Btrfs: Go back to kmaps instead of page_address in extent_buffers
[linux-block.git] / fs / btrfs / ctree.c
CommitLineData
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
5f39d397 19#include <linux/highmem.h>
eb60ceac
CM
20#include "ctree.h"
21#include "disk-io.h"
7f5c1516 22#include "transaction.h"
5f39d397 23#include "print-tree.h"
9a8dd150 24
e089f05c
CM
25static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
d4dbff95
CM
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size);
5f39d397
CM
30static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src);
33static int balance_node_right(struct btrfs_trans_handle *trans,
34 struct btrfs_root *root,
35 struct extent_buffer *dst_buf,
36 struct extent_buffer *src_buf);
e089f05c
CM
37static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
d97e63b6 39
df24a2b9 40inline void btrfs_init_path(struct btrfs_path *p)
2c90e5d6 41{
df24a2b9 42 memset(p, 0, sizeof(*p));
2c90e5d6
CM
43}
44
df24a2b9 45struct btrfs_path *btrfs_alloc_path(void)
2c90e5d6 46{
df24a2b9
CM
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
2cc58cf2 49 if (path) {
df24a2b9 50 btrfs_init_path(path);
2cc58cf2
CM
51 path->reada = 1;
52 }
df24a2b9 53 return path;
2c90e5d6
CM
54}
55
df24a2b9 56void btrfs_free_path(struct btrfs_path *p)
be0e5c09 57{
df24a2b9
CM
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
be0e5c09
CM
60}
61
234b63a0 62void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
eb60ceac
CM
63{
64 int i;
234b63a0 65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
eb60ceac
CM
66 if (!p->nodes[i])
67 break;
5f39d397 68 free_extent_buffer(p->nodes[i]);
eb60ceac 69 }
aa5d6bed 70 memset(p, 0, sizeof(*p));
eb60ceac
CM
71}
72
5f39d397
CM
73static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
74 struct btrfs_root *root,
75 struct extent_buffer *buf,
76 struct extent_buffer *parent, int parent_slot,
77 struct extent_buffer **cow_ret,
78 u64 search_start, u64 empty_size)
02217ed2 79{
5f39d397 80 struct extent_buffer *cow;
6702ed49
CM
81 int ret = 0;
82 int different_trans = 0;
02217ed2 83
6702ed49 84 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
5f39d397 85
6702ed49 86 cow = btrfs_alloc_free_block(trans, root, search_start, empty_size);
54aa1f4d
CM
87 if (IS_ERR(cow))
88 return PTR_ERR(cow);
6702ed49 89
5f39d397 90 if (buf->len != root->sectorsize || cow->len != root->sectorsize)
2c90e5d6 91 WARN_ON(1);
6702ed49 92
5f39d397
CM
93 copy_extent_buffer(cow, buf, 0, 0, cow->len);
94 btrfs_set_header_blocknr(cow, extent_buffer_blocknr(cow));
95 btrfs_set_header_generation(cow, trans->transid);
96 btrfs_set_header_owner(cow, root->root_key.objectid);
6702ed49 97
5f39d397
CM
98 WARN_ON(btrfs_header_generation(buf) > trans->transid);
99 if (btrfs_header_generation(buf) != trans->transid) {
6702ed49
CM
100 different_trans = 1;
101 ret = btrfs_inc_ref(trans, root, buf);
102 if (ret)
103 return ret;
104 } else {
6702ed49
CM
105 clean_tree_block(trans, root, buf);
106 }
107
02217ed2
CM
108 if (buf == root->node) {
109 root->node = cow;
5f39d397 110 extent_buffer_get(cow);
2c90e5d6 111 if (buf != root->commit_root) {
5f39d397
CM
112 btrfs_free_extent(trans, root,
113 extent_buffer_blocknr(buf), 1, 1);
2c90e5d6 114 }
5f39d397 115 free_extent_buffer(buf);
02217ed2 116 } else {
5f39d397
CM
117 btrfs_set_node_blockptr(parent, parent_slot,
118 extent_buffer_blocknr(cow));
d6025579 119 btrfs_mark_buffer_dirty(parent);
5f39d397
CM
120 WARN_ON(btrfs_header_generation(parent) != trans->transid);
121 btrfs_free_extent(trans, root, extent_buffer_blocknr(buf),1,1);
02217ed2 122 }
5f39d397 123 free_extent_buffer(buf);
ccd467d6 124 btrfs_mark_buffer_dirty(cow);
2c90e5d6 125 *cow_ret = cow;
02217ed2
CM
126 return 0;
127}
128
5f39d397
CM
129int btrfs_cow_block(struct btrfs_trans_handle *trans,
130 struct btrfs_root *root, struct extent_buffer *buf,
131 struct extent_buffer *parent, int parent_slot,
132 struct extent_buffer **cow_ret)
6702ed49
CM
133{
134 u64 search_start;
135 if (trans->transaction != root->fs_info->running_transaction) {
136 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
137 root->fs_info->running_transaction->transid);
138 WARN_ON(1);
139 }
140 if (trans->transid != root->fs_info->generation) {
141 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
142 root->fs_info->generation);
143 WARN_ON(1);
144 }
5f39d397 145 if (btrfs_header_generation(buf) == trans->transid) {
6702ed49
CM
146 *cow_ret = buf;
147 return 0;
148 }
149
5f39d397 150 search_start = extent_buffer_blocknr(buf) & ~((u64)65535);
6702ed49
CM
151 return __btrfs_cow_block(trans, root, buf, parent,
152 parent_slot, cow_ret, search_start, 0);
153}
154
155static 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
5f39d397
CM
164#if 0
165static int should_defrag_leaf(struct extent_buffer *eb)
2cc58cf2 166{
5f39d397
CM
167 return 0;
168 struct btrfs_leaf *leaf = btrfs_buffer_leaf(eb);
2cc58cf2
CM
169 struct btrfs_disk_key *key;
170 u32 nritems;
171
172 if (buffer_defrag(bh))
173 return 1;
174
175 nritems = btrfs_header_nritems(&leaf->header);
176 if (nritems == 0)
177 return 0;
178
179 key = &leaf->items[0].key;
180 if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
181 return 1;
182
183 key = &leaf->items[nritems-1].key;
184 if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
185 return 1;
186 if (nritems > 4) {
187 key = &leaf->items[nritems/2].key;
188 if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
189 return 1;
190 }
191 return 0;
192}
5f39d397 193#endif
2cc58cf2 194
6702ed49 195int btrfs_realloc_node(struct btrfs_trans_handle *trans,
5f39d397 196 struct btrfs_root *root, struct extent_buffer *parent,
e9d0b13b 197 int cache_only, u64 *last_ret)
6702ed49 198{
5f39d397
CM
199 return 0;
200#if 0
6702ed49 201 struct btrfs_node *parent_node;
5f39d397
CM
202 struct extent_buffer *cur_eb;
203 struct extent_buffer *tmp_eb;
6702ed49 204 u64 blocknr;
e9d0b13b
CM
205 u64 search_start = *last_ret;
206 u64 last_block = 0;
6702ed49
CM
207 u64 other;
208 u32 parent_nritems;
209 int start_slot;
210 int end_slot;
211 int i;
212 int err = 0;
f2183bde 213 int parent_level;
6702ed49
CM
214
215 if (trans->transaction != root->fs_info->running_transaction) {
216 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
217 root->fs_info->running_transaction->transid);
218 WARN_ON(1);
219 }
220 if (trans->transid != root->fs_info->generation) {
221 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
222 root->fs_info->generation);
223 WARN_ON(1);
224 }
86479a04
CM
225 if (buffer_defrag_done(parent))
226 return 0;
227
6702ed49
CM
228 parent_node = btrfs_buffer_node(parent);
229 parent_nritems = btrfs_header_nritems(&parent_node->header);
f2183bde 230 parent_level = btrfs_header_level(&parent_node->header);
6702ed49
CM
231
232 start_slot = 0;
233 end_slot = parent_nritems;
234
235 if (parent_nritems == 1)
236 return 0;
237
238 for (i = start_slot; i < end_slot; i++) {
239 int close = 1;
240 blocknr = btrfs_node_blockptr(parent_node, i);
e9d0b13b
CM
241 if (last_block == 0)
242 last_block = blocknr;
6702ed49
CM
243 if (i > 0) {
244 other = btrfs_node_blockptr(parent_node, i - 1);
245 close = close_blocks(blocknr, other);
246 }
247 if (close && i < end_slot - 1) {
248 other = btrfs_node_blockptr(parent_node, i + 1);
249 close = close_blocks(blocknr, other);
250 }
e9d0b13b
CM
251 if (close) {
252 last_block = blocknr;
6702ed49 253 continue;
e9d0b13b 254 }
6702ed49
CM
255
256 cur_bh = btrfs_find_tree_block(root, blocknr);
257 if (!cur_bh || !buffer_uptodate(cur_bh) ||
2cc58cf2
CM
258 buffer_locked(cur_bh) ||
259 (parent_level != 1 && !buffer_defrag(cur_bh)) ||
260 (parent_level == 1 && !should_defrag_leaf(cur_bh))) {
6702ed49
CM
261 if (cache_only) {
262 brelse(cur_bh);
263 continue;
264 }
f2183bde
CM
265 if (!cur_bh || !buffer_uptodate(cur_bh) ||
266 buffer_locked(cur_bh)) {
267 brelse(cur_bh);
268 cur_bh = read_tree_block(root, blocknr);
269 }
6702ed49 270 }
e9d0b13b
CM
271 if (search_start == 0)
272 search_start = last_block & ~((u64)65535);
273
6702ed49
CM
274 err = __btrfs_cow_block(trans, root, cur_bh, parent, i,
275 &tmp_bh, search_start,
276 min(8, end_slot - i));
252c38f0
Y
277 if (err) {
278 brelse(cur_bh);
6702ed49 279 break;
252c38f0 280 }
6702ed49 281 search_start = bh_blocknr(tmp_bh);
f2183bde
CM
282 *last_ret = search_start;
283 if (parent_level == 1)
284 clear_buffer_defrag(tmp_bh);
86479a04 285 set_buffer_defrag_done(tmp_bh);
6702ed49
CM
286 brelse(tmp_bh);
287 }
288 return err;
5f39d397 289#endif
6702ed49
CM
290}
291
74123bd7
CM
292/*
293 * The leaf data grows from end-to-front in the node.
294 * this returns the address of the start of the last item,
295 * which is the stop of the leaf data stack
296 */
123abc88 297static inline unsigned int leaf_data_end(struct btrfs_root *root,
5f39d397 298 struct extent_buffer *leaf)
be0e5c09 299{
5f39d397 300 u32 nr = btrfs_header_nritems(leaf);
be0e5c09 301 if (nr == 0)
123abc88 302 return BTRFS_LEAF_DATA_SIZE(root);
5f39d397 303 return btrfs_item_offset_nr(leaf, nr - 1);
be0e5c09
CM
304}
305
74123bd7
CM
306/*
307 * compare two keys in a memcmp fashion
308 */
9aca1d51 309static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
be0e5c09 310{
e2fa7227
CM
311 struct btrfs_key k1;
312
313 btrfs_disk_key_to_cpu(&k1, disk);
314
315 if (k1.objectid > k2->objectid)
be0e5c09 316 return 1;
e2fa7227 317 if (k1.objectid < k2->objectid)
be0e5c09 318 return -1;
5f39d397 319 if (k1.type > k2->type)
f254e52c 320 return 1;
5f39d397 321 if (k1.type < k2->type)
f254e52c 322 return -1;
70b2befd
CM
323 if (k1.offset > k2->offset)
324 return 1;
325 if (k1.offset < k2->offset)
326 return -1;
be0e5c09
CM
327 return 0;
328}
74123bd7 329
123abc88
CM
330static int check_node(struct btrfs_root *root, struct btrfs_path *path,
331 int level)
aa5d6bed 332{
5f39d397
CM
333 struct extent_buffer *parent = NULL;
334 struct extent_buffer *node = path->nodes[level];
335 struct btrfs_disk_key parent_key;
336 struct btrfs_disk_key node_key;
aa5d6bed 337 int parent_slot;
8d7be552
CM
338 int slot;
339 struct btrfs_key cpukey;
5f39d397 340 u32 nritems = btrfs_header_nritems(node);
aa5d6bed
CM
341
342 if (path->nodes[level + 1])
5f39d397 343 parent = path->nodes[level + 1];
a1f39630 344
8d7be552 345 slot = path->slots[level];
7518a238
CM
346 BUG_ON(nritems == 0);
347 if (parent) {
a1f39630 348 parent_slot = path->slots[level + 1];
5f39d397
CM
349 btrfs_node_key(parent, &parent_key, parent_slot);
350 btrfs_node_key(node, &node_key, 0);
351 BUG_ON(memcmp(&parent_key, &node_key,
e2fa7227 352 sizeof(struct btrfs_disk_key)));
1d4f8a0c 353 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
5f39d397 354 btrfs_header_blocknr(node));
aa5d6bed 355 }
123abc88 356 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
8d7be552 357 if (slot != 0) {
5f39d397
CM
358 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
359 btrfs_node_key(node, &node_key, slot);
360 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
8d7be552
CM
361 }
362 if (slot < nritems - 1) {
5f39d397
CM
363 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
364 btrfs_node_key(node, &node_key, slot);
365 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
aa5d6bed
CM
366 }
367 return 0;
368}
369
123abc88
CM
370static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
371 int level)
aa5d6bed 372{
5f39d397
CM
373 struct extent_buffer *leaf = path->nodes[level];
374 struct extent_buffer *parent = NULL;
aa5d6bed 375 int parent_slot;
8d7be552 376 struct btrfs_key cpukey;
5f39d397
CM
377 struct btrfs_disk_key parent_key;
378 struct btrfs_disk_key leaf_key;
379 int slot = path->slots[0];
8d7be552 380
5f39d397 381 u32 nritems = btrfs_header_nritems(leaf);
aa5d6bed
CM
382
383 if (path->nodes[level + 1])
5f39d397 384 parent = path->nodes[level + 1];
7518a238
CM
385
386 if (nritems == 0)
387 return 0;
388
389 if (parent) {
a1f39630 390 parent_slot = path->slots[level + 1];
5f39d397
CM
391 btrfs_node_key(parent, &parent_key, parent_slot);
392 btrfs_item_key(leaf, &leaf_key, 0);
6702ed49 393
5f39d397 394 BUG_ON(memcmp(&parent_key, &leaf_key,
e2fa7227 395 sizeof(struct btrfs_disk_key)));
1d4f8a0c 396 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
5f39d397
CM
397 btrfs_header_blocknr(leaf));
398 }
399#if 0
400 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
401 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
402 btrfs_item_key(leaf, &leaf_key, i);
403 if (comp_keys(&leaf_key, &cpukey) >= 0) {
404 btrfs_print_leaf(root, leaf);
405 printk("slot %d offset bad key\n", i);
406 BUG_ON(1);
407 }
408 if (btrfs_item_offset_nr(leaf, i) !=
409 btrfs_item_end_nr(leaf, i + 1)) {
410 btrfs_print_leaf(root, leaf);
411 printk("slot %d offset bad\n", i);
412 BUG_ON(1);
413 }
414 if (i == 0) {
415 if (btrfs_item_offset_nr(leaf, i) +
416 btrfs_item_size_nr(leaf, i) !=
417 BTRFS_LEAF_DATA_SIZE(root)) {
418 btrfs_print_leaf(root, leaf);
419 printk("slot %d first offset bad\n", i);
420 BUG_ON(1);
421 }
422 }
aa5d6bed 423 }
5f39d397
CM
424 if (nritems > 0) {
425 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
426 btrfs_print_leaf(root, leaf);
427 printk("slot %d bad size \n", nritems - 1);
428 BUG_ON(1);
429 }
430 }
431#endif
432 if (slot != 0 && slot < nritems - 1) {
433 btrfs_item_key(leaf, &leaf_key, slot);
434 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
435 if (comp_keys(&leaf_key, &cpukey) <= 0) {
436 btrfs_print_leaf(root, leaf);
437 printk("slot %d offset bad key\n", slot);
438 BUG_ON(1);
439 }
440 if (btrfs_item_offset_nr(leaf, slot - 1) !=
441 btrfs_item_end_nr(leaf, slot)) {
442 btrfs_print_leaf(root, leaf);
443 printk("slot %d offset bad\n", slot);
444 BUG_ON(1);
445 }
8d7be552
CM
446 }
447 if (slot < nritems - 1) {
5f39d397
CM
448 btrfs_item_key(leaf, &leaf_key, slot);
449 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
450 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
451 if (btrfs_item_offset_nr(leaf, slot) !=
452 btrfs_item_end_nr(leaf, slot + 1)) {
453 btrfs_print_leaf(root, leaf);
454 printk("slot %d offset bad\n", slot);
455 BUG_ON(1);
456 }
aa5d6bed 457 }
5f39d397
CM
458 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
459 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
aa5d6bed
CM
460 return 0;
461}
462
123abc88
CM
463static int check_block(struct btrfs_root *root, struct btrfs_path *path,
464 int level)
aa5d6bed 465{
5f39d397 466 struct extent_buffer *buf = path->nodes[level];
5f39d397 467
479965d6
CM
468 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
469 (unsigned long)btrfs_header_fsid(buf),
470 BTRFS_FSID_SIZE)) {
5f39d397 471 printk("warning bad block %Lu\n", buf->start);
479965d6 472 BUG();
5f39d397 473 }
aa5d6bed 474 if (level == 0)
123abc88
CM
475 return check_leaf(root, path, level);
476 return check_node(root, path, level);
aa5d6bed
CM
477}
478
74123bd7 479/*
5f39d397
CM
480 * search for key in the extent_buffer. The items start at offset p,
481 * and they are item_size apart. There are 'max' items in p.
482 *
74123bd7
CM
483 * the slot in the array is returned via slot, and it points to
484 * the place where you would insert key if it is not found in
485 * the array.
486 *
487 * slot may point to max if the key is bigger than all of the keys
488 */
5f39d397
CM
489static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
490 int item_size, struct btrfs_key *key,
491 int max, int *slot)
be0e5c09
CM
492{
493 int low = 0;
494 int high = max;
495 int mid;
496 int ret;
479965d6 497 struct btrfs_disk_key *tmp = NULL;
5f39d397
CM
498 struct btrfs_disk_key unaligned;
499 unsigned long offset;
500 char *map_token = NULL;
501 char *kaddr = NULL;
502 unsigned long map_start = 0;
503 unsigned long map_len = 0;
479965d6 504 int err;
be0e5c09
CM
505
506 while(low < high) {
507 mid = (low + high) / 2;
5f39d397
CM
508 offset = p + mid * item_size;
509
510 if (!map_token || offset < map_start ||
511 (offset + sizeof(struct btrfs_disk_key)) >
512 map_start + map_len) {
479965d6 513 if (map_token) {
5f39d397 514 unmap_extent_buffer(eb, map_token, KM_USER0);
479965d6
CM
515 map_token = NULL;
516 }
517 err = map_extent_buffer(eb, offset,
518 sizeof(struct btrfs_disk_key),
519 &map_token, &kaddr,
520 &map_start, &map_len, KM_USER0);
521
522 if (!err) {
523 tmp = (struct btrfs_disk_key *)(kaddr + offset -
524 map_start);
525 } else {
526 read_extent_buffer(eb, &unaligned,
527 offset, sizeof(unaligned));
528 tmp = &unaligned;
529 }
5f39d397 530
5f39d397
CM
531 } else {
532 tmp = (struct btrfs_disk_key *)(kaddr + offset -
533 map_start);
534 }
be0e5c09
CM
535 ret = comp_keys(tmp, key);
536
537 if (ret < 0)
538 low = mid + 1;
539 else if (ret > 0)
540 high = mid;
541 else {
542 *slot = mid;
479965d6
CM
543 if (map_token)
544 unmap_extent_buffer(eb, map_token, KM_USER0);
be0e5c09
CM
545 return 0;
546 }
547 }
548 *slot = low;
5f39d397
CM
549 if (map_token)
550 unmap_extent_buffer(eb, map_token, KM_USER0);
be0e5c09
CM
551 return 1;
552}
553
97571fd0
CM
554/*
555 * simple bin_search frontend that does the right thing for
556 * leaves vs nodes
557 */
5f39d397
CM
558static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
559 int level, int *slot)
be0e5c09 560{
5f39d397
CM
561 if (level == 0) {
562 return generic_bin_search(eb,
563 offsetof(struct btrfs_leaf, items),
0783fcfc 564 sizeof(struct btrfs_item),
5f39d397 565 key, btrfs_header_nritems(eb),
7518a238 566 slot);
be0e5c09 567 } else {
5f39d397
CM
568 return generic_bin_search(eb,
569 offsetof(struct btrfs_node, ptrs),
123abc88 570 sizeof(struct btrfs_key_ptr),
5f39d397 571 key, btrfs_header_nritems(eb),
7518a238 572 slot);
be0e5c09
CM
573 }
574 return -1;
575}
576
5f39d397
CM
577static struct extent_buffer *read_node_slot(struct btrfs_root *root,
578 struct extent_buffer *parent, int slot)
bb803951 579{
bb803951
CM
580 if (slot < 0)
581 return NULL;
5f39d397 582 if (slot >= btrfs_header_nritems(parent))
bb803951 583 return NULL;
5f39d397 584 return read_tree_block(root, btrfs_node_blockptr(parent, slot));
bb803951
CM
585}
586
e089f05c
CM
587static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
588 *root, struct btrfs_path *path, int level)
bb803951 589{
5f39d397
CM
590 struct extent_buffer *right = NULL;
591 struct extent_buffer *mid;
592 struct extent_buffer *left = NULL;
593 struct extent_buffer *parent = NULL;
bb803951
CM
594 int ret = 0;
595 int wret;
596 int pslot;
bb803951 597 int orig_slot = path->slots[level];
54aa1f4d 598 int err_on_enospc = 0;
79f95c82 599 u64 orig_ptr;
bb803951
CM
600
601 if (level == 0)
602 return 0;
603
5f39d397 604 mid = path->nodes[level];
1d4f8a0c 605 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
79f95c82 606
234b63a0 607 if (level < BTRFS_MAX_LEVEL - 1)
5f39d397 608 parent = path->nodes[level + 1];
bb803951
CM
609 pslot = path->slots[level + 1];
610
40689478
CM
611 /*
612 * deal with the case where there is only one pointer in the root
613 * by promoting the node below to a root
614 */
5f39d397
CM
615 if (!parent) {
616 struct extent_buffer *child;
617 u64 blocknr = extent_buffer_blocknr(mid);
bb803951 618
5f39d397 619 if (btrfs_header_nritems(mid) != 1)
bb803951
CM
620 return 0;
621
622 /* promote the child to a root */
5f39d397 623 child = read_node_slot(root, mid, 0);
bb803951
CM
624 BUG_ON(!child);
625 root->node = child;
626 path->nodes[level] = NULL;
5f39d397
CM
627 clean_tree_block(trans, root, mid);
628 wait_on_tree_block_writeback(root, mid);
bb803951 629 /* once for the path */
5f39d397 630 free_extent_buffer(mid);
bb803951 631 /* once for the root ptr */
5f39d397 632 free_extent_buffer(mid);
e089f05c 633 return btrfs_free_extent(trans, root, blocknr, 1, 1);
bb803951 634 }
5f39d397 635 if (btrfs_header_nritems(mid) >
123abc88 636 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
bb803951
CM
637 return 0;
638
5f39d397 639 if (btrfs_header_nritems(mid) < 2)
54aa1f4d
CM
640 err_on_enospc = 1;
641
5f39d397
CM
642 left = read_node_slot(root, parent, pslot - 1);
643 if (left) {
644 wret = btrfs_cow_block(trans, root, left,
645 parent, pslot - 1, &left);
54aa1f4d
CM
646 if (wret) {
647 ret = wret;
648 goto enospc;
649 }
2cc58cf2 650 }
5f39d397
CM
651 right = read_node_slot(root, parent, pslot + 1);
652 if (right) {
653 wret = btrfs_cow_block(trans, root, right,
654 parent, pslot + 1, &right);
2cc58cf2
CM
655 if (wret) {
656 ret = wret;
657 goto enospc;
658 }
659 }
660
661 /* first, try to make some room in the middle buffer */
5f39d397
CM
662 if (left) {
663 orig_slot += btrfs_header_nritems(left);
664 wret = push_node_left(trans, root, left, mid);
79f95c82
CM
665 if (wret < 0)
666 ret = wret;
5f39d397 667 if (btrfs_header_nritems(mid) < 2)
54aa1f4d 668 err_on_enospc = 1;
bb803951 669 }
79f95c82
CM
670
671 /*
672 * then try to empty the right most buffer into the middle
673 */
5f39d397
CM
674 if (right) {
675 wret = push_node_left(trans, root, mid, right);
54aa1f4d 676 if (wret < 0 && wret != -ENOSPC)
79f95c82 677 ret = wret;
5f39d397
CM
678 if (btrfs_header_nritems(right) == 0) {
679 u64 blocknr = extent_buffer_blocknr(right);
680 clean_tree_block(trans, root, right);
681 wait_on_tree_block_writeback(root, right);
682 free_extent_buffer(right);
bb803951 683 right = NULL;
e089f05c
CM
684 wret = del_ptr(trans, root, path, level + 1, pslot +
685 1);
bb803951
CM
686 if (wret)
687 ret = wret;
e089f05c 688 wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
bb803951
CM
689 if (wret)
690 ret = wret;
691 } else {
5f39d397
CM
692 struct btrfs_disk_key right_key;
693 btrfs_node_key(right, &right_key, 0);
694 btrfs_set_node_key(parent, &right_key, pslot + 1);
695 btrfs_mark_buffer_dirty(parent);
bb803951
CM
696 }
697 }
5f39d397 698 if (btrfs_header_nritems(mid) == 1) {
79f95c82
CM
699 /*
700 * we're not allowed to leave a node with one item in the
701 * tree during a delete. A deletion from lower in the tree
702 * could try to delete the only pointer in this node.
703 * So, pull some keys from the left.
704 * There has to be a left pointer at this point because
705 * otherwise we would have pulled some pointers from the
706 * right
707 */
5f39d397
CM
708 BUG_ON(!left);
709 wret = balance_node_right(trans, root, mid, left);
54aa1f4d 710 if (wret < 0) {
79f95c82 711 ret = wret;
54aa1f4d
CM
712 goto enospc;
713 }
79f95c82
CM
714 BUG_ON(wret == 1);
715 }
5f39d397 716 if (btrfs_header_nritems(mid) == 0) {
79f95c82 717 /* we've managed to empty the middle node, drop it */
5f39d397
CM
718 u64 blocknr = extent_buffer_blocknr(mid);
719 clean_tree_block(trans, root, mid);
720 wait_on_tree_block_writeback(root, mid);
721 free_extent_buffer(mid);
bb803951 722 mid = NULL;
e089f05c 723 wret = del_ptr(trans, root, path, level + 1, pslot);
bb803951
CM
724 if (wret)
725 ret = wret;
e089f05c 726 wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
bb803951
CM
727 if (wret)
728 ret = wret;
79f95c82
CM
729 } else {
730 /* update the parent key to reflect our changes */
5f39d397
CM
731 struct btrfs_disk_key mid_key;
732 btrfs_node_key(mid, &mid_key, 0);
733 btrfs_set_node_key(parent, &mid_key, pslot);
734 btrfs_mark_buffer_dirty(parent);
79f95c82 735 }
bb803951 736
79f95c82 737 /* update the path */
5f39d397
CM
738 if (left) {
739 if (btrfs_header_nritems(left) > orig_slot) {
740 extent_buffer_get(left);
741 path->nodes[level] = left;
bb803951
CM
742 path->slots[level + 1] -= 1;
743 path->slots[level] = orig_slot;
5f39d397
CM
744 if (mid)
745 free_extent_buffer(mid);
bb803951 746 } else {
5f39d397 747 orig_slot -= btrfs_header_nritems(left);
bb803951
CM
748 path->slots[level] = orig_slot;
749 }
750 }
79f95c82 751 /* double check we haven't messed things up */
123abc88 752 check_block(root, path, level);
e20d96d6 753 if (orig_ptr !=
5f39d397 754 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
79f95c82 755 BUG();
54aa1f4d 756enospc:
5f39d397
CM
757 if (right)
758 free_extent_buffer(right);
759 if (left)
760 free_extent_buffer(left);
bb803951
CM
761 return ret;
762}
763
e66f709b
CM
764/* returns zero if the push worked, non-zero otherwise */
765static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
766 struct btrfs_root *root,
767 struct btrfs_path *path, int level)
768{
5f39d397
CM
769 struct extent_buffer *right = NULL;
770 struct extent_buffer *mid;
771 struct extent_buffer *left = NULL;
772 struct extent_buffer *parent = NULL;
e66f709b
CM
773 int ret = 0;
774 int wret;
775 int pslot;
776 int orig_slot = path->slots[level];
777 u64 orig_ptr;
778
779 if (level == 0)
780 return 1;
781
5f39d397 782 mid = path->nodes[level];
e66f709b
CM
783 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
784
785 if (level < BTRFS_MAX_LEVEL - 1)
5f39d397 786 parent = path->nodes[level + 1];
e66f709b
CM
787 pslot = path->slots[level + 1];
788
5f39d397 789 if (!parent)
e66f709b 790 return 1;
e66f709b 791
5f39d397 792 left = read_node_slot(root, parent, pslot - 1);
e66f709b
CM
793
794 /* first, try to make some room in the middle buffer */
5f39d397 795 if (left) {
e66f709b 796 u32 left_nr;
5f39d397 797 left_nr = btrfs_header_nritems(left);
33ade1f8
CM
798 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
799 wret = 1;
800 } else {
5f39d397
CM
801 ret = btrfs_cow_block(trans, root, left, parent,
802 pslot - 1, &left);
54aa1f4d
CM
803 if (ret)
804 wret = 1;
805 else {
54aa1f4d 806 wret = push_node_left(trans, root,
5f39d397 807 left, mid);
54aa1f4d 808 }
33ade1f8 809 }
e66f709b
CM
810 if (wret < 0)
811 ret = wret;
812 if (wret == 0) {
5f39d397 813 struct btrfs_disk_key disk_key;
e66f709b 814 orig_slot += left_nr;
5f39d397
CM
815 btrfs_node_key(mid, &disk_key, 0);
816 btrfs_set_node_key(parent, &disk_key, pslot);
817 btrfs_mark_buffer_dirty(parent);
818 if (btrfs_header_nritems(left) > orig_slot) {
819 path->nodes[level] = left;
e66f709b
CM
820 path->slots[level + 1] -= 1;
821 path->slots[level] = orig_slot;
5f39d397 822 free_extent_buffer(mid);
e66f709b
CM
823 } else {
824 orig_slot -=
5f39d397 825 btrfs_header_nritems(left);
e66f709b 826 path->slots[level] = orig_slot;
5f39d397 827 free_extent_buffer(left);
e66f709b
CM
828 }
829 check_node(root, path, level);
830 return 0;
831 }
5f39d397 832 free_extent_buffer(left);
e66f709b 833 }
5f39d397 834 right= read_node_slot(root, parent, pslot + 1);
e66f709b
CM
835
836 /*
837 * then try to empty the right most buffer into the middle
838 */
5f39d397 839 if (right) {
33ade1f8 840 u32 right_nr;
5f39d397 841 right_nr = btrfs_header_nritems(right);
33ade1f8
CM
842 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
843 wret = 1;
844 } else {
5f39d397
CM
845 ret = btrfs_cow_block(trans, root, right,
846 parent, pslot + 1,
847 &right);
54aa1f4d
CM
848 if (ret)
849 wret = 1;
850 else {
54aa1f4d 851 wret = balance_node_right(trans, root,
5f39d397 852 right, mid);
54aa1f4d 853 }
33ade1f8 854 }
e66f709b
CM
855 if (wret < 0)
856 ret = wret;
857 if (wret == 0) {
5f39d397
CM
858 struct btrfs_disk_key disk_key;
859
860 btrfs_node_key(right, &disk_key, 0);
861 btrfs_set_node_key(parent, &disk_key, pslot + 1);
862 btrfs_mark_buffer_dirty(parent);
863
864 if (btrfs_header_nritems(mid) <= orig_slot) {
865 path->nodes[level] = right;
e66f709b
CM
866 path->slots[level + 1] += 1;
867 path->slots[level] = orig_slot -
5f39d397
CM
868 btrfs_header_nritems(mid);
869 free_extent_buffer(mid);
e66f709b 870 } else {
5f39d397 871 free_extent_buffer(right);
e66f709b
CM
872 }
873 check_node(root, path, level);
874 return 0;
875 }
5f39d397 876 free_extent_buffer(right);
e66f709b
CM
877 }
878 check_node(root, path, level);
879 return 1;
880}
881
3c69faec
CM
882/*
883 * readahead one full node of leaves
884 */
885static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
6702ed49 886 int level, int slot)
3c69faec 887{
5f39d397 888 struct extent_buffer *node;
3c69faec
CM
889 int i;
890 u32 nritems;
3c69faec
CM
891 u64 blocknr;
892 u64 search;
893 u64 cluster_start;
894 int ret;
895 int nread = 0;
896 int direction = path->reada;
897 struct radix_tree_root found;
898 unsigned long gang[8];
5f39d397 899 struct extent_buffer *eb;
3c69faec 900
6702ed49
CM
901 if (level == 0)
902 return;
903
904 if (!path->nodes[level])
3c69faec
CM
905 return;
906
5f39d397 907 node = path->nodes[level];
3c69faec 908 search = btrfs_node_blockptr(node, slot);
5f39d397
CM
909 eb = btrfs_find_tree_block(root, search);
910 if (eb) {
911 free_extent_buffer(eb);
3c69faec
CM
912 return;
913 }
914
915 init_bit_radix(&found);
5f39d397 916 nritems = btrfs_header_nritems(node);
3c69faec 917 for (i = slot; i < nritems; i++) {
3c69faec
CM
918 blocknr = btrfs_node_blockptr(node, i);
919 set_radix_bit(&found, blocknr);
920 }
921 if (direction > 0) {
922 cluster_start = search - 4;
923 if (cluster_start > search)
924 cluster_start = 0;
925 } else
926 cluster_start = search + 4;
927 while(1) {
928 ret = find_first_radix_bit(&found, gang, 0, ARRAY_SIZE(gang));
929 if (!ret)
930 break;
931 for (i = 0; i < ret; i++) {
932 blocknr = gang[i];
933 clear_radix_bit(&found, blocknr);
2cc58cf2 934 if (path->reada == 1 && nread > 16)
3c69faec 935 continue;
f2183bde 936 if (close_blocks(cluster_start, blocknr)) {
3c69faec
CM
937 readahead_tree_block(root, blocknr);
938 nread++;
3c69faec 939 cluster_start = blocknr;
3c69faec
CM
940 }
941 }
942 }
943}
74123bd7
CM
944/*
945 * look for key in the tree. path is filled in with nodes along the way
946 * if key is found, we return zero and you can find the item in the leaf
947 * level of the path (level 0)
948 *
949 * If the key isn't found, the path points to the slot where it should
aa5d6bed
CM
950 * be inserted, and 1 is returned. If there are other errors during the
951 * search a negative error number is returned.
97571fd0
CM
952 *
953 * if ins_len > 0, nodes and leaves will be split as we walk down the
954 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
955 * possible)
74123bd7 956 */
e089f05c
CM
957int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
958 *root, struct btrfs_key *key, struct btrfs_path *p, int
959 ins_len, int cow)
be0e5c09 960{
5f39d397 961 struct extent_buffer *b;
3c69faec 962 u64 blocknr;
be0e5c09
CM
963 int slot;
964 int ret;
965 int level;
3c69faec 966 int should_reada = p->reada;
9f3a7427
CM
967 u8 lowest_level = 0;
968
6702ed49
CM
969 lowest_level = p->lowest_level;
970 WARN_ON(lowest_level && ins_len);
22b0ebda
CM
971 WARN_ON(p->nodes[0] != NULL);
972 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
bb803951
CM
973again:
974 b = root->node;
5f39d397 975 extent_buffer_get(b);
eb60ceac 976 while (b) {
5f39d397 977 level = btrfs_header_level(b);
02217ed2
CM
978 if (cow) {
979 int wret;
e20d96d6
CM
980 wret = btrfs_cow_block(trans, root, b,
981 p->nodes[level + 1],
982 p->slots[level + 1],
252c38f0 983 &b);
54aa1f4d 984 if (wret) {
5f39d397 985 free_extent_buffer(b);
54aa1f4d
CM
986 return wret;
987 }
02217ed2
CM
988 }
989 BUG_ON(!cow && ins_len);
5f39d397 990 if (level != btrfs_header_level(b))
2c90e5d6 991 WARN_ON(1);
5f39d397 992 level = btrfs_header_level(b);
eb60ceac 993 p->nodes[level] = b;
123abc88 994 ret = check_block(root, p, level);
aa5d6bed
CM
995 if (ret)
996 return -1;
5f39d397
CM
997 ret = bin_search(b, key, level, &slot);
998 if (level != 0) {
be0e5c09
CM
999 if (ret && slot > 0)
1000 slot -= 1;
1001 p->slots[level] = slot;
5f39d397 1002 if (ins_len > 0 && btrfs_header_nritems(b) >=
d4dbff95 1003 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
e089f05c 1004 int sret = split_node(trans, root, p, level);
5c680ed6
CM
1005 BUG_ON(sret > 0);
1006 if (sret)
1007 return sret;
1008 b = p->nodes[level];
5c680ed6 1009 slot = p->slots[level];
bb803951 1010 } else if (ins_len < 0) {
e089f05c
CM
1011 int sret = balance_level(trans, root, p,
1012 level);
bb803951
CM
1013 if (sret)
1014 return sret;
1015 b = p->nodes[level];
1016 if (!b)
1017 goto again;
bb803951 1018 slot = p->slots[level];
5f39d397 1019 BUG_ON(btrfs_header_nritems(b) == 1);
5c680ed6 1020 }
9f3a7427
CM
1021 /* this is only true while dropping a snapshot */
1022 if (level == lowest_level)
1023 break;
5f39d397 1024 blocknr = btrfs_node_blockptr(b, slot);
6702ed49
CM
1025 if (should_reada)
1026 reada_for_search(root, p, level, slot);
5f39d397 1027 b = read_tree_block(root, btrfs_node_blockptr(b, slot));
be0e5c09
CM
1028 } else {
1029 p->slots[level] = slot;
5f39d397 1030 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
0783fcfc 1031 sizeof(struct btrfs_item) + ins_len) {
d4dbff95
CM
1032 int sret = split_leaf(trans, root, key,
1033 p, ins_len);
5c680ed6
CM
1034 BUG_ON(sret > 0);
1035 if (sret)
1036 return sret;
1037 }
be0e5c09
CM
1038 return ret;
1039 }
1040 }
aa5d6bed 1041 return 1;
be0e5c09
CM
1042}
1043
74123bd7
CM
1044/*
1045 * adjust the pointers going up the tree, starting at level
1046 * making sure the right key of each node is points to 'key'.
1047 * This is used after shifting pointers to the left, so it stops
1048 * fixing up pointers when a given leaf/node is not in slot 0 of the
1049 * higher levels
aa5d6bed
CM
1050 *
1051 * If this fails to write a tree block, it returns -1, but continues
1052 * fixing up the blocks in ram so the tree is consistent.
74123bd7 1053 */
5f39d397
CM
1054static int fixup_low_keys(struct btrfs_trans_handle *trans,
1055 struct btrfs_root *root, struct btrfs_path *path,
1056 struct btrfs_disk_key *key, int level)
be0e5c09
CM
1057{
1058 int i;
aa5d6bed 1059 int ret = 0;
5f39d397
CM
1060 struct extent_buffer *t;
1061
234b63a0 1062 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
be0e5c09 1063 int tslot = path->slots[i];
eb60ceac 1064 if (!path->nodes[i])
be0e5c09 1065 break;
5f39d397
CM
1066 t = path->nodes[i];
1067 btrfs_set_node_key(t, key, tslot);
d6025579 1068 btrfs_mark_buffer_dirty(path->nodes[i]);
be0e5c09
CM
1069 if (tslot != 0)
1070 break;
1071 }
aa5d6bed 1072 return ret;
be0e5c09
CM
1073}
1074
74123bd7
CM
1075/*
1076 * try to push data from one node into the next node left in the
79f95c82 1077 * tree.
aa5d6bed
CM
1078 *
1079 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1080 * error, and > 0 if there was no room in the left hand block.
74123bd7 1081 */
e089f05c 1082static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
5f39d397
CM
1083 *root, struct extent_buffer *dst,
1084 struct extent_buffer *src)
be0e5c09 1085{
be0e5c09 1086 int push_items = 0;
bb803951
CM
1087 int src_nritems;
1088 int dst_nritems;
aa5d6bed 1089 int ret = 0;
be0e5c09 1090
5f39d397
CM
1091 src_nritems = btrfs_header_nritems(src);
1092 dst_nritems = btrfs_header_nritems(dst);
123abc88 1093 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
54aa1f4d 1094
eb60ceac 1095 if (push_items <= 0) {
be0e5c09 1096 return 1;
eb60ceac 1097 }
be0e5c09 1098
bb803951 1099 if (src_nritems < push_items)
79f95c82
CM
1100 push_items = src_nritems;
1101
5f39d397
CM
1102 copy_extent_buffer(dst, src,
1103 btrfs_node_key_ptr_offset(dst_nritems),
1104 btrfs_node_key_ptr_offset(0),
1105 push_items * sizeof(struct btrfs_key_ptr));
1106
bb803951 1107 if (push_items < src_nritems) {
5f39d397
CM
1108 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1109 btrfs_node_key_ptr_offset(push_items),
1110 (src_nritems - push_items) *
1111 sizeof(struct btrfs_key_ptr));
1112 }
1113 btrfs_set_header_nritems(src, src_nritems - push_items);
1114 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1115 btrfs_mark_buffer_dirty(src);
1116 btrfs_mark_buffer_dirty(dst);
79f95c82
CM
1117 return ret;
1118}
1119
1120/*
1121 * try to push data from one node into the next node right in the
1122 * tree.
1123 *
1124 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1125 * error, and > 0 if there was no room in the right hand block.
1126 *
1127 * this will only push up to 1/2 the contents of the left node over
1128 */
5f39d397
CM
1129static int balance_node_right(struct btrfs_trans_handle *trans,
1130 struct btrfs_root *root,
1131 struct extent_buffer *dst,
1132 struct extent_buffer *src)
79f95c82 1133{
79f95c82
CM
1134 int push_items = 0;
1135 int max_push;
1136 int src_nritems;
1137 int dst_nritems;
1138 int ret = 0;
79f95c82 1139
5f39d397
CM
1140 src_nritems = btrfs_header_nritems(src);
1141 dst_nritems = btrfs_header_nritems(dst);
123abc88 1142 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
5f39d397 1143 if (push_items <= 0)
79f95c82 1144 return 1;
79f95c82
CM
1145
1146 max_push = src_nritems / 2 + 1;
1147 /* don't try to empty the node */
252c38f0 1148 if (max_push >= src_nritems)
79f95c82 1149 return 1;
252c38f0 1150
79f95c82
CM
1151 if (max_push < push_items)
1152 push_items = max_push;
1153
5f39d397
CM
1154 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1155 btrfs_node_key_ptr_offset(0),
1156 (dst_nritems) *
1157 sizeof(struct btrfs_key_ptr));
d6025579 1158
5f39d397
CM
1159 copy_extent_buffer(dst, src,
1160 btrfs_node_key_ptr_offset(0),
1161 btrfs_node_key_ptr_offset(src_nritems - push_items),
1162 push_items * sizeof(struct btrfs_key_ptr));
79f95c82 1163
5f39d397
CM
1164 btrfs_set_header_nritems(src, src_nritems - push_items);
1165 btrfs_set_header_nritems(dst, dst_nritems + push_items);
79f95c82 1166
5f39d397
CM
1167 btrfs_mark_buffer_dirty(src);
1168 btrfs_mark_buffer_dirty(dst);
aa5d6bed 1169 return ret;
be0e5c09
CM
1170}
1171
97571fd0
CM
1172/*
1173 * helper function to insert a new root level in the tree.
1174 * A new node is allocated, and a single item is inserted to
1175 * point to the existing root
aa5d6bed
CM
1176 *
1177 * returns zero on success or < 0 on failure.
97571fd0 1178 */
5f39d397
CM
1179static int insert_new_root(struct btrfs_trans_handle *trans,
1180 struct btrfs_root *root,
1181 struct btrfs_path *path, int level)
5c680ed6 1182{
5f39d397
CM
1183 struct extent_buffer *lower;
1184 struct extent_buffer *c;
1185 struct btrfs_disk_key lower_key;
5c680ed6
CM
1186
1187 BUG_ON(path->nodes[level]);
1188 BUG_ON(path->nodes[level-1] != root->node);
1189
5f39d397
CM
1190 c = btrfs_alloc_free_block(trans, root,
1191 extent_buffer_blocknr(root->node), 0);
1192 if (IS_ERR(c))
1193 return PTR_ERR(c);
1194 memset_extent_buffer(c, 0, 0, root->nodesize);
1195 btrfs_set_header_nritems(c, 1);
1196 btrfs_set_header_level(c, level);
1197 btrfs_set_header_blocknr(c, extent_buffer_blocknr(c));
1198 btrfs_set_header_generation(c, trans->transid);
1199 btrfs_set_header_owner(c, root->root_key.objectid);
1200 lower = path->nodes[level-1];
1201
1202 write_extent_buffer(c, root->fs_info->fsid,
1203 (unsigned long)btrfs_header_fsid(c),
1204 BTRFS_FSID_SIZE);
1205 if (level == 1)
1206 btrfs_item_key(lower, &lower_key, 0);
5c680ed6 1207 else
5f39d397
CM
1208 btrfs_node_key(lower, &lower_key, 0);
1209 btrfs_set_node_key(c, &lower_key, 0);
1210 btrfs_set_node_blockptr(c, 0, extent_buffer_blocknr(lower));
d5719762 1211
5f39d397 1212 btrfs_mark_buffer_dirty(c);
d5719762 1213
5c680ed6 1214 /* the super has an extra ref to root->node */
5f39d397
CM
1215 free_extent_buffer(root->node);
1216 root->node = c;
1217 extent_buffer_get(c);
1218 path->nodes[level] = c;
5c680ed6
CM
1219 path->slots[level] = 0;
1220 return 0;
1221}
1222
74123bd7
CM
1223/*
1224 * worker function to insert a single pointer in a node.
1225 * the node should have enough room for the pointer already
97571fd0 1226 *
74123bd7
CM
1227 * slot and level indicate where you want the key to go, and
1228 * blocknr is the block the key points to.
aa5d6bed
CM
1229 *
1230 * returns zero on success and < 0 on any error
74123bd7 1231 */
e089f05c
CM
1232static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1233 *root, struct btrfs_path *path, struct btrfs_disk_key
1234 *key, u64 blocknr, int slot, int level)
74123bd7 1235{
5f39d397 1236 struct extent_buffer *lower;
74123bd7 1237 int nritems;
5c680ed6
CM
1238
1239 BUG_ON(!path->nodes[level]);
5f39d397
CM
1240 lower = path->nodes[level];
1241 nritems = btrfs_header_nritems(lower);
74123bd7
CM
1242 if (slot > nritems)
1243 BUG();
123abc88 1244 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
74123bd7
CM
1245 BUG();
1246 if (slot != nritems) {
5f39d397
CM
1247 memmove_extent_buffer(lower,
1248 btrfs_node_key_ptr_offset(slot + 1),
1249 btrfs_node_key_ptr_offset(slot),
d6025579 1250 (nritems - slot) * sizeof(struct btrfs_key_ptr));
74123bd7 1251 }
5f39d397 1252 btrfs_set_node_key(lower, key, slot);
1d4f8a0c 1253 btrfs_set_node_blockptr(lower, slot, blocknr);
5f39d397
CM
1254 btrfs_set_header_nritems(lower, nritems + 1);
1255 btrfs_mark_buffer_dirty(lower);
098f59c2 1256 check_node(root, path, level);
74123bd7
CM
1257 return 0;
1258}
1259
97571fd0
CM
1260/*
1261 * split the node at the specified level in path in two.
1262 * The path is corrected to point to the appropriate node after the split
1263 *
1264 * Before splitting this tries to make some room in the node by pushing
1265 * left and right, if either one works, it returns right away.
aa5d6bed
CM
1266 *
1267 * returns 0 on success and < 0 on failure
97571fd0 1268 */
e089f05c
CM
1269static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1270 *root, struct btrfs_path *path, int level)
be0e5c09 1271{
5f39d397
CM
1272 struct extent_buffer *c;
1273 struct extent_buffer *split;
1274 struct btrfs_disk_key disk_key;
be0e5c09 1275 int mid;
5c680ed6 1276 int ret;
aa5d6bed 1277 int wret;
7518a238 1278 u32 c_nritems;
eb60ceac 1279
5f39d397
CM
1280 c = path->nodes[level];
1281 if (c == root->node) {
5c680ed6 1282 /* trying to split the root, lets make a new one */
e089f05c 1283 ret = insert_new_root(trans, root, path, level + 1);
5c680ed6
CM
1284 if (ret)
1285 return ret;
e66f709b
CM
1286 } else {
1287 ret = push_nodes_for_insert(trans, root, path, level);
5f39d397
CM
1288 c = path->nodes[level];
1289 if (!ret && btrfs_header_nritems(c) <
e66f709b
CM
1290 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1291 return 0;
54aa1f4d
CM
1292 if (ret < 0)
1293 return ret;
be0e5c09 1294 }
e66f709b 1295
5f39d397
CM
1296 c_nritems = btrfs_header_nritems(c);
1297 split = btrfs_alloc_free_block(trans, root,
1298 extent_buffer_blocknr(c), 0);
1299 if (IS_ERR(split))
1300 return PTR_ERR(split);
1301
1302 btrfs_set_header_flags(split, btrfs_header_flags(c));
1303 btrfs_set_header_level(split, btrfs_header_level(c));
1304 btrfs_set_header_blocknr(split, extent_buffer_blocknr(split));
1305 btrfs_set_header_generation(split, trans->transid);
1306 btrfs_set_header_owner(split, root->root_key.objectid);
1307 write_extent_buffer(split, root->fs_info->fsid,
1308 (unsigned long)btrfs_header_fsid(split),
1309 BTRFS_FSID_SIZE);
54aa1f4d 1310
7518a238 1311 mid = (c_nritems + 1) / 2;
5f39d397
CM
1312
1313 copy_extent_buffer(split, c,
1314 btrfs_node_key_ptr_offset(0),
1315 btrfs_node_key_ptr_offset(mid),
1316 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1317 btrfs_set_header_nritems(split, c_nritems - mid);
1318 btrfs_set_header_nritems(c, mid);
aa5d6bed
CM
1319 ret = 0;
1320
5f39d397
CM
1321 btrfs_mark_buffer_dirty(c);
1322 btrfs_mark_buffer_dirty(split);
1323
1324 btrfs_node_key(split, &disk_key, 0);
1325 wret = insert_ptr(trans, root, path, &disk_key,
1326 extent_buffer_blocknr(split),
1327 path->slots[level + 1] + 1,
123abc88 1328 level + 1);
aa5d6bed
CM
1329 if (wret)
1330 ret = wret;
1331
5de08d7d 1332 if (path->slots[level] >= mid) {
5c680ed6 1333 path->slots[level] -= mid;
5f39d397
CM
1334 free_extent_buffer(c);
1335 path->nodes[level] = split;
5c680ed6
CM
1336 path->slots[level + 1] += 1;
1337 } else {
5f39d397 1338 free_extent_buffer(split);
be0e5c09 1339 }
aa5d6bed 1340 return ret;
be0e5c09
CM
1341}
1342
74123bd7
CM
1343/*
1344 * how many bytes are required to store the items in a leaf. start
1345 * and nr indicate which items in the leaf to check. This totals up the
1346 * space used both by the item structs and the item data
1347 */
5f39d397 1348static int leaf_space_used(struct extent_buffer *l, int start, int nr)
be0e5c09
CM
1349{
1350 int data_len;
5f39d397 1351 int nritems = btrfs_header_nritems(l);
d4dbff95 1352 int end = min(nritems, start + nr) - 1;
be0e5c09
CM
1353
1354 if (!nr)
1355 return 0;
5f39d397
CM
1356 data_len = btrfs_item_end_nr(l, start);
1357 data_len = data_len - btrfs_item_offset_nr(l, end);
0783fcfc 1358 data_len += sizeof(struct btrfs_item) * nr;
d4dbff95 1359 WARN_ON(data_len < 0);
be0e5c09
CM
1360 return data_len;
1361}
1362
d4dbff95
CM
1363/*
1364 * The space between the end of the leaf items and
1365 * the start of the leaf data. IOW, how much room
1366 * the leaf has left for both items and data
1367 */
5f39d397 1368int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
d4dbff95 1369{
5f39d397
CM
1370 int nritems = btrfs_header_nritems(leaf);
1371 int ret;
1372 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1373 if (ret < 0) {
1374 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1375 ret, BTRFS_LEAF_DATA_SIZE(root),
1376 leaf_space_used(leaf, 0, nritems), nritems);
1377 }
1378 return ret;
d4dbff95
CM
1379}
1380
00ec4c51
CM
1381/*
1382 * push some data in the path leaf to the right, trying to free up at
1383 * least data_size bytes. returns zero if the push worked, nonzero otherwise
aa5d6bed
CM
1384 *
1385 * returns 1 if the push failed because the other node didn't have enough
1386 * room, 0 if everything worked out and < 0 if there were major errors.
00ec4c51 1387 */
e089f05c
CM
1388static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1389 *root, struct btrfs_path *path, int data_size)
00ec4c51 1390{
5f39d397
CM
1391 struct extent_buffer *left = path->nodes[0];
1392 struct extent_buffer *right;
1393 struct extent_buffer *upper;
1394 struct btrfs_disk_key disk_key;
00ec4c51
CM
1395 int slot;
1396 int i;
1397 int free_space;
1398 int push_space = 0;
1399 int push_items = 0;
0783fcfc 1400 struct btrfs_item *item;
7518a238
CM
1401 u32 left_nritems;
1402 u32 right_nritems;
5f39d397 1403 u32 data_end;
54aa1f4d 1404 int ret;
00ec4c51
CM
1405
1406 slot = path->slots[1];
1407 if (!path->nodes[1]) {
1408 return 1;
1409 }
1410 upper = path->nodes[1];
5f39d397 1411 if (slot >= btrfs_header_nritems(upper) - 1)
00ec4c51 1412 return 1;
5f39d397
CM
1413
1414 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1));
123abc88 1415 free_space = btrfs_leaf_free_space(root, right);
0783fcfc 1416 if (free_space < data_size + sizeof(struct btrfs_item)) {
5f39d397 1417 free_extent_buffer(right);
00ec4c51
CM
1418 return 1;
1419 }
5f39d397 1420
02217ed2 1421 /* cow and double check */
5f39d397
CM
1422 ret = btrfs_cow_block(trans, root, right, upper,
1423 slot + 1, &right);
54aa1f4d 1424 if (ret) {
5f39d397 1425 free_extent_buffer(right);
54aa1f4d
CM
1426 return 1;
1427 }
123abc88 1428 free_space = btrfs_leaf_free_space(root, right);
0783fcfc 1429 if (free_space < data_size + sizeof(struct btrfs_item)) {
5f39d397 1430 free_extent_buffer(right);
02217ed2
CM
1431 return 1;
1432 }
1433
5f39d397 1434 left_nritems = btrfs_header_nritems(left);
a429e513 1435 if (left_nritems == 0) {
5f39d397 1436 free_extent_buffer(right);
a429e513
CM
1437 return 1;
1438 }
5f39d397 1439
a429e513 1440 for (i = left_nritems - 1; i >= 1; i--) {
5f39d397 1441 item = btrfs_item_nr(left, i);
00ec4c51
CM
1442 if (path->slots[0] == i)
1443 push_space += data_size + sizeof(*item);
5f39d397 1444 if (btrfs_item_size(left, item) + sizeof(*item) + push_space >
0783fcfc 1445 free_space)
00ec4c51
CM
1446 break;
1447 push_items++;
5f39d397 1448 push_space += btrfs_item_size(left, item) + sizeof(*item);
00ec4c51 1449 }
5f39d397 1450
00ec4c51 1451 if (push_items == 0) {
5f39d397 1452 free_extent_buffer(right);
00ec4c51
CM
1453 return 1;
1454 }
5f39d397 1455
a429e513
CM
1456 if (push_items == left_nritems)
1457 WARN_ON(1);
5f39d397 1458
00ec4c51 1459 /* push left to right */
5f39d397
CM
1460 right_nritems = btrfs_header_nritems(right);
1461 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
123abc88 1462 push_space -= leaf_data_end(root, left);
5f39d397 1463
00ec4c51 1464 /* make room in the right data area */
5f39d397
CM
1465 data_end = leaf_data_end(root, right);
1466 memmove_extent_buffer(right,
1467 btrfs_leaf_data(right) + data_end - push_space,
1468 btrfs_leaf_data(right) + data_end,
1469 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1470
00ec4c51 1471 /* copy from the left data area */
5f39d397 1472 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
d6025579
CM
1473 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1474 btrfs_leaf_data(left) + leaf_data_end(root, left),
1475 push_space);
5f39d397
CM
1476
1477 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1478 btrfs_item_nr_offset(0),
1479 right_nritems * sizeof(struct btrfs_item));
1480
00ec4c51 1481 /* copy the items from left to right */
5f39d397
CM
1482 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1483 btrfs_item_nr_offset(left_nritems - push_items),
1484 push_items * sizeof(struct btrfs_item));
00ec4c51
CM
1485
1486 /* update the item pointers */
7518a238 1487 right_nritems += push_items;
5f39d397 1488 btrfs_set_header_nritems(right, right_nritems);
123abc88 1489 push_space = BTRFS_LEAF_DATA_SIZE(root);
7518a238 1490 for (i = 0; i < right_nritems; i++) {
5f39d397
CM
1491 item = btrfs_item_nr(right, i);
1492 btrfs_set_item_offset(right, item, push_space -
1493 btrfs_item_size(right, item));
1494 push_space = btrfs_item_offset(right, item);
00ec4c51 1495 }
7518a238 1496 left_nritems -= push_items;
5f39d397 1497 btrfs_set_header_nritems(left, left_nritems);
00ec4c51 1498
5f39d397
CM
1499 btrfs_mark_buffer_dirty(left);
1500 btrfs_mark_buffer_dirty(right);
a429e513 1501
5f39d397
CM
1502 btrfs_item_key(right, &disk_key, 0);
1503 btrfs_set_node_key(upper, &disk_key, slot + 1);
d6025579 1504 btrfs_mark_buffer_dirty(upper);
02217ed2 1505
00ec4c51 1506 /* then fixup the leaf pointer in the path */
7518a238
CM
1507 if (path->slots[0] >= left_nritems) {
1508 path->slots[0] -= left_nritems;
5f39d397
CM
1509 free_extent_buffer(path->nodes[0]);
1510 path->nodes[0] = right;
00ec4c51
CM
1511 path->slots[1] += 1;
1512 } else {
5f39d397 1513 free_extent_buffer(right);
00ec4c51 1514 }
098f59c2
CM
1515 if (path->nodes[1])
1516 check_node(root, path, 1);
00ec4c51
CM
1517 return 0;
1518}
74123bd7
CM
1519/*
1520 * push some data in the path leaf to the left, trying to free up at
1521 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1522 */
e089f05c
CM
1523static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1524 *root, struct btrfs_path *path, int data_size)
be0e5c09 1525{
5f39d397
CM
1526 struct btrfs_disk_key disk_key;
1527 struct extent_buffer *right = path->nodes[0];
1528 struct extent_buffer *left;
be0e5c09
CM
1529 int slot;
1530 int i;
1531 int free_space;
1532 int push_space = 0;
1533 int push_items = 0;
0783fcfc 1534 struct btrfs_item *item;
7518a238 1535 u32 old_left_nritems;
5f39d397 1536 u32 right_nritems;
aa5d6bed
CM
1537 int ret = 0;
1538 int wret;
be0e5c09
CM
1539
1540 slot = path->slots[1];
5f39d397 1541 if (slot == 0)
be0e5c09 1542 return 1;
5f39d397 1543 if (!path->nodes[1])
be0e5c09 1544 return 1;
5f39d397
CM
1545
1546 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1547 slot - 1));
123abc88 1548 free_space = btrfs_leaf_free_space(root, left);
0783fcfc 1549 if (free_space < data_size + sizeof(struct btrfs_item)) {
5f39d397 1550 free_extent_buffer(left);
be0e5c09
CM
1551 return 1;
1552 }
02217ed2
CM
1553
1554 /* cow and double check */
5f39d397
CM
1555 ret = btrfs_cow_block(trans, root, left,
1556 path->nodes[1], slot - 1, &left);
54aa1f4d
CM
1557 if (ret) {
1558 /* we hit -ENOSPC, but it isn't fatal here */
5f39d397 1559 free_extent_buffer(left);
54aa1f4d
CM
1560 return 1;
1561 }
123abc88 1562 free_space = btrfs_leaf_free_space(root, left);
0783fcfc 1563 if (free_space < data_size + sizeof(struct btrfs_item)) {
5f39d397 1564 free_extent_buffer(left);
02217ed2
CM
1565 return 1;
1566 }
1567
5f39d397
CM
1568 right_nritems = btrfs_header_nritems(right);
1569 if (right_nritems == 0) {
1570 free_extent_buffer(left);
a429e513
CM
1571 return 1;
1572 }
1573
5f39d397
CM
1574 for (i = 0; i < right_nritems - 1; i++) {
1575 item = btrfs_item_nr(right, i);
be0e5c09
CM
1576 if (path->slots[0] == i)
1577 push_space += data_size + sizeof(*item);
5f39d397 1578 if (btrfs_item_size(right, item) + sizeof(*item) + push_space >
0783fcfc 1579 free_space)
be0e5c09
CM
1580 break;
1581 push_items++;
5f39d397 1582 push_space += btrfs_item_size(right, item) + sizeof(*item);
be0e5c09
CM
1583 }
1584 if (push_items == 0) {
5f39d397 1585 free_extent_buffer(left);
be0e5c09
CM
1586 return 1;
1587 }
5f39d397 1588 if (push_items == btrfs_header_nritems(right))
a429e513 1589 WARN_ON(1);
5f39d397 1590
be0e5c09 1591 /* push data from right to left */
5f39d397
CM
1592 copy_extent_buffer(left, right,
1593 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1594 btrfs_item_nr_offset(0),
1595 push_items * sizeof(struct btrfs_item));
1596
123abc88 1597 push_space = BTRFS_LEAF_DATA_SIZE(root) -
5f39d397
CM
1598 btrfs_item_offset_nr(right, push_items -1);
1599
1600 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
d6025579
CM
1601 leaf_data_end(root, left) - push_space,
1602 btrfs_leaf_data(right) +
5f39d397 1603 btrfs_item_offset_nr(right, push_items - 1),
d6025579 1604 push_space);
5f39d397 1605 old_left_nritems = btrfs_header_nritems(left);
eb60ceac
CM
1606 BUG_ON(old_left_nritems < 0);
1607
0783fcfc 1608 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
5f39d397
CM
1609 u32 ioff;
1610 item = btrfs_item_nr(left, i);
1611 ioff = btrfs_item_offset(left, item);
1612 btrfs_set_item_offset(left, item,
1613 ioff - (BTRFS_LEAF_DATA_SIZE(root) -
1614 btrfs_item_offset_nr(left, old_left_nritems - 1)));
be0e5c09 1615 }
5f39d397 1616 btrfs_set_header_nritems(left, old_left_nritems + push_items);
be0e5c09
CM
1617
1618 /* fixup right node */
5f39d397
CM
1619 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1620 leaf_data_end(root, right);
1621 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1622 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1623 btrfs_leaf_data(right) +
1624 leaf_data_end(root, right), push_space);
1625
1626 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1627 btrfs_item_nr_offset(push_items),
1628 (btrfs_header_nritems(right) - push_items) *
1629 sizeof(struct btrfs_item));
1630
1631 right_nritems = btrfs_header_nritems(right) - push_items;
1632 btrfs_set_header_nritems(right, right_nritems);
123abc88 1633 push_space = BTRFS_LEAF_DATA_SIZE(root);
eb60ceac 1634
5f39d397
CM
1635 for (i = 0; i < right_nritems; i++) {
1636 item = btrfs_item_nr(right, i);
1637 btrfs_set_item_offset(right, item, push_space -
1638 btrfs_item_size(right, item));
1639 push_space = btrfs_item_offset(right, item);
be0e5c09 1640 }
eb60ceac 1641
5f39d397
CM
1642 btrfs_mark_buffer_dirty(left);
1643 btrfs_mark_buffer_dirty(right);
098f59c2 1644
5f39d397
CM
1645 btrfs_item_key(right, &disk_key, 0);
1646 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
aa5d6bed
CM
1647 if (wret)
1648 ret = wret;
be0e5c09
CM
1649
1650 /* then fixup the leaf pointer in the path */
1651 if (path->slots[0] < push_items) {
1652 path->slots[0] += old_left_nritems;
5f39d397
CM
1653 free_extent_buffer(path->nodes[0]);
1654 path->nodes[0] = left;
be0e5c09
CM
1655 path->slots[1] -= 1;
1656 } else {
5f39d397 1657 free_extent_buffer(left);
be0e5c09
CM
1658 path->slots[0] -= push_items;
1659 }
eb60ceac 1660 BUG_ON(path->slots[0] < 0);
098f59c2
CM
1661 if (path->nodes[1])
1662 check_node(root, path, 1);
aa5d6bed 1663 return ret;
be0e5c09
CM
1664}
1665
74123bd7
CM
1666/*
1667 * split the path's leaf in two, making sure there is at least data_size
1668 * available for the resulting leaf level of the path.
aa5d6bed
CM
1669 *
1670 * returns 0 if all went well and < 0 on failure.
74123bd7 1671 */
e089f05c 1672static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
d4dbff95
CM
1673 *root, struct btrfs_key *ins_key,
1674 struct btrfs_path *path, int data_size)
be0e5c09 1675{
5f39d397 1676 struct extent_buffer *l;
7518a238 1677 u32 nritems;
eb60ceac
CM
1678 int mid;
1679 int slot;
5f39d397 1680 struct extent_buffer *right;
0783fcfc 1681 int space_needed = data_size + sizeof(struct btrfs_item);
be0e5c09
CM
1682 int data_copy_size;
1683 int rt_data_off;
1684 int i;
d4dbff95 1685 int ret = 0;
aa5d6bed 1686 int wret;
d4dbff95
CM
1687 int double_split = 0;
1688 struct btrfs_disk_key disk_key;
aa5d6bed 1689
40689478 1690 /* first try to make some room by pushing left and right */
e089f05c 1691 wret = push_leaf_left(trans, root, path, data_size);
eaee50e8
CM
1692 if (wret < 0)
1693 return wret;
1694 if (wret) {
e089f05c 1695 wret = push_leaf_right(trans, root, path, data_size);
eaee50e8
CM
1696 if (wret < 0)
1697 return wret;
1698 }
5f39d397 1699 l = path->nodes[0];
aa5d6bed
CM
1700
1701 /* did the pushes work? */
123abc88
CM
1702 if (btrfs_leaf_free_space(root, l) >=
1703 sizeof(struct btrfs_item) + data_size)
aa5d6bed
CM
1704 return 0;
1705
5c680ed6 1706 if (!path->nodes[1]) {
e089f05c 1707 ret = insert_new_root(trans, root, path, 1);
5c680ed6
CM
1708 if (ret)
1709 return ret;
1710 }
eb60ceac 1711 slot = path->slots[0];
5f39d397 1712 nritems = btrfs_header_nritems(l);
eb60ceac 1713 mid = (nritems + 1)/ 2;
54aa1f4d 1714
5f39d397
CM
1715 right = btrfs_alloc_free_block(trans, root,
1716 extent_buffer_blocknr(l), 0);
1717 if (IS_ERR(right))
1718 return PTR_ERR(right);
1719
1720 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1721 btrfs_set_header_blocknr(right, extent_buffer_blocknr(right));
1722 btrfs_set_header_generation(right, trans->transid);
1723 btrfs_set_header_owner(right, root->root_key.objectid);
1724 btrfs_set_header_level(right, 0);
1725 write_extent_buffer(right, root->fs_info->fsid,
1726 (unsigned long)btrfs_header_fsid(right),
1727 BTRFS_FSID_SIZE);
1728
d4dbff95
CM
1729 if (mid <= slot) {
1730 if (nritems == 1 ||
1731 leaf_space_used(l, mid, nritems - mid) + space_needed >
1732 BTRFS_LEAF_DATA_SIZE(root)) {
1733 if (slot >= nritems) {
1734 btrfs_cpu_key_to_disk(&disk_key, ins_key);
5f39d397 1735 btrfs_set_header_nritems(right, 0);
d4dbff95
CM
1736 wret = insert_ptr(trans, root, path,
1737 &disk_key,
5f39d397 1738 extent_buffer_blocknr(right),
d4dbff95
CM
1739 path->slots[1] + 1, 1);
1740 if (wret)
1741 ret = wret;
5f39d397
CM
1742 free_extent_buffer(path->nodes[0]);
1743 path->nodes[0] = right;
d4dbff95
CM
1744 path->slots[0] = 0;
1745 path->slots[1] += 1;
1746 return ret;
1747 }
1748 mid = slot;
1749 double_split = 1;
1750 }
1751 } else {
1752 if (leaf_space_used(l, 0, mid + 1) + space_needed >
1753 BTRFS_LEAF_DATA_SIZE(root)) {
1754 if (slot == 0) {
1755 btrfs_cpu_key_to_disk(&disk_key, ins_key);
5f39d397 1756 btrfs_set_header_nritems(right, 0);
d4dbff95
CM
1757 wret = insert_ptr(trans, root, path,
1758 &disk_key,
5f39d397 1759 extent_buffer_blocknr(right),
098f59c2 1760 path->slots[1], 1);
d4dbff95
CM
1761 if (wret)
1762 ret = wret;
5f39d397
CM
1763 free_extent_buffer(path->nodes[0]);
1764 path->nodes[0] = right;
d4dbff95 1765 path->slots[0] = 0;
a429e513
CM
1766 if (path->slots[1] == 0) {
1767 wret = fixup_low_keys(trans, root,
1768 path, &disk_key, 1);
1769 if (wret)
1770 ret = wret;
1771 }
d4dbff95
CM
1772 return ret;
1773 }
1774 mid = slot;
1775 double_split = 1;
1776 }
1777 }
5f39d397
CM
1778 nritems = nritems - mid;
1779 btrfs_set_header_nritems(right, nritems);
1780 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1781
1782 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1783 btrfs_item_nr_offset(mid),
1784 nritems * sizeof(struct btrfs_item));
1785
1786 copy_extent_buffer(right, l,
d6025579
CM
1787 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1788 data_copy_size, btrfs_leaf_data(l) +
1789 leaf_data_end(root, l), data_copy_size);
5f39d397 1790
123abc88 1791 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
5f39d397 1792 btrfs_item_end_nr(l, mid);
74123bd7 1793
5f39d397
CM
1794 for (i = 0; i < nritems; i++) {
1795 struct btrfs_item *item = btrfs_item_nr(right, i);
1796 u32 ioff = btrfs_item_offset(right, item);
1797 btrfs_set_item_offset(right, item, ioff + rt_data_off);
0783fcfc 1798 }
74123bd7 1799
5f39d397 1800 btrfs_set_header_nritems(l, mid);
aa5d6bed 1801 ret = 0;
5f39d397
CM
1802 btrfs_item_key(right, &disk_key, 0);
1803 wret = insert_ptr(trans, root, path, &disk_key,
1804 extent_buffer_blocknr(right), path->slots[1] + 1, 1);
aa5d6bed
CM
1805 if (wret)
1806 ret = wret;
5f39d397
CM
1807
1808 btrfs_mark_buffer_dirty(right);
1809 btrfs_mark_buffer_dirty(l);
eb60ceac 1810 BUG_ON(path->slots[0] != slot);
5f39d397 1811
be0e5c09 1812 if (mid <= slot) {
5f39d397
CM
1813 free_extent_buffer(path->nodes[0]);
1814 path->nodes[0] = right;
be0e5c09
CM
1815 path->slots[0] -= mid;
1816 path->slots[1] += 1;
eb60ceac 1817 } else
5f39d397
CM
1818 free_extent_buffer(right);
1819
eb60ceac 1820 BUG_ON(path->slots[0] < 0);
098f59c2 1821 check_node(root, path, 1);
5f39d397 1822 check_leaf(root, path, 0);
d4dbff95
CM
1823
1824 if (!double_split)
1825 return ret;
5f39d397
CM
1826
1827 right = btrfs_alloc_free_block(trans, root,
1828 extent_buffer_blocknr(l), 0);
1829 if (IS_ERR(right))
1830 return PTR_ERR(right);
1831
1832 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1833 btrfs_set_header_blocknr(right, extent_buffer_blocknr(right));
1834 btrfs_set_header_generation(right, trans->transid);
1835 btrfs_set_header_owner(right, root->root_key.objectid);
1836 btrfs_set_header_level(right, 0);
1837 write_extent_buffer(right, root->fs_info->fsid,
1838 (unsigned long)btrfs_header_fsid(right),
1839 BTRFS_FSID_SIZE);
1840
d4dbff95 1841 btrfs_cpu_key_to_disk(&disk_key, ins_key);
5f39d397 1842 btrfs_set_header_nritems(right, 0);
d4dbff95
CM
1843 wret = insert_ptr(trans, root, path,
1844 &disk_key,
5f39d397 1845 extent_buffer_blocknr(right),
d4dbff95
CM
1846 path->slots[1], 1);
1847 if (wret)
1848 ret = wret;
a429e513
CM
1849 if (path->slots[1] == 0) {
1850 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1851 if (wret)
1852 ret = wret;
1853 }
5f39d397
CM
1854 free_extent_buffer(path->nodes[0]);
1855 path->nodes[0] = right;
d4dbff95
CM
1856 path->slots[0] = 0;
1857 check_node(root, path, 1);
1858 check_leaf(root, path, 0);
be0e5c09
CM
1859 return ret;
1860}
1861
b18c6685
CM
1862int btrfs_truncate_item(struct btrfs_trans_handle *trans,
1863 struct btrfs_root *root,
1864 struct btrfs_path *path,
1865 u32 new_size)
1866{
1867 int ret = 0;
1868 int slot;
1869 int slot_orig;
5f39d397
CM
1870 struct extent_buffer *leaf;
1871 struct btrfs_item *item;
b18c6685
CM
1872 u32 nritems;
1873 unsigned int data_end;
1874 unsigned int old_data_start;
1875 unsigned int old_size;
1876 unsigned int size_diff;
1877 int i;
1878
1879 slot_orig = path->slots[0];
5f39d397 1880 leaf = path->nodes[0];
b18c6685 1881
5f39d397 1882 nritems = btrfs_header_nritems(leaf);
b18c6685
CM
1883 data_end = leaf_data_end(root, leaf);
1884
1885 slot = path->slots[0];
5f39d397
CM
1886 old_data_start = btrfs_item_offset_nr(leaf, slot);
1887 old_size = btrfs_item_size_nr(leaf, slot);
b18c6685
CM
1888 BUG_ON(old_size <= new_size);
1889 size_diff = old_size - new_size;
1890
1891 BUG_ON(slot < 0);
1892 BUG_ON(slot >= nritems);
1893
1894 /*
1895 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1896 */
1897 /* first correct the data pointers */
1898 for (i = slot; i < nritems; i++) {
5f39d397
CM
1899 u32 ioff;
1900 item = btrfs_item_nr(leaf, i);
1901 ioff = btrfs_item_offset(leaf, item);
1902 btrfs_set_item_offset(leaf, item, ioff + size_diff);
b18c6685
CM
1903 }
1904 /* shift the data */
5f39d397 1905 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
b18c6685
CM
1906 data_end + size_diff, btrfs_leaf_data(leaf) +
1907 data_end, old_data_start + new_size - data_end);
5f39d397
CM
1908
1909 item = btrfs_item_nr(leaf, slot);
1910 btrfs_set_item_size(leaf, item, new_size);
1911 btrfs_mark_buffer_dirty(leaf);
b18c6685
CM
1912
1913 ret = 0;
5f39d397
CM
1914 if (btrfs_leaf_free_space(root, leaf) < 0) {
1915 btrfs_print_leaf(root, leaf);
b18c6685 1916 BUG();
5f39d397 1917 }
b18c6685
CM
1918 check_leaf(root, path, 0);
1919 return ret;
1920}
1921
5f39d397
CM
1922int btrfs_extend_item(struct btrfs_trans_handle *trans,
1923 struct btrfs_root *root, struct btrfs_path *path,
1924 u32 data_size)
6567e837
CM
1925{
1926 int ret = 0;
1927 int slot;
1928 int slot_orig;
5f39d397
CM
1929 struct extent_buffer *leaf;
1930 struct btrfs_item *item;
6567e837
CM
1931 u32 nritems;
1932 unsigned int data_end;
1933 unsigned int old_data;
1934 unsigned int old_size;
1935 int i;
1936
1937 slot_orig = path->slots[0];
5f39d397 1938 leaf = path->nodes[0];
6567e837 1939
5f39d397 1940 nritems = btrfs_header_nritems(leaf);
6567e837
CM
1941 data_end = leaf_data_end(root, leaf);
1942
5f39d397
CM
1943 if (btrfs_leaf_free_space(root, leaf) < data_size) {
1944 btrfs_print_leaf(root, leaf);
6567e837 1945 BUG();
5f39d397 1946 }
6567e837 1947 slot = path->slots[0];
5f39d397 1948 old_data = btrfs_item_end_nr(leaf, slot);
6567e837
CM
1949
1950 BUG_ON(slot < 0);
1951 BUG_ON(slot >= nritems);
1952
1953 /*
1954 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1955 */
1956 /* first correct the data pointers */
1957 for (i = slot; i < nritems; i++) {
5f39d397
CM
1958 u32 ioff;
1959 item = btrfs_item_nr(leaf, i);
1960 ioff = btrfs_item_offset(leaf, item);
1961 btrfs_set_item_offset(leaf, item, ioff - data_size);
6567e837 1962 }
5f39d397 1963
6567e837 1964 /* shift the data */
5f39d397 1965 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
6567e837
CM
1966 data_end - data_size, btrfs_leaf_data(leaf) +
1967 data_end, old_data - data_end);
5f39d397 1968
6567e837 1969 data_end = old_data;
5f39d397
CM
1970 old_size = btrfs_item_size_nr(leaf, slot);
1971 item = btrfs_item_nr(leaf, slot);
1972 btrfs_set_item_size(leaf, item, old_size + data_size);
1973 btrfs_mark_buffer_dirty(leaf);
6567e837
CM
1974
1975 ret = 0;
5f39d397
CM
1976 if (btrfs_leaf_free_space(root, leaf) < 0) {
1977 btrfs_print_leaf(root, leaf);
6567e837 1978 BUG();
5f39d397 1979 }
6567e837
CM
1980 check_leaf(root, path, 0);
1981 return ret;
1982}
1983
74123bd7
CM
1984/*
1985 * Given a key and some data, insert an item into the tree.
1986 * This does all the path init required, making room in the tree if needed.
1987 */
5f39d397
CM
1988int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
1989 struct btrfs_root *root,
1990 struct btrfs_path *path,
1991 struct btrfs_key *cpu_key, u32 data_size)
be0e5c09 1992{
5f39d397
CM
1993 struct extent_buffer *leaf;
1994 struct btrfs_item *item;
aa5d6bed 1995 int ret = 0;
be0e5c09 1996 int slot;
eb60ceac 1997 int slot_orig;
7518a238 1998 u32 nritems;
be0e5c09 1999 unsigned int data_end;
e2fa7227
CM
2000 struct btrfs_disk_key disk_key;
2001
2002 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
be0e5c09 2003
74123bd7 2004 /* create a root if there isn't one */
5c680ed6 2005 if (!root->node)
cfaa7295 2006 BUG();
5f39d397 2007
e089f05c 2008 ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
eb60ceac 2009 if (ret == 0) {
f0930a37 2010 return -EEXIST;
aa5d6bed 2011 }
ed2ff2cb
CM
2012 if (ret < 0)
2013 goto out;
be0e5c09 2014
62e2749e 2015 slot_orig = path->slots[0];
5f39d397 2016 leaf = path->nodes[0];
74123bd7 2017
5f39d397 2018 nritems = btrfs_header_nritems(leaf);
123abc88 2019 data_end = leaf_data_end(root, leaf);
eb60ceac 2020
123abc88 2021 if (btrfs_leaf_free_space(root, leaf) <
d4dbff95 2022 sizeof(struct btrfs_item) + data_size) {
be0e5c09 2023 BUG();
d4dbff95 2024 }
5f39d397 2025
62e2749e 2026 slot = path->slots[0];
eb60ceac 2027 BUG_ON(slot < 0);
5f39d397 2028
be0e5c09
CM
2029 if (slot != nritems) {
2030 int i;
5f39d397 2031 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
be0e5c09 2032
5f39d397
CM
2033 if (old_data < data_end) {
2034 btrfs_print_leaf(root, leaf);
2035 printk("slot %d old_data %d data_end %d\n",
2036 slot, old_data, data_end);
2037 BUG_ON(1);
2038 }
be0e5c09
CM
2039 /*
2040 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2041 */
2042 /* first correct the data pointers */
0783fcfc 2043 for (i = slot; i < nritems; i++) {
5f39d397
CM
2044 u32 ioff;
2045 item = btrfs_item_nr(leaf, i);
2046 ioff = btrfs_item_offset(leaf, item);
2047 btrfs_set_item_offset(leaf, item, ioff - data_size);
0783fcfc 2048 }
be0e5c09
CM
2049
2050 /* shift the items */
5f39d397
CM
2051 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2052 btrfs_item_nr_offset(slot),
d6025579 2053 (nritems - slot) * sizeof(struct btrfs_item));
be0e5c09
CM
2054
2055 /* shift the data */
5f39d397 2056 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
d6025579
CM
2057 data_end - data_size, btrfs_leaf_data(leaf) +
2058 data_end, old_data - data_end);
be0e5c09
CM
2059 data_end = old_data;
2060 }
5f39d397 2061
62e2749e 2062 /* setup the item for the new data */
5f39d397
CM
2063 btrfs_set_item_key(leaf, &disk_key, slot);
2064 item = btrfs_item_nr(leaf, slot);
2065 btrfs_set_item_offset(leaf, item, data_end - data_size);
2066 btrfs_set_item_size(leaf, item, data_size);
2067 btrfs_set_header_nritems(leaf, nritems + 1);
2068 btrfs_mark_buffer_dirty(leaf);
aa5d6bed
CM
2069
2070 ret = 0;
8e19f2cd 2071 if (slot == 0)
e089f05c 2072 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
aa5d6bed 2073
5f39d397
CM
2074 if (btrfs_leaf_free_space(root, leaf) < 0) {
2075 btrfs_print_leaf(root, leaf);
be0e5c09 2076 BUG();
5f39d397 2077 }
62e2749e 2078 check_leaf(root, path, 0);
ed2ff2cb 2079out:
62e2749e
CM
2080 return ret;
2081}
2082
2083/*
2084 * Given a key and some data, insert an item into the tree.
2085 * This does all the path init required, making room in the tree if needed.
2086 */
e089f05c
CM
2087int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2088 *root, struct btrfs_key *cpu_key, void *data, u32
2089 data_size)
62e2749e
CM
2090{
2091 int ret = 0;
2c90e5d6 2092 struct btrfs_path *path;
5f39d397
CM
2093 struct extent_buffer *leaf;
2094 unsigned long ptr;
62e2749e 2095
2c90e5d6
CM
2096 path = btrfs_alloc_path();
2097 BUG_ON(!path);
2c90e5d6 2098 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
62e2749e 2099 if (!ret) {
5f39d397
CM
2100 leaf = path->nodes[0];
2101 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2102 write_extent_buffer(leaf, data, ptr, data_size);
2103 btrfs_mark_buffer_dirty(leaf);
62e2749e 2104 }
2c90e5d6 2105 btrfs_free_path(path);
aa5d6bed 2106 return ret;
be0e5c09
CM
2107}
2108
74123bd7 2109/*
5de08d7d 2110 * delete the pointer from a given node.
74123bd7
CM
2111 *
2112 * If the delete empties a node, the node is removed from the tree,
2113 * continuing all the way the root if required. The root is converted into
2114 * a leaf if all the nodes are emptied.
2115 */
e089f05c
CM
2116static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2117 struct btrfs_path *path, int level, int slot)
be0e5c09 2118{
5f39d397 2119 struct extent_buffer *parent = path->nodes[level];
7518a238 2120 u32 nritems;
aa5d6bed 2121 int ret = 0;
bb803951 2122 int wret;
be0e5c09 2123
5f39d397 2124 nritems = btrfs_header_nritems(parent);
bb803951 2125 if (slot != nritems -1) {
5f39d397
CM
2126 memmove_extent_buffer(parent,
2127 btrfs_node_key_ptr_offset(slot),
2128 btrfs_node_key_ptr_offset(slot + 1),
d6025579
CM
2129 sizeof(struct btrfs_key_ptr) *
2130 (nritems - slot - 1));
bb803951 2131 }
7518a238 2132 nritems--;
5f39d397 2133 btrfs_set_header_nritems(parent, nritems);
7518a238 2134 if (nritems == 0 && parent == root->node) {
5f39d397 2135 BUG_ON(btrfs_header_level(root->node) != 1);
bb803951 2136 /* just turn the root into a leaf and break */
5f39d397 2137 btrfs_set_header_level(root->node, 0);
bb803951 2138 } else if (slot == 0) {
5f39d397
CM
2139 struct btrfs_disk_key disk_key;
2140
2141 btrfs_node_key(parent, &disk_key, 0);
2142 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
0f70abe2
CM
2143 if (wret)
2144 ret = wret;
be0e5c09 2145 }
d6025579 2146 btrfs_mark_buffer_dirty(parent);
aa5d6bed 2147 return ret;
be0e5c09
CM
2148}
2149
74123bd7
CM
2150/*
2151 * delete the item at the leaf level in path. If that empties
2152 * the leaf, remove it from the tree
2153 */
e089f05c
CM
2154int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2155 struct btrfs_path *path)
be0e5c09 2156{
be0e5c09 2157 int slot;
5f39d397
CM
2158 struct extent_buffer *leaf;
2159 struct btrfs_item *item;
be0e5c09
CM
2160 int doff;
2161 int dsize;
aa5d6bed
CM
2162 int ret = 0;
2163 int wret;
7518a238 2164 u32 nritems;
be0e5c09 2165
5f39d397 2166 leaf = path->nodes[0];
4920c9ac 2167 slot = path->slots[0];
5f39d397
CM
2168 doff = btrfs_item_offset_nr(leaf, slot);
2169 dsize = btrfs_item_size_nr(leaf, slot);
2170 nritems = btrfs_header_nritems(leaf);
be0e5c09 2171
7518a238 2172 if (slot != nritems - 1) {
be0e5c09 2173 int i;
123abc88 2174 int data_end = leaf_data_end(root, leaf);
5f39d397
CM
2175
2176 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
d6025579
CM
2177 data_end + dsize,
2178 btrfs_leaf_data(leaf) + data_end,
2179 doff - data_end);
5f39d397 2180
0783fcfc 2181 for (i = slot + 1; i < nritems; i++) {
5f39d397
CM
2182 u32 ioff;
2183 item = btrfs_item_nr(leaf, i);
2184 ioff = btrfs_item_offset(leaf, item);
2185 btrfs_set_item_offset(leaf, item, ioff + dsize);
0783fcfc 2186 }
5f39d397
CM
2187 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2188 btrfs_item_nr_offset(slot + 1),
d6025579
CM
2189 sizeof(struct btrfs_item) *
2190 (nritems - slot - 1));
be0e5c09 2191 }
5f39d397 2192 btrfs_set_header_nritems(leaf, nritems - 1);
7518a238 2193 nritems--;
5f39d397 2194
74123bd7 2195 /* delete the leaf if we've emptied it */
7518a238 2196 if (nritems == 0) {
5f39d397
CM
2197 if (leaf == root->node) {
2198 btrfs_set_header_level(leaf, 0);
9a8dd150 2199 } else {
5f39d397
CM
2200 clean_tree_block(trans, root, leaf);
2201 wait_on_tree_block_writeback(root, leaf);
e089f05c 2202 wret = del_ptr(trans, root, path, 1, path->slots[1]);
aa5d6bed
CM
2203 if (wret)
2204 ret = wret;
e089f05c 2205 wret = btrfs_free_extent(trans, root,
5f39d397
CM
2206 extent_buffer_blocknr(leaf),
2207 1, 1);
0f70abe2
CM
2208 if (wret)
2209 ret = wret;
9a8dd150 2210 }
be0e5c09 2211 } else {
7518a238 2212 int used = leaf_space_used(leaf, 0, nritems);
aa5d6bed 2213 if (slot == 0) {
5f39d397
CM
2214 struct btrfs_disk_key disk_key;
2215
2216 btrfs_item_key(leaf, &disk_key, 0);
e089f05c 2217 wret = fixup_low_keys(trans, root, path,
5f39d397 2218 &disk_key, 1);
aa5d6bed
CM
2219 if (wret)
2220 ret = wret;
2221 }
aa5d6bed 2222
74123bd7 2223 /* delete the leaf if it is mostly empty */
123abc88 2224 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
be0e5c09
CM
2225 /* push_leaf_left fixes the path.
2226 * make sure the path still points to our leaf
2227 * for possible call to del_ptr below
2228 */
4920c9ac 2229 slot = path->slots[1];
5f39d397
CM
2230 extent_buffer_get(leaf);
2231
e089f05c 2232 wret = push_leaf_left(trans, root, path, 1);
54aa1f4d 2233 if (wret < 0 && wret != -ENOSPC)
aa5d6bed 2234 ret = wret;
5f39d397
CM
2235
2236 if (path->nodes[0] == leaf &&
2237 btrfs_header_nritems(leaf)) {
e089f05c 2238 wret = push_leaf_right(trans, root, path, 1);
54aa1f4d 2239 if (wret < 0 && wret != -ENOSPC)
aa5d6bed
CM
2240 ret = wret;
2241 }
5f39d397
CM
2242
2243 if (btrfs_header_nritems(leaf) == 0) {
2244 u64 blocknr = extent_buffer_blocknr(leaf);
2245
2246 clean_tree_block(trans, root, leaf);
2247 wait_on_tree_block_writeback(root, leaf);
2248
e089f05c 2249 wret = del_ptr(trans, root, path, 1, slot);
aa5d6bed
CM
2250 if (wret)
2251 ret = wret;
5f39d397
CM
2252
2253 free_extent_buffer(leaf);
e089f05c
CM
2254 wret = btrfs_free_extent(trans, root, blocknr,
2255 1, 1);
0f70abe2
CM
2256 if (wret)
2257 ret = wret;
5de08d7d 2258 } else {
5f39d397
CM
2259 btrfs_mark_buffer_dirty(leaf);
2260 free_extent_buffer(leaf);
be0e5c09 2261 }
d5719762 2262 } else {
5f39d397 2263 btrfs_mark_buffer_dirty(leaf);
be0e5c09
CM
2264 }
2265 }
aa5d6bed 2266 return ret;
be0e5c09
CM
2267}
2268
97571fd0
CM
2269/*
2270 * walk up the tree as far as required to find the next leaf.
0f70abe2
CM
2271 * returns 0 if it found something or 1 if there are no greater leaves.
2272 * returns < 0 on io errors.
97571fd0 2273 */
234b63a0 2274int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
d97e63b6
CM
2275{
2276 int slot;
2277 int level = 1;
2278 u64 blocknr;
5f39d397
CM
2279 struct extent_buffer *c;
2280 struct extent_buffer *next = NULL;
d97e63b6 2281
234b63a0 2282 while(level < BTRFS_MAX_LEVEL) {
d97e63b6 2283 if (!path->nodes[level])
0f70abe2 2284 return 1;
5f39d397 2285
d97e63b6
CM
2286 slot = path->slots[level] + 1;
2287 c = path->nodes[level];
5f39d397 2288 if (slot >= btrfs_header_nritems(c)) {
d97e63b6
CM
2289 level++;
2290 continue;
2291 }
5f39d397
CM
2292
2293 blocknr = btrfs_node_blockptr(c, slot);
cfaa7295 2294 if (next)
5f39d397
CM
2295 free_extent_buffer(next);
2296
6702ed49
CM
2297 if (path->reada)
2298 reada_for_search(root, path, level, slot);
5f39d397 2299
d97e63b6
CM
2300 next = read_tree_block(root, blocknr);
2301 break;
2302 }
2303 path->slots[level] = slot;
2304 while(1) {
2305 level--;
2306 c = path->nodes[level];
5f39d397 2307 free_extent_buffer(c);
d97e63b6
CM
2308 path->nodes[level] = next;
2309 path->slots[level] = 0;
2310 if (!level)
2311 break;
6702ed49 2312 if (path->reada)
32020611 2313 reada_for_search(root, path, level, 0);
5f39d397 2314 next = read_tree_block(root, btrfs_node_blockptr(next, 0));
d97e63b6
CM
2315 }
2316 return 0;
2317}