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