]); |
1105 | path->nodes[0] = right_buffer; | |
be0e5c09 CM |
1106 | path->slots[0] -= mid; |
1107 | path->slots[1] += 1; | |
eb60ceac CM |
1108 | } else |
1109 | tree_block_release(root, right_buffer); | |
1110 | BUG_ON(path->slots[0] < 0); | |
be0e5c09 CM |
1111 | return ret; |
1112 | } | |
1113 | ||
74123bd7 CM |
1114 | /* |
1115 | * Given a key and some data, insert an item into the tree. | |
1116 | * This does all the path init required, making room in the tree if needed. | |
1117 | */ | |
e2fa7227 | 1118 | int insert_item(struct ctree_root *root, struct btrfs_key *cpu_key, |
be0e5c09 CM |
1119 | void *data, int data_size) |
1120 | { | |
aa5d6bed | 1121 | int ret = 0; |
be0e5c09 | 1122 | int slot; |
eb60ceac | 1123 | int slot_orig; |
be0e5c09 | 1124 | struct leaf *leaf; |
eb60ceac | 1125 | struct tree_buffer *leaf_buf; |
7518a238 | 1126 | u32 nritems; |
be0e5c09 CM |
1127 | unsigned int data_end; |
1128 | struct ctree_path path; | |
e2fa7227 CM |
1129 | struct btrfs_disk_key disk_key; |
1130 | ||
1131 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1132 | |
74123bd7 | 1133 | /* create a root if there isn't one */ |
5c680ed6 | 1134 | if (!root->node) |
cfaa7295 | 1135 | BUG(); |
be0e5c09 | 1136 | init_path(&path); |
e2fa7227 | 1137 | ret = search_slot(root, cpu_key, &path, data_size, 1); |
eb60ceac CM |
1138 | if (ret == 0) { |
1139 | release_path(root, &path); | |
f0930a37 | 1140 | return -EEXIST; |
aa5d6bed | 1141 | } |
ed2ff2cb CM |
1142 | if (ret < 0) |
1143 | goto out; | |
be0e5c09 | 1144 | |
eb60ceac CM |
1145 | slot_orig = path.slots[0]; |
1146 | leaf_buf = path.nodes[0]; | |
1147 | leaf = &leaf_buf->leaf; | |
74123bd7 | 1148 | |
7518a238 | 1149 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1150 | data_end = leaf_data_end(leaf); |
eb60ceac | 1151 | |
0783fcfc | 1152 | if (leaf_free_space(leaf) < sizeof(struct btrfs_item) + data_size) |
be0e5c09 CM |
1153 | BUG(); |
1154 | ||
1155 | slot = path.slots[0]; | |
eb60ceac | 1156 | BUG_ON(slot < 0); |
be0e5c09 CM |
1157 | if (slot != nritems) { |
1158 | int i; | |
0783fcfc | 1159 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1160 | |
1161 | /* | |
1162 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1163 | */ | |
1164 | /* first correct the data pointers */ | |
0783fcfc CM |
1165 | for (i = slot; i < nritems; i++) { |
1166 | u16 ioff = btrfs_item_offset(leaf->items + i); | |
1167 | btrfs_set_item_offset(leaf->items + i, | |
1168 | ioff - data_size); | |
1169 | } | |
be0e5c09 CM |
1170 | |
1171 | /* shift the items */ | |
1172 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
0783fcfc | 1173 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
1174 | |
1175 | /* shift the data */ | |
1176 | memmove(leaf->data + data_end - data_size, leaf->data + | |
1177 | data_end, old_data - data_end); | |
1178 | data_end = old_data; | |
1179 | } | |
74123bd7 | 1180 | /* copy the new data in */ |
e2fa7227 CM |
1181 | memcpy(&leaf->items[slot].key, &disk_key, |
1182 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1183 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1184 | btrfs_set_item_size(leaf->items + slot, data_size); | |
be0e5c09 | 1185 | memcpy(leaf->data + data_end - data_size, data, data_size); |
7518a238 | 1186 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
aa5d6bed CM |
1187 | |
1188 | ret = 0; | |
8e19f2cd | 1189 | if (slot == 0) |
e2fa7227 | 1190 | ret = fixup_low_keys(root, &path, &disk_key, 1); |
aa5d6bed | 1191 | |
02217ed2 | 1192 | BUG_ON(list_empty(&leaf_buf->dirty)); |
be0e5c09 CM |
1193 | if (leaf_free_space(leaf) < 0) |
1194 | BUG(); | |
bb803951 | 1195 | check_leaf(&path, 0); |
ed2ff2cb | 1196 | out: |
eb60ceac | 1197 | release_path(root, &path); |
aa5d6bed | 1198 | return ret; |
be0e5c09 CM |
1199 | } |
1200 | ||
74123bd7 | 1201 | /* |
5de08d7d | 1202 | * delete the pointer from a given node. |
74123bd7 CM |
1203 | * |
1204 | * If the delete empties a node, the node is removed from the tree, | |
1205 | * continuing all the way the root if required. The root is converted into | |
1206 | * a leaf if all the nodes are emptied. | |
1207 | */ | |
bb803951 CM |
1208 | static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, |
1209 | int slot) | |
be0e5c09 | 1210 | { |
be0e5c09 | 1211 | struct node *node; |
bb803951 | 1212 | struct tree_buffer *parent = path->nodes[level]; |
7518a238 | 1213 | u32 nritems; |
aa5d6bed | 1214 | int ret = 0; |
bb803951 | 1215 | int wret; |
be0e5c09 | 1216 | |
bb803951 | 1217 | node = &parent->node; |
7518a238 | 1218 | nritems = btrfs_header_nritems(&node->header); |
bb803951 CM |
1219 | if (slot != nritems -1) { |
1220 | memmove(node->keys + slot, node->keys + slot + 1, | |
e2fa7227 | 1221 | sizeof(struct btrfs_disk_key) * (nritems - slot - 1)); |
bb803951 CM |
1222 | memmove(node->blockptrs + slot, |
1223 | node->blockptrs + slot + 1, | |
1224 | sizeof(u64) * (nritems - slot - 1)); | |
1225 | } | |
7518a238 CM |
1226 | nritems--; |
1227 | btrfs_set_header_nritems(&node->header, nritems); | |
1228 | if (nritems == 0 && parent == root->node) { | |
1229 | BUG_ON(btrfs_header_level(&root->node->node.header) != 1); | |
bb803951 | 1230 | /* just turn the root into a leaf and break */ |
7518a238 | 1231 | btrfs_set_header_level(&root->node->node.header, 0); |
bb803951 CM |
1232 | } else if (slot == 0) { |
1233 | wret = fixup_low_keys(root, path, node->keys, level + 1); | |
0f70abe2 CM |
1234 | if (wret) |
1235 | ret = wret; | |
be0e5c09 | 1236 | } |
02217ed2 | 1237 | BUG_ON(list_empty(&parent->dirty)); |
aa5d6bed | 1238 | return ret; |
be0e5c09 CM |
1239 | } |
1240 | ||
74123bd7 CM |
1241 | /* |
1242 | * delete the item at the leaf level in path. If that empties | |
1243 | * the leaf, remove it from the tree | |
1244 | */ | |
4920c9ac | 1245 | int del_item(struct ctree_root *root, struct ctree_path *path) |
be0e5c09 | 1246 | { |
be0e5c09 CM |
1247 | int slot; |
1248 | struct leaf *leaf; | |
eb60ceac | 1249 | struct tree_buffer *leaf_buf; |
be0e5c09 CM |
1250 | int doff; |
1251 | int dsize; | |
aa5d6bed CM |
1252 | int ret = 0; |
1253 | int wret; | |
7518a238 | 1254 | u32 nritems; |
be0e5c09 | 1255 | |
eb60ceac CM |
1256 | leaf_buf = path->nodes[0]; |
1257 | leaf = &leaf_buf->leaf; | |
4920c9ac | 1258 | slot = path->slots[0]; |
0783fcfc CM |
1259 | doff = btrfs_item_offset(leaf->items + slot); |
1260 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1261 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1262 | |
7518a238 | 1263 | if (slot != nritems - 1) { |
be0e5c09 CM |
1264 | int i; |
1265 | int data_end = leaf_data_end(leaf); | |
1266 | memmove(leaf->data + data_end + dsize, | |
1267 | leaf->data + data_end, | |
1268 | doff - data_end); | |
0783fcfc CM |
1269 | for (i = slot + 1; i < nritems; i++) { |
1270 | u16 ioff = btrfs_item_offset(leaf->items + i); | |
1271 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); | |
1272 | } | |
be0e5c09 | 1273 | memmove(leaf->items + slot, leaf->items + slot + 1, |
0783fcfc | 1274 | sizeof(struct btrfs_item) * |
7518a238 | 1275 | (nritems - slot - 1)); |
be0e5c09 | 1276 | } |
7518a238 CM |
1277 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1278 | nritems--; | |
74123bd7 | 1279 | /* delete the leaf if we've emptied it */ |
7518a238 | 1280 | if (nritems == 0) { |
eb60ceac | 1281 | if (leaf_buf == root->node) { |
7518a238 | 1282 | btrfs_set_header_level(&leaf->header, 0); |
02217ed2 | 1283 | BUG_ON(list_empty(&leaf_buf->dirty)); |
9a8dd150 | 1284 | } else { |
ed2ff2cb | 1285 | clean_tree_block(root, leaf_buf); |
bb803951 | 1286 | wret = del_ptr(root, path, 1, path->slots[1]); |
aa5d6bed CM |
1287 | if (wret) |
1288 | ret = wret; | |
0f70abe2 CM |
1289 | wret = free_extent(root, leaf_buf->blocknr, 1); |
1290 | if (wret) | |
1291 | ret = wret; | |
9a8dd150 | 1292 | } |
be0e5c09 | 1293 | } else { |
7518a238 | 1294 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed CM |
1295 | if (slot == 0) { |
1296 | wret = fixup_low_keys(root, path, | |
1297 | &leaf->items[0].key, 1); | |
1298 | if (wret) | |
1299 | ret = wret; | |
1300 | } | |
02217ed2 | 1301 | BUG_ON(list_empty(&leaf_buf->dirty)); |
aa5d6bed | 1302 | |
74123bd7 | 1303 | /* delete the leaf if it is mostly empty */ |
5de08d7d | 1304 | if (used < LEAF_DATA_SIZE / 3) { |
be0e5c09 CM |
1305 | /* push_leaf_left fixes the path. |
1306 | * make sure the path still points to our leaf | |
1307 | * for possible call to del_ptr below | |
1308 | */ | |
4920c9ac | 1309 | slot = path->slots[1]; |
eb60ceac | 1310 | leaf_buf->count++; |
aa5d6bed CM |
1311 | wret = push_leaf_left(root, path, 1); |
1312 | if (wret < 0) | |
1313 | ret = wret; | |
f0930a37 | 1314 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1315 | btrfs_header_nritems(&leaf->header)) { |
aa5d6bed CM |
1316 | wret = push_leaf_right(root, path, 1); |
1317 | if (wret < 0) | |
1318 | ret = wret; | |
1319 | } | |
7518a238 | 1320 | if (btrfs_header_nritems(&leaf->header) == 0) { |
5de08d7d | 1321 | u64 blocknr = leaf_buf->blocknr; |
ed2ff2cb | 1322 | clean_tree_block(root, leaf_buf); |
bb803951 | 1323 | wret = del_ptr(root, path, 1, slot); |
aa5d6bed CM |
1324 | if (wret) |
1325 | ret = wret; | |
5de08d7d | 1326 | tree_block_release(root, leaf_buf); |
0f70abe2 CM |
1327 | wret = free_extent(root, blocknr, 1); |
1328 | if (wret) | |
1329 | ret = wret; | |
5de08d7d CM |
1330 | } else { |
1331 | tree_block_release(root, leaf_buf); | |
be0e5c09 CM |
1332 | } |
1333 | } | |
1334 | } | |
aa5d6bed | 1335 | return ret; |
be0e5c09 CM |
1336 | } |
1337 | ||
97571fd0 CM |
1338 | /* |
1339 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1340 | * returns 0 if it found something or 1 if there are no greater leaves. |
1341 | * returns < 0 on io errors. | |
97571fd0 | 1342 | */ |
d97e63b6 CM |
1343 | int next_leaf(struct ctree_root *root, struct ctree_path *path) |
1344 | { | |
1345 | int slot; | |
1346 | int level = 1; | |
1347 | u64 blocknr; | |
1348 | struct tree_buffer *c; | |
cfaa7295 | 1349 | struct tree_buffer *next = NULL; |
d97e63b6 CM |
1350 | |
1351 | while(level < MAX_LEVEL) { | |
1352 | if (!path->nodes[level]) | |
0f70abe2 | 1353 | return 1; |
d97e63b6 CM |
1354 | slot = path->slots[level] + 1; |
1355 | c = path->nodes[level]; | |
7518a238 | 1356 | if (slot >= btrfs_header_nritems(&c->node.header)) { |
d97e63b6 CM |
1357 | level++; |
1358 | continue; | |
1359 | } | |
1d4f8a0c | 1360 | blocknr = btrfs_node_blockptr(&c->node, slot); |
cfaa7295 CM |
1361 | if (next) |
1362 | tree_block_release(root, next); | |
d97e63b6 CM |
1363 | next = read_tree_block(root, blocknr); |
1364 | break; | |
1365 | } | |
1366 | path->slots[level] = slot; | |
1367 | while(1) { | |
1368 | level--; | |
1369 | c = path->nodes[level]; | |
1370 | tree_block_release(root, c); | |
1371 | path->nodes[level] = next; | |
1372 | path->slots[level] = 0; | |
1373 | if (!level) | |
1374 | break; | |
1d4f8a0c CM |
1375 | next = read_tree_block(root, |
1376 | btrfs_node_blockptr(&next->node, 0)); | |
d97e63b6 CM |
1377 | } |
1378 | return 0; | |
1379 | } | |
1380 | ||
02217ed2 | 1381 |