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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
eb60ceac CM |
19 | #include "ctree.h" |
20 | #include "disk-io.h" | |
7f5c1516 | 21 | #include "transaction.h" |
9a8dd150 | 22 | |
e089f05c CM |
23 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
24 | *root, struct btrfs_path *path, int level); | |
25 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 CM |
26 | *root, struct btrfs_key *ins_key, |
27 | struct btrfs_path *path, int data_size); | |
e089f05c | 28 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 | 29 | *root, struct buffer_head *dst, struct buffer_head |
e089f05c CM |
30 | *src); |
31 | static int balance_node_right(struct btrfs_trans_handle *trans, struct | |
e20d96d6 CM |
32 | btrfs_root *root, struct buffer_head *dst_buf, |
33 | struct buffer_head *src_buf); | |
e089f05c CM |
34 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
35 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 36 | |
df24a2b9 | 37 | inline void btrfs_init_path(struct btrfs_path *p) |
2c90e5d6 | 38 | { |
df24a2b9 | 39 | memset(p, 0, sizeof(*p)); |
2c90e5d6 CM |
40 | } |
41 | ||
df24a2b9 | 42 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 43 | { |
df24a2b9 CM |
44 | struct btrfs_path *path; |
45 | path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS); | |
2cc58cf2 | 46 | if (path) { |
df24a2b9 | 47 | btrfs_init_path(path); |
2cc58cf2 CM |
48 | path->reada = 1; |
49 | } | |
df24a2b9 | 50 | return path; |
2c90e5d6 CM |
51 | } |
52 | ||
df24a2b9 | 53 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 54 | { |
df24a2b9 CM |
55 | btrfs_release_path(NULL, p); |
56 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
57 | } |
58 | ||
234b63a0 | 59 | void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
60 | { |
61 | int i; | |
234b63a0 | 62 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
eb60ceac CM |
63 | if (!p->nodes[i]) |
64 | break; | |
234b63a0 | 65 | btrfs_block_release(root, p->nodes[i]); |
eb60ceac | 66 | } |
aa5d6bed | 67 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
68 | } |
69 | ||
6702ed49 | 70 | static int __btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
71 | *root, struct buffer_head *buf, struct buffer_head |
72 | *parent, int parent_slot, struct buffer_head | |
6702ed49 | 73 | **cow_ret, u64 search_start, u64 empty_size) |
02217ed2 | 74 | { |
e20d96d6 CM |
75 | struct buffer_head *cow; |
76 | struct btrfs_node *cow_node; | |
6702ed49 CM |
77 | int ret = 0; |
78 | int different_trans = 0; | |
02217ed2 | 79 | |
6702ed49 | 80 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
ccd467d6 | 81 | WARN_ON(!buffer_uptodate(buf)); |
6702ed49 | 82 | cow = btrfs_alloc_free_block(trans, root, search_start, empty_size); |
54aa1f4d CM |
83 | if (IS_ERR(cow)) |
84 | return PTR_ERR(cow); | |
6702ed49 | 85 | |
e20d96d6 | 86 | cow_node = btrfs_buffer_node(cow); |
2c90e5d6 CM |
87 | if (buf->b_size != root->blocksize || cow->b_size != root->blocksize) |
88 | WARN_ON(1); | |
6702ed49 | 89 | |
e20d96d6 | 90 | memcpy(cow_node, btrfs_buffer_node(buf), root->blocksize); |
7eccb903 | 91 | btrfs_set_header_blocknr(&cow_node->header, bh_blocknr(cow)); |
7f5c1516 | 92 | btrfs_set_header_generation(&cow_node->header, trans->transid); |
4d775673 | 93 | btrfs_set_header_owner(&cow_node->header, root->root_key.objectid); |
6702ed49 CM |
94 | |
95 | WARN_ON(btrfs_header_generation(btrfs_buffer_header(buf)) > | |
96 | trans->transid); | |
97 | if (btrfs_header_generation(btrfs_buffer_header(buf)) != | |
98 | trans->transid) { | |
99 | different_trans = 1; | |
100 | ret = btrfs_inc_ref(trans, root, buf); | |
101 | if (ret) | |
102 | return ret; | |
103 | } else { | |
6702ed49 CM |
104 | clean_tree_block(trans, root, buf); |
105 | } | |
106 | ||
02217ed2 CM |
107 | if (buf == root->node) { |
108 | root->node = cow; | |
e20d96d6 | 109 | get_bh(cow); |
2c90e5d6 | 110 | if (buf != root->commit_root) { |
7eccb903 | 111 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
2c90e5d6 | 112 | } |
234b63a0 | 113 | btrfs_block_release(root, buf); |
02217ed2 | 114 | } else { |
e20d96d6 | 115 | btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot, |
7eccb903 | 116 | bh_blocknr(cow)); |
d6025579 | 117 | btrfs_mark_buffer_dirty(parent); |
6702ed49 CM |
118 | WARN_ON(btrfs_header_generation(btrfs_buffer_header(parent)) != |
119 | trans->transid); | |
7eccb903 | 120 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
02217ed2 | 121 | } |
234b63a0 | 122 | btrfs_block_release(root, buf); |
ccd467d6 | 123 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 124 | *cow_ret = cow; |
02217ed2 CM |
125 | return 0; |
126 | } | |
127 | ||
6702ed49 CM |
128 | int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root |
129 | *root, struct buffer_head *buf, struct buffer_head | |
130 | *parent, int parent_slot, struct buffer_head | |
131 | **cow_ret) | |
132 | { | |
133 | u64 search_start; | |
134 | if (trans->transaction != root->fs_info->running_transaction) { | |
135 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
136 | root->fs_info->running_transaction->transid); | |
137 | WARN_ON(1); | |
138 | } | |
139 | if (trans->transid != root->fs_info->generation) { | |
140 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
141 | root->fs_info->generation); | |
142 | WARN_ON(1); | |
143 | } | |
144 | if (btrfs_header_generation(btrfs_buffer_header(buf)) == | |
145 | trans->transid) { | |
146 | *cow_ret = buf; | |
147 | return 0; | |
148 | } | |
149 | ||
150 | search_start = bh_blocknr(buf) & ~((u64)65535); | |
151 | return __btrfs_cow_block(trans, root, buf, parent, | |
152 | parent_slot, cow_ret, search_start, 0); | |
153 | } | |
154 | ||
155 | static int close_blocks(u64 blocknr, u64 other) | |
156 | { | |
157 | if (blocknr < other && other - blocknr < 8) | |
158 | return 1; | |
159 | if (blocknr > other && blocknr - other < 8) | |
160 | return 1; | |
161 | return 0; | |
162 | } | |
163 | ||
2cc58cf2 CM |
164 | static int should_defrag_leaf(struct buffer_head *bh) |
165 | { | |
166 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(bh); | |
167 | struct btrfs_disk_key *key; | |
168 | u32 nritems; | |
169 | ||
170 | if (buffer_defrag(bh)) | |
171 | return 1; | |
172 | ||
173 | nritems = btrfs_header_nritems(&leaf->header); | |
174 | if (nritems == 0) | |
175 | return 0; | |
176 | ||
177 | key = &leaf->items[0].key; | |
178 | if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY) | |
179 | return 1; | |
180 | ||
181 | key = &leaf->items[nritems-1].key; | |
182 | if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY) | |
183 | return 1; | |
184 | if (nritems > 4) { | |
185 | key = &leaf->items[nritems/2].key; | |
186 | if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY) | |
187 | return 1; | |
188 | } | |
189 | return 0; | |
190 | } | |
191 | ||
6702ed49 CM |
192 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
193 | struct btrfs_root *root, struct buffer_head *parent, | |
e9d0b13b | 194 | int cache_only, u64 *last_ret) |
6702ed49 CM |
195 | { |
196 | struct btrfs_node *parent_node; | |
197 | struct buffer_head *cur_bh; | |
198 | struct buffer_head *tmp_bh; | |
199 | u64 blocknr; | |
e9d0b13b CM |
200 | u64 search_start = *last_ret; |
201 | u64 last_block = 0; | |
6702ed49 CM |
202 | u64 other; |
203 | u32 parent_nritems; | |
204 | int start_slot; | |
205 | int end_slot; | |
206 | int i; | |
207 | int err = 0; | |
f2183bde | 208 | int parent_level; |
6702ed49 CM |
209 | |
210 | if (trans->transaction != root->fs_info->running_transaction) { | |
211 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
212 | root->fs_info->running_transaction->transid); | |
213 | WARN_ON(1); | |
214 | } | |
215 | if (trans->transid != root->fs_info->generation) { | |
216 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
217 | root->fs_info->generation); | |
218 | WARN_ON(1); | |
219 | } | |
86479a04 CM |
220 | if (buffer_defrag_done(parent)) |
221 | return 0; | |
222 | ||
6702ed49 CM |
223 | parent_node = btrfs_buffer_node(parent); |
224 | parent_nritems = btrfs_header_nritems(&parent_node->header); | |
f2183bde | 225 | parent_level = btrfs_header_level(&parent_node->header); |
6702ed49 CM |
226 | |
227 | start_slot = 0; | |
228 | end_slot = parent_nritems; | |
229 | ||
230 | if (parent_nritems == 1) | |
231 | return 0; | |
232 | ||
233 | for (i = start_slot; i < end_slot; i++) { | |
234 | int close = 1; | |
235 | blocknr = btrfs_node_blockptr(parent_node, i); | |
e9d0b13b CM |
236 | if (last_block == 0) |
237 | last_block = blocknr; | |
6702ed49 CM |
238 | if (i > 0) { |
239 | other = btrfs_node_blockptr(parent_node, i - 1); | |
240 | close = close_blocks(blocknr, other); | |
241 | } | |
242 | if (close && i < end_slot - 1) { | |
243 | other = btrfs_node_blockptr(parent_node, i + 1); | |
244 | close = close_blocks(blocknr, other); | |
245 | } | |
e9d0b13b CM |
246 | if (close) { |
247 | last_block = blocknr; | |
6702ed49 | 248 | continue; |
e9d0b13b | 249 | } |
6702ed49 CM |
250 | |
251 | cur_bh = btrfs_find_tree_block(root, blocknr); | |
252 | if (!cur_bh || !buffer_uptodate(cur_bh) || | |
2cc58cf2 CM |
253 | buffer_locked(cur_bh) || |
254 | (parent_level != 1 && !buffer_defrag(cur_bh)) || | |
255 | (parent_level == 1 && !should_defrag_leaf(cur_bh))) { | |
6702ed49 CM |
256 | if (cache_only) { |
257 | brelse(cur_bh); | |
258 | continue; | |
259 | } | |
f2183bde CM |
260 | if (!cur_bh || !buffer_uptodate(cur_bh) || |
261 | buffer_locked(cur_bh)) { | |
262 | brelse(cur_bh); | |
263 | cur_bh = read_tree_block(root, blocknr); | |
264 | } | |
6702ed49 | 265 | } |
e9d0b13b CM |
266 | if (search_start == 0) |
267 | search_start = last_block & ~((u64)65535); | |
268 | ||
6702ed49 CM |
269 | err = __btrfs_cow_block(trans, root, cur_bh, parent, i, |
270 | &tmp_bh, search_start, | |
271 | min(8, end_slot - i)); | |
252c38f0 Y |
272 | if (err) { |
273 | brelse(cur_bh); | |
6702ed49 | 274 | break; |
252c38f0 | 275 | } |
6702ed49 | 276 | search_start = bh_blocknr(tmp_bh); |
f2183bde CM |
277 | *last_ret = search_start; |
278 | if (parent_level == 1) | |
279 | clear_buffer_defrag(tmp_bh); | |
86479a04 | 280 | set_buffer_defrag_done(tmp_bh); |
6702ed49 CM |
281 | brelse(tmp_bh); |
282 | } | |
283 | return err; | |
284 | } | |
285 | ||
74123bd7 CM |
286 | /* |
287 | * The leaf data grows from end-to-front in the node. | |
288 | * this returns the address of the start of the last item, | |
289 | * which is the stop of the leaf data stack | |
290 | */ | |
123abc88 CM |
291 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
292 | struct btrfs_leaf *leaf) | |
be0e5c09 | 293 | { |
7518a238 | 294 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 295 | if (nr == 0) |
123abc88 | 296 | return BTRFS_LEAF_DATA_SIZE(root); |
0783fcfc | 297 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
298 | } |
299 | ||
74123bd7 CM |
300 | /* |
301 | * compare two keys in a memcmp fashion | |
302 | */ | |
9aca1d51 | 303 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 304 | { |
e2fa7227 CM |
305 | struct btrfs_key k1; |
306 | ||
307 | btrfs_disk_key_to_cpu(&k1, disk); | |
308 | ||
309 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 310 | return 1; |
e2fa7227 | 311 | if (k1.objectid < k2->objectid) |
be0e5c09 | 312 | return -1; |
f254e52c CM |
313 | if (k1.flags > k2->flags) |
314 | return 1; | |
315 | if (k1.flags < k2->flags) | |
316 | return -1; | |
70b2befd CM |
317 | if (k1.offset > k2->offset) |
318 | return 1; | |
319 | if (k1.offset < k2->offset) | |
320 | return -1; | |
be0e5c09 CM |
321 | return 0; |
322 | } | |
74123bd7 | 323 | |
123abc88 CM |
324 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
325 | int level) | |
aa5d6bed | 326 | { |
234b63a0 | 327 | struct btrfs_node *parent = NULL; |
e20d96d6 | 328 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
aa5d6bed | 329 | int parent_slot; |
8d7be552 CM |
330 | int slot; |
331 | struct btrfs_key cpukey; | |
7518a238 | 332 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
333 | |
334 | if (path->nodes[level + 1]) | |
e20d96d6 | 335 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
a1f39630 | 336 | |
8d7be552 | 337 | slot = path->slots[level]; |
2cc58cf2 | 338 | BUG_ON(!buffer_uptodate(path->nodes[level])); |
7518a238 CM |
339 | BUG_ON(nritems == 0); |
340 | if (parent) { | |
e2fa7227 | 341 | struct btrfs_disk_key *parent_key; |
a1f39630 A |
342 | |
343 | parent_slot = path->slots[level + 1]; | |
123abc88 CM |
344 | parent_key = &parent->ptrs[parent_slot].key; |
345 | BUG_ON(memcmp(parent_key, &node->ptrs[0].key, | |
e2fa7227 | 346 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 347 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 348 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 349 | } |
123abc88 | 350 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
8d7be552 CM |
351 | if (slot != 0) { |
352 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[slot - 1].key); | |
353 | BUG_ON(comp_keys(&node->ptrs[slot].key, &cpukey) <= 0); | |
354 | } | |
355 | if (slot < nritems - 1) { | |
356 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[slot + 1].key); | |
357 | BUG_ON(comp_keys(&node->ptrs[slot].key, &cpukey) >= 0); | |
aa5d6bed CM |
358 | } |
359 | return 0; | |
360 | } | |
361 | ||
123abc88 CM |
362 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
363 | int level) | |
aa5d6bed | 364 | { |
e20d96d6 | 365 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[level]); |
234b63a0 | 366 | struct btrfs_node *parent = NULL; |
aa5d6bed | 367 | int parent_slot; |
8d7be552 CM |
368 | int slot = path->slots[0]; |
369 | struct btrfs_key cpukey; | |
370 | ||
7518a238 | 371 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
372 | |
373 | if (path->nodes[level + 1]) | |
e20d96d6 | 374 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
a1f39630 | 375 | |
123abc88 | 376 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
7518a238 CM |
377 | |
378 | if (nritems == 0) | |
379 | return 0; | |
380 | ||
381 | if (parent) { | |
e2fa7227 | 382 | struct btrfs_disk_key *parent_key; |
a1f39630 A |
383 | |
384 | parent_slot = path->slots[level + 1]; | |
123abc88 | 385 | parent_key = &parent->ptrs[parent_slot].key; |
6702ed49 | 386 | |
aa5d6bed | 387 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, |
e2fa7227 | 388 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 389 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 390 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 391 | } |
8d7be552 CM |
392 | if (slot != 0) { |
393 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[slot - 1].key); | |
394 | BUG_ON(comp_keys(&leaf->items[slot].key, &cpukey) <= 0); | |
395 | BUG_ON(btrfs_item_offset(leaf->items + slot - 1) != | |
396 | btrfs_item_end(leaf->items + slot)); | |
397 | } | |
398 | if (slot < nritems - 1) { | |
399 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[slot + 1].key); | |
400 | BUG_ON(comp_keys(&leaf->items[slot].key, &cpukey) >= 0); | |
401 | BUG_ON(btrfs_item_offset(leaf->items + slot) != | |
402 | btrfs_item_end(leaf->items + slot + 1)); | |
aa5d6bed | 403 | } |
8d7be552 CM |
404 | BUG_ON(btrfs_item_offset(leaf->items) + |
405 | btrfs_item_size(leaf->items) != BTRFS_LEAF_DATA_SIZE(root)); | |
aa5d6bed CM |
406 | return 0; |
407 | } | |
408 | ||
123abc88 CM |
409 | static int check_block(struct btrfs_root *root, struct btrfs_path *path, |
410 | int level) | |
aa5d6bed | 411 | { |
3eb0314d CM |
412 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
413 | if (memcmp(node->header.fsid, root->fs_info->disk_super->fsid, | |
414 | sizeof(node->header.fsid))) | |
415 | BUG(); | |
aa5d6bed | 416 | if (level == 0) |
123abc88 CM |
417 | return check_leaf(root, path, level); |
418 | return check_node(root, path, level); | |
aa5d6bed CM |
419 | } |
420 | ||
74123bd7 CM |
421 | /* |
422 | * search for key in the array p. items p are item_size apart | |
423 | * and there are 'max' items in p | |
424 | * the slot in the array is returned via slot, and it points to | |
425 | * the place where you would insert key if it is not found in | |
426 | * the array. | |
427 | * | |
428 | * slot may point to max if the key is bigger than all of the keys | |
429 | */ | |
9aca1d51 | 430 | static int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
431 | int max, int *slot) |
432 | { | |
433 | int low = 0; | |
434 | int high = max; | |
435 | int mid; | |
436 | int ret; | |
e2fa7227 | 437 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
438 | |
439 | while(low < high) { | |
440 | mid = (low + high) / 2; | |
e2fa7227 | 441 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
442 | ret = comp_keys(tmp, key); |
443 | ||
444 | if (ret < 0) | |
445 | low = mid + 1; | |
446 | else if (ret > 0) | |
447 | high = mid; | |
448 | else { | |
449 | *slot = mid; | |
450 | return 0; | |
451 | } | |
452 | } | |
453 | *slot = low; | |
454 | return 1; | |
455 | } | |
456 | ||
97571fd0 CM |
457 | /* |
458 | * simple bin_search frontend that does the right thing for | |
459 | * leaves vs nodes | |
460 | */ | |
9aca1d51 | 461 | static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 462 | { |
7518a238 | 463 | if (btrfs_is_leaf(c)) { |
234b63a0 | 464 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
0783fcfc CM |
465 | return generic_bin_search((void *)l->items, |
466 | sizeof(struct btrfs_item), | |
7518a238 CM |
467 | key, btrfs_header_nritems(&c->header), |
468 | slot); | |
be0e5c09 | 469 | } else { |
123abc88 CM |
470 | return generic_bin_search((void *)c->ptrs, |
471 | sizeof(struct btrfs_key_ptr), | |
7518a238 CM |
472 | key, btrfs_header_nritems(&c->header), |
473 | slot); | |
be0e5c09 CM |
474 | } |
475 | return -1; | |
476 | } | |
477 | ||
e20d96d6 CM |
478 | static struct buffer_head *read_node_slot(struct btrfs_root *root, |
479 | struct buffer_head *parent_buf, | |
bb803951 CM |
480 | int slot) |
481 | { | |
e20d96d6 | 482 | struct btrfs_node *node = btrfs_buffer_node(parent_buf); |
bb803951 CM |
483 | if (slot < 0) |
484 | return NULL; | |
7518a238 | 485 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 486 | return NULL; |
1d4f8a0c | 487 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
488 | } |
489 | ||
e089f05c CM |
490 | static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root |
491 | *root, struct btrfs_path *path, int level) | |
bb803951 | 492 | { |
e20d96d6 CM |
493 | struct buffer_head *right_buf; |
494 | struct buffer_head *mid_buf; | |
495 | struct buffer_head *left_buf; | |
496 | struct buffer_head *parent_buf = NULL; | |
234b63a0 CM |
497 | struct btrfs_node *right = NULL; |
498 | struct btrfs_node *mid; | |
499 | struct btrfs_node *left = NULL; | |
500 | struct btrfs_node *parent = NULL; | |
bb803951 CM |
501 | int ret = 0; |
502 | int wret; | |
503 | int pslot; | |
bb803951 | 504 | int orig_slot = path->slots[level]; |
54aa1f4d | 505 | int err_on_enospc = 0; |
79f95c82 | 506 | u64 orig_ptr; |
bb803951 CM |
507 | |
508 | if (level == 0) | |
509 | return 0; | |
510 | ||
511 | mid_buf = path->nodes[level]; | |
e20d96d6 | 512 | mid = btrfs_buffer_node(mid_buf); |
1d4f8a0c | 513 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 514 | |
234b63a0 | 515 | if (level < BTRFS_MAX_LEVEL - 1) |
bb803951 CM |
516 | parent_buf = path->nodes[level + 1]; |
517 | pslot = path->slots[level + 1]; | |
518 | ||
40689478 CM |
519 | /* |
520 | * deal with the case where there is only one pointer in the root | |
521 | * by promoting the node below to a root | |
522 | */ | |
bb803951 | 523 | if (!parent_buf) { |
e20d96d6 | 524 | struct buffer_head *child; |
7eccb903 | 525 | u64 blocknr = bh_blocknr(mid_buf); |
bb803951 | 526 | |
7518a238 | 527 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
528 | return 0; |
529 | ||
530 | /* promote the child to a root */ | |
531 | child = read_node_slot(root, mid_buf, 0); | |
532 | BUG_ON(!child); | |
533 | root->node = child; | |
534 | path->nodes[level] = NULL; | |
d6025579 CM |
535 | clean_tree_block(trans, root, mid_buf); |
536 | wait_on_buffer(mid_buf); | |
bb803951 | 537 | /* once for the path */ |
234b63a0 | 538 | btrfs_block_release(root, mid_buf); |
bb803951 | 539 | /* once for the root ptr */ |
234b63a0 | 540 | btrfs_block_release(root, mid_buf); |
e089f05c | 541 | return btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 | 542 | } |
e20d96d6 | 543 | parent = btrfs_buffer_node(parent_buf); |
bb803951 | 544 | |
123abc88 CM |
545 | if (btrfs_header_nritems(&mid->header) > |
546 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
bb803951 CM |
547 | return 0; |
548 | ||
54aa1f4d CM |
549 | if (btrfs_header_nritems(&mid->header) < 2) |
550 | err_on_enospc = 1; | |
551 | ||
bb803951 | 552 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
bb803951 | 553 | if (left_buf) { |
54aa1f4d CM |
554 | wret = btrfs_cow_block(trans, root, left_buf, |
555 | parent_buf, pslot - 1, &left_buf); | |
556 | if (wret) { | |
557 | ret = wret; | |
558 | goto enospc; | |
559 | } | |
2cc58cf2 CM |
560 | } |
561 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
562 | if (right_buf) { | |
563 | wret = btrfs_cow_block(trans, root, right_buf, | |
564 | parent_buf, pslot + 1, &right_buf); | |
565 | if (wret) { | |
566 | ret = wret; | |
567 | goto enospc; | |
568 | } | |
569 | } | |
570 | ||
571 | /* first, try to make some room in the middle buffer */ | |
572 | if (left_buf) { | |
e20d96d6 | 573 | left = btrfs_buffer_node(left_buf); |
7518a238 | 574 | orig_slot += btrfs_header_nritems(&left->header); |
e089f05c | 575 | wret = push_node_left(trans, root, left_buf, mid_buf); |
79f95c82 CM |
576 | if (wret < 0) |
577 | ret = wret; | |
54aa1f4d CM |
578 | if (btrfs_header_nritems(&mid->header) < 2) |
579 | err_on_enospc = 1; | |
bb803951 | 580 | } |
79f95c82 CM |
581 | |
582 | /* | |
583 | * then try to empty the right most buffer into the middle | |
584 | */ | |
bb803951 | 585 | if (right_buf) { |
e20d96d6 | 586 | right = btrfs_buffer_node(right_buf); |
e089f05c | 587 | wret = push_node_left(trans, root, mid_buf, right_buf); |
54aa1f4d | 588 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 589 | ret = wret; |
7518a238 | 590 | if (btrfs_header_nritems(&right->header) == 0) { |
7eccb903 | 591 | u64 blocknr = bh_blocknr(right_buf); |
e089f05c | 592 | clean_tree_block(trans, root, right_buf); |
d6025579 CM |
593 | wait_on_buffer(right_buf); |
594 | btrfs_block_release(root, right_buf); | |
bb803951 CM |
595 | right_buf = NULL; |
596 | right = NULL; | |
e089f05c CM |
597 | wret = del_ptr(trans, root, path, level + 1, pslot + |
598 | 1); | |
bb803951 CM |
599 | if (wret) |
600 | ret = wret; | |
e089f05c | 601 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
602 | if (wret) |
603 | ret = wret; | |
604 | } else { | |
d6025579 CM |
605 | btrfs_memcpy(root, parent, |
606 | &parent->ptrs[pslot + 1].key, | |
607 | &right->ptrs[0].key, | |
608 | sizeof(struct btrfs_disk_key)); | |
609 | btrfs_mark_buffer_dirty(parent_buf); | |
bb803951 CM |
610 | } |
611 | } | |
7518a238 | 612 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
613 | /* |
614 | * we're not allowed to leave a node with one item in the | |
615 | * tree during a delete. A deletion from lower in the tree | |
616 | * could try to delete the only pointer in this node. | |
617 | * So, pull some keys from the left. | |
618 | * There has to be a left pointer at this point because | |
619 | * otherwise we would have pulled some pointers from the | |
620 | * right | |
621 | */ | |
622 | BUG_ON(!left_buf); | |
e089f05c | 623 | wret = balance_node_right(trans, root, mid_buf, left_buf); |
54aa1f4d | 624 | if (wret < 0) { |
79f95c82 | 625 | ret = wret; |
54aa1f4d CM |
626 | goto enospc; |
627 | } | |
79f95c82 CM |
628 | BUG_ON(wret == 1); |
629 | } | |
7518a238 | 630 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 631 | /* we've managed to empty the middle node, drop it */ |
7eccb903 | 632 | u64 blocknr = bh_blocknr(mid_buf); |
e089f05c | 633 | clean_tree_block(trans, root, mid_buf); |
d6025579 CM |
634 | wait_on_buffer(mid_buf); |
635 | btrfs_block_release(root, mid_buf); | |
bb803951 CM |
636 | mid_buf = NULL; |
637 | mid = NULL; | |
e089f05c | 638 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
639 | if (wret) |
640 | ret = wret; | |
e089f05c | 641 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
642 | if (wret) |
643 | ret = wret; | |
79f95c82 CM |
644 | } else { |
645 | /* update the parent key to reflect our changes */ | |
d6025579 CM |
646 | btrfs_memcpy(root, parent, |
647 | &parent->ptrs[pslot].key, &mid->ptrs[0].key, | |
648 | sizeof(struct btrfs_disk_key)); | |
649 | btrfs_mark_buffer_dirty(parent_buf); | |
79f95c82 | 650 | } |
bb803951 | 651 | |
79f95c82 | 652 | /* update the path */ |
bb803951 | 653 | if (left_buf) { |
7518a238 | 654 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
e20d96d6 | 655 | get_bh(left_buf); |
bb803951 CM |
656 | path->nodes[level] = left_buf; |
657 | path->slots[level + 1] -= 1; | |
658 | path->slots[level] = orig_slot; | |
659 | if (mid_buf) | |
234b63a0 | 660 | btrfs_block_release(root, mid_buf); |
bb803951 | 661 | } else { |
7518a238 | 662 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
663 | path->slots[level] = orig_slot; |
664 | } | |
665 | } | |
79f95c82 | 666 | /* double check we haven't messed things up */ |
123abc88 | 667 | check_block(root, path, level); |
e20d96d6 CM |
668 | if (orig_ptr != |
669 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]), | |
670 | path->slots[level])) | |
79f95c82 | 671 | BUG(); |
54aa1f4d | 672 | enospc: |
bb803951 | 673 | if (right_buf) |
234b63a0 | 674 | btrfs_block_release(root, right_buf); |
bb803951 | 675 | if (left_buf) |
234b63a0 | 676 | btrfs_block_release(root, left_buf); |
bb803951 CM |
677 | return ret; |
678 | } | |
679 | ||
e66f709b CM |
680 | /* returns zero if the push worked, non-zero otherwise */ |
681 | static int push_nodes_for_insert(struct btrfs_trans_handle *trans, | |
682 | struct btrfs_root *root, | |
683 | struct btrfs_path *path, int level) | |
684 | { | |
685 | struct buffer_head *right_buf; | |
686 | struct buffer_head *mid_buf; | |
687 | struct buffer_head *left_buf; | |
688 | struct buffer_head *parent_buf = NULL; | |
689 | struct btrfs_node *right = NULL; | |
690 | struct btrfs_node *mid; | |
691 | struct btrfs_node *left = NULL; | |
692 | struct btrfs_node *parent = NULL; | |
693 | int ret = 0; | |
694 | int wret; | |
695 | int pslot; | |
696 | int orig_slot = path->slots[level]; | |
697 | u64 orig_ptr; | |
698 | ||
699 | if (level == 0) | |
700 | return 1; | |
701 | ||
702 | mid_buf = path->nodes[level]; | |
703 | mid = btrfs_buffer_node(mid_buf); | |
704 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); | |
705 | ||
706 | if (level < BTRFS_MAX_LEVEL - 1) | |
707 | parent_buf = path->nodes[level + 1]; | |
708 | pslot = path->slots[level + 1]; | |
709 | ||
710 | if (!parent_buf) | |
711 | return 1; | |
712 | parent = btrfs_buffer_node(parent_buf); | |
713 | ||
714 | left_buf = read_node_slot(root, parent_buf, pslot - 1); | |
715 | ||
716 | /* first, try to make some room in the middle buffer */ | |
717 | if (left_buf) { | |
718 | u32 left_nr; | |
e66f709b CM |
719 | left = btrfs_buffer_node(left_buf); |
720 | left_nr = btrfs_header_nritems(&left->header); | |
33ade1f8 CM |
721 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
722 | wret = 1; | |
723 | } else { | |
54aa1f4d CM |
724 | ret = btrfs_cow_block(trans, root, left_buf, parent_buf, |
725 | pslot - 1, &left_buf); | |
726 | if (ret) | |
727 | wret = 1; | |
728 | else { | |
729 | left = btrfs_buffer_node(left_buf); | |
730 | wret = push_node_left(trans, root, | |
731 | left_buf, mid_buf); | |
732 | } | |
33ade1f8 | 733 | } |
e66f709b CM |
734 | if (wret < 0) |
735 | ret = wret; | |
736 | if (wret == 0) { | |
737 | orig_slot += left_nr; | |
738 | btrfs_memcpy(root, parent, | |
739 | &parent->ptrs[pslot].key, | |
740 | &mid->ptrs[0].key, | |
741 | sizeof(struct btrfs_disk_key)); | |
742 | btrfs_mark_buffer_dirty(parent_buf); | |
743 | if (btrfs_header_nritems(&left->header) > orig_slot) { | |
744 | path->nodes[level] = left_buf; | |
745 | path->slots[level + 1] -= 1; | |
746 | path->slots[level] = orig_slot; | |
747 | btrfs_block_release(root, mid_buf); | |
748 | } else { | |
749 | orig_slot -= | |
750 | btrfs_header_nritems(&left->header); | |
751 | path->slots[level] = orig_slot; | |
752 | btrfs_block_release(root, left_buf); | |
753 | } | |
754 | check_node(root, path, level); | |
755 | return 0; | |
756 | } | |
757 | btrfs_block_release(root, left_buf); | |
758 | } | |
759 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
760 | ||
761 | /* | |
762 | * then try to empty the right most buffer into the middle | |
763 | */ | |
764 | if (right_buf) { | |
33ade1f8 | 765 | u32 right_nr; |
e66f709b | 766 | right = btrfs_buffer_node(right_buf); |
33ade1f8 CM |
767 | right_nr = btrfs_header_nritems(&right->header); |
768 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
769 | wret = 1; | |
770 | } else { | |
54aa1f4d CM |
771 | ret = btrfs_cow_block(trans, root, right_buf, |
772 | parent_buf, pslot + 1, | |
773 | &right_buf); | |
774 | if (ret) | |
775 | wret = 1; | |
776 | else { | |
777 | right = btrfs_buffer_node(right_buf); | |
778 | wret = balance_node_right(trans, root, | |
779 | right_buf, mid_buf); | |
780 | } | |
33ade1f8 | 781 | } |
e66f709b CM |
782 | if (wret < 0) |
783 | ret = wret; | |
784 | if (wret == 0) { | |
785 | btrfs_memcpy(root, parent, | |
786 | &parent->ptrs[pslot + 1].key, | |
787 | &right->ptrs[0].key, | |
788 | sizeof(struct btrfs_disk_key)); | |
789 | btrfs_mark_buffer_dirty(parent_buf); | |
790 | if (btrfs_header_nritems(&mid->header) <= orig_slot) { | |
791 | path->nodes[level] = right_buf; | |
792 | path->slots[level + 1] += 1; | |
793 | path->slots[level] = orig_slot - | |
794 | btrfs_header_nritems(&mid->header); | |
795 | btrfs_block_release(root, mid_buf); | |
796 | } else { | |
797 | btrfs_block_release(root, right_buf); | |
798 | } | |
799 | check_node(root, path, level); | |
800 | return 0; | |
801 | } | |
802 | btrfs_block_release(root, right_buf); | |
803 | } | |
804 | check_node(root, path, level); | |
805 | return 1; | |
806 | } | |
807 | ||
3c69faec CM |
808 | /* |
809 | * readahead one full node of leaves | |
810 | */ | |
811 | static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, | |
6702ed49 | 812 | int level, int slot) |
3c69faec CM |
813 | { |
814 | struct btrfs_node *node; | |
815 | int i; | |
816 | u32 nritems; | |
817 | u64 item_objectid; | |
818 | u64 blocknr; | |
819 | u64 search; | |
820 | u64 cluster_start; | |
821 | int ret; | |
822 | int nread = 0; | |
823 | int direction = path->reada; | |
824 | struct radix_tree_root found; | |
825 | unsigned long gang[8]; | |
826 | struct buffer_head *bh; | |
827 | ||
6702ed49 CM |
828 | if (level == 0) |
829 | return; | |
830 | ||
831 | if (!path->nodes[level]) | |
3c69faec CM |
832 | return; |
833 | ||
6702ed49 | 834 | node = btrfs_buffer_node(path->nodes[level]); |
3c69faec CM |
835 | search = btrfs_node_blockptr(node, slot); |
836 | bh = btrfs_find_tree_block(root, search); | |
837 | if (bh) { | |
838 | brelse(bh); | |
839 | return; | |
840 | } | |
841 | ||
842 | init_bit_radix(&found); | |
843 | nritems = btrfs_header_nritems(&node->header); | |
844 | for (i = slot; i < nritems; i++) { | |
845 | item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key); | |
846 | blocknr = btrfs_node_blockptr(node, i); | |
847 | set_radix_bit(&found, blocknr); | |
848 | } | |
849 | if (direction > 0) { | |
850 | cluster_start = search - 4; | |
851 | if (cluster_start > search) | |
852 | cluster_start = 0; | |
853 | } else | |
854 | cluster_start = search + 4; | |
855 | while(1) { | |
856 | ret = find_first_radix_bit(&found, gang, 0, ARRAY_SIZE(gang)); | |
857 | if (!ret) | |
858 | break; | |
859 | for (i = 0; i < ret; i++) { | |
860 | blocknr = gang[i]; | |
861 | clear_radix_bit(&found, blocknr); | |
2cc58cf2 | 862 | if (path->reada == 1 && nread > 16) |
3c69faec | 863 | continue; |
f2183bde | 864 | if (close_blocks(cluster_start, blocknr)) { |
3c69faec CM |
865 | readahead_tree_block(root, blocknr); |
866 | nread++; | |
3c69faec | 867 | cluster_start = blocknr; |
3c69faec CM |
868 | } |
869 | } | |
870 | } | |
871 | } | |
74123bd7 CM |
872 | /* |
873 | * look for key in the tree. path is filled in with nodes along the way | |
874 | * if key is found, we return zero and you can find the item in the leaf | |
875 | * level of the path (level 0) | |
876 | * | |
877 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
878 | * be inserted, and 1 is returned. If there are other errors during the |
879 | * search a negative error number is returned. | |
97571fd0 CM |
880 | * |
881 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
882 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
883 | * possible) | |
74123bd7 | 884 | */ |
e089f05c CM |
885 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
886 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
887 | ins_len, int cow) | |
be0e5c09 | 888 | { |
e20d96d6 | 889 | struct buffer_head *b; |
234b63a0 | 890 | struct btrfs_node *c; |
3c69faec | 891 | u64 blocknr; |
be0e5c09 CM |
892 | int slot; |
893 | int ret; | |
894 | int level; | |
3c69faec | 895 | int should_reada = p->reada; |
9f3a7427 CM |
896 | u8 lowest_level = 0; |
897 | ||
6702ed49 CM |
898 | lowest_level = p->lowest_level; |
899 | WARN_ON(lowest_level && ins_len); | |
22b0ebda CM |
900 | WARN_ON(p->nodes[0] != NULL); |
901 | WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex)); | |
bb803951 CM |
902 | again: |
903 | b = root->node; | |
e20d96d6 | 904 | get_bh(b); |
eb60ceac | 905 | while (b) { |
e20d96d6 CM |
906 | c = btrfs_buffer_node(b); |
907 | level = btrfs_header_level(&c->header); | |
02217ed2 CM |
908 | if (cow) { |
909 | int wret; | |
e20d96d6 CM |
910 | wret = btrfs_cow_block(trans, root, b, |
911 | p->nodes[level + 1], | |
912 | p->slots[level + 1], | |
252c38f0 | 913 | &b); |
54aa1f4d | 914 | if (wret) { |
252c38f0 | 915 | btrfs_block_release(root, b); |
54aa1f4d CM |
916 | return wret; |
917 | } | |
2c90e5d6 | 918 | c = btrfs_buffer_node(b); |
02217ed2 CM |
919 | } |
920 | BUG_ON(!cow && ins_len); | |
2c90e5d6 CM |
921 | if (level != btrfs_header_level(&c->header)) |
922 | WARN_ON(1); | |
923 | level = btrfs_header_level(&c->header); | |
eb60ceac | 924 | p->nodes[level] = b; |
123abc88 | 925 | ret = check_block(root, p, level); |
aa5d6bed CM |
926 | if (ret) |
927 | return -1; | |
be0e5c09 | 928 | ret = bin_search(c, key, &slot); |
7518a238 | 929 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
930 | if (ret && slot > 0) |
931 | slot -= 1; | |
932 | p->slots[level] = slot; | |
d4dbff95 CM |
933 | if (ins_len > 0 && btrfs_header_nritems(&c->header) >= |
934 | BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
e089f05c | 935 | int sret = split_node(trans, root, p, level); |
5c680ed6 CM |
936 | BUG_ON(sret > 0); |
937 | if (sret) | |
938 | return sret; | |
939 | b = p->nodes[level]; | |
e20d96d6 | 940 | c = btrfs_buffer_node(b); |
5c680ed6 | 941 | slot = p->slots[level]; |
bb803951 | 942 | } else if (ins_len < 0) { |
e089f05c CM |
943 | int sret = balance_level(trans, root, p, |
944 | level); | |
bb803951 CM |
945 | if (sret) |
946 | return sret; | |
947 | b = p->nodes[level]; | |
948 | if (!b) | |
949 | goto again; | |
e20d96d6 | 950 | c = btrfs_buffer_node(b); |
bb803951 | 951 | slot = p->slots[level]; |
7518a238 | 952 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 953 | } |
9f3a7427 CM |
954 | /* this is only true while dropping a snapshot */ |
955 | if (level == lowest_level) | |
956 | break; | |
3c69faec | 957 | blocknr = btrfs_node_blockptr(c, slot); |
6702ed49 CM |
958 | if (should_reada) |
959 | reada_for_search(root, p, level, slot); | |
1d4f8a0c | 960 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
3c69faec | 961 | |
be0e5c09 | 962 | } else { |
234b63a0 | 963 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
be0e5c09 | 964 | p->slots[level] = slot; |
123abc88 | 965 | if (ins_len > 0 && btrfs_leaf_free_space(root, l) < |
0783fcfc | 966 | sizeof(struct btrfs_item) + ins_len) { |
d4dbff95 CM |
967 | int sret = split_leaf(trans, root, key, |
968 | p, ins_len); | |
5c680ed6 CM |
969 | BUG_ON(sret > 0); |
970 | if (sret) | |
971 | return sret; | |
972 | } | |
be0e5c09 CM |
973 | return ret; |
974 | } | |
975 | } | |
aa5d6bed | 976 | return 1; |
be0e5c09 CM |
977 | } |
978 | ||
74123bd7 CM |
979 | /* |
980 | * adjust the pointers going up the tree, starting at level | |
981 | * making sure the right key of each node is points to 'key'. | |
982 | * This is used after shifting pointers to the left, so it stops | |
983 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
984 | * higher levels | |
aa5d6bed CM |
985 | * |
986 | * If this fails to write a tree block, it returns -1, but continues | |
987 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 988 | */ |
e089f05c CM |
989 | static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root |
990 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
991 | *key, int level) | |
be0e5c09 CM |
992 | { |
993 | int i; | |
aa5d6bed | 994 | int ret = 0; |
234b63a0 CM |
995 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
996 | struct btrfs_node *t; | |
be0e5c09 | 997 | int tslot = path->slots[i]; |
eb60ceac | 998 | if (!path->nodes[i]) |
be0e5c09 | 999 | break; |
e20d96d6 | 1000 | t = btrfs_buffer_node(path->nodes[i]); |
d6025579 CM |
1001 | btrfs_memcpy(root, t, &t->ptrs[tslot].key, key, sizeof(*key)); |
1002 | btrfs_mark_buffer_dirty(path->nodes[i]); | |
be0e5c09 CM |
1003 | if (tslot != 0) |
1004 | break; | |
1005 | } | |
aa5d6bed | 1006 | return ret; |
be0e5c09 CM |
1007 | } |
1008 | ||
74123bd7 CM |
1009 | /* |
1010 | * try to push data from one node into the next node left in the | |
79f95c82 | 1011 | * tree. |
aa5d6bed CM |
1012 | * |
1013 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1014 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1015 | */ |
e089f05c | 1016 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
1017 | *root, struct buffer_head *dst_buf, struct |
1018 | buffer_head *src_buf) | |
be0e5c09 | 1019 | { |
e20d96d6 CM |
1020 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
1021 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
be0e5c09 | 1022 | int push_items = 0; |
bb803951 CM |
1023 | int src_nritems; |
1024 | int dst_nritems; | |
aa5d6bed | 1025 | int ret = 0; |
be0e5c09 | 1026 | |
7518a238 CM |
1027 | src_nritems = btrfs_header_nritems(&src->header); |
1028 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 1029 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
54aa1f4d | 1030 | |
eb60ceac | 1031 | if (push_items <= 0) { |
be0e5c09 | 1032 | return 1; |
eb60ceac | 1033 | } |
be0e5c09 | 1034 | |
bb803951 | 1035 | if (src_nritems < push_items) |
79f95c82 CM |
1036 | push_items = src_nritems; |
1037 | ||
d6025579 CM |
1038 | btrfs_memcpy(root, dst, dst->ptrs + dst_nritems, src->ptrs, |
1039 | push_items * sizeof(struct btrfs_key_ptr)); | |
bb803951 | 1040 | if (push_items < src_nritems) { |
d6025579 | 1041 | btrfs_memmove(root, src, src->ptrs, src->ptrs + push_items, |
e2fa7227 | 1042 | (src_nritems - push_items) * |
123abc88 | 1043 | sizeof(struct btrfs_key_ptr)); |
bb803951 | 1044 | } |
7518a238 CM |
1045 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
1046 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
d6025579 CM |
1047 | btrfs_mark_buffer_dirty(src_buf); |
1048 | btrfs_mark_buffer_dirty(dst_buf); | |
79f95c82 CM |
1049 | return ret; |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * try to push data from one node into the next node right in the | |
1054 | * tree. | |
1055 | * | |
1056 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
1057 | * error, and > 0 if there was no room in the right hand block. | |
1058 | * | |
1059 | * this will only push up to 1/2 the contents of the left node over | |
1060 | */ | |
e089f05c | 1061 | static int balance_node_right(struct btrfs_trans_handle *trans, struct |
e20d96d6 CM |
1062 | btrfs_root *root, struct buffer_head *dst_buf, |
1063 | struct buffer_head *src_buf) | |
79f95c82 | 1064 | { |
e20d96d6 CM |
1065 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
1066 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
79f95c82 CM |
1067 | int push_items = 0; |
1068 | int max_push; | |
1069 | int src_nritems; | |
1070 | int dst_nritems; | |
1071 | int ret = 0; | |
79f95c82 | 1072 | |
7518a238 CM |
1073 | src_nritems = btrfs_header_nritems(&src->header); |
1074 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 1075 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
79f95c82 CM |
1076 | if (push_items <= 0) { |
1077 | return 1; | |
1078 | } | |
1079 | ||
1080 | max_push = src_nritems / 2 + 1; | |
1081 | /* don't try to empty the node */ | |
252c38f0 | 1082 | if (max_push >= src_nritems) |
79f95c82 | 1083 | return 1; |
252c38f0 | 1084 | |
79f95c82 CM |
1085 | if (max_push < push_items) |
1086 | push_items = max_push; | |
1087 | ||
d6025579 CM |
1088 | btrfs_memmove(root, dst, dst->ptrs + push_items, dst->ptrs, |
1089 | dst_nritems * sizeof(struct btrfs_key_ptr)); | |
1090 | ||
1091 | btrfs_memcpy(root, dst, dst->ptrs, | |
1092 | src->ptrs + src_nritems - push_items, | |
1093 | push_items * sizeof(struct btrfs_key_ptr)); | |
79f95c82 | 1094 | |
7518a238 CM |
1095 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
1096 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 1097 | |
d6025579 CM |
1098 | btrfs_mark_buffer_dirty(src_buf); |
1099 | btrfs_mark_buffer_dirty(dst_buf); | |
aa5d6bed | 1100 | return ret; |
be0e5c09 CM |
1101 | } |
1102 | ||
97571fd0 CM |
1103 | /* |
1104 | * helper function to insert a new root level in the tree. | |
1105 | * A new node is allocated, and a single item is inserted to | |
1106 | * point to the existing root | |
aa5d6bed CM |
1107 | * |
1108 | * returns zero on success or < 0 on failure. | |
97571fd0 | 1109 | */ |
e089f05c CM |
1110 | static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root |
1111 | *root, struct btrfs_path *path, int level) | |
5c680ed6 | 1112 | { |
e20d96d6 | 1113 | struct buffer_head *t; |
234b63a0 CM |
1114 | struct btrfs_node *lower; |
1115 | struct btrfs_node *c; | |
e2fa7227 | 1116 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
1117 | |
1118 | BUG_ON(path->nodes[level]); | |
1119 | BUG_ON(path->nodes[level-1] != root->node); | |
1120 | ||
6702ed49 | 1121 | t = btrfs_alloc_free_block(trans, root, root->node->b_blocknr, 0); |
54aa1f4d CM |
1122 | if (IS_ERR(t)) |
1123 | return PTR_ERR(t); | |
e20d96d6 | 1124 | c = btrfs_buffer_node(t); |
123abc88 | 1125 | memset(c, 0, root->blocksize); |
7518a238 CM |
1126 | btrfs_set_header_nritems(&c->header, 1); |
1127 | btrfs_set_header_level(&c->header, level); | |
7eccb903 | 1128 | btrfs_set_header_blocknr(&c->header, bh_blocknr(t)); |
7f5c1516 | 1129 | btrfs_set_header_generation(&c->header, trans->transid); |
4d775673 | 1130 | btrfs_set_header_owner(&c->header, root->root_key.objectid); |
e20d96d6 | 1131 | lower = btrfs_buffer_node(path->nodes[level-1]); |
3eb0314d CM |
1132 | memcpy(c->header.fsid, root->fs_info->disk_super->fsid, |
1133 | sizeof(c->header.fsid)); | |
7518a238 | 1134 | if (btrfs_is_leaf(lower)) |
234b63a0 | 1135 | lower_key = &((struct btrfs_leaf *)lower)->items[0].key; |
5c680ed6 | 1136 | else |
123abc88 | 1137 | lower_key = &lower->ptrs[0].key; |
d6025579 CM |
1138 | btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key, |
1139 | sizeof(struct btrfs_disk_key)); | |
7eccb903 | 1140 | btrfs_set_node_blockptr(c, 0, bh_blocknr(path->nodes[level - 1])); |
d5719762 | 1141 | |
d6025579 | 1142 | btrfs_mark_buffer_dirty(t); |
d5719762 | 1143 | |
5c680ed6 | 1144 | /* the super has an extra ref to root->node */ |
234b63a0 | 1145 | btrfs_block_release(root, root->node); |
5c680ed6 | 1146 | root->node = t; |
e20d96d6 | 1147 | get_bh(t); |
5c680ed6 CM |
1148 | path->nodes[level] = t; |
1149 | path->slots[level] = 0; | |
1150 | return 0; | |
1151 | } | |
1152 | ||
74123bd7 CM |
1153 | /* |
1154 | * worker function to insert a single pointer in a node. | |
1155 | * the node should have enough room for the pointer already | |
97571fd0 | 1156 | * |
74123bd7 CM |
1157 | * slot and level indicate where you want the key to go, and |
1158 | * blocknr is the block the key points to. | |
aa5d6bed CM |
1159 | * |
1160 | * returns zero on success and < 0 on any error | |
74123bd7 | 1161 | */ |
e089f05c CM |
1162 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
1163 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
1164 | *key, u64 blocknr, int slot, int level) | |
74123bd7 | 1165 | { |
234b63a0 | 1166 | struct btrfs_node *lower; |
74123bd7 | 1167 | int nritems; |
5c680ed6 CM |
1168 | |
1169 | BUG_ON(!path->nodes[level]); | |
e20d96d6 | 1170 | lower = btrfs_buffer_node(path->nodes[level]); |
7518a238 | 1171 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
1172 | if (slot > nritems) |
1173 | BUG(); | |
123abc88 | 1174 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
1175 | BUG(); |
1176 | if (slot != nritems) { | |
d6025579 CM |
1177 | btrfs_memmove(root, lower, lower->ptrs + slot + 1, |
1178 | lower->ptrs + slot, | |
1179 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
74123bd7 | 1180 | } |
d6025579 CM |
1181 | btrfs_memcpy(root, lower, &lower->ptrs[slot].key, |
1182 | key, sizeof(struct btrfs_disk_key)); | |
1d4f8a0c | 1183 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 1184 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
d6025579 | 1185 | btrfs_mark_buffer_dirty(path->nodes[level]); |
098f59c2 | 1186 | check_node(root, path, level); |
74123bd7 CM |
1187 | return 0; |
1188 | } | |
1189 | ||
97571fd0 CM |
1190 | /* |
1191 | * split the node at the specified level in path in two. | |
1192 | * The path is corrected to point to the appropriate node after the split | |
1193 | * | |
1194 | * Before splitting this tries to make some room in the node by pushing | |
1195 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
1196 | * |
1197 | * returns 0 on success and < 0 on failure | |
97571fd0 | 1198 | */ |
e089f05c CM |
1199 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
1200 | *root, struct btrfs_path *path, int level) | |
be0e5c09 | 1201 | { |
e20d96d6 | 1202 | struct buffer_head *t; |
234b63a0 | 1203 | struct btrfs_node *c; |
e20d96d6 | 1204 | struct buffer_head *split_buffer; |
234b63a0 | 1205 | struct btrfs_node *split; |
be0e5c09 | 1206 | int mid; |
5c680ed6 | 1207 | int ret; |
aa5d6bed | 1208 | int wret; |
7518a238 | 1209 | u32 c_nritems; |
eb60ceac | 1210 | |
5c680ed6 | 1211 | t = path->nodes[level]; |
e20d96d6 | 1212 | c = btrfs_buffer_node(t); |
5c680ed6 CM |
1213 | if (t == root->node) { |
1214 | /* trying to split the root, lets make a new one */ | |
e089f05c | 1215 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
1216 | if (ret) |
1217 | return ret; | |
e66f709b CM |
1218 | } else { |
1219 | ret = push_nodes_for_insert(trans, root, path, level); | |
1220 | t = path->nodes[level]; | |
1221 | c = btrfs_buffer_node(t); | |
1222 | if (!ret && | |
1223 | btrfs_header_nritems(&c->header) < | |
1224 | BTRFS_NODEPTRS_PER_BLOCK(root) - 1) | |
1225 | return 0; | |
54aa1f4d CM |
1226 | if (ret < 0) |
1227 | return ret; | |
be0e5c09 | 1228 | } |
e66f709b | 1229 | |
7518a238 | 1230 | c_nritems = btrfs_header_nritems(&c->header); |
6702ed49 | 1231 | split_buffer = btrfs_alloc_free_block(trans, root, t->b_blocknr, 0); |
54aa1f4d CM |
1232 | if (IS_ERR(split_buffer)) |
1233 | return PTR_ERR(split_buffer); | |
1234 | ||
e20d96d6 | 1235 | split = btrfs_buffer_node(split_buffer); |
7518a238 | 1236 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
9a6f11ed | 1237 | btrfs_set_header_level(&split->header, btrfs_header_level(&c->header)); |
7eccb903 | 1238 | btrfs_set_header_blocknr(&split->header, bh_blocknr(split_buffer)); |
7f5c1516 | 1239 | btrfs_set_header_generation(&split->header, trans->transid); |
4d775673 | 1240 | btrfs_set_header_owner(&split->header, root->root_key.objectid); |
3eb0314d CM |
1241 | memcpy(split->header.fsid, root->fs_info->disk_super->fsid, |
1242 | sizeof(split->header.fsid)); | |
7518a238 | 1243 | mid = (c_nritems + 1) / 2; |
d6025579 CM |
1244 | btrfs_memcpy(root, split, split->ptrs, c->ptrs + mid, |
1245 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
7518a238 CM |
1246 | btrfs_set_header_nritems(&split->header, c_nritems - mid); |
1247 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
1248 | ret = 0; |
1249 | ||
d6025579 CM |
1250 | btrfs_mark_buffer_dirty(t); |
1251 | btrfs_mark_buffer_dirty(split_buffer); | |
e089f05c | 1252 | wret = insert_ptr(trans, root, path, &split->ptrs[0].key, |
7eccb903 | 1253 | bh_blocknr(split_buffer), path->slots[level + 1] + 1, |
123abc88 | 1254 | level + 1); |
aa5d6bed CM |
1255 | if (wret) |
1256 | ret = wret; | |
1257 | ||
5de08d7d | 1258 | if (path->slots[level] >= mid) { |
5c680ed6 | 1259 | path->slots[level] -= mid; |
234b63a0 | 1260 | btrfs_block_release(root, t); |
5c680ed6 CM |
1261 | path->nodes[level] = split_buffer; |
1262 | path->slots[level + 1] += 1; | |
1263 | } else { | |
234b63a0 | 1264 | btrfs_block_release(root, split_buffer); |
be0e5c09 | 1265 | } |
aa5d6bed | 1266 | return ret; |
be0e5c09 CM |
1267 | } |
1268 | ||
74123bd7 CM |
1269 | /* |
1270 | * how many bytes are required to store the items in a leaf. start | |
1271 | * and nr indicate which items in the leaf to check. This totals up the | |
1272 | * space used both by the item structs and the item data | |
1273 | */ | |
234b63a0 | 1274 | static int leaf_space_used(struct btrfs_leaf *l, int start, int nr) |
be0e5c09 CM |
1275 | { |
1276 | int data_len; | |
d4dbff95 CM |
1277 | int nritems = btrfs_header_nritems(&l->header); |
1278 | int end = min(nritems, start + nr) - 1; | |
be0e5c09 CM |
1279 | |
1280 | if (!nr) | |
1281 | return 0; | |
0783fcfc CM |
1282 | data_len = btrfs_item_end(l->items + start); |
1283 | data_len = data_len - btrfs_item_offset(l->items + end); | |
1284 | data_len += sizeof(struct btrfs_item) * nr; | |
d4dbff95 | 1285 | WARN_ON(data_len < 0); |
be0e5c09 CM |
1286 | return data_len; |
1287 | } | |
1288 | ||
d4dbff95 CM |
1289 | /* |
1290 | * The space between the end of the leaf items and | |
1291 | * the start of the leaf data. IOW, how much room | |
1292 | * the leaf has left for both items and data | |
1293 | */ | |
1294 | int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf) | |
1295 | { | |
1296 | int nritems = btrfs_header_nritems(&leaf->header); | |
1297 | return BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
1298 | } | |
1299 | ||
00ec4c51 CM |
1300 | /* |
1301 | * push some data in the path leaf to the right, trying to free up at | |
1302 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
1303 | * |
1304 | * returns 1 if the push failed because the other node didn't have enough | |
1305 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 1306 | */ |
e089f05c CM |
1307 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
1308 | *root, struct btrfs_path *path, int data_size) | |
00ec4c51 | 1309 | { |
e20d96d6 CM |
1310 | struct buffer_head *left_buf = path->nodes[0]; |
1311 | struct btrfs_leaf *left = btrfs_buffer_leaf(left_buf); | |
234b63a0 | 1312 | struct btrfs_leaf *right; |
e20d96d6 CM |
1313 | struct buffer_head *right_buf; |
1314 | struct buffer_head *upper; | |
1315 | struct btrfs_node *upper_node; | |
00ec4c51 CM |
1316 | int slot; |
1317 | int i; | |
1318 | int free_space; | |
1319 | int push_space = 0; | |
1320 | int push_items = 0; | |
0783fcfc | 1321 | struct btrfs_item *item; |
7518a238 CM |
1322 | u32 left_nritems; |
1323 | u32 right_nritems; | |
54aa1f4d | 1324 | int ret; |
00ec4c51 CM |
1325 | |
1326 | slot = path->slots[1]; | |
1327 | if (!path->nodes[1]) { | |
1328 | return 1; | |
1329 | } | |
1330 | upper = path->nodes[1]; | |
e20d96d6 CM |
1331 | upper_node = btrfs_buffer_node(upper); |
1332 | if (slot >= btrfs_header_nritems(&upper_node->header) - 1) { | |
00ec4c51 CM |
1333 | return 1; |
1334 | } | |
e20d96d6 CM |
1335 | right_buf = read_tree_block(root, |
1336 | btrfs_node_blockptr(btrfs_buffer_node(upper), slot + 1)); | |
1337 | right = btrfs_buffer_leaf(right_buf); | |
123abc88 | 1338 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 1339 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1340 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
1341 | return 1; |
1342 | } | |
02217ed2 | 1343 | /* cow and double check */ |
54aa1f4d CM |
1344 | ret = btrfs_cow_block(trans, root, right_buf, upper, |
1345 | slot + 1, &right_buf); | |
1346 | if (ret) { | |
1347 | btrfs_block_release(root, right_buf); | |
1348 | return 1; | |
1349 | } | |
e20d96d6 | 1350 | right = btrfs_buffer_leaf(right_buf); |
123abc88 | 1351 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 1352 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1353 | btrfs_block_release(root, right_buf); |
02217ed2 CM |
1354 | return 1; |
1355 | } | |
1356 | ||
7518a238 | 1357 | left_nritems = btrfs_header_nritems(&left->header); |
a429e513 CM |
1358 | if (left_nritems == 0) { |
1359 | btrfs_block_release(root, right_buf); | |
1360 | return 1; | |
1361 | } | |
1362 | for (i = left_nritems - 1; i >= 1; i--) { | |
00ec4c51 CM |
1363 | item = left->items + i; |
1364 | if (path->slots[0] == i) | |
1365 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1366 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1367 | free_space) | |
00ec4c51 CM |
1368 | break; |
1369 | push_items++; | |
0783fcfc | 1370 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
1371 | } |
1372 | if (push_items == 0) { | |
234b63a0 | 1373 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
1374 | return 1; |
1375 | } | |
a429e513 CM |
1376 | if (push_items == left_nritems) |
1377 | WARN_ON(1); | |
7518a238 | 1378 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 1379 | /* push left to right */ |
0783fcfc | 1380 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
123abc88 | 1381 | push_space -= leaf_data_end(root, left); |
00ec4c51 | 1382 | /* make room in the right data area */ |
d6025579 CM |
1383 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1384 | leaf_data_end(root, right) - push_space, | |
1385 | btrfs_leaf_data(right) + | |
1386 | leaf_data_end(root, right), BTRFS_LEAF_DATA_SIZE(root) - | |
1387 | leaf_data_end(root, right)); | |
00ec4c51 | 1388 | /* copy from the left data area */ |
d6025579 CM |
1389 | btrfs_memcpy(root, right, btrfs_leaf_data(right) + |
1390 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1391 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
1392 | push_space); | |
1393 | btrfs_memmove(root, right, right->items + push_items, right->items, | |
0783fcfc | 1394 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 1395 | /* copy the items from left to right */ |
d6025579 CM |
1396 | btrfs_memcpy(root, right, right->items, left->items + |
1397 | left_nritems - push_items, | |
1398 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
1399 | |
1400 | /* update the item pointers */ | |
7518a238 CM |
1401 | right_nritems += push_items; |
1402 | btrfs_set_header_nritems(&right->header, right_nritems); | |
123abc88 | 1403 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 1404 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
1405 | btrfs_set_item_offset(right->items + i, push_space - |
1406 | btrfs_item_size(right->items + i)); | |
1407 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 1408 | } |
7518a238 CM |
1409 | left_nritems -= push_items; |
1410 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 1411 | |
d6025579 CM |
1412 | btrfs_mark_buffer_dirty(left_buf); |
1413 | btrfs_mark_buffer_dirty(right_buf); | |
a429e513 | 1414 | |
d6025579 | 1415 | btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key, |
e2fa7227 | 1416 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
d6025579 | 1417 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 1418 | |
00ec4c51 | 1419 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
1420 | if (path->slots[0] >= left_nritems) { |
1421 | path->slots[0] -= left_nritems; | |
234b63a0 | 1422 | btrfs_block_release(root, path->nodes[0]); |
00ec4c51 CM |
1423 | path->nodes[0] = right_buf; |
1424 | path->slots[1] += 1; | |
1425 | } else { | |
234b63a0 | 1426 | btrfs_block_release(root, right_buf); |
00ec4c51 | 1427 | } |
098f59c2 CM |
1428 | if (path->nodes[1]) |
1429 | check_node(root, path, 1); | |
00ec4c51 CM |
1430 | return 0; |
1431 | } | |
74123bd7 CM |
1432 | /* |
1433 | * push some data in the path leaf to the left, trying to free up at | |
1434 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
1435 | */ | |
e089f05c CM |
1436 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
1437 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 1438 | { |
e20d96d6 CM |
1439 | struct buffer_head *right_buf = path->nodes[0]; |
1440 | struct btrfs_leaf *right = btrfs_buffer_leaf(right_buf); | |
1441 | struct buffer_head *t; | |
234b63a0 | 1442 | struct btrfs_leaf *left; |
be0e5c09 CM |
1443 | int slot; |
1444 | int i; | |
1445 | int free_space; | |
1446 | int push_space = 0; | |
1447 | int push_items = 0; | |
0783fcfc | 1448 | struct btrfs_item *item; |
7518a238 | 1449 | u32 old_left_nritems; |
aa5d6bed CM |
1450 | int ret = 0; |
1451 | int wret; | |
be0e5c09 CM |
1452 | |
1453 | slot = path->slots[1]; | |
1454 | if (slot == 0) { | |
1455 | return 1; | |
1456 | } | |
1457 | if (!path->nodes[1]) { | |
1458 | return 1; | |
1459 | } | |
e20d96d6 CM |
1460 | t = read_tree_block(root, |
1461 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[1]), slot - 1)); | |
1462 | left = btrfs_buffer_leaf(t); | |
123abc88 | 1463 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 1464 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1465 | btrfs_block_release(root, t); |
be0e5c09 CM |
1466 | return 1; |
1467 | } | |
02217ed2 CM |
1468 | |
1469 | /* cow and double check */ | |
54aa1f4d CM |
1470 | ret = btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t); |
1471 | if (ret) { | |
1472 | /* we hit -ENOSPC, but it isn't fatal here */ | |
252c38f0 | 1473 | btrfs_block_release(root, t); |
54aa1f4d CM |
1474 | return 1; |
1475 | } | |
e20d96d6 | 1476 | left = btrfs_buffer_leaf(t); |
123abc88 | 1477 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 1478 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1479 | btrfs_block_release(root, t); |
02217ed2 CM |
1480 | return 1; |
1481 | } | |
1482 | ||
a429e513 CM |
1483 | if (btrfs_header_nritems(&right->header) == 0) { |
1484 | btrfs_block_release(root, t); | |
1485 | return 1; | |
1486 | } | |
1487 | ||
1488 | for (i = 0; i < btrfs_header_nritems(&right->header) - 1; i++) { | |
be0e5c09 CM |
1489 | item = right->items + i; |
1490 | if (path->slots[0] == i) | |
1491 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1492 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1493 | free_space) | |
be0e5c09 CM |
1494 | break; |
1495 | push_items++; | |
0783fcfc | 1496 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
1497 | } |
1498 | if (push_items == 0) { | |
234b63a0 | 1499 | btrfs_block_release(root, t); |
be0e5c09 CM |
1500 | return 1; |
1501 | } | |
a429e513 CM |
1502 | if (push_items == btrfs_header_nritems(&right->header)) |
1503 | WARN_ON(1); | |
be0e5c09 | 1504 | /* push data from right to left */ |
d6025579 CM |
1505 | btrfs_memcpy(root, left, left->items + |
1506 | btrfs_header_nritems(&left->header), | |
1507 | right->items, push_items * sizeof(struct btrfs_item)); | |
123abc88 | 1508 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
0783fcfc | 1509 | btrfs_item_offset(right->items + push_items -1); |
d6025579 CM |
1510 | btrfs_memcpy(root, left, btrfs_leaf_data(left) + |
1511 | leaf_data_end(root, left) - push_space, | |
1512 | btrfs_leaf_data(right) + | |
1513 | btrfs_item_offset(right->items + push_items - 1), | |
1514 | push_space); | |
7518a238 | 1515 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
1516 | BUG_ON(old_left_nritems < 0); |
1517 | ||
0783fcfc | 1518 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
123abc88 CM |
1519 | u32 ioff = btrfs_item_offset(left->items + i); |
1520 | btrfs_set_item_offset(left->items + i, ioff - | |
1521 | (BTRFS_LEAF_DATA_SIZE(root) - | |
0783fcfc CM |
1522 | btrfs_item_offset(left->items + |
1523 | old_left_nritems - 1))); | |
be0e5c09 | 1524 | } |
7518a238 | 1525 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
1526 | |
1527 | /* fixup right node */ | |
0783fcfc | 1528 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
123abc88 | 1529 | leaf_data_end(root, right); |
d6025579 CM |
1530 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1531 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1532 | btrfs_leaf_data(right) + | |
1533 | leaf_data_end(root, right), push_space); | |
1534 | btrfs_memmove(root, right, right->items, right->items + push_items, | |
7518a238 | 1535 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 1536 | sizeof(struct btrfs_item)); |
7518a238 CM |
1537 | btrfs_set_header_nritems(&right->header, |
1538 | btrfs_header_nritems(&right->header) - | |
1539 | push_items); | |
123abc88 | 1540 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
eb60ceac | 1541 | |
7518a238 | 1542 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
1543 | btrfs_set_item_offset(right->items + i, push_space - |
1544 | btrfs_item_size(right->items + i)); | |
1545 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1546 | } |
eb60ceac | 1547 | |
d6025579 CM |
1548 | btrfs_mark_buffer_dirty(t); |
1549 | btrfs_mark_buffer_dirty(right_buf); | |
098f59c2 | 1550 | |
e089f05c | 1551 | wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1); |
aa5d6bed CM |
1552 | if (wret) |
1553 | ret = wret; | |
be0e5c09 CM |
1554 | |
1555 | /* then fixup the leaf pointer in the path */ | |
1556 | if (path->slots[0] < push_items) { | |
1557 | path->slots[0] += old_left_nritems; | |
234b63a0 | 1558 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1559 | path->nodes[0] = t; |
be0e5c09 CM |
1560 | path->slots[1] -= 1; |
1561 | } else { | |
234b63a0 | 1562 | btrfs_block_release(root, t); |
be0e5c09 CM |
1563 | path->slots[0] -= push_items; |
1564 | } | |
eb60ceac | 1565 | BUG_ON(path->slots[0] < 0); |
098f59c2 CM |
1566 | if (path->nodes[1]) |
1567 | check_node(root, path, 1); | |
aa5d6bed | 1568 | return ret; |
be0e5c09 CM |
1569 | } |
1570 | ||
74123bd7 CM |
1571 | /* |
1572 | * split the path's leaf in two, making sure there is at least data_size | |
1573 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1574 | * |
1575 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1576 | */ |
e089f05c | 1577 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
d4dbff95 CM |
1578 | *root, struct btrfs_key *ins_key, |
1579 | struct btrfs_path *path, int data_size) | |
be0e5c09 | 1580 | { |
e20d96d6 | 1581 | struct buffer_head *l_buf; |
234b63a0 | 1582 | struct btrfs_leaf *l; |
7518a238 | 1583 | u32 nritems; |
eb60ceac CM |
1584 | int mid; |
1585 | int slot; | |
234b63a0 | 1586 | struct btrfs_leaf *right; |
e20d96d6 | 1587 | struct buffer_head *right_buffer; |
0783fcfc | 1588 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1589 | int data_copy_size; |
1590 | int rt_data_off; | |
1591 | int i; | |
d4dbff95 | 1592 | int ret = 0; |
aa5d6bed | 1593 | int wret; |
d4dbff95 CM |
1594 | int double_split = 0; |
1595 | struct btrfs_disk_key disk_key; | |
aa5d6bed | 1596 | |
40689478 | 1597 | /* first try to make some room by pushing left and right */ |
e089f05c | 1598 | wret = push_leaf_left(trans, root, path, data_size); |
eaee50e8 CM |
1599 | if (wret < 0) |
1600 | return wret; | |
1601 | if (wret) { | |
e089f05c | 1602 | wret = push_leaf_right(trans, root, path, data_size); |
eaee50e8 CM |
1603 | if (wret < 0) |
1604 | return wret; | |
1605 | } | |
aa5d6bed | 1606 | l_buf = path->nodes[0]; |
e20d96d6 | 1607 | l = btrfs_buffer_leaf(l_buf); |
aa5d6bed CM |
1608 | |
1609 | /* did the pushes work? */ | |
123abc88 CM |
1610 | if (btrfs_leaf_free_space(root, l) >= |
1611 | sizeof(struct btrfs_item) + data_size) | |
aa5d6bed CM |
1612 | return 0; |
1613 | ||
5c680ed6 | 1614 | if (!path->nodes[1]) { |
e089f05c | 1615 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
1616 | if (ret) |
1617 | return ret; | |
1618 | } | |
eb60ceac | 1619 | slot = path->slots[0]; |
7518a238 | 1620 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1621 | mid = (nritems + 1)/ 2; |
54aa1f4d | 1622 | |
6702ed49 | 1623 | right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr, 0); |
54aa1f4d CM |
1624 | if (IS_ERR(right_buffer)) |
1625 | return PTR_ERR(right_buffer); | |
1626 | ||
e20d96d6 | 1627 | right = btrfs_buffer_leaf(right_buffer); |
123abc88 | 1628 | memset(&right->header, 0, sizeof(right->header)); |
7eccb903 | 1629 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
7f5c1516 | 1630 | btrfs_set_header_generation(&right->header, trans->transid); |
4d775673 | 1631 | btrfs_set_header_owner(&right->header, root->root_key.objectid); |
7518a238 | 1632 | btrfs_set_header_level(&right->header, 0); |
3eb0314d CM |
1633 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1634 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1635 | if (mid <= slot) { |
1636 | if (nritems == 1 || | |
1637 | leaf_space_used(l, mid, nritems - mid) + space_needed > | |
1638 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1639 | if (slot >= nritems) { | |
1640 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1641 | btrfs_set_header_nritems(&right->header, 0); | |
1642 | wret = insert_ptr(trans, root, path, | |
1643 | &disk_key, | |
7eccb903 | 1644 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1645 | path->slots[1] + 1, 1); |
1646 | if (wret) | |
1647 | ret = wret; | |
1648 | btrfs_block_release(root, path->nodes[0]); | |
1649 | path->nodes[0] = right_buffer; | |
1650 | path->slots[0] = 0; | |
1651 | path->slots[1] += 1; | |
1652 | return ret; | |
1653 | } | |
1654 | mid = slot; | |
1655 | double_split = 1; | |
1656 | } | |
1657 | } else { | |
1658 | if (leaf_space_used(l, 0, mid + 1) + space_needed > | |
1659 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1660 | if (slot == 0) { | |
1661 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1662 | btrfs_set_header_nritems(&right->header, 0); | |
1663 | wret = insert_ptr(trans, root, path, | |
1664 | &disk_key, | |
7eccb903 | 1665 | bh_blocknr(right_buffer), |
098f59c2 | 1666 | path->slots[1], 1); |
d4dbff95 CM |
1667 | if (wret) |
1668 | ret = wret; | |
1669 | btrfs_block_release(root, path->nodes[0]); | |
1670 | path->nodes[0] = right_buffer; | |
1671 | path->slots[0] = 0; | |
a429e513 CM |
1672 | if (path->slots[1] == 0) { |
1673 | wret = fixup_low_keys(trans, root, | |
1674 | path, &disk_key, 1); | |
1675 | if (wret) | |
1676 | ret = wret; | |
1677 | } | |
d4dbff95 CM |
1678 | return ret; |
1679 | } | |
1680 | mid = slot; | |
1681 | double_split = 1; | |
1682 | } | |
1683 | } | |
1684 | btrfs_set_header_nritems(&right->header, nritems - mid); | |
123abc88 CM |
1685 | data_copy_size = btrfs_item_end(l->items + mid) - |
1686 | leaf_data_end(root, l); | |
d6025579 CM |
1687 | btrfs_memcpy(root, right, right->items, l->items + mid, |
1688 | (nritems - mid) * sizeof(struct btrfs_item)); | |
1689 | btrfs_memcpy(root, right, | |
1690 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
1691 | data_copy_size, btrfs_leaf_data(l) + | |
1692 | leaf_data_end(root, l), data_copy_size); | |
123abc88 CM |
1693 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
1694 | btrfs_item_end(l->items + mid); | |
74123bd7 | 1695 | |
0783fcfc | 1696 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
123abc88 | 1697 | u32 ioff = btrfs_item_offset(right->items + i); |
0783fcfc CM |
1698 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); |
1699 | } | |
74123bd7 | 1700 | |
7518a238 | 1701 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed | 1702 | ret = 0; |
e089f05c | 1703 | wret = insert_ptr(trans, root, path, &right->items[0].key, |
7eccb903 | 1704 | bh_blocknr(right_buffer), path->slots[1] + 1, 1); |
aa5d6bed CM |
1705 | if (wret) |
1706 | ret = wret; | |
d6025579 CM |
1707 | btrfs_mark_buffer_dirty(right_buffer); |
1708 | btrfs_mark_buffer_dirty(l_buf); | |
eb60ceac | 1709 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1710 | if (mid <= slot) { |
234b63a0 | 1711 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1712 | path->nodes[0] = right_buffer; |
be0e5c09 CM |
1713 | path->slots[0] -= mid; |
1714 | path->slots[1] += 1; | |
eb60ceac | 1715 | } else |
234b63a0 | 1716 | btrfs_block_release(root, right_buffer); |
eb60ceac | 1717 | BUG_ON(path->slots[0] < 0); |
098f59c2 | 1718 | check_node(root, path, 1); |
d4dbff95 CM |
1719 | |
1720 | if (!double_split) | |
1721 | return ret; | |
6702ed49 | 1722 | right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr, 0); |
54aa1f4d CM |
1723 | if (IS_ERR(right_buffer)) |
1724 | return PTR_ERR(right_buffer); | |
1725 | ||
d4dbff95 CM |
1726 | right = btrfs_buffer_leaf(right_buffer); |
1727 | memset(&right->header, 0, sizeof(right->header)); | |
7eccb903 | 1728 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
d4dbff95 | 1729 | btrfs_set_header_generation(&right->header, trans->transid); |
4d775673 | 1730 | btrfs_set_header_owner(&right->header, root->root_key.objectid); |
d4dbff95 | 1731 | btrfs_set_header_level(&right->header, 0); |
3eb0314d CM |
1732 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1733 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1734 | btrfs_cpu_key_to_disk(&disk_key, ins_key); |
1735 | btrfs_set_header_nritems(&right->header, 0); | |
1736 | wret = insert_ptr(trans, root, path, | |
1737 | &disk_key, | |
7eccb903 | 1738 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1739 | path->slots[1], 1); |
1740 | if (wret) | |
1741 | ret = wret; | |
a429e513 CM |
1742 | if (path->slots[1] == 0) { |
1743 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
1744 | if (wret) | |
1745 | ret = wret; | |
1746 | } | |
d4dbff95 CM |
1747 | btrfs_block_release(root, path->nodes[0]); |
1748 | path->nodes[0] = right_buffer; | |
1749 | path->slots[0] = 0; | |
1750 | check_node(root, path, 1); | |
1751 | check_leaf(root, path, 0); | |
be0e5c09 CM |
1752 | return ret; |
1753 | } | |
1754 | ||
b18c6685 CM |
1755 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
1756 | struct btrfs_root *root, | |
1757 | struct btrfs_path *path, | |
1758 | u32 new_size) | |
1759 | { | |
1760 | int ret = 0; | |
1761 | int slot; | |
1762 | int slot_orig; | |
1763 | struct btrfs_leaf *leaf; | |
1764 | struct buffer_head *leaf_buf; | |
1765 | u32 nritems; | |
1766 | unsigned int data_end; | |
1767 | unsigned int old_data_start; | |
1768 | unsigned int old_size; | |
1769 | unsigned int size_diff; | |
1770 | int i; | |
1771 | ||
1772 | slot_orig = path->slots[0]; | |
1773 | leaf_buf = path->nodes[0]; | |
1774 | leaf = btrfs_buffer_leaf(leaf_buf); | |
1775 | ||
1776 | nritems = btrfs_header_nritems(&leaf->header); | |
1777 | data_end = leaf_data_end(root, leaf); | |
1778 | ||
1779 | slot = path->slots[0]; | |
1780 | old_data_start = btrfs_item_offset(leaf->items + slot); | |
1781 | old_size = btrfs_item_size(leaf->items + slot); | |
1782 | BUG_ON(old_size <= new_size); | |
1783 | size_diff = old_size - new_size; | |
1784 | ||
1785 | BUG_ON(slot < 0); | |
1786 | BUG_ON(slot >= nritems); | |
1787 | ||
1788 | /* | |
1789 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1790 | */ | |
1791 | /* first correct the data pointers */ | |
1792 | for (i = slot; i < nritems; i++) { | |
1793 | u32 ioff = btrfs_item_offset(leaf->items + i); | |
1794 | btrfs_set_item_offset(leaf->items + i, | |
1795 | ioff + size_diff); | |
1796 | } | |
1797 | /* shift the data */ | |
b18c6685 CM |
1798 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1799 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
1800 | data_end, old_data_start + new_size - data_end); | |
1801 | btrfs_set_item_size(leaf->items + slot, new_size); | |
1802 | btrfs_mark_buffer_dirty(leaf_buf); | |
1803 | ||
1804 | ret = 0; | |
1805 | if (btrfs_leaf_free_space(root, leaf) < 0) | |
1806 | BUG(); | |
1807 | check_leaf(root, path, 0); | |
1808 | return ret; | |
1809 | } | |
1810 | ||
6567e837 CM |
1811 | int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1812 | *root, struct btrfs_path *path, u32 data_size) | |
1813 | { | |
1814 | int ret = 0; | |
1815 | int slot; | |
1816 | int slot_orig; | |
1817 | struct btrfs_leaf *leaf; | |
1818 | struct buffer_head *leaf_buf; | |
1819 | u32 nritems; | |
1820 | unsigned int data_end; | |
1821 | unsigned int old_data; | |
1822 | unsigned int old_size; | |
1823 | int i; | |
1824 | ||
1825 | slot_orig = path->slots[0]; | |
1826 | leaf_buf = path->nodes[0]; | |
1827 | leaf = btrfs_buffer_leaf(leaf_buf); | |
1828 | ||
1829 | nritems = btrfs_header_nritems(&leaf->header); | |
1830 | data_end = leaf_data_end(root, leaf); | |
1831 | ||
1832 | if (btrfs_leaf_free_space(root, leaf) < data_size) | |
1833 | BUG(); | |
1834 | slot = path->slots[0]; | |
1835 | old_data = btrfs_item_end(leaf->items + slot); | |
1836 | ||
1837 | BUG_ON(slot < 0); | |
1838 | BUG_ON(slot >= nritems); | |
1839 | ||
1840 | /* | |
1841 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1842 | */ | |
1843 | /* first correct the data pointers */ | |
1844 | for (i = slot; i < nritems; i++) { | |
1845 | u32 ioff = btrfs_item_offset(leaf->items + i); | |
1846 | btrfs_set_item_offset(leaf->items + i, | |
1847 | ioff - data_size); | |
1848 | } | |
1849 | /* shift the data */ | |
1850 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + | |
1851 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1852 | data_end, old_data - data_end); | |
1853 | data_end = old_data; | |
1854 | old_size = btrfs_item_size(leaf->items + slot); | |
1855 | btrfs_set_item_size(leaf->items + slot, old_size + data_size); | |
1856 | btrfs_mark_buffer_dirty(leaf_buf); | |
1857 | ||
1858 | ret = 0; | |
1859 | if (btrfs_leaf_free_space(root, leaf) < 0) | |
1860 | BUG(); | |
1861 | check_leaf(root, path, 0); | |
1862 | return ret; | |
1863 | } | |
1864 | ||
74123bd7 CM |
1865 | /* |
1866 | * Given a key and some data, insert an item into the tree. | |
1867 | * This does all the path init required, making room in the tree if needed. | |
1868 | */ | |
e089f05c CM |
1869 | int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1870 | *root, struct btrfs_path *path, struct btrfs_key | |
1871 | *cpu_key, u32 data_size) | |
be0e5c09 | 1872 | { |
aa5d6bed | 1873 | int ret = 0; |
be0e5c09 | 1874 | int slot; |
eb60ceac | 1875 | int slot_orig; |
234b63a0 | 1876 | struct btrfs_leaf *leaf; |
e20d96d6 | 1877 | struct buffer_head *leaf_buf; |
7518a238 | 1878 | u32 nritems; |
be0e5c09 | 1879 | unsigned int data_end; |
e2fa7227 CM |
1880 | struct btrfs_disk_key disk_key; |
1881 | ||
1882 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1883 | |
74123bd7 | 1884 | /* create a root if there isn't one */ |
5c680ed6 | 1885 | if (!root->node) |
cfaa7295 | 1886 | BUG(); |
e089f05c | 1887 | ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1); |
eb60ceac | 1888 | if (ret == 0) { |
f0930a37 | 1889 | return -EEXIST; |
aa5d6bed | 1890 | } |
ed2ff2cb CM |
1891 | if (ret < 0) |
1892 | goto out; | |
be0e5c09 | 1893 | |
62e2749e CM |
1894 | slot_orig = path->slots[0]; |
1895 | leaf_buf = path->nodes[0]; | |
e20d96d6 | 1896 | leaf = btrfs_buffer_leaf(leaf_buf); |
74123bd7 | 1897 | |
7518a238 | 1898 | nritems = btrfs_header_nritems(&leaf->header); |
123abc88 | 1899 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 1900 | |
123abc88 | 1901 | if (btrfs_leaf_free_space(root, leaf) < |
d4dbff95 | 1902 | sizeof(struct btrfs_item) + data_size) { |
be0e5c09 | 1903 | BUG(); |
d4dbff95 | 1904 | } |
62e2749e | 1905 | slot = path->slots[0]; |
eb60ceac | 1906 | BUG_ON(slot < 0); |
be0e5c09 CM |
1907 | if (slot != nritems) { |
1908 | int i; | |
0783fcfc | 1909 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1910 | |
1911 | /* | |
1912 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1913 | */ | |
1914 | /* first correct the data pointers */ | |
0783fcfc | 1915 | for (i = slot; i < nritems; i++) { |
123abc88 | 1916 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1917 | btrfs_set_item_offset(leaf->items + i, |
1918 | ioff - data_size); | |
1919 | } | |
be0e5c09 CM |
1920 | |
1921 | /* shift the items */ | |
d6025579 CM |
1922 | btrfs_memmove(root, leaf, leaf->items + slot + 1, |
1923 | leaf->items + slot, | |
1924 | (nritems - slot) * sizeof(struct btrfs_item)); | |
be0e5c09 CM |
1925 | |
1926 | /* shift the data */ | |
d6025579 CM |
1927 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1928 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1929 | data_end, old_data - data_end); | |
be0e5c09 CM |
1930 | data_end = old_data; |
1931 | } | |
62e2749e | 1932 | /* setup the item for the new data */ |
d6025579 CM |
1933 | btrfs_memcpy(root, leaf, &leaf->items[slot].key, &disk_key, |
1934 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1935 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1936 | btrfs_set_item_size(leaf->items + slot, data_size); | |
7518a238 | 1937 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
d6025579 | 1938 | btrfs_mark_buffer_dirty(leaf_buf); |
aa5d6bed CM |
1939 | |
1940 | ret = 0; | |
8e19f2cd | 1941 | if (slot == 0) |
e089f05c | 1942 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 1943 | |
123abc88 | 1944 | if (btrfs_leaf_free_space(root, leaf) < 0) |
be0e5c09 | 1945 | BUG(); |
62e2749e | 1946 | check_leaf(root, path, 0); |
ed2ff2cb | 1947 | out: |
62e2749e CM |
1948 | return ret; |
1949 | } | |
1950 | ||
1951 | /* | |
1952 | * Given a key and some data, insert an item into the tree. | |
1953 | * This does all the path init required, making room in the tree if needed. | |
1954 | */ | |
e089f05c CM |
1955 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1956 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
1957 | data_size) | |
62e2749e CM |
1958 | { |
1959 | int ret = 0; | |
2c90e5d6 | 1960 | struct btrfs_path *path; |
62e2749e CM |
1961 | u8 *ptr; |
1962 | ||
2c90e5d6 CM |
1963 | path = btrfs_alloc_path(); |
1964 | BUG_ON(!path); | |
2c90e5d6 | 1965 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 1966 | if (!ret) { |
2c90e5d6 CM |
1967 | ptr = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
1968 | path->slots[0], u8); | |
1969 | btrfs_memcpy(root, path->nodes[0]->b_data, | |
d6025579 | 1970 | ptr, data, data_size); |
2c90e5d6 | 1971 | btrfs_mark_buffer_dirty(path->nodes[0]); |
62e2749e | 1972 | } |
2c90e5d6 | 1973 | btrfs_free_path(path); |
aa5d6bed | 1974 | return ret; |
be0e5c09 CM |
1975 | } |
1976 | ||
74123bd7 | 1977 | /* |
5de08d7d | 1978 | * delete the pointer from a given node. |
74123bd7 CM |
1979 | * |
1980 | * If the delete empties a node, the node is removed from the tree, | |
1981 | * continuing all the way the root if required. The root is converted into | |
1982 | * a leaf if all the nodes are emptied. | |
1983 | */ | |
e089f05c CM |
1984 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1985 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 1986 | { |
234b63a0 | 1987 | struct btrfs_node *node; |
e20d96d6 | 1988 | struct buffer_head *parent = path->nodes[level]; |
7518a238 | 1989 | u32 nritems; |
aa5d6bed | 1990 | int ret = 0; |
bb803951 | 1991 | int wret; |
be0e5c09 | 1992 | |
e20d96d6 | 1993 | node = btrfs_buffer_node(parent); |
7518a238 | 1994 | nritems = btrfs_header_nritems(&node->header); |
bb803951 | 1995 | if (slot != nritems -1) { |
d6025579 CM |
1996 | btrfs_memmove(root, node, node->ptrs + slot, |
1997 | node->ptrs + slot + 1, | |
1998 | sizeof(struct btrfs_key_ptr) * | |
1999 | (nritems - slot - 1)); | |
bb803951 | 2000 | } |
7518a238 CM |
2001 | nritems--; |
2002 | btrfs_set_header_nritems(&node->header, nritems); | |
2003 | if (nritems == 0 && parent == root->node) { | |
e20d96d6 CM |
2004 | struct btrfs_header *header = btrfs_buffer_header(root->node); |
2005 | BUG_ON(btrfs_header_level(header) != 1); | |
bb803951 | 2006 | /* just turn the root into a leaf and break */ |
e20d96d6 | 2007 | btrfs_set_header_level(header, 0); |
bb803951 | 2008 | } else if (slot == 0) { |
e089f05c | 2009 | wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key, |
123abc88 | 2010 | level + 1); |
0f70abe2 CM |
2011 | if (wret) |
2012 | ret = wret; | |
be0e5c09 | 2013 | } |
d6025579 | 2014 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 2015 | return ret; |
be0e5c09 CM |
2016 | } |
2017 | ||
74123bd7 CM |
2018 | /* |
2019 | * delete the item at the leaf level in path. If that empties | |
2020 | * the leaf, remove it from the tree | |
2021 | */ | |
e089f05c CM |
2022 | int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
2023 | struct btrfs_path *path) | |
be0e5c09 | 2024 | { |
be0e5c09 | 2025 | int slot; |
234b63a0 | 2026 | struct btrfs_leaf *leaf; |
e20d96d6 | 2027 | struct buffer_head *leaf_buf; |
be0e5c09 CM |
2028 | int doff; |
2029 | int dsize; | |
aa5d6bed CM |
2030 | int ret = 0; |
2031 | int wret; | |
7518a238 | 2032 | u32 nritems; |
be0e5c09 | 2033 | |
eb60ceac | 2034 | leaf_buf = path->nodes[0]; |
e20d96d6 | 2035 | leaf = btrfs_buffer_leaf(leaf_buf); |
4920c9ac | 2036 | slot = path->slots[0]; |
0783fcfc CM |
2037 | doff = btrfs_item_offset(leaf->items + slot); |
2038 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 2039 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 2040 | |
7518a238 | 2041 | if (slot != nritems - 1) { |
be0e5c09 | 2042 | int i; |
123abc88 | 2043 | int data_end = leaf_data_end(root, leaf); |
d6025579 CM |
2044 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
2045 | data_end + dsize, | |
2046 | btrfs_leaf_data(leaf) + data_end, | |
2047 | doff - data_end); | |
0783fcfc | 2048 | for (i = slot + 1; i < nritems; i++) { |
123abc88 | 2049 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
2050 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); |
2051 | } | |
d6025579 CM |
2052 | btrfs_memmove(root, leaf, leaf->items + slot, |
2053 | leaf->items + slot + 1, | |
2054 | sizeof(struct btrfs_item) * | |
2055 | (nritems - slot - 1)); | |
be0e5c09 | 2056 | } |
7518a238 CM |
2057 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
2058 | nritems--; | |
74123bd7 | 2059 | /* delete the leaf if we've emptied it */ |
7518a238 | 2060 | if (nritems == 0) { |
eb60ceac | 2061 | if (leaf_buf == root->node) { |
7518a238 | 2062 | btrfs_set_header_level(&leaf->header, 0); |
9a8dd150 | 2063 | } else { |
e089f05c | 2064 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 2065 | wait_on_buffer(leaf_buf); |
e089f05c | 2066 | wret = del_ptr(trans, root, path, 1, path->slots[1]); |
aa5d6bed CM |
2067 | if (wret) |
2068 | ret = wret; | |
e089f05c | 2069 | wret = btrfs_free_extent(trans, root, |
7eccb903 | 2070 | bh_blocknr(leaf_buf), 1, 1); |
0f70abe2 CM |
2071 | if (wret) |
2072 | ret = wret; | |
9a8dd150 | 2073 | } |
be0e5c09 | 2074 | } else { |
7518a238 | 2075 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 2076 | if (slot == 0) { |
e089f05c CM |
2077 | wret = fixup_low_keys(trans, root, path, |
2078 | &leaf->items[0].key, 1); | |
aa5d6bed CM |
2079 | if (wret) |
2080 | ret = wret; | |
2081 | } | |
aa5d6bed | 2082 | |
74123bd7 | 2083 | /* delete the leaf if it is mostly empty */ |
123abc88 | 2084 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
2085 | /* push_leaf_left fixes the path. |
2086 | * make sure the path still points to our leaf | |
2087 | * for possible call to del_ptr below | |
2088 | */ | |
4920c9ac | 2089 | slot = path->slots[1]; |
e20d96d6 | 2090 | get_bh(leaf_buf); |
e089f05c | 2091 | wret = push_leaf_left(trans, root, path, 1); |
54aa1f4d | 2092 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 2093 | ret = wret; |
f0930a37 | 2094 | if (path->nodes[0] == leaf_buf && |
7518a238 | 2095 | btrfs_header_nritems(&leaf->header)) { |
e089f05c | 2096 | wret = push_leaf_right(trans, root, path, 1); |
54aa1f4d | 2097 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
2098 | ret = wret; |
2099 | } | |
7518a238 | 2100 | if (btrfs_header_nritems(&leaf->header) == 0) { |
7eccb903 | 2101 | u64 blocknr = bh_blocknr(leaf_buf); |
e089f05c | 2102 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 2103 | wait_on_buffer(leaf_buf); |
e089f05c | 2104 | wret = del_ptr(trans, root, path, 1, slot); |
aa5d6bed CM |
2105 | if (wret) |
2106 | ret = wret; | |
234b63a0 | 2107 | btrfs_block_release(root, leaf_buf); |
e089f05c CM |
2108 | wret = btrfs_free_extent(trans, root, blocknr, |
2109 | 1, 1); | |
0f70abe2 CM |
2110 | if (wret) |
2111 | ret = wret; | |
5de08d7d | 2112 | } else { |
d6025579 | 2113 | btrfs_mark_buffer_dirty(leaf_buf); |
234b63a0 | 2114 | btrfs_block_release(root, leaf_buf); |
be0e5c09 | 2115 | } |
d5719762 | 2116 | } else { |
d6025579 | 2117 | btrfs_mark_buffer_dirty(leaf_buf); |
be0e5c09 CM |
2118 | } |
2119 | } | |
aa5d6bed | 2120 | return ret; |
be0e5c09 CM |
2121 | } |
2122 | ||
97571fd0 CM |
2123 | /* |
2124 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
2125 | * returns 0 if it found something or 1 if there are no greater leaves. |
2126 | * returns < 0 on io errors. | |
97571fd0 | 2127 | */ |
234b63a0 | 2128 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
2129 | { |
2130 | int slot; | |
2131 | int level = 1; | |
2132 | u64 blocknr; | |
e20d96d6 CM |
2133 | struct buffer_head *c; |
2134 | struct btrfs_node *c_node; | |
2135 | struct buffer_head *next = NULL; | |
d97e63b6 | 2136 | |
234b63a0 | 2137 | while(level < BTRFS_MAX_LEVEL) { |
d97e63b6 | 2138 | if (!path->nodes[level]) |
0f70abe2 | 2139 | return 1; |
d97e63b6 CM |
2140 | slot = path->slots[level] + 1; |
2141 | c = path->nodes[level]; | |
e20d96d6 CM |
2142 | c_node = btrfs_buffer_node(c); |
2143 | if (slot >= btrfs_header_nritems(&c_node->header)) { | |
d97e63b6 CM |
2144 | level++; |
2145 | continue; | |
2146 | } | |
e20d96d6 | 2147 | blocknr = btrfs_node_blockptr(c_node, slot); |
cfaa7295 | 2148 | if (next) |
234b63a0 | 2149 | btrfs_block_release(root, next); |
6702ed49 CM |
2150 | if (path->reada) |
2151 | reada_for_search(root, path, level, slot); | |
d97e63b6 CM |
2152 | next = read_tree_block(root, blocknr); |
2153 | break; | |
2154 | } | |
2155 | path->slots[level] = slot; | |
2156 | while(1) { | |
2157 | level--; | |
2158 | c = path->nodes[level]; | |
234b63a0 | 2159 | btrfs_block_release(root, c); |
d97e63b6 CM |
2160 | path->nodes[level] = next; |
2161 | path->slots[level] = 0; | |
2162 | if (!level) | |
2163 | break; | |
6702ed49 | 2164 | if (path->reada) |
32020611 | 2165 | reada_for_search(root, path, level, 0); |
1d4f8a0c | 2166 | next = read_tree_block(root, |
e20d96d6 | 2167 | btrfs_node_blockptr(btrfs_buffer_node(next), 0)); |
d97e63b6 CM |
2168 | } |
2169 | return 0; | |
2170 | } |