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