Commit | Line | Data |
---|---|---|
2e635a27 | 1 | #include <linux/module.h> |
eb60ceac CM |
2 | #include "ctree.h" |
3 | #include "disk-io.h" | |
7f5c1516 | 4 | #include "transaction.h" |
9a8dd150 | 5 | |
e089f05c CM |
6 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
7 | *root, struct btrfs_path *path, int level); | |
8 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
9 | *root, struct btrfs_path *path, int data_size); | |
10 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
e20d96d6 | 11 | *root, struct buffer_head *dst, struct buffer_head |
e089f05c CM |
12 | *src); |
13 | static int balance_node_right(struct btrfs_trans_handle *trans, struct | |
e20d96d6 CM |
14 | btrfs_root *root, struct buffer_head *dst_buf, |
15 | struct buffer_head *src_buf); | |
e089f05c CM |
16 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
17 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 18 | |
234b63a0 | 19 | inline void btrfs_init_path(struct btrfs_path *p) |
be0e5c09 CM |
20 | { |
21 | memset(p, 0, sizeof(*p)); | |
22 | } | |
23 | ||
234b63a0 | 24 | void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
25 | { |
26 | int i; | |
234b63a0 | 27 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
eb60ceac CM |
28 | if (!p->nodes[i]) |
29 | break; | |
234b63a0 | 30 | btrfs_block_release(root, p->nodes[i]); |
eb60ceac | 31 | } |
aa5d6bed | 32 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
33 | } |
34 | ||
e089f05c | 35 | static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
36 | *root, struct buffer_head *buf, struct buffer_head |
37 | *parent, int parent_slot, struct buffer_head | |
e089f05c | 38 | **cow_ret) |
02217ed2 | 39 | { |
e20d96d6 CM |
40 | struct buffer_head *cow; |
41 | struct btrfs_node *cow_node; | |
02217ed2 | 42 | |
7f5c1516 CM |
43 | if (btrfs_header_generation(btrfs_buffer_header(buf)) == |
44 | trans->transid) { | |
02217ed2 CM |
45 | *cow_ret = buf; |
46 | return 0; | |
47 | } | |
e089f05c | 48 | cow = btrfs_alloc_free_block(trans, root); |
e20d96d6 CM |
49 | cow_node = btrfs_buffer_node(cow); |
50 | memcpy(cow_node, btrfs_buffer_node(buf), root->blocksize); | |
51 | btrfs_set_header_blocknr(&cow_node->header, cow->b_blocknr); | |
7f5c1516 | 52 | btrfs_set_header_generation(&cow_node->header, trans->transid); |
02217ed2 | 53 | *cow_ret = cow; |
d5719762 | 54 | mark_buffer_dirty(cow); |
e089f05c | 55 | btrfs_inc_ref(trans, root, buf); |
02217ed2 CM |
56 | if (buf == root->node) { |
57 | root->node = cow; | |
e20d96d6 | 58 | get_bh(cow); |
a28ec197 | 59 | if (buf != root->commit_root) |
e20d96d6 | 60 | btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1); |
234b63a0 | 61 | btrfs_block_release(root, buf); |
02217ed2 | 62 | } else { |
e20d96d6 CM |
63 | btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot, |
64 | cow->b_blocknr); | |
d5719762 | 65 | mark_buffer_dirty(parent); |
e20d96d6 | 66 | btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1); |
02217ed2 | 67 | } |
234b63a0 | 68 | btrfs_block_release(root, buf); |
02217ed2 CM |
69 | return 0; |
70 | } | |
71 | ||
74123bd7 CM |
72 | /* |
73 | * The leaf data grows from end-to-front in the node. | |
74 | * this returns the address of the start of the last item, | |
75 | * which is the stop of the leaf data stack | |
76 | */ | |
123abc88 CM |
77 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
78 | struct btrfs_leaf *leaf) | |
be0e5c09 | 79 | { |
7518a238 | 80 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 81 | if (nr == 0) |
123abc88 | 82 | return BTRFS_LEAF_DATA_SIZE(root); |
0783fcfc | 83 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
84 | } |
85 | ||
74123bd7 CM |
86 | /* |
87 | * The space between the end of the leaf items and | |
88 | * the start of the leaf data. IOW, how much room | |
89 | * the leaf has left for both items and data | |
90 | */ | |
123abc88 | 91 | int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf) |
be0e5c09 | 92 | { |
123abc88 | 93 | int data_end = leaf_data_end(root, leaf); |
7518a238 | 94 | int nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 95 | char *items_end = (char *)(leaf->items + nritems + 1); |
123abc88 | 96 | return (char *)(btrfs_leaf_data(leaf) + data_end) - (char *)items_end; |
be0e5c09 CM |
97 | } |
98 | ||
74123bd7 CM |
99 | /* |
100 | * compare two keys in a memcmp fashion | |
101 | */ | |
9aca1d51 | 102 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 103 | { |
e2fa7227 CM |
104 | struct btrfs_key k1; |
105 | ||
106 | btrfs_disk_key_to_cpu(&k1, disk); | |
107 | ||
108 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 109 | return 1; |
e2fa7227 | 110 | if (k1.objectid < k2->objectid) |
be0e5c09 | 111 | return -1; |
a8a2ee0c CM |
112 | if (k1.offset > k2->offset) |
113 | return 1; | |
114 | if (k1.offset < k2->offset) | |
115 | return -1; | |
f254e52c CM |
116 | if (k1.flags > k2->flags) |
117 | return 1; | |
118 | if (k1.flags < k2->flags) | |
119 | return -1; | |
be0e5c09 CM |
120 | return 0; |
121 | } | |
74123bd7 | 122 | |
123abc88 CM |
123 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
124 | int level) | |
aa5d6bed CM |
125 | { |
126 | int i; | |
234b63a0 | 127 | struct btrfs_node *parent = NULL; |
e20d96d6 | 128 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
aa5d6bed | 129 | int parent_slot; |
7518a238 | 130 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
131 | |
132 | if (path->nodes[level + 1]) | |
e20d96d6 | 133 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 134 | parent_slot = path->slots[level + 1]; |
7518a238 CM |
135 | BUG_ON(nritems == 0); |
136 | if (parent) { | |
e2fa7227 | 137 | struct btrfs_disk_key *parent_key; |
123abc88 CM |
138 | parent_key = &parent->ptrs[parent_slot].key; |
139 | BUG_ON(memcmp(parent_key, &node->ptrs[0].key, | |
e2fa7227 | 140 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 141 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 142 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 143 | } |
123abc88 | 144 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
7518a238 | 145 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 | 146 | struct btrfs_key cpukey; |
123abc88 CM |
147 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key); |
148 | BUG_ON(comp_keys(&node->ptrs[i].key, &cpukey) >= 0); | |
aa5d6bed CM |
149 | } |
150 | return 0; | |
151 | } | |
152 | ||
123abc88 CM |
153 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
154 | int level) | |
aa5d6bed CM |
155 | { |
156 | int i; | |
e20d96d6 | 157 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[level]); |
234b63a0 | 158 | struct btrfs_node *parent = NULL; |
aa5d6bed | 159 | int parent_slot; |
7518a238 | 160 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
161 | |
162 | if (path->nodes[level + 1]) | |
e20d96d6 | 163 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 164 | parent_slot = path->slots[level + 1]; |
123abc88 | 165 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
7518a238 CM |
166 | |
167 | if (nritems == 0) | |
168 | return 0; | |
169 | ||
170 | if (parent) { | |
e2fa7227 | 171 | struct btrfs_disk_key *parent_key; |
123abc88 | 172 | parent_key = &parent->ptrs[parent_slot].key; |
aa5d6bed | 173 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, |
e2fa7227 | 174 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 175 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 176 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 177 | } |
7518a238 | 178 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 CM |
179 | struct btrfs_key cpukey; |
180 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key); | |
aa5d6bed | 181 | BUG_ON(comp_keys(&leaf->items[i].key, |
e2fa7227 | 182 | &cpukey) >= 0); |
0783fcfc CM |
183 | BUG_ON(btrfs_item_offset(leaf->items + i) != |
184 | btrfs_item_end(leaf->items + i + 1)); | |
aa5d6bed | 185 | if (i == 0) { |
0783fcfc CM |
186 | BUG_ON(btrfs_item_offset(leaf->items + i) + |
187 | btrfs_item_size(leaf->items + i) != | |
123abc88 | 188 | BTRFS_LEAF_DATA_SIZE(root)); |
aa5d6bed CM |
189 | } |
190 | } | |
aa5d6bed CM |
191 | return 0; |
192 | } | |
193 | ||
123abc88 CM |
194 | static int check_block(struct btrfs_root *root, struct btrfs_path *path, |
195 | int level) | |
aa5d6bed CM |
196 | { |
197 | if (level == 0) | |
123abc88 CM |
198 | return check_leaf(root, path, level); |
199 | return check_node(root, path, level); | |
aa5d6bed CM |
200 | } |
201 | ||
74123bd7 CM |
202 | /* |
203 | * search for key in the array p. items p are item_size apart | |
204 | * and there are 'max' items in p | |
205 | * the slot in the array is returned via slot, and it points to | |
206 | * the place where you would insert key if it is not found in | |
207 | * the array. | |
208 | * | |
209 | * slot may point to max if the key is bigger than all of the keys | |
210 | */ | |
9aca1d51 | 211 | static int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
212 | int max, int *slot) |
213 | { | |
214 | int low = 0; | |
215 | int high = max; | |
216 | int mid; | |
217 | int ret; | |
e2fa7227 | 218 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
219 | |
220 | while(low < high) { | |
221 | mid = (low + high) / 2; | |
e2fa7227 | 222 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
223 | ret = comp_keys(tmp, key); |
224 | ||
225 | if (ret < 0) | |
226 | low = mid + 1; | |
227 | else if (ret > 0) | |
228 | high = mid; | |
229 | else { | |
230 | *slot = mid; | |
231 | return 0; | |
232 | } | |
233 | } | |
234 | *slot = low; | |
235 | return 1; | |
236 | } | |
237 | ||
97571fd0 CM |
238 | /* |
239 | * simple bin_search frontend that does the right thing for | |
240 | * leaves vs nodes | |
241 | */ | |
9aca1d51 | 242 | static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 243 | { |
7518a238 | 244 | if (btrfs_is_leaf(c)) { |
234b63a0 | 245 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
0783fcfc CM |
246 | return generic_bin_search((void *)l->items, |
247 | sizeof(struct btrfs_item), | |
7518a238 CM |
248 | key, btrfs_header_nritems(&c->header), |
249 | slot); | |
be0e5c09 | 250 | } else { |
123abc88 CM |
251 | return generic_bin_search((void *)c->ptrs, |
252 | sizeof(struct btrfs_key_ptr), | |
7518a238 CM |
253 | key, btrfs_header_nritems(&c->header), |
254 | slot); | |
be0e5c09 CM |
255 | } |
256 | return -1; | |
257 | } | |
258 | ||
e20d96d6 CM |
259 | static struct buffer_head *read_node_slot(struct btrfs_root *root, |
260 | struct buffer_head *parent_buf, | |
bb803951 CM |
261 | int slot) |
262 | { | |
e20d96d6 | 263 | struct btrfs_node *node = btrfs_buffer_node(parent_buf); |
bb803951 CM |
264 | if (slot < 0) |
265 | return NULL; | |
7518a238 | 266 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 267 | return NULL; |
1d4f8a0c | 268 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
269 | } |
270 | ||
e089f05c CM |
271 | static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root |
272 | *root, struct btrfs_path *path, int level) | |
bb803951 | 273 | { |
e20d96d6 CM |
274 | struct buffer_head *right_buf; |
275 | struct buffer_head *mid_buf; | |
276 | struct buffer_head *left_buf; | |
277 | struct buffer_head *parent_buf = NULL; | |
234b63a0 CM |
278 | struct btrfs_node *right = NULL; |
279 | struct btrfs_node *mid; | |
280 | struct btrfs_node *left = NULL; | |
281 | struct btrfs_node *parent = NULL; | |
bb803951 CM |
282 | int ret = 0; |
283 | int wret; | |
284 | int pslot; | |
bb803951 | 285 | int orig_slot = path->slots[level]; |
79f95c82 | 286 | u64 orig_ptr; |
bb803951 CM |
287 | |
288 | if (level == 0) | |
289 | return 0; | |
290 | ||
291 | mid_buf = path->nodes[level]; | |
e20d96d6 | 292 | mid = btrfs_buffer_node(mid_buf); |
1d4f8a0c | 293 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 294 | |
234b63a0 | 295 | if (level < BTRFS_MAX_LEVEL - 1) |
bb803951 CM |
296 | parent_buf = path->nodes[level + 1]; |
297 | pslot = path->slots[level + 1]; | |
298 | ||
40689478 CM |
299 | /* |
300 | * deal with the case where there is only one pointer in the root | |
301 | * by promoting the node below to a root | |
302 | */ | |
bb803951 | 303 | if (!parent_buf) { |
e20d96d6 CM |
304 | struct buffer_head *child; |
305 | u64 blocknr = mid_buf->b_blocknr; | |
bb803951 | 306 | |
7518a238 | 307 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
308 | return 0; |
309 | ||
310 | /* promote the child to a root */ | |
311 | child = read_node_slot(root, mid_buf, 0); | |
312 | BUG_ON(!child); | |
313 | root->node = child; | |
314 | path->nodes[level] = NULL; | |
315 | /* once for the path */ | |
234b63a0 | 316 | btrfs_block_release(root, mid_buf); |
bb803951 | 317 | /* once for the root ptr */ |
234b63a0 | 318 | btrfs_block_release(root, mid_buf); |
e089f05c CM |
319 | clean_tree_block(trans, root, mid_buf); |
320 | return btrfs_free_extent(trans, root, blocknr, 1, 1); | |
bb803951 | 321 | } |
e20d96d6 | 322 | parent = btrfs_buffer_node(parent_buf); |
bb803951 | 323 | |
123abc88 CM |
324 | if (btrfs_header_nritems(&mid->header) > |
325 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
bb803951 CM |
326 | return 0; |
327 | ||
bb803951 CM |
328 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
329 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
330 | |
331 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 332 | if (left_buf) { |
e089f05c CM |
333 | btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1, |
334 | &left_buf); | |
e20d96d6 | 335 | left = btrfs_buffer_node(left_buf); |
7518a238 | 336 | orig_slot += btrfs_header_nritems(&left->header); |
e089f05c | 337 | wret = push_node_left(trans, root, left_buf, mid_buf); |
79f95c82 CM |
338 | if (wret < 0) |
339 | ret = wret; | |
bb803951 | 340 | } |
79f95c82 CM |
341 | |
342 | /* | |
343 | * then try to empty the right most buffer into the middle | |
344 | */ | |
bb803951 | 345 | if (right_buf) { |
e089f05c CM |
346 | btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1, |
347 | &right_buf); | |
e20d96d6 | 348 | right = btrfs_buffer_node(right_buf); |
e089f05c | 349 | wret = push_node_left(trans, root, mid_buf, right_buf); |
79f95c82 CM |
350 | if (wret < 0) |
351 | ret = wret; | |
7518a238 | 352 | if (btrfs_header_nritems(&right->header) == 0) { |
e20d96d6 | 353 | u64 blocknr = right_buf->b_blocknr; |
234b63a0 | 354 | btrfs_block_release(root, right_buf); |
e089f05c | 355 | clean_tree_block(trans, root, right_buf); |
bb803951 CM |
356 | right_buf = NULL; |
357 | right = NULL; | |
e089f05c CM |
358 | wret = del_ptr(trans, root, path, level + 1, pslot + |
359 | 1); | |
bb803951 CM |
360 | if (wret) |
361 | ret = wret; | |
e089f05c | 362 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
363 | if (wret) |
364 | ret = wret; | |
365 | } else { | |
123abc88 CM |
366 | memcpy(&parent->ptrs[pslot + 1].key, |
367 | &right->ptrs[0].key, | |
e2fa7227 | 368 | sizeof(struct btrfs_disk_key)); |
d5719762 | 369 | mark_buffer_dirty(parent_buf); |
bb803951 CM |
370 | } |
371 | } | |
7518a238 | 372 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
373 | /* |
374 | * we're not allowed to leave a node with one item in the | |
375 | * tree during a delete. A deletion from lower in the tree | |
376 | * could try to delete the only pointer in this node. | |
377 | * So, pull some keys from the left. | |
378 | * There has to be a left pointer at this point because | |
379 | * otherwise we would have pulled some pointers from the | |
380 | * right | |
381 | */ | |
382 | BUG_ON(!left_buf); | |
e089f05c | 383 | wret = balance_node_right(trans, root, mid_buf, left_buf); |
79f95c82 CM |
384 | if (wret < 0) |
385 | ret = wret; | |
386 | BUG_ON(wret == 1); | |
387 | } | |
7518a238 | 388 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 389 | /* we've managed to empty the middle node, drop it */ |
e20d96d6 | 390 | u64 blocknr = mid_buf->b_blocknr; |
234b63a0 | 391 | btrfs_block_release(root, mid_buf); |
e089f05c | 392 | clean_tree_block(trans, root, mid_buf); |
bb803951 CM |
393 | mid_buf = NULL; |
394 | mid = NULL; | |
e089f05c | 395 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
396 | if (wret) |
397 | ret = wret; | |
e089f05c | 398 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
399 | if (wret) |
400 | ret = wret; | |
79f95c82 CM |
401 | } else { |
402 | /* update the parent key to reflect our changes */ | |
123abc88 | 403 | memcpy(&parent->ptrs[pslot].key, &mid->ptrs[0].key, |
e2fa7227 | 404 | sizeof(struct btrfs_disk_key)); |
d5719762 | 405 | mark_buffer_dirty(parent_buf); |
79f95c82 | 406 | } |
bb803951 | 407 | |
79f95c82 | 408 | /* update the path */ |
bb803951 | 409 | if (left_buf) { |
7518a238 | 410 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
e20d96d6 | 411 | get_bh(left_buf); |
bb803951 CM |
412 | path->nodes[level] = left_buf; |
413 | path->slots[level + 1] -= 1; | |
414 | path->slots[level] = orig_slot; | |
415 | if (mid_buf) | |
234b63a0 | 416 | btrfs_block_release(root, mid_buf); |
bb803951 | 417 | } else { |
7518a238 | 418 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
419 | path->slots[level] = orig_slot; |
420 | } | |
421 | } | |
79f95c82 | 422 | /* double check we haven't messed things up */ |
123abc88 | 423 | check_block(root, path, level); |
e20d96d6 CM |
424 | if (orig_ptr != |
425 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]), | |
426 | path->slots[level])) | |
79f95c82 | 427 | BUG(); |
bb803951 CM |
428 | |
429 | if (right_buf) | |
234b63a0 | 430 | btrfs_block_release(root, right_buf); |
bb803951 | 431 | if (left_buf) |
234b63a0 | 432 | btrfs_block_release(root, left_buf); |
bb803951 CM |
433 | return ret; |
434 | } | |
435 | ||
74123bd7 CM |
436 | /* |
437 | * look for key in the tree. path is filled in with nodes along the way | |
438 | * if key is found, we return zero and you can find the item in the leaf | |
439 | * level of the path (level 0) | |
440 | * | |
441 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
442 | * be inserted, and 1 is returned. If there are other errors during the |
443 | * search a negative error number is returned. | |
97571fd0 CM |
444 | * |
445 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
446 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
447 | * possible) | |
74123bd7 | 448 | */ |
e089f05c CM |
449 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
450 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
451 | ins_len, int cow) | |
be0e5c09 | 452 | { |
e20d96d6 CM |
453 | struct buffer_head *b; |
454 | struct buffer_head *cow_buf; | |
234b63a0 | 455 | struct btrfs_node *c; |
be0e5c09 CM |
456 | int slot; |
457 | int ret; | |
458 | int level; | |
5c680ed6 | 459 | |
bb803951 CM |
460 | again: |
461 | b = root->node; | |
e20d96d6 | 462 | get_bh(b); |
eb60ceac | 463 | while (b) { |
e20d96d6 CM |
464 | c = btrfs_buffer_node(b); |
465 | level = btrfs_header_level(&c->header); | |
02217ed2 CM |
466 | if (cow) { |
467 | int wret; | |
e20d96d6 CM |
468 | wret = btrfs_cow_block(trans, root, b, |
469 | p->nodes[level + 1], | |
470 | p->slots[level + 1], | |
e089f05c | 471 | &cow_buf); |
02217ed2 CM |
472 | b = cow_buf; |
473 | } | |
474 | BUG_ON(!cow && ins_len); | |
e20d96d6 | 475 | c = btrfs_buffer_node(b); |
eb60ceac | 476 | p->nodes[level] = b; |
123abc88 | 477 | ret = check_block(root, p, level); |
aa5d6bed CM |
478 | if (ret) |
479 | return -1; | |
be0e5c09 | 480 | ret = bin_search(c, key, &slot); |
7518a238 | 481 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
482 | if (ret && slot > 0) |
483 | slot -= 1; | |
484 | p->slots[level] = slot; | |
7518a238 | 485 | if (ins_len > 0 && btrfs_header_nritems(&c->header) == |
123abc88 | 486 | BTRFS_NODEPTRS_PER_BLOCK(root)) { |
e089f05c | 487 | int sret = split_node(trans, root, p, level); |
5c680ed6 CM |
488 | BUG_ON(sret > 0); |
489 | if (sret) | |
490 | return sret; | |
491 | b = p->nodes[level]; | |
e20d96d6 | 492 | c = btrfs_buffer_node(b); |
5c680ed6 | 493 | slot = p->slots[level]; |
bb803951 | 494 | } else if (ins_len < 0) { |
e089f05c CM |
495 | int sret = balance_level(trans, root, p, |
496 | level); | |
bb803951 CM |
497 | if (sret) |
498 | return sret; | |
499 | b = p->nodes[level]; | |
500 | if (!b) | |
501 | goto again; | |
e20d96d6 | 502 | c = btrfs_buffer_node(b); |
bb803951 | 503 | slot = p->slots[level]; |
7518a238 | 504 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 505 | } |
1d4f8a0c | 506 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
be0e5c09 | 507 | } else { |
234b63a0 | 508 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
be0e5c09 | 509 | p->slots[level] = slot; |
123abc88 | 510 | if (ins_len > 0 && btrfs_leaf_free_space(root, l) < |
0783fcfc | 511 | sizeof(struct btrfs_item) + ins_len) { |
e089f05c | 512 | int sret = split_leaf(trans, root, p, ins_len); |
5c680ed6 CM |
513 | BUG_ON(sret > 0); |
514 | if (sret) | |
515 | return sret; | |
516 | } | |
be0e5c09 CM |
517 | return ret; |
518 | } | |
519 | } | |
aa5d6bed | 520 | return 1; |
be0e5c09 CM |
521 | } |
522 | ||
74123bd7 CM |
523 | /* |
524 | * adjust the pointers going up the tree, starting at level | |
525 | * making sure the right key of each node is points to 'key'. | |
526 | * This is used after shifting pointers to the left, so it stops | |
527 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
528 | * higher levels | |
aa5d6bed CM |
529 | * |
530 | * If this fails to write a tree block, it returns -1, but continues | |
531 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 532 | */ |
e089f05c CM |
533 | static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root |
534 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
535 | *key, int level) | |
be0e5c09 CM |
536 | { |
537 | int i; | |
aa5d6bed | 538 | int ret = 0; |
234b63a0 CM |
539 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
540 | struct btrfs_node *t; | |
be0e5c09 | 541 | int tslot = path->slots[i]; |
eb60ceac | 542 | if (!path->nodes[i]) |
be0e5c09 | 543 | break; |
e20d96d6 | 544 | t = btrfs_buffer_node(path->nodes[i]); |
123abc88 | 545 | memcpy(&t->ptrs[tslot].key, key, sizeof(*key)); |
d5719762 | 546 | mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
547 | if (tslot != 0) |
548 | break; | |
549 | } | |
aa5d6bed | 550 | return ret; |
be0e5c09 CM |
551 | } |
552 | ||
74123bd7 CM |
553 | /* |
554 | * try to push data from one node into the next node left in the | |
79f95c82 | 555 | * tree. |
aa5d6bed CM |
556 | * |
557 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
558 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 559 | */ |
e089f05c | 560 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
561 | *root, struct buffer_head *dst_buf, struct |
562 | buffer_head *src_buf) | |
be0e5c09 | 563 | { |
e20d96d6 CM |
564 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
565 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
be0e5c09 | 566 | int push_items = 0; |
bb803951 CM |
567 | int src_nritems; |
568 | int dst_nritems; | |
aa5d6bed | 569 | int ret = 0; |
be0e5c09 | 570 | |
7518a238 CM |
571 | src_nritems = btrfs_header_nritems(&src->header); |
572 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 573 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
eb60ceac | 574 | if (push_items <= 0) { |
be0e5c09 | 575 | return 1; |
eb60ceac | 576 | } |
be0e5c09 | 577 | |
bb803951 | 578 | if (src_nritems < push_items) |
79f95c82 CM |
579 | push_items = src_nritems; |
580 | ||
123abc88 CM |
581 | memcpy(dst->ptrs + dst_nritems, src->ptrs, |
582 | push_items * sizeof(struct btrfs_key_ptr)); | |
bb803951 | 583 | if (push_items < src_nritems) { |
123abc88 | 584 | memmove(src->ptrs, src->ptrs + push_items, |
e2fa7227 | 585 | (src_nritems - push_items) * |
123abc88 | 586 | sizeof(struct btrfs_key_ptr)); |
bb803951 | 587 | } |
7518a238 CM |
588 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
589 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
d5719762 CM |
590 | mark_buffer_dirty(src_buf); |
591 | mark_buffer_dirty(dst_buf); | |
79f95c82 CM |
592 | return ret; |
593 | } | |
594 | ||
595 | /* | |
596 | * try to push data from one node into the next node right in the | |
597 | * tree. | |
598 | * | |
599 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
600 | * error, and > 0 if there was no room in the right hand block. | |
601 | * | |
602 | * this will only push up to 1/2 the contents of the left node over | |
603 | */ | |
e089f05c | 604 | static int balance_node_right(struct btrfs_trans_handle *trans, struct |
e20d96d6 CM |
605 | btrfs_root *root, struct buffer_head *dst_buf, |
606 | struct buffer_head *src_buf) | |
79f95c82 | 607 | { |
e20d96d6 CM |
608 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
609 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
79f95c82 CM |
610 | int push_items = 0; |
611 | int max_push; | |
612 | int src_nritems; | |
613 | int dst_nritems; | |
614 | int ret = 0; | |
79f95c82 | 615 | |
7518a238 CM |
616 | src_nritems = btrfs_header_nritems(&src->header); |
617 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 618 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
79f95c82 CM |
619 | if (push_items <= 0) { |
620 | return 1; | |
621 | } | |
622 | ||
623 | max_push = src_nritems / 2 + 1; | |
624 | /* don't try to empty the node */ | |
625 | if (max_push > src_nritems) | |
626 | return 1; | |
627 | if (max_push < push_items) | |
628 | push_items = max_push; | |
629 | ||
123abc88 CM |
630 | memmove(dst->ptrs + push_items, dst->ptrs, |
631 | dst_nritems * sizeof(struct btrfs_key_ptr)); | |
632 | memcpy(dst->ptrs, src->ptrs + src_nritems - push_items, | |
633 | push_items * sizeof(struct btrfs_key_ptr)); | |
79f95c82 | 634 | |
7518a238 CM |
635 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
636 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 637 | |
d5719762 CM |
638 | mark_buffer_dirty(src_buf); |
639 | mark_buffer_dirty(dst_buf); | |
aa5d6bed | 640 | return ret; |
be0e5c09 CM |
641 | } |
642 | ||
97571fd0 CM |
643 | /* |
644 | * helper function to insert a new root level in the tree. | |
645 | * A new node is allocated, and a single item is inserted to | |
646 | * point to the existing root | |
aa5d6bed CM |
647 | * |
648 | * returns zero on success or < 0 on failure. | |
97571fd0 | 649 | */ |
e089f05c CM |
650 | static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root |
651 | *root, struct btrfs_path *path, int level) | |
5c680ed6 | 652 | { |
e20d96d6 | 653 | struct buffer_head *t; |
234b63a0 CM |
654 | struct btrfs_node *lower; |
655 | struct btrfs_node *c; | |
e2fa7227 | 656 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
657 | |
658 | BUG_ON(path->nodes[level]); | |
659 | BUG_ON(path->nodes[level-1] != root->node); | |
660 | ||
e089f05c | 661 | t = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 662 | c = btrfs_buffer_node(t); |
123abc88 | 663 | memset(c, 0, root->blocksize); |
7518a238 CM |
664 | btrfs_set_header_nritems(&c->header, 1); |
665 | btrfs_set_header_level(&c->header, level); | |
e20d96d6 | 666 | btrfs_set_header_blocknr(&c->header, t->b_blocknr); |
7f5c1516 | 667 | btrfs_set_header_generation(&c->header, trans->transid); |
7518a238 | 668 | btrfs_set_header_parentid(&c->header, |
e20d96d6 CM |
669 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
670 | lower = btrfs_buffer_node(path->nodes[level-1]); | |
7518a238 | 671 | if (btrfs_is_leaf(lower)) |
234b63a0 | 672 | lower_key = &((struct btrfs_leaf *)lower)->items[0].key; |
5c680ed6 | 673 | else |
123abc88 CM |
674 | lower_key = &lower->ptrs[0].key; |
675 | memcpy(&c->ptrs[0].key, lower_key, sizeof(struct btrfs_disk_key)); | |
e20d96d6 | 676 | btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->b_blocknr); |
d5719762 CM |
677 | |
678 | mark_buffer_dirty(t); | |
679 | ||
5c680ed6 | 680 | /* the super has an extra ref to root->node */ |
234b63a0 | 681 | btrfs_block_release(root, root->node); |
5c680ed6 | 682 | root->node = t; |
e20d96d6 | 683 | get_bh(t); |
5c680ed6 CM |
684 | path->nodes[level] = t; |
685 | path->slots[level] = 0; | |
686 | return 0; | |
687 | } | |
688 | ||
74123bd7 CM |
689 | /* |
690 | * worker function to insert a single pointer in a node. | |
691 | * the node should have enough room for the pointer already | |
97571fd0 | 692 | * |
74123bd7 CM |
693 | * slot and level indicate where you want the key to go, and |
694 | * blocknr is the block the key points to. | |
aa5d6bed CM |
695 | * |
696 | * returns zero on success and < 0 on any error | |
74123bd7 | 697 | */ |
e089f05c CM |
698 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
699 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
700 | *key, u64 blocknr, int slot, int level) | |
74123bd7 | 701 | { |
234b63a0 | 702 | struct btrfs_node *lower; |
74123bd7 | 703 | int nritems; |
5c680ed6 CM |
704 | |
705 | BUG_ON(!path->nodes[level]); | |
e20d96d6 | 706 | lower = btrfs_buffer_node(path->nodes[level]); |
7518a238 | 707 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
708 | if (slot > nritems) |
709 | BUG(); | |
123abc88 | 710 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
711 | BUG(); |
712 | if (slot != nritems) { | |
123abc88 CM |
713 | memmove(lower->ptrs + slot + 1, lower->ptrs + slot, |
714 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
74123bd7 | 715 | } |
123abc88 | 716 | memcpy(&lower->ptrs[slot].key, key, sizeof(struct btrfs_disk_key)); |
1d4f8a0c | 717 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 718 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
d5719762 | 719 | mark_buffer_dirty(path->nodes[level]); |
74123bd7 CM |
720 | return 0; |
721 | } | |
722 | ||
97571fd0 CM |
723 | /* |
724 | * split the node at the specified level in path in two. | |
725 | * The path is corrected to point to the appropriate node after the split | |
726 | * | |
727 | * Before splitting this tries to make some room in the node by pushing | |
728 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
729 | * |
730 | * returns 0 on success and < 0 on failure | |
97571fd0 | 731 | */ |
e089f05c CM |
732 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
733 | *root, struct btrfs_path *path, int level) | |
be0e5c09 | 734 | { |
e20d96d6 | 735 | struct buffer_head *t; |
234b63a0 | 736 | struct btrfs_node *c; |
e20d96d6 | 737 | struct buffer_head *split_buffer; |
234b63a0 | 738 | struct btrfs_node *split; |
be0e5c09 | 739 | int mid; |
5c680ed6 | 740 | int ret; |
aa5d6bed | 741 | int wret; |
7518a238 | 742 | u32 c_nritems; |
eb60ceac | 743 | |
5c680ed6 | 744 | t = path->nodes[level]; |
e20d96d6 | 745 | c = btrfs_buffer_node(t); |
5c680ed6 CM |
746 | if (t == root->node) { |
747 | /* trying to split the root, lets make a new one */ | |
e089f05c | 748 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
749 | if (ret) |
750 | return ret; | |
be0e5c09 | 751 | } |
7518a238 | 752 | c_nritems = btrfs_header_nritems(&c->header); |
e089f05c | 753 | split_buffer = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 754 | split = btrfs_buffer_node(split_buffer); |
7518a238 | 755 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
9a6f11ed | 756 | btrfs_set_header_level(&split->header, btrfs_header_level(&c->header)); |
e20d96d6 | 757 | btrfs_set_header_blocknr(&split->header, split_buffer->b_blocknr); |
7f5c1516 | 758 | btrfs_set_header_generation(&split->header, trans->transid); |
7518a238 | 759 | btrfs_set_header_parentid(&split->header, |
e20d96d6 | 760 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
7518a238 | 761 | mid = (c_nritems + 1) / 2; |
123abc88 CM |
762 | memcpy(split->ptrs, c->ptrs + mid, |
763 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
7518a238 CM |
764 | btrfs_set_header_nritems(&split->header, c_nritems - mid); |
765 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
766 | ret = 0; |
767 | ||
d5719762 CM |
768 | mark_buffer_dirty(t); |
769 | mark_buffer_dirty(split_buffer); | |
e089f05c | 770 | wret = insert_ptr(trans, root, path, &split->ptrs[0].key, |
e20d96d6 | 771 | split_buffer->b_blocknr, path->slots[level + 1] + 1, |
123abc88 | 772 | level + 1); |
aa5d6bed CM |
773 | if (wret) |
774 | ret = wret; | |
775 | ||
5de08d7d | 776 | if (path->slots[level] >= mid) { |
5c680ed6 | 777 | path->slots[level] -= mid; |
234b63a0 | 778 | btrfs_block_release(root, t); |
5c680ed6 CM |
779 | path->nodes[level] = split_buffer; |
780 | path->slots[level + 1] += 1; | |
781 | } else { | |
234b63a0 | 782 | btrfs_block_release(root, split_buffer); |
be0e5c09 | 783 | } |
aa5d6bed | 784 | return ret; |
be0e5c09 CM |
785 | } |
786 | ||
74123bd7 CM |
787 | /* |
788 | * how many bytes are required to store the items in a leaf. start | |
789 | * and nr indicate which items in the leaf to check. This totals up the | |
790 | * space used both by the item structs and the item data | |
791 | */ | |
234b63a0 | 792 | static int leaf_space_used(struct btrfs_leaf *l, int start, int nr) |
be0e5c09 CM |
793 | { |
794 | int data_len; | |
795 | int end = start + nr - 1; | |
796 | ||
797 | if (!nr) | |
798 | return 0; | |
0783fcfc CM |
799 | data_len = btrfs_item_end(l->items + start); |
800 | data_len = data_len - btrfs_item_offset(l->items + end); | |
801 | data_len += sizeof(struct btrfs_item) * nr; | |
be0e5c09 CM |
802 | return data_len; |
803 | } | |
804 | ||
00ec4c51 CM |
805 | /* |
806 | * push some data in the path leaf to the right, trying to free up at | |
807 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
808 | * |
809 | * returns 1 if the push failed because the other node didn't have enough | |
810 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 811 | */ |
e089f05c CM |
812 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
813 | *root, struct btrfs_path *path, int data_size) | |
00ec4c51 | 814 | { |
e20d96d6 CM |
815 | struct buffer_head *left_buf = path->nodes[0]; |
816 | struct btrfs_leaf *left = btrfs_buffer_leaf(left_buf); | |
234b63a0 | 817 | struct btrfs_leaf *right; |
e20d96d6 CM |
818 | struct buffer_head *right_buf; |
819 | struct buffer_head *upper; | |
820 | struct btrfs_node *upper_node; | |
00ec4c51 CM |
821 | int slot; |
822 | int i; | |
823 | int free_space; | |
824 | int push_space = 0; | |
825 | int push_items = 0; | |
0783fcfc | 826 | struct btrfs_item *item; |
7518a238 CM |
827 | u32 left_nritems; |
828 | u32 right_nritems; | |
00ec4c51 CM |
829 | |
830 | slot = path->slots[1]; | |
831 | if (!path->nodes[1]) { | |
832 | return 1; | |
833 | } | |
834 | upper = path->nodes[1]; | |
e20d96d6 CM |
835 | upper_node = btrfs_buffer_node(upper); |
836 | if (slot >= btrfs_header_nritems(&upper_node->header) - 1) { | |
00ec4c51 CM |
837 | return 1; |
838 | } | |
e20d96d6 CM |
839 | right_buf = read_tree_block(root, |
840 | btrfs_node_blockptr(btrfs_buffer_node(upper), slot + 1)); | |
841 | right = btrfs_buffer_leaf(right_buf); | |
123abc88 | 842 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 843 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 844 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
845 | return 1; |
846 | } | |
02217ed2 | 847 | /* cow and double check */ |
e089f05c | 848 | btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf); |
e20d96d6 | 849 | right = btrfs_buffer_leaf(right_buf); |
123abc88 | 850 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 851 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 852 | btrfs_block_release(root, right_buf); |
02217ed2 CM |
853 | return 1; |
854 | } | |
855 | ||
7518a238 CM |
856 | left_nritems = btrfs_header_nritems(&left->header); |
857 | for (i = left_nritems - 1; i >= 0; i--) { | |
00ec4c51 CM |
858 | item = left->items + i; |
859 | if (path->slots[0] == i) | |
860 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
861 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
862 | free_space) | |
00ec4c51 CM |
863 | break; |
864 | push_items++; | |
0783fcfc | 865 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
866 | } |
867 | if (push_items == 0) { | |
234b63a0 | 868 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
869 | return 1; |
870 | } | |
7518a238 | 871 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 872 | /* push left to right */ |
0783fcfc | 873 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
123abc88 | 874 | push_space -= leaf_data_end(root, left); |
00ec4c51 | 875 | /* make room in the right data area */ |
123abc88 CM |
876 | memmove(btrfs_leaf_data(right) + leaf_data_end(root, right) - |
877 | push_space, btrfs_leaf_data(right) + leaf_data_end(root, right), | |
878 | BTRFS_LEAF_DATA_SIZE(root) - leaf_data_end(root, right)); | |
00ec4c51 | 879 | /* copy from the left data area */ |
123abc88 CM |
880 | memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - push_space, |
881 | btrfs_leaf_data(left) + leaf_data_end(root, left), push_space); | |
00ec4c51 | 882 | memmove(right->items + push_items, right->items, |
0783fcfc | 883 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 884 | /* copy the items from left to right */ |
7518a238 | 885 | memcpy(right->items, left->items + left_nritems - push_items, |
0783fcfc | 886 | push_items * sizeof(struct btrfs_item)); |
00ec4c51 CM |
887 | |
888 | /* update the item pointers */ | |
7518a238 CM |
889 | right_nritems += push_items; |
890 | btrfs_set_header_nritems(&right->header, right_nritems); | |
123abc88 | 891 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 892 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
893 | btrfs_set_item_offset(right->items + i, push_space - |
894 | btrfs_item_size(right->items + i)); | |
895 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 896 | } |
7518a238 CM |
897 | left_nritems -= push_items; |
898 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 899 | |
d5719762 CM |
900 | mark_buffer_dirty(left_buf); |
901 | mark_buffer_dirty(right_buf); | |
e20d96d6 | 902 | memcpy(&upper_node->ptrs[slot + 1].key, |
e2fa7227 | 903 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
d5719762 | 904 | mark_buffer_dirty(upper); |
02217ed2 | 905 | |
00ec4c51 | 906 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
907 | if (path->slots[0] >= left_nritems) { |
908 | path->slots[0] -= left_nritems; | |
234b63a0 | 909 | btrfs_block_release(root, path->nodes[0]); |
00ec4c51 CM |
910 | path->nodes[0] = right_buf; |
911 | path->slots[1] += 1; | |
912 | } else { | |
234b63a0 | 913 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
914 | } |
915 | return 0; | |
916 | } | |
74123bd7 CM |
917 | /* |
918 | * push some data in the path leaf to the left, trying to free up at | |
919 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
920 | */ | |
e089f05c CM |
921 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
922 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 923 | { |
e20d96d6 CM |
924 | struct buffer_head *right_buf = path->nodes[0]; |
925 | struct btrfs_leaf *right = btrfs_buffer_leaf(right_buf); | |
926 | struct buffer_head *t; | |
234b63a0 | 927 | struct btrfs_leaf *left; |
be0e5c09 CM |
928 | int slot; |
929 | int i; | |
930 | int free_space; | |
931 | int push_space = 0; | |
932 | int push_items = 0; | |
0783fcfc | 933 | struct btrfs_item *item; |
7518a238 | 934 | u32 old_left_nritems; |
aa5d6bed CM |
935 | int ret = 0; |
936 | int wret; | |
be0e5c09 CM |
937 | |
938 | slot = path->slots[1]; | |
939 | if (slot == 0) { | |
940 | return 1; | |
941 | } | |
942 | if (!path->nodes[1]) { | |
943 | return 1; | |
944 | } | |
e20d96d6 CM |
945 | t = read_tree_block(root, |
946 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[1]), slot - 1)); | |
947 | left = btrfs_buffer_leaf(t); | |
123abc88 | 948 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 949 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 950 | btrfs_block_release(root, t); |
be0e5c09 CM |
951 | return 1; |
952 | } | |
02217ed2 CM |
953 | |
954 | /* cow and double check */ | |
e089f05c | 955 | btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t); |
e20d96d6 | 956 | left = btrfs_buffer_leaf(t); |
123abc88 | 957 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 958 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 959 | btrfs_block_release(root, t); |
02217ed2 CM |
960 | return 1; |
961 | } | |
962 | ||
7518a238 | 963 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
be0e5c09 CM |
964 | item = right->items + i; |
965 | if (path->slots[0] == i) | |
966 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
967 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
968 | free_space) | |
be0e5c09 CM |
969 | break; |
970 | push_items++; | |
0783fcfc | 971 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
972 | } |
973 | if (push_items == 0) { | |
234b63a0 | 974 | btrfs_block_release(root, t); |
be0e5c09 CM |
975 | return 1; |
976 | } | |
977 | /* push data from right to left */ | |
7518a238 | 978 | memcpy(left->items + btrfs_header_nritems(&left->header), |
0783fcfc | 979 | right->items, push_items * sizeof(struct btrfs_item)); |
123abc88 | 980 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
0783fcfc | 981 | btrfs_item_offset(right->items + push_items -1); |
123abc88 CM |
982 | memcpy(btrfs_leaf_data(left) + leaf_data_end(root, left) - push_space, |
983 | btrfs_leaf_data(right) + | |
984 | btrfs_item_offset(right->items + push_items - 1), | |
be0e5c09 | 985 | push_space); |
7518a238 | 986 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
987 | BUG_ON(old_left_nritems < 0); |
988 | ||
0783fcfc | 989 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
123abc88 CM |
990 | u32 ioff = btrfs_item_offset(left->items + i); |
991 | btrfs_set_item_offset(left->items + i, ioff - | |
992 | (BTRFS_LEAF_DATA_SIZE(root) - | |
0783fcfc CM |
993 | btrfs_item_offset(left->items + |
994 | old_left_nritems - 1))); | |
be0e5c09 | 995 | } |
7518a238 | 996 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
997 | |
998 | /* fixup right node */ | |
0783fcfc | 999 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
123abc88 CM |
1000 | leaf_data_end(root, right); |
1001 | memmove(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
1002 | push_space, btrfs_leaf_data(right) + | |
1003 | leaf_data_end(root, right), push_space); | |
be0e5c09 | 1004 | memmove(right->items, right->items + push_items, |
7518a238 | 1005 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 1006 | sizeof(struct btrfs_item)); |
7518a238 CM |
1007 | btrfs_set_header_nritems(&right->header, |
1008 | btrfs_header_nritems(&right->header) - | |
1009 | push_items); | |
123abc88 | 1010 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
eb60ceac | 1011 | |
7518a238 | 1012 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
1013 | btrfs_set_item_offset(right->items + i, push_space - |
1014 | btrfs_item_size(right->items + i)); | |
1015 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1016 | } |
eb60ceac | 1017 | |
d5719762 CM |
1018 | mark_buffer_dirty(t); |
1019 | mark_buffer_dirty(right_buf); | |
eb60ceac | 1020 | |
e089f05c | 1021 | wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1); |
aa5d6bed CM |
1022 | if (wret) |
1023 | ret = wret; | |
be0e5c09 CM |
1024 | |
1025 | /* then fixup the leaf pointer in the path */ | |
1026 | if (path->slots[0] < push_items) { | |
1027 | path->slots[0] += old_left_nritems; | |
234b63a0 | 1028 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1029 | path->nodes[0] = t; |
be0e5c09 CM |
1030 | path->slots[1] -= 1; |
1031 | } else { | |
234b63a0 | 1032 | btrfs_block_release(root, t); |
be0e5c09 CM |
1033 | path->slots[0] -= push_items; |
1034 | } | |
eb60ceac | 1035 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 1036 | return ret; |
be0e5c09 CM |
1037 | } |
1038 | ||
74123bd7 CM |
1039 | /* |
1040 | * split the path's leaf in two, making sure there is at least data_size | |
1041 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1042 | * |
1043 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1044 | */ |
e089f05c CM |
1045 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
1046 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 1047 | { |
e20d96d6 | 1048 | struct buffer_head *l_buf; |
234b63a0 | 1049 | struct btrfs_leaf *l; |
7518a238 | 1050 | u32 nritems; |
eb60ceac CM |
1051 | int mid; |
1052 | int slot; | |
234b63a0 | 1053 | struct btrfs_leaf *right; |
e20d96d6 | 1054 | struct buffer_head *right_buffer; |
0783fcfc | 1055 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1056 | int data_copy_size; |
1057 | int rt_data_off; | |
1058 | int i; | |
1059 | int ret; | |
aa5d6bed CM |
1060 | int wret; |
1061 | ||
40689478 | 1062 | /* first try to make some room by pushing left and right */ |
e089f05c | 1063 | wret = push_leaf_left(trans, root, path, data_size); |
eaee50e8 CM |
1064 | if (wret < 0) |
1065 | return wret; | |
1066 | if (wret) { | |
e089f05c | 1067 | wret = push_leaf_right(trans, root, path, data_size); |
eaee50e8 CM |
1068 | if (wret < 0) |
1069 | return wret; | |
1070 | } | |
aa5d6bed | 1071 | l_buf = path->nodes[0]; |
e20d96d6 | 1072 | l = btrfs_buffer_leaf(l_buf); |
aa5d6bed CM |
1073 | |
1074 | /* did the pushes work? */ | |
123abc88 CM |
1075 | if (btrfs_leaf_free_space(root, l) >= |
1076 | sizeof(struct btrfs_item) + data_size) | |
aa5d6bed CM |
1077 | return 0; |
1078 | ||
5c680ed6 | 1079 | if (!path->nodes[1]) { |
e089f05c | 1080 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
1081 | if (ret) |
1082 | return ret; | |
1083 | } | |
eb60ceac | 1084 | slot = path->slots[0]; |
7518a238 | 1085 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1086 | mid = (nritems + 1)/ 2; |
e089f05c | 1087 | right_buffer = btrfs_alloc_free_block(trans, root); |
eb60ceac CM |
1088 | BUG_ON(!right_buffer); |
1089 | BUG_ON(mid == nritems); | |
e20d96d6 | 1090 | right = btrfs_buffer_leaf(right_buffer); |
123abc88 | 1091 | memset(&right->header, 0, sizeof(right->header)); |
be0e5c09 | 1092 | if (mid <= slot) { |
97571fd0 | 1093 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 | 1094 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
123abc88 | 1095 | BTRFS_LEAF_DATA_SIZE(root)) |
be0e5c09 CM |
1096 | BUG(); |
1097 | } else { | |
97571fd0 | 1098 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 | 1099 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
123abc88 | 1100 | BTRFS_LEAF_DATA_SIZE(root)) |
be0e5c09 CM |
1101 | BUG(); |
1102 | } | |
7518a238 | 1103 | btrfs_set_header_nritems(&right->header, nritems - mid); |
e20d96d6 | 1104 | btrfs_set_header_blocknr(&right->header, right_buffer->b_blocknr); |
7f5c1516 | 1105 | btrfs_set_header_generation(&right->header, trans->transid); |
7518a238 CM |
1106 | btrfs_set_header_level(&right->header, 0); |
1107 | btrfs_set_header_parentid(&right->header, | |
e20d96d6 | 1108 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
123abc88 CM |
1109 | data_copy_size = btrfs_item_end(l->items + mid) - |
1110 | leaf_data_end(root, l); | |
be0e5c09 | 1111 | memcpy(right->items, l->items + mid, |
0783fcfc | 1112 | (nritems - mid) * sizeof(struct btrfs_item)); |
123abc88 CM |
1113 | memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - |
1114 | data_copy_size, btrfs_leaf_data(l) + | |
1115 | leaf_data_end(root, l), data_copy_size); | |
1116 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
1117 | btrfs_item_end(l->items + mid); | |
74123bd7 | 1118 | |
0783fcfc | 1119 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
123abc88 | 1120 | u32 ioff = btrfs_item_offset(right->items + i); |
0783fcfc CM |
1121 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); |
1122 | } | |
74123bd7 | 1123 | |
7518a238 | 1124 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed | 1125 | ret = 0; |
e089f05c | 1126 | wret = insert_ptr(trans, root, path, &right->items[0].key, |
e20d96d6 | 1127 | right_buffer->b_blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1128 | if (wret) |
1129 | ret = wret; | |
d5719762 CM |
1130 | mark_buffer_dirty(right_buffer); |
1131 | mark_buffer_dirty(l_buf); | |
eb60ceac | 1132 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1133 | if (mid <= slot) { |
234b63a0 | 1134 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1135 | path->nodes[0] = right_buffer; |
be0e5c09 CM |
1136 | path->slots[0] -= mid; |
1137 | path->slots[1] += 1; | |
eb60ceac | 1138 | } else |
234b63a0 | 1139 | btrfs_block_release(root, right_buffer); |
eb60ceac | 1140 | BUG_ON(path->slots[0] < 0); |
be0e5c09 CM |
1141 | return ret; |
1142 | } | |
1143 | ||
74123bd7 CM |
1144 | /* |
1145 | * Given a key and some data, insert an item into the tree. | |
1146 | * This does all the path init required, making room in the tree if needed. | |
1147 | */ | |
e089f05c CM |
1148 | int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1149 | *root, struct btrfs_path *path, struct btrfs_key | |
1150 | *cpu_key, u32 data_size) | |
be0e5c09 | 1151 | { |
aa5d6bed | 1152 | int ret = 0; |
be0e5c09 | 1153 | int slot; |
eb60ceac | 1154 | int slot_orig; |
234b63a0 | 1155 | struct btrfs_leaf *leaf; |
e20d96d6 | 1156 | struct buffer_head *leaf_buf; |
7518a238 | 1157 | u32 nritems; |
be0e5c09 | 1158 | unsigned int data_end; |
e2fa7227 CM |
1159 | struct btrfs_disk_key disk_key; |
1160 | ||
1161 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1162 | |
74123bd7 | 1163 | /* create a root if there isn't one */ |
5c680ed6 | 1164 | if (!root->node) |
cfaa7295 | 1165 | BUG(); |
e089f05c | 1166 | ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1); |
eb60ceac | 1167 | if (ret == 0) { |
f0930a37 | 1168 | return -EEXIST; |
aa5d6bed | 1169 | } |
ed2ff2cb CM |
1170 | if (ret < 0) |
1171 | goto out; | |
be0e5c09 | 1172 | |
62e2749e CM |
1173 | slot_orig = path->slots[0]; |
1174 | leaf_buf = path->nodes[0]; | |
e20d96d6 | 1175 | leaf = btrfs_buffer_leaf(leaf_buf); |
74123bd7 | 1176 | |
7518a238 | 1177 | nritems = btrfs_header_nritems(&leaf->header); |
123abc88 | 1178 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 1179 | |
123abc88 | 1180 | if (btrfs_leaf_free_space(root, leaf) < |
234b63a0 | 1181 | sizeof(struct btrfs_item) + data_size) |
be0e5c09 CM |
1182 | BUG(); |
1183 | ||
62e2749e | 1184 | slot = path->slots[0]; |
eb60ceac | 1185 | BUG_ON(slot < 0); |
be0e5c09 CM |
1186 | if (slot != nritems) { |
1187 | int i; | |
0783fcfc | 1188 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1189 | |
1190 | /* | |
1191 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1192 | */ | |
1193 | /* first correct the data pointers */ | |
0783fcfc | 1194 | for (i = slot; i < nritems; i++) { |
123abc88 | 1195 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1196 | btrfs_set_item_offset(leaf->items + i, |
1197 | ioff - data_size); | |
1198 | } | |
be0e5c09 CM |
1199 | |
1200 | /* shift the items */ | |
1201 | memmove(leaf->items + slot + 1, leaf->items + slot, | |
0783fcfc | 1202 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
1203 | |
1204 | /* shift the data */ | |
123abc88 CM |
1205 | memmove(btrfs_leaf_data(leaf) + data_end - data_size, |
1206 | btrfs_leaf_data(leaf) + | |
be0e5c09 CM |
1207 | data_end, old_data - data_end); |
1208 | data_end = old_data; | |
1209 | } | |
62e2749e | 1210 | /* setup the item for the new data */ |
e2fa7227 CM |
1211 | memcpy(&leaf->items[slot].key, &disk_key, |
1212 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1213 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1214 | btrfs_set_item_size(leaf->items + slot, data_size); | |
7518a238 | 1215 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
d5719762 | 1216 | mark_buffer_dirty(leaf_buf); |
aa5d6bed CM |
1217 | |
1218 | ret = 0; | |
8e19f2cd | 1219 | if (slot == 0) |
e089f05c | 1220 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 1221 | |
123abc88 | 1222 | if (btrfs_leaf_free_space(root, leaf) < 0) |
be0e5c09 | 1223 | BUG(); |
62e2749e | 1224 | check_leaf(root, path, 0); |
ed2ff2cb | 1225 | out: |
62e2749e CM |
1226 | return ret; |
1227 | } | |
1228 | ||
1229 | /* | |
1230 | * Given a key and some data, insert an item into the tree. | |
1231 | * This does all the path init required, making room in the tree if needed. | |
1232 | */ | |
e089f05c CM |
1233 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1234 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
1235 | data_size) | |
62e2749e CM |
1236 | { |
1237 | int ret = 0; | |
1238 | struct btrfs_path path; | |
1239 | u8 *ptr; | |
1240 | ||
1241 | btrfs_init_path(&path); | |
e089f05c | 1242 | ret = btrfs_insert_empty_item(trans, root, &path, cpu_key, data_size); |
62e2749e | 1243 | if (!ret) { |
e20d96d6 CM |
1244 | ptr = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), |
1245 | path.slots[0], u8); | |
62e2749e | 1246 | memcpy(ptr, data, data_size); |
d5719762 | 1247 | mark_buffer_dirty(path.nodes[0]); |
62e2749e | 1248 | } |
234b63a0 | 1249 | btrfs_release_path(root, &path); |
aa5d6bed | 1250 | return ret; |
be0e5c09 CM |
1251 | } |
1252 | ||
74123bd7 | 1253 | /* |
5de08d7d | 1254 | * delete the pointer from a given node. |
74123bd7 CM |
1255 | * |
1256 | * If the delete empties a node, the node is removed from the tree, | |
1257 | * continuing all the way the root if required. The root is converted into | |
1258 | * a leaf if all the nodes are emptied. | |
1259 | */ | |
e089f05c CM |
1260 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1261 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 1262 | { |
234b63a0 | 1263 | struct btrfs_node *node; |
e20d96d6 | 1264 | struct buffer_head *parent = path->nodes[level]; |
7518a238 | 1265 | u32 nritems; |
aa5d6bed | 1266 | int ret = 0; |
bb803951 | 1267 | int wret; |
be0e5c09 | 1268 | |
e20d96d6 | 1269 | node = btrfs_buffer_node(parent); |
7518a238 | 1270 | nritems = btrfs_header_nritems(&node->header); |
bb803951 | 1271 | if (slot != nritems -1) { |
123abc88 CM |
1272 | memmove(node->ptrs + slot, node->ptrs + slot + 1, |
1273 | sizeof(struct btrfs_key_ptr) * (nritems - slot - 1)); | |
bb803951 | 1274 | } |
7518a238 CM |
1275 | nritems--; |
1276 | btrfs_set_header_nritems(&node->header, nritems); | |
1277 | if (nritems == 0 && parent == root->node) { | |
e20d96d6 CM |
1278 | struct btrfs_header *header = btrfs_buffer_header(root->node); |
1279 | BUG_ON(btrfs_header_level(header) != 1); | |
bb803951 | 1280 | /* just turn the root into a leaf and break */ |
e20d96d6 | 1281 | btrfs_set_header_level(header, 0); |
bb803951 | 1282 | } else if (slot == 0) { |
e089f05c | 1283 | wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key, |
123abc88 | 1284 | level + 1); |
0f70abe2 CM |
1285 | if (wret) |
1286 | ret = wret; | |
be0e5c09 | 1287 | } |
d5719762 | 1288 | mark_buffer_dirty(parent); |
aa5d6bed | 1289 | return ret; |
be0e5c09 CM |
1290 | } |
1291 | ||
74123bd7 CM |
1292 | /* |
1293 | * delete the item at the leaf level in path. If that empties | |
1294 | * the leaf, remove it from the tree | |
1295 | */ | |
e089f05c CM |
1296 | int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1297 | struct btrfs_path *path) | |
be0e5c09 | 1298 | { |
be0e5c09 | 1299 | int slot; |
234b63a0 | 1300 | struct btrfs_leaf *leaf; |
e20d96d6 | 1301 | struct buffer_head *leaf_buf; |
be0e5c09 CM |
1302 | int doff; |
1303 | int dsize; | |
aa5d6bed CM |
1304 | int ret = 0; |
1305 | int wret; | |
7518a238 | 1306 | u32 nritems; |
be0e5c09 | 1307 | |
eb60ceac | 1308 | leaf_buf = path->nodes[0]; |
e20d96d6 | 1309 | leaf = btrfs_buffer_leaf(leaf_buf); |
4920c9ac | 1310 | slot = path->slots[0]; |
0783fcfc CM |
1311 | doff = btrfs_item_offset(leaf->items + slot); |
1312 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1313 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1314 | |
7518a238 | 1315 | if (slot != nritems - 1) { |
be0e5c09 | 1316 | int i; |
123abc88 CM |
1317 | int data_end = leaf_data_end(root, leaf); |
1318 | memmove(btrfs_leaf_data(leaf) + data_end + dsize, | |
1319 | btrfs_leaf_data(leaf) + data_end, | |
be0e5c09 | 1320 | doff - data_end); |
0783fcfc | 1321 | for (i = slot + 1; i < nritems; i++) { |
123abc88 | 1322 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1323 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); |
1324 | } | |
be0e5c09 | 1325 | memmove(leaf->items + slot, leaf->items + slot + 1, |
0783fcfc | 1326 | sizeof(struct btrfs_item) * |
7518a238 | 1327 | (nritems - slot - 1)); |
be0e5c09 | 1328 | } |
7518a238 CM |
1329 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1330 | nritems--; | |
74123bd7 | 1331 | /* delete the leaf if we've emptied it */ |
7518a238 | 1332 | if (nritems == 0) { |
eb60ceac | 1333 | if (leaf_buf == root->node) { |
7518a238 | 1334 | btrfs_set_header_level(&leaf->header, 0); |
9a8dd150 | 1335 | } else { |
e089f05c CM |
1336 | clean_tree_block(trans, root, leaf_buf); |
1337 | wret = del_ptr(trans, root, path, 1, path->slots[1]); | |
aa5d6bed CM |
1338 | if (wret) |
1339 | ret = wret; | |
e089f05c | 1340 | wret = btrfs_free_extent(trans, root, |
e20d96d6 | 1341 | leaf_buf->b_blocknr, 1, 1); |
0f70abe2 CM |
1342 | if (wret) |
1343 | ret = wret; | |
9a8dd150 | 1344 | } |
be0e5c09 | 1345 | } else { |
7518a238 | 1346 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 1347 | if (slot == 0) { |
e089f05c CM |
1348 | wret = fixup_low_keys(trans, root, path, |
1349 | &leaf->items[0].key, 1); | |
aa5d6bed CM |
1350 | if (wret) |
1351 | ret = wret; | |
1352 | } | |
aa5d6bed | 1353 | |
74123bd7 | 1354 | /* delete the leaf if it is mostly empty */ |
123abc88 | 1355 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
1356 | /* push_leaf_left fixes the path. |
1357 | * make sure the path still points to our leaf | |
1358 | * for possible call to del_ptr below | |
1359 | */ | |
4920c9ac | 1360 | slot = path->slots[1]; |
e20d96d6 | 1361 | get_bh(leaf_buf); |
e089f05c | 1362 | wret = push_leaf_left(trans, root, path, 1); |
aa5d6bed CM |
1363 | if (wret < 0) |
1364 | ret = wret; | |
f0930a37 | 1365 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1366 | btrfs_header_nritems(&leaf->header)) { |
e089f05c | 1367 | wret = push_leaf_right(trans, root, path, 1); |
aa5d6bed CM |
1368 | if (wret < 0) |
1369 | ret = wret; | |
1370 | } | |
7518a238 | 1371 | if (btrfs_header_nritems(&leaf->header) == 0) { |
e20d96d6 | 1372 | u64 blocknr = leaf_buf->b_blocknr; |
e089f05c CM |
1373 | clean_tree_block(trans, root, leaf_buf); |
1374 | wret = del_ptr(trans, root, path, 1, slot); | |
aa5d6bed CM |
1375 | if (wret) |
1376 | ret = wret; | |
234b63a0 | 1377 | btrfs_block_release(root, leaf_buf); |
e089f05c CM |
1378 | wret = btrfs_free_extent(trans, root, blocknr, |
1379 | 1, 1); | |
0f70abe2 CM |
1380 | if (wret) |
1381 | ret = wret; | |
5de08d7d | 1382 | } else { |
d5719762 | 1383 | mark_buffer_dirty(leaf_buf); |
234b63a0 | 1384 | btrfs_block_release(root, leaf_buf); |
be0e5c09 | 1385 | } |
d5719762 CM |
1386 | } else { |
1387 | mark_buffer_dirty(leaf_buf); | |
be0e5c09 CM |
1388 | } |
1389 | } | |
aa5d6bed | 1390 | return ret; |
be0e5c09 CM |
1391 | } |
1392 | ||
97571fd0 CM |
1393 | /* |
1394 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1395 | * returns 0 if it found something or 1 if there are no greater leaves. |
1396 | * returns < 0 on io errors. | |
97571fd0 | 1397 | */ |
234b63a0 | 1398 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
1399 | { |
1400 | int slot; | |
1401 | int level = 1; | |
1402 | u64 blocknr; | |
e20d96d6 CM |
1403 | struct buffer_head *c; |
1404 | struct btrfs_node *c_node; | |
1405 | struct buffer_head *next = NULL; | |
d97e63b6 | 1406 | |
234b63a0 | 1407 | while(level < BTRFS_MAX_LEVEL) { |
d97e63b6 | 1408 | if (!path->nodes[level]) |
0f70abe2 | 1409 | return 1; |
d97e63b6 CM |
1410 | slot = path->slots[level] + 1; |
1411 | c = path->nodes[level]; | |
e20d96d6 CM |
1412 | c_node = btrfs_buffer_node(c); |
1413 | if (slot >= btrfs_header_nritems(&c_node->header)) { | |
d97e63b6 CM |
1414 | level++; |
1415 | continue; | |
1416 | } | |
e20d96d6 | 1417 | blocknr = btrfs_node_blockptr(c_node, slot); |
cfaa7295 | 1418 | if (next) |
234b63a0 | 1419 | btrfs_block_release(root, next); |
d97e63b6 CM |
1420 | next = read_tree_block(root, blocknr); |
1421 | break; | |
1422 | } | |
1423 | path->slots[level] = slot; | |
1424 | while(1) { | |
1425 | level--; | |
1426 | c = path->nodes[level]; | |
234b63a0 | 1427 | btrfs_block_release(root, c); |
d97e63b6 CM |
1428 | path->nodes[level] = next; |
1429 | path->slots[level] = 0; | |
1430 | if (!level) | |
1431 | break; | |
1d4f8a0c | 1432 | next = read_tree_block(root, |
e20d96d6 | 1433 | btrfs_node_blockptr(btrfs_buffer_node(next), 0)); |
d97e63b6 CM |
1434 | } |
1435 | return 0; | |
1436 | } |