]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - fs/btrfs/ctree.c
projects / mirror_ubuntu-zesty-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Btrfs: Copy correct tree when inserting into slot 0
[mirror_ubuntu-zesty-kernel.git] / fs / btrfs / ctree.c
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
19 #include <linux/sched.h>
20 #include "ctree.h"
21 #include "disk-io.h"
22 #include "transaction.h"
23 #include "print-tree.h"
24
25 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size, int extend);
30 static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src);
33 static 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);
37 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
39
40 inline void btrfs_init_path(struct btrfs_path *p)
41 {
42 memset(p, 0, sizeof(*p));
43 }
44
45 struct btrfs_path *btrfs_alloc_path(void)
46 {
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
49 if (path) {
50 btrfs_init_path(path);
51 path->reada = 1;
52 }
53 return path;
54 }
55
56 void btrfs_free_path(struct btrfs_path *p)
57 {
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
60 }
61
62 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
63 {
64 int i;
65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
66 if (!p->nodes[i])
67 break;
68 free_extent_buffer(p->nodes[i]);
69 }
70 memset(p, 0, sizeof(*p));
71 }
72
73 int btrfs_copy_root(struct btrfs_trans_handle *trans,
74 struct btrfs_root *root,
75 struct extent_buffer *buf,
76 struct extent_buffer **cow_ret, u64 new_root_objectid)
77 {
78 struct extent_buffer *cow;
79 u32 nritems;
80 int ret = 0;
81 int level;
82 struct btrfs_key first_key;
83 struct btrfs_root *new_root;
84
85 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
86 if (!new_root)
87 return -ENOMEM;
88
89 memcpy(new_root, root, sizeof(*new_root));
90 new_root->root_key.objectid = new_root_objectid;
91
92 WARN_ON(root->ref_cows && trans->transid !=
93 root->fs_info->running_transaction->transid);
94 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
95
96 level = btrfs_header_level(buf);
97 nritems = btrfs_header_nritems(buf);
98 if (nritems) {
99 if (level == 0)
100 btrfs_item_key_to_cpu(buf, &first_key, 0);
101 else
102 btrfs_node_key_to_cpu(buf, &first_key, 0);
103 } else {
104 first_key.objectid = 0;
105 }
106 cow = __btrfs_alloc_free_block(trans, new_root, buf->len,
107 new_root_objectid,
108 trans->transid, first_key.objectid,
109 level, buf->start, 0);
110 if (IS_ERR(cow)) {
111 kfree(new_root);
112 return PTR_ERR(cow);
113 }
114
115 copy_extent_buffer(cow, buf, 0, 0, cow->len);
116 btrfs_set_header_bytenr(cow, cow->start);
117 btrfs_set_header_generation(cow, trans->transid);
118 btrfs_set_header_owner(cow, new_root_objectid);
119
120 WARN_ON(btrfs_header_generation(buf) > trans->transid);
121 ret = btrfs_inc_ref(trans, new_root, buf);
122 kfree(new_root);
123
124 if (ret)
125 return ret;
126
127 btrfs_mark_buffer_dirty(cow);
128 *cow_ret = cow;
129 return 0;
130 }
131
132 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
133 struct btrfs_root *root,
134 struct extent_buffer *buf,
135 struct extent_buffer *parent, int parent_slot,
136 struct extent_buffer **cow_ret,
137 u64 search_start, u64 empty_size)
138 {
139 u64 root_gen;
140 struct extent_buffer *cow;
141 u32 nritems;
142 int ret = 0;
143 int different_trans = 0;
144 int level;
145 struct btrfs_key first_key;
146
147 if (root->ref_cows) {
148 root_gen = trans->transid;
149 } else {
150 root_gen = 0;
151 }
152
153 WARN_ON(root->ref_cows && trans->transid !=
154 root->fs_info->running_transaction->transid);
155 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
156
157 level = btrfs_header_level(buf);
158 nritems = btrfs_header_nritems(buf);
159 if (nritems) {
160 if (level == 0)
161 btrfs_item_key_to_cpu(buf, &first_key, 0);
162 else
163 btrfs_node_key_to_cpu(buf, &first_key, 0);
164 } else {
165 first_key.objectid = 0;
166 }
167 cow = __btrfs_alloc_free_block(trans, root, buf->len,
168 root->root_key.objectid,
169 root_gen, first_key.objectid, level,
170 search_start, empty_size);
171 if (IS_ERR(cow))
172 return PTR_ERR(cow);
173
174 copy_extent_buffer(cow, buf, 0, 0, cow->len);
175 btrfs_set_header_bytenr(cow, cow->start);
176 btrfs_set_header_generation(cow, trans->transid);
177 btrfs_set_header_owner(cow, root->root_key.objectid);
178
179 WARN_ON(btrfs_header_generation(buf) > trans->transid);
180 if (btrfs_header_generation(buf) != trans->transid) {
181 different_trans = 1;
182 ret = btrfs_inc_ref(trans, root, buf);
183 if (ret)
184 return ret;
185 } else {
186 clean_tree_block(trans, root, buf);
187 }
188
189 if (buf == root->node) {
190 root_gen = btrfs_header_generation(buf);
191 root->node = cow;
192 extent_buffer_get(cow);
193 if (buf != root->commit_root) {
194 btrfs_free_extent(trans, root, buf->start,
195 buf->len, root->root_key.objectid,
196 root_gen, 0, 0, 1);
197 }
198 free_extent_buffer(buf);
199 } else {
200 root_gen = btrfs_header_generation(parent);
201 btrfs_set_node_blockptr(parent, parent_slot,
202 cow->start);
203 WARN_ON(trans->transid == 0);
204 btrfs_set_node_ptr_generation(parent, parent_slot,
205 trans->transid);
206 btrfs_mark_buffer_dirty(parent);
207 WARN_ON(btrfs_header_generation(parent) != trans->transid);
208 btrfs_free_extent(trans, root, buf->start, buf->len,
209 btrfs_header_owner(parent), root_gen,
210 0, 0, 1);
211 }
212 free_extent_buffer(buf);
213 btrfs_mark_buffer_dirty(cow);
214 *cow_ret = cow;
215 return 0;
216 }
217
218 int btrfs_cow_block(struct btrfs_trans_handle *trans,
219 struct btrfs_root *root, struct extent_buffer *buf,
220 struct extent_buffer *parent, int parent_slot,
221 struct extent_buffer **cow_ret)
222 {
223 u64 search_start;
224 u64 header_trans;
225 int ret;
226
227 if (trans->transaction != root->fs_info->running_transaction) {
228 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
229 root->fs_info->running_transaction->transid);
230 WARN_ON(1);
231 }
232 if (trans->transid != root->fs_info->generation) {
233 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
234 root->fs_info->generation);
235 WARN_ON(1);
236 }
237
238 header_trans = btrfs_header_generation(buf);
239 if (header_trans == trans->transid) {
240 *cow_ret = buf;
241 return 0;
242 }
243
244 search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
245 ret = __btrfs_cow_block(trans, root, buf, parent,
246 parent_slot, cow_ret, search_start, 0);
247 return ret;
248 }
249
250 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
251 {
252 if (blocknr < other && other - (blocknr + blocksize) < 32768)
253 return 1;
254 if (blocknr > other && blocknr - (other + blocksize) < 32768)
255 return 1;
256 return 0;
257 }
258
259 /*
260 * compare two keys in a memcmp fashion
261 */
262 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
263 {
264 struct btrfs_key k1;
265
266 btrfs_disk_key_to_cpu(&k1, disk);
267
268 if (k1.objectid > k2->objectid)
269 return 1;
270 if (k1.objectid < k2->objectid)
271 return -1;
272 if (k1.type > k2->type)
273 return 1;
274 if (k1.type < k2->type)
275 return -1;
276 if (k1.offset > k2->offset)
277 return 1;
278 if (k1.offset < k2->offset)
279 return -1;
280 return 0;
281 }
282
283
284 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
285 struct btrfs_root *root, struct extent_buffer *parent,
286 int start_slot, int cache_only, u64 *last_ret,
287 struct btrfs_key *progress)
288 {
289 struct extent_buffer *cur;
290 struct extent_buffer *tmp;
291 u64 blocknr;
292 u64 search_start = *last_ret;
293 u64 last_block = 0;
294 u64 other;
295 u32 parent_nritems;
296 int end_slot;
297 int i;
298 int err = 0;
299 int parent_level;
300 int uptodate;
301 u32 blocksize;
302 int progress_passed = 0;
303 struct btrfs_disk_key disk_key;
304
305 parent_level = btrfs_header_level(parent);
306 if (cache_only && parent_level != 1)
307 return 0;
308
309 if (trans->transaction != root->fs_info->running_transaction) {
310 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
311 root->fs_info->running_transaction->transid);
312 WARN_ON(1);
313 }
314 if (trans->transid != root->fs_info->generation) {
315 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
316 root->fs_info->generation);
317 WARN_ON(1);
318 }
319
320 parent_nritems = btrfs_header_nritems(parent);
321 blocksize = btrfs_level_size(root, parent_level - 1);
322 end_slot = parent_nritems;
323
324 if (parent_nritems == 1)
325 return 0;
326
327 for (i = start_slot; i < end_slot; i++) {
328 int close = 1;
329
330 if (!parent->map_token) {
331 map_extent_buffer(parent,
332 btrfs_node_key_ptr_offset(i),
333 sizeof(struct btrfs_key_ptr),
334 &parent->map_token, &parent->kaddr,
335 &parent->map_start, &parent->map_len,
336 KM_USER1);
337 }
338 btrfs_node_key(parent, &disk_key, i);
339 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
340 continue;
341
342 progress_passed = 1;
343 blocknr = btrfs_node_blockptr(parent, i);
344 if (last_block == 0)
345 last_block = blocknr;
346
347 if (i > 0) {
348 other = btrfs_node_blockptr(parent, i - 1);
349 close = close_blocks(blocknr, other, blocksize);
350 }
351 if (close && i < end_slot - 2) {
352 other = btrfs_node_blockptr(parent, i + 1);
353 close = close_blocks(blocknr, other, blocksize);
354 }
355 if (close) {
356 last_block = blocknr;
357 continue;
358 }
359 if (parent->map_token) {
360 unmap_extent_buffer(parent, parent->map_token,
361 KM_USER1);
362 parent->map_token = NULL;
363 }
364
365 cur = btrfs_find_tree_block(root, blocknr, blocksize);
366 if (cur)
367 uptodate = btrfs_buffer_uptodate(cur);
368 else
369 uptodate = 0;
370 if (!cur || !uptodate) {
371 if (cache_only) {
372 free_extent_buffer(cur);
373 continue;
374 }
375 if (!cur) {
376 cur = read_tree_block(root, blocknr,
377 blocksize);
378 } else if (!uptodate) {
379 btrfs_read_buffer(cur);
380 }
381 }
382 if (search_start == 0)
383 search_start = last_block;
384
385 err = __btrfs_cow_block(trans, root, cur, parent, i,
386 &tmp, search_start,
387 min(16 * blocksize,
388 (end_slot - i) * blocksize));
389 if (err) {
390 free_extent_buffer(cur);
391 break;
392 }
393 search_start = tmp->start;
394 last_block = tmp->start;
395 *last_ret = search_start;
396 if (parent_level == 1)
397 btrfs_clear_buffer_defrag(tmp);
398 free_extent_buffer(tmp);
399 }
400 if (parent->map_token) {
401 unmap_extent_buffer(parent, parent->map_token,
402 KM_USER1);
403 parent->map_token = NULL;
404 }
405 return err;
406 }
407
408 /*
409 * The leaf data grows from end-to-front in the node.
410 * this returns the address of the start of the last item,
411 * which is the stop of the leaf data stack
412 */
413 static inline unsigned int leaf_data_end(struct btrfs_root *root,
414 struct extent_buffer *leaf)
415 {
416 u32 nr = btrfs_header_nritems(leaf);
417 if (nr == 0)
418 return BTRFS_LEAF_DATA_SIZE(root);
419 return btrfs_item_offset_nr(leaf, nr - 1);
420 }
421
422 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
423 int level)
424 {
425 struct extent_buffer *parent = NULL;
426 struct extent_buffer *node = path->nodes[level];
427 struct btrfs_disk_key parent_key;
428 struct btrfs_disk_key node_key;
429 int parent_slot;
430 int slot;
431 struct btrfs_key cpukey;
432 u32 nritems = btrfs_header_nritems(node);
433
434 if (path->nodes[level + 1])
435 parent = path->nodes[level + 1];
436
437 slot = path->slots[level];
438 BUG_ON(nritems == 0);
439 if (parent) {
440 parent_slot = path->slots[level + 1];
441 btrfs_node_key(parent, &parent_key, parent_slot);
442 btrfs_node_key(node, &node_key, 0);
443 BUG_ON(memcmp(&parent_key, &node_key,
444 sizeof(struct btrfs_disk_key)));
445 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
446 btrfs_header_bytenr(node));
447 }
448 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
449 if (slot != 0) {
450 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
451 btrfs_node_key(node, &node_key, slot);
452 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
453 }
454 if (slot < nritems - 1) {
455 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
456 btrfs_node_key(node, &node_key, slot);
457 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
458 }
459 return 0;
460 }
461
462 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
463 int level)
464 {
465 struct extent_buffer *leaf = path->nodes[level];
466 struct extent_buffer *parent = NULL;
467 int parent_slot;
468 struct btrfs_key cpukey;
469 struct btrfs_disk_key parent_key;
470 struct btrfs_disk_key leaf_key;
471 int slot = path->slots[0];
472
473 u32 nritems = btrfs_header_nritems(leaf);
474
475 if (path->nodes[level + 1])
476 parent = path->nodes[level + 1];
477
478 if (nritems == 0)
479 return 0;
480
481 if (parent) {
482 parent_slot = path->slots[level + 1];
483 btrfs_node_key(parent, &parent_key, parent_slot);
484 btrfs_item_key(leaf, &leaf_key, 0);
485
486 BUG_ON(memcmp(&parent_key, &leaf_key,
487 sizeof(struct btrfs_disk_key)));
488 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
489 btrfs_header_bytenr(leaf));
490 }
491 #if 0
492 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
493 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
494 btrfs_item_key(leaf, &leaf_key, i);
495 if (comp_keys(&leaf_key, &cpukey) >= 0) {
496 btrfs_print_leaf(root, leaf);
497 printk("slot %d offset bad key\n", i);
498 BUG_ON(1);
499 }
500 if (btrfs_item_offset_nr(leaf, i) !=
501 btrfs_item_end_nr(leaf, i + 1)) {
502 btrfs_print_leaf(root, leaf);
503 printk("slot %d offset bad\n", i);
504 BUG_ON(1);
505 }
506 if (i == 0) {
507 if (btrfs_item_offset_nr(leaf, i) +
508 btrfs_item_size_nr(leaf, i) !=
509 BTRFS_LEAF_DATA_SIZE(root)) {
510 btrfs_print_leaf(root, leaf);
511 printk("slot %d first offset bad\n", i);
512 BUG_ON(1);
513 }
514 }
515 }
516 if (nritems > 0) {
517 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
518 btrfs_print_leaf(root, leaf);
519 printk("slot %d bad size \n", nritems - 1);
520 BUG_ON(1);
521 }
522 }
523 #endif
524 if (slot != 0 && slot < nritems - 1) {
525 btrfs_item_key(leaf, &leaf_key, slot);
526 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
527 if (comp_keys(&leaf_key, &cpukey) <= 0) {
528 btrfs_print_leaf(root, leaf);
529 printk("slot %d offset bad key\n", slot);
530 BUG_ON(1);
531 }
532 if (btrfs_item_offset_nr(leaf, slot - 1) !=
533 btrfs_item_end_nr(leaf, slot)) {
534 btrfs_print_leaf(root, leaf);
535 printk("slot %d offset bad\n", slot);
536 BUG_ON(1);
537 }
538 }
539 if (slot < nritems - 1) {
540 btrfs_item_key(leaf, &leaf_key, slot);
541 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
542 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
543 if (btrfs_item_offset_nr(leaf, slot) !=
544 btrfs_item_end_nr(leaf, slot + 1)) {
545 btrfs_print_leaf(root, leaf);
546 printk("slot %d offset bad\n", slot);
547 BUG_ON(1);
548 }
549 }
550 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
551 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
552 return 0;
553 }
554
555 static int noinline check_block(struct btrfs_root *root,
556 struct btrfs_path *path, int level)
557 {
558 return 0;
559 #if 0
560 struct extent_buffer *buf = path->nodes[level];
561
562 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
563 (unsigned long)btrfs_header_fsid(buf),
564 BTRFS_FSID_SIZE)) {
565 printk("warning bad block %Lu\n", buf->start);
566 return 1;
567 }
568 #endif
569 if (level == 0)
570 return check_leaf(root, path, level);
571 return check_node(root, path, level);
572 }
573
574 /*
575 * search for key in the extent_buffer. The items start at offset p,
576 * and they are item_size apart. There are 'max' items in p.
577 *
578 * the slot in the array is returned via slot, and it points to
579 * the place where you would insert key if it is not found in
580 * the array.
581 *
582 * slot may point to max if the key is bigger than all of the keys
583 */
584 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
585 int item_size, struct btrfs_key *key,
586 int max, int *slot)
587 {
588 int low = 0;
589 int high = max;
590 int mid;
591 int ret;
592 struct btrfs_disk_key *tmp = NULL;
593 struct btrfs_disk_key unaligned;
594 unsigned long offset;
595 char *map_token = NULL;
596 char *kaddr = NULL;
597 unsigned long map_start = 0;
598 unsigned long map_len = 0;
599 int err;
600
601 while(low < high) {
602 mid = (low + high) / 2;
603 offset = p + mid * item_size;
604
605 if (!map_token || offset < map_start ||
606 (offset + sizeof(struct btrfs_disk_key)) >
607 map_start + map_len) {
608 if (map_token) {
609 unmap_extent_buffer(eb, map_token, KM_USER0);
610 map_token = NULL;
611 }
612 err = map_extent_buffer(eb, offset,
613 sizeof(struct btrfs_disk_key),
614 &map_token, &kaddr,
615 &map_start, &map_len, KM_USER0);
616
617 if (!err) {
618 tmp = (struct btrfs_disk_key *)(kaddr + offset -
619 map_start);
620 } else {
621 read_extent_buffer(eb, &unaligned,
622 offset, sizeof(unaligned));
623 tmp = &unaligned;
624 }
625
626 } else {
627 tmp = (struct btrfs_disk_key *)(kaddr + offset -
628 map_start);
629 }
630 ret = comp_keys(tmp, key);
631
632 if (ret < 0)
633 low = mid + 1;
634 else if (ret > 0)
635 high = mid;
636 else {
637 *slot = mid;
638 if (map_token)
639 unmap_extent_buffer(eb, map_token, KM_USER0);
640 return 0;
641 }
642 }
643 *slot = low;
644 if (map_token)
645 unmap_extent_buffer(eb, map_token, KM_USER0);
646 return 1;
647 }
648
649 /*
650 * simple bin_search frontend that does the right thing for
651 * leaves vs nodes
652 */
653 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
654 int level, int *slot)
655 {
656 if (level == 0) {
657 return generic_bin_search(eb,
658 offsetof(struct btrfs_leaf, items),
659 sizeof(struct btrfs_item),
660 key, btrfs_header_nritems(eb),
661 slot);
662 } else {
663 return generic_bin_search(eb,
664 offsetof(struct btrfs_node, ptrs),
665 sizeof(struct btrfs_key_ptr),
666 key, btrfs_header_nritems(eb),
667 slot);
668 }
669 return -1;
670 }
671
672 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
673 struct extent_buffer *parent, int slot)
674 {
675 if (slot < 0)
676 return NULL;
677 if (slot >= btrfs_header_nritems(parent))
678 return NULL;
679 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
680 btrfs_level_size(root, btrfs_header_level(parent) - 1));
681 }
682
683 static int balance_level(struct btrfs_trans_handle *trans,
684 struct btrfs_root *root,
685 struct btrfs_path *path, int level)
686 {
687 struct extent_buffer *right = NULL;
688 struct extent_buffer *mid;
689 struct extent_buffer *left = NULL;
690 struct extent_buffer *parent = NULL;
691 int ret = 0;
692 int wret;
693 int pslot;
694 int orig_slot = path->slots[level];
695 int err_on_enospc = 0;
696 u64 orig_ptr;
697
698 if (level == 0)
699 return 0;
700
701 mid = path->nodes[level];
702 WARN_ON(btrfs_header_generation(mid) != trans->transid);
703
704 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
705
706 if (level < BTRFS_MAX_LEVEL - 1)
707 parent = path->nodes[level + 1];
708 pslot = path->slots[level + 1];
709
710 /*
711 * deal with the case where there is only one pointer in the root
712 * by promoting the node below to a root
713 */
714 if (!parent) {
715 struct extent_buffer *child;
716
717 if (btrfs_header_nritems(mid) != 1)
718 return 0;
719
720 /* promote the child to a root */
721 child = read_node_slot(root, mid, 0);
722 BUG_ON(!child);
723 root->node = child;
724 path->nodes[level] = NULL;
725 clean_tree_block(trans, root, mid);
726 wait_on_tree_block_writeback(root, mid);
727 /* once for the path */
728 free_extent_buffer(mid);
729 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
730 root->root_key.objectid,
731 btrfs_header_generation(mid), 0, 0, 1);
732 /* once for the root ptr */
733 free_extent_buffer(mid);
734 return ret;
735 }
736 if (btrfs_header_nritems(mid) >
737 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
738 return 0;
739
740 if (btrfs_header_nritems(mid) < 2)
741 err_on_enospc = 1;
742
743 left = read_node_slot(root, parent, pslot - 1);
744 if (left) {
745 wret = btrfs_cow_block(trans, root, left,
746 parent, pslot - 1, &left);
747 if (wret) {
748 ret = wret;
749 goto enospc;
750 }
751 }
752 right = read_node_slot(root, parent, pslot + 1);
753 if (right) {
754 wret = btrfs_cow_block(trans, root, right,
755 parent, pslot + 1, &right);
756 if (wret) {
757 ret = wret;
758 goto enospc;
759 }
760 }
761
762 /* first, try to make some room in the middle buffer */
763 if (left) {
764 orig_slot += btrfs_header_nritems(left);
765 wret = push_node_left(trans, root, left, mid);
766 if (wret < 0)
767 ret = wret;
768 if (btrfs_header_nritems(mid) < 2)
769 err_on_enospc = 1;
770 }
771
772 /*
773 * then try to empty the right most buffer into the middle
774 */
775 if (right) {
776 wret = push_node_left(trans, root, mid, right);
777 if (wret < 0 && wret != -ENOSPC)
778 ret = wret;
779 if (btrfs_header_nritems(right) == 0) {
780 u64 bytenr = right->start;
781 u64 generation = btrfs_header_generation(parent);
782 u32 blocksize = right->len;
783
784 clean_tree_block(trans, root, right);
785 wait_on_tree_block_writeback(root, right);
786 free_extent_buffer(right);
787 right = NULL;
788 wret = del_ptr(trans, root, path, level + 1, pslot +
789 1);
790 if (wret)
791 ret = wret;
792 wret = btrfs_free_extent(trans, root, bytenr,
793 blocksize,
794 btrfs_header_owner(parent),
795 generation, 0, 0, 1);
796 if (wret)
797 ret = wret;
798 } else {
799 struct btrfs_disk_key right_key;
800 btrfs_node_key(right, &right_key, 0);
801 btrfs_set_node_key(parent, &right_key, pslot + 1);
802 btrfs_mark_buffer_dirty(parent);
803 }
804 }
805 if (btrfs_header_nritems(mid) == 1) {
806 /*
807 * we're not allowed to leave a node with one item in the
808 * tree during a delete. A deletion from lower in the tree
809 * could try to delete the only pointer in this node.
810 * So, pull some keys from the left.
811 * There has to be a left pointer at this point because
812 * otherwise we would have pulled some pointers from the
813 * right
814 */
815 BUG_ON(!left);
816 wret = balance_node_right(trans, root, mid, left);
817 if (wret < 0) {
818 ret = wret;
819 goto enospc;
820 }
821 BUG_ON(wret == 1);
822 }
823 if (btrfs_header_nritems(mid) == 0) {
824 /* we've managed to empty the middle node, drop it */
825 u64 root_gen = btrfs_header_generation(parent);
826 u64 bytenr = mid->start;
827 u32 blocksize = mid->len;
828 clean_tree_block(trans, root, mid);
829 wait_on_tree_block_writeback(root, mid);
830 free_extent_buffer(mid);
831 mid = NULL;
832 wret = del_ptr(trans, root, path, level + 1, pslot);
833 if (wret)
834 ret = wret;
835 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
836 btrfs_header_owner(parent),
837 root_gen, 0, 0, 1);
838 if (wret)
839 ret = wret;
840 } else {
841 /* update the parent key to reflect our changes */
842 struct btrfs_disk_key mid_key;
843 btrfs_node_key(mid, &mid_key, 0);
844 btrfs_set_node_key(parent, &mid_key, pslot);
845 btrfs_mark_buffer_dirty(parent);
846 }
847
848 /* update the path */
849 if (left) {
850 if (btrfs_header_nritems(left) > orig_slot) {
851 extent_buffer_get(left);
852 path->nodes[level] = left;
853 path->slots[level + 1] -= 1;
854 path->slots[level] = orig_slot;
855 if (mid)
856 free_extent_buffer(mid);
857 } else {
858 orig_slot -= btrfs_header_nritems(left);
859 path->slots[level] = orig_slot;
860 }
861 }
862 /* double check we haven't messed things up */
863 check_block(root, path, level);
864 if (orig_ptr !=
865 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
866 BUG();
867 enospc:
868 if (right)
869 free_extent_buffer(right);
870 if (left)
871 free_extent_buffer(left);
872 return ret;
873 }
874
875 /* returns zero if the push worked, non-zero otherwise */
876 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
877 struct btrfs_root *root,
878 struct btrfs_path *path, int level)
879 {
880 struct extent_buffer *right = NULL;
881 struct extent_buffer *mid;
882 struct extent_buffer *left = NULL;
883 struct extent_buffer *parent = NULL;
884 int ret = 0;
885 int wret;
886 int pslot;
887 int orig_slot = path->slots[level];
888 u64 orig_ptr;
889
890 if (level == 0)
891 return 1;
892
893 mid = path->nodes[level];
894 WARN_ON(btrfs_header_generation(mid) != trans->transid);
895 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
896
897 if (level < BTRFS_MAX_LEVEL - 1)
898 parent = path->nodes[level + 1];
899 pslot = path->slots[level + 1];
900
901 if (!parent)
902 return 1;
903
904 left = read_node_slot(root, parent, pslot - 1);
905
906 /* first, try to make some room in the middle buffer */
907 if (left) {
908 u32 left_nr;
909 left_nr = btrfs_header_nritems(left);
910 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
911 wret = 1;
912 } else {
913 ret = btrfs_cow_block(trans, root, left, parent,
914 pslot - 1, &left);
915 if (ret)
916 wret = 1;
917 else {
918 wret = push_node_left(trans, root,
919 left, mid);
920 }
921 }
922 if (wret < 0)
923 ret = wret;
924 if (wret == 0) {
925 struct btrfs_disk_key disk_key;
926 orig_slot += left_nr;
927 btrfs_node_key(mid, &disk_key, 0);
928 btrfs_set_node_key(parent, &disk_key, pslot);
929 btrfs_mark_buffer_dirty(parent);
930 if (btrfs_header_nritems(left) > orig_slot) {
931 path->nodes[level] = left;
932 path->slots[level + 1] -= 1;
933 path->slots[level] = orig_slot;
934 free_extent_buffer(mid);
935 } else {
936 orig_slot -=
937 btrfs_header_nritems(left);
938 path->slots[level] = orig_slot;
939 free_extent_buffer(left);
940 }
941 return 0;
942 }
943 free_extent_buffer(left);
944 }
945 right= read_node_slot(root, parent, pslot + 1);
946
947 /*
948 * then try to empty the right most buffer into the middle
949 */
950 if (right) {
951 u32 right_nr;
952 right_nr = btrfs_header_nritems(right);
953 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
954 wret = 1;
955 } else {
956 ret = btrfs_cow_block(trans, root, right,
957 parent, pslot + 1,
958 &right);
959 if (ret)
960 wret = 1;
961 else {
962 wret = balance_node_right(trans, root,
963 right, mid);
964 }
965 }
966 if (wret < 0)
967 ret = wret;
968 if (wret == 0) {
969 struct btrfs_disk_key disk_key;
970
971 btrfs_node_key(right, &disk_key, 0);
972 btrfs_set_node_key(parent, &disk_key, pslot + 1);
973 btrfs_mark_buffer_dirty(parent);
974
975 if (btrfs_header_nritems(mid) <= orig_slot) {
976 path->nodes[level] = right;
977 path->slots[level + 1] += 1;
978 path->slots[level] = orig_slot -
979 btrfs_header_nritems(mid);
980 free_extent_buffer(mid);
981 } else {
982 free_extent_buffer(right);
983 }
984 return 0;
985 }
986 free_extent_buffer(right);
987 }
988 return 1;
989 }
990
991 /*
992 * readahead one full node of leaves
993 */
994 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
995 int level, int slot, u64 objectid)
996 {
997 struct extent_buffer *node;
998 struct btrfs_disk_key disk_key;
999 u32 nritems;
1000 u64 search;
1001 u64 lowest_read;
1002 u64 highest_read;
1003 u64 nread = 0;
1004 int direction = path->reada;
1005 struct extent_buffer *eb;
1006 u32 nr;
1007 u32 blocksize;
1008 u32 nscan = 0;
1009
1010 if (level != 1)
1011 return;
1012
1013 if (!path->nodes[level])
1014 return;
1015
1016 node = path->nodes[level];
1017 search = btrfs_node_blockptr(node, slot);
1018 blocksize = btrfs_level_size(root, level - 1);
1019 eb = btrfs_find_tree_block(root, search, blocksize);
1020 if (eb) {
1021 free_extent_buffer(eb);
1022 return;
1023 }
1024
1025 highest_read = search;
1026 lowest_read = search;
1027
1028 nritems = btrfs_header_nritems(node);
1029 nr = slot;
1030 while(1) {
1031 if (direction < 0) {
1032 if (nr == 0)
1033 break;
1034 nr--;
1035 } else if (direction > 0) {
1036 nr++;
1037 if (nr >= nritems)
1038 break;
1039 }
1040 if (path->reada < 0 && objectid) {
1041 btrfs_node_key(node, &disk_key, nr);
1042 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1043 break;
1044 }
1045 search = btrfs_node_blockptr(node, nr);
1046 if ((search >= lowest_read && search <= highest_read) ||
1047 (search < lowest_read && lowest_read - search <= 32768) ||
1048 (search > highest_read && search - highest_read <= 32768)) {
1049 readahead_tree_block(root, search, blocksize);
1050 nread += blocksize;
1051 }
1052 nscan++;
1053 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1054 break;
1055 if(nread > (1024 * 1024) || nscan > 128)
1056 break;
1057
1058 if (search < lowest_read)
1059 lowest_read = search;
1060 if (search > highest_read)
1061 highest_read = search;
1062 }
1063 }
1064 /*
1065 * look for key in the tree. path is filled in with nodes along the way
1066 * if key is found, we return zero and you can find the item in the leaf
1067 * level of the path (level 0)
1068 *
1069 * If the key isn't found, the path points to the slot where it should
1070 * be inserted, and 1 is returned. If there are other errors during the
1071 * search a negative error number is returned.
1072 *
1073 * if ins_len > 0, nodes and leaves will be split as we walk down the
1074 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1075 * possible)
1076 */
1077 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1078 *root, struct btrfs_key *key, struct btrfs_path *p, int
1079 ins_len, int cow)
1080 {
1081 struct extent_buffer *b;
1082 u64 bytenr;
1083 u64 ptr_gen;
1084 int slot;
1085 int ret;
1086 int level;
1087 int should_reada = p->reada;
1088 u8 lowest_level = 0;
1089
1090 lowest_level = p->lowest_level;
1091 WARN_ON(lowest_level && ins_len);
1092 WARN_ON(p->nodes[0] != NULL);
1093 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1094 again:
1095 b = root->node;
1096 extent_buffer_get(b);
1097 while (b) {
1098 level = btrfs_header_level(b);
1099 if (cow) {
1100 int wret;
1101 wret = btrfs_cow_block(trans, root, b,
1102 p->nodes[level + 1],
1103 p->slots[level + 1],
1104 &b);
1105 if (wret) {
1106 free_extent_buffer(b);
1107 return wret;
1108 }
1109 }
1110 BUG_ON(!cow && ins_len);
1111 if (level != btrfs_header_level(b))
1112 WARN_ON(1);
1113 level = btrfs_header_level(b);
1114 p->nodes[level] = b;
1115 ret = check_block(root, p, level);
1116 if (ret)
1117 return -1;
1118 ret = bin_search(b, key, level, &slot);
1119 if (level != 0) {
1120 if (ret && slot > 0)
1121 slot -= 1;
1122 p->slots[level] = slot;
1123 if (ins_len > 0 && btrfs_header_nritems(b) >=
1124 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1125 int sret = split_node(trans, root, p, level);
1126 BUG_ON(sret > 0);
1127 if (sret)
1128 return sret;
1129 b = p->nodes[level];
1130 slot = p->slots[level];
1131 } else if (ins_len < 0) {
1132 int sret = balance_level(trans, root, p,
1133 level);
1134 if (sret)
1135 return sret;
1136 b = p->nodes[level];
1137 if (!b) {
1138 btrfs_release_path(NULL, p);
1139 goto again;
1140 }
1141 slot = p->slots[level];
1142 BUG_ON(btrfs_header_nritems(b) == 1);
1143 }
1144 /* this is only true while dropping a snapshot */
1145 if (level == lowest_level)
1146 break;
1147 bytenr = btrfs_node_blockptr(b, slot);
1148 ptr_gen = btrfs_node_ptr_generation(b, slot);
1149 if (should_reada)
1150 reada_for_search(root, p, level, slot,
1151 key->objectid);
1152 b = read_tree_block(root, bytenr,
1153 btrfs_level_size(root, level - 1));
1154 if (ptr_gen != btrfs_header_generation(b)) {
1155 printk("block %llu bad gen wanted %llu "
1156 "found %llu\n",
1157 (unsigned long long)b->start,
1158 (unsigned long long)ptr_gen,
1159 (unsigned long long)btrfs_header_generation(b));
1160 }
1161 } else {
1162 p->slots[level] = slot;
1163 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1164 sizeof(struct btrfs_item) + ins_len) {
1165 int sret = split_leaf(trans, root, key,
1166 p, ins_len, ret == 0);
1167 BUG_ON(sret > 0);
1168 if (sret)
1169 return sret;
1170 }
1171 return ret;
1172 }
1173 }
1174 return 1;
1175 }
1176
1177 /*
1178 * adjust the pointers going up the tree, starting at level
1179 * making sure the right key of each node is points to 'key'.
1180 * This is used after shifting pointers to the left, so it stops
1181 * fixing up pointers when a given leaf/node is not in slot 0 of the
1182 * higher levels
1183 *
1184 * If this fails to write a tree block, it returns -1, but continues
1185 * fixing up the blocks in ram so the tree is consistent.
1186 */
1187 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1188 struct btrfs_root *root, struct btrfs_path *path,
1189 struct btrfs_disk_key *key, int level)
1190 {
1191 int i;
1192 int ret = 0;
1193 struct extent_buffer *t;
1194
1195 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1196 int tslot = path->slots[i];
1197 if (!path->nodes[i])
1198 break;
1199 t = path->nodes[i];
1200 btrfs_set_node_key(t, key, tslot);
1201 btrfs_mark_buffer_dirty(path->nodes[i]);
1202 if (tslot != 0)
1203 break;
1204 }
1205 return ret;
1206 }
1207
1208 /*
1209 * try to push data from one node into the next node left in the
1210 * tree.
1211 *
1212 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1213 * error, and > 0 if there was no room in the left hand block.
1214 */
1215 static int push_node_left(struct btrfs_trans_handle *trans,
1216 struct btrfs_root *root, struct extent_buffer *dst,
1217 struct extent_buffer *src)
1218 {
1219 int push_items = 0;
1220 int src_nritems;
1221 int dst_nritems;
1222 int ret = 0;
1223
1224 src_nritems = btrfs_header_nritems(src);
1225 dst_nritems = btrfs_header_nritems(dst);
1226 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1227 WARN_ON(btrfs_header_generation(src) != trans->transid);
1228 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1229
1230 if (push_items <= 0) {
1231 return 1;
1232 }
1233
1234 if (src_nritems < push_items)
1235 push_items = src_nritems;
1236
1237 copy_extent_buffer(dst, src,
1238 btrfs_node_key_ptr_offset(dst_nritems),
1239 btrfs_node_key_ptr_offset(0),
1240 push_items * sizeof(struct btrfs_key_ptr));
1241
1242 if (push_items < src_nritems) {
1243 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1244 btrfs_node_key_ptr_offset(push_items),
1245 (src_nritems - push_items) *
1246 sizeof(struct btrfs_key_ptr));
1247 }
1248 btrfs_set_header_nritems(src, src_nritems - push_items);
1249 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1250 btrfs_mark_buffer_dirty(src);
1251 btrfs_mark_buffer_dirty(dst);
1252 return ret;
1253 }
1254
1255 /*
1256 * try to push data from one node into the next node right in the
1257 * tree.
1258 *
1259 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1260 * error, and > 0 if there was no room in the right hand block.
1261 *
1262 * this will only push up to 1/2 the contents of the left node over
1263 */
1264 static int balance_node_right(struct btrfs_trans_handle *trans,
1265 struct btrfs_root *root,
1266 struct extent_buffer *dst,
1267 struct extent_buffer *src)
1268 {
1269 int push_items = 0;
1270 int max_push;
1271 int src_nritems;
1272 int dst_nritems;
1273 int ret = 0;
1274
1275 WARN_ON(btrfs_header_generation(src) != trans->transid);
1276 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1277
1278 src_nritems = btrfs_header_nritems(src);
1279 dst_nritems = btrfs_header_nritems(dst);
1280 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1281 if (push_items <= 0)
1282 return 1;
1283
1284 max_push = src_nritems / 2 + 1;
1285 /* don't try to empty the node */
1286 if (max_push >= src_nritems)
1287 return 1;
1288
1289 if (max_push < push_items)
1290 push_items = max_push;
1291
1292 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1293 btrfs_node_key_ptr_offset(0),
1294 (dst_nritems) *
1295 sizeof(struct btrfs_key_ptr));
1296
1297 copy_extent_buffer(dst, src,
1298 btrfs_node_key_ptr_offset(0),
1299 btrfs_node_key_ptr_offset(src_nritems - push_items),
1300 push_items * sizeof(struct btrfs_key_ptr));
1301
1302 btrfs_set_header_nritems(src, src_nritems - push_items);
1303 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1304
1305 btrfs_mark_buffer_dirty(src);
1306 btrfs_mark_buffer_dirty(dst);
1307 return ret;
1308 }
1309
1310 /*
1311 * helper function to insert a new root level in the tree.
1312 * A new node is allocated, and a single item is inserted to
1313 * point to the existing root
1314 *
1315 * returns zero on success or < 0 on failure.
1316 */
1317 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1318 struct btrfs_root *root,
1319 struct btrfs_path *path, int level)
1320 {
1321 u64 root_gen;
1322 u64 lower_gen;
1323 struct extent_buffer *lower;
1324 struct extent_buffer *c;
1325 struct btrfs_disk_key lower_key;
1326
1327 BUG_ON(path->nodes[level]);
1328 BUG_ON(path->nodes[level-1] != root->node);
1329
1330 if (root->ref_cows)
1331 root_gen = trans->transid;
1332 else
1333 root_gen = 0;
1334
1335 lower = path->nodes[level-1];
1336 if (level == 1)
1337 btrfs_item_key(lower, &lower_key, 0);
1338 else
1339 btrfs_node_key(lower, &lower_key, 0);
1340
1341 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1342 root->root_key.objectid,
1343 root_gen, lower_key.objectid, level,
1344 root->node->start, 0);
1345 if (IS_ERR(c))
1346 return PTR_ERR(c);
1347 memset_extent_buffer(c, 0, 0, root->nodesize);
1348 btrfs_set_header_nritems(c, 1);
1349 btrfs_set_header_level(c, level);
1350 btrfs_set_header_bytenr(c, c->start);
1351 btrfs_set_header_generation(c, trans->transid);
1352 btrfs_set_header_owner(c, root->root_key.objectid);
1353
1354 write_extent_buffer(c, root->fs_info->fsid,
1355 (unsigned long)btrfs_header_fsid(c),
1356 BTRFS_FSID_SIZE);
1357 btrfs_set_node_key(c, &lower_key, 0);
1358 btrfs_set_node_blockptr(c, 0, lower->start);
1359 lower_gen = btrfs_header_generation(lower);
1360 WARN_ON(lower_gen == 0);
1361
1362 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1363
1364 btrfs_mark_buffer_dirty(c);
1365
1366 /* the super has an extra ref to root->node */
1367 free_extent_buffer(root->node);
1368 root->node = c;
1369 extent_buffer_get(c);
1370 path->nodes[level] = c;
1371 path->slots[level] = 0;
1372
1373 if (root->ref_cows && lower_gen != trans->transid) {
1374 struct btrfs_path *back_path = btrfs_alloc_path();
1375 int ret;
1376 ret = btrfs_insert_extent_backref(trans,
1377 root->fs_info->extent_root,
1378 path, lower->start,
1379 root->root_key.objectid,
1380 trans->transid, 0, 0);
1381 BUG_ON(ret);
1382 btrfs_free_path(back_path);
1383 }
1384 return 0;
1385 }
1386
1387 /*
1388 * worker function to insert a single pointer in a node.
1389 * the node should have enough room for the pointer already
1390 *
1391 * slot and level indicate where you want the key to go, and
1392 * blocknr is the block the key points to.
1393 *
1394 * returns zero on success and < 0 on any error
1395 */
1396 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1397 *root, struct btrfs_path *path, struct btrfs_disk_key
1398 *key, u64 bytenr, int slot, int level)
1399 {
1400 struct extent_buffer *lower;
1401 int nritems;
1402
1403 BUG_ON(!path->nodes[level]);
1404 lower = path->nodes[level];
1405 nritems = btrfs_header_nritems(lower);
1406 if (slot > nritems)
1407 BUG();
1408 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1409 BUG();
1410 if (slot != nritems) {
1411 memmove_extent_buffer(lower,
1412 btrfs_node_key_ptr_offset(slot + 1),
1413 btrfs_node_key_ptr_offset(slot),
1414 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1415 }
1416 btrfs_set_node_key(lower, key, slot);
1417 btrfs_set_node_blockptr(lower, slot, bytenr);
1418 WARN_ON(trans->transid == 0);
1419 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1420 btrfs_set_header_nritems(lower, nritems + 1);
1421 btrfs_mark_buffer_dirty(lower);
1422 return 0;
1423 }
1424
1425 /*
1426 * split the node at the specified level in path in two.
1427 * The path is corrected to point to the appropriate node after the split
1428 *
1429 * Before splitting this tries to make some room in the node by pushing
1430 * left and right, if either one works, it returns right away.
1431 *
1432 * returns 0 on success and < 0 on failure
1433 */
1434 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1435 *root, struct btrfs_path *path, int level)
1436 {
1437 u64 root_gen;
1438 struct extent_buffer *c;
1439 struct extent_buffer *split;
1440 struct btrfs_disk_key disk_key;
1441 int mid;
1442 int ret;
1443 int wret;
1444 u32 c_nritems;
1445
1446 c = path->nodes[level];
1447 WARN_ON(btrfs_header_generation(c) != trans->transid);
1448 if (c == root->node) {
1449 /* trying to split the root, lets make a new one */
1450 ret = insert_new_root(trans, root, path, level + 1);
1451 if (ret)
1452 return ret;
1453 } else {
1454 ret = push_nodes_for_insert(trans, root, path, level);
1455 c = path->nodes[level];
1456 if (!ret && btrfs_header_nritems(c) <
1457 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1458 return 0;
1459 if (ret < 0)
1460 return ret;
1461 }
1462
1463 c_nritems = btrfs_header_nritems(c);
1464 if (root->ref_cows)
1465 root_gen = trans->transid;
1466 else
1467 root_gen = 0;
1468
1469 btrfs_node_key(c, &disk_key, 0);
1470 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1471 root->root_key.objectid,
1472 root_gen,
1473 btrfs_disk_key_objectid(&disk_key),
1474 level, c->start, 0);
1475 if (IS_ERR(split))
1476 return PTR_ERR(split);
1477
1478 btrfs_set_header_flags(split, btrfs_header_flags(c));
1479 btrfs_set_header_level(split, btrfs_header_level(c));
1480 btrfs_set_header_bytenr(split, split->start);
1481 btrfs_set_header_generation(split, trans->transid);
1482 btrfs_set_header_owner(split, root->root_key.objectid);
1483 write_extent_buffer(split, root->fs_info->fsid,
1484 (unsigned long)btrfs_header_fsid(split),
1485 BTRFS_FSID_SIZE);
1486
1487 mid = (c_nritems + 1) / 2;
1488
1489 copy_extent_buffer(split, c,
1490 btrfs_node_key_ptr_offset(0),
1491 btrfs_node_key_ptr_offset(mid),
1492 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1493 btrfs_set_header_nritems(split, c_nritems - mid);
1494 btrfs_set_header_nritems(c, mid);
1495 ret = 0;
1496
1497 btrfs_mark_buffer_dirty(c);
1498 btrfs_mark_buffer_dirty(split);
1499
1500 btrfs_node_key(split, &disk_key, 0);
1501 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1502 path->slots[level + 1] + 1,
1503 level + 1);
1504 if (wret)
1505 ret = wret;
1506
1507 if (path->slots[level] >= mid) {
1508 path->slots[level] -= mid;
1509 free_extent_buffer(c);
1510 path->nodes[level] = split;
1511 path->slots[level + 1] += 1;
1512 } else {
1513 free_extent_buffer(split);
1514 }
1515 return ret;
1516 }
1517
1518 /*
1519 * how many bytes are required to store the items in a leaf. start
1520 * and nr indicate which items in the leaf to check. This totals up the
1521 * space used both by the item structs and the item data
1522 */
1523 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1524 {
1525 int data_len;
1526 int nritems = btrfs_header_nritems(l);
1527 int end = min(nritems, start + nr) - 1;
1528
1529 if (!nr)
1530 return 0;
1531 data_len = btrfs_item_end_nr(l, start);
1532 data_len = data_len - btrfs_item_offset_nr(l, end);
1533 data_len += sizeof(struct btrfs_item) * nr;
1534 WARN_ON(data_len < 0);
1535 return data_len;
1536 }
1537
1538 /*
1539 * The space between the end of the leaf items and
1540 * the start of the leaf data. IOW, how much room
1541 * the leaf has left for both items and data
1542 */
1543 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1544 {
1545 int nritems = btrfs_header_nritems(leaf);
1546 int ret;
1547 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1548 if (ret < 0) {
1549 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1550 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1551 leaf_space_used(leaf, 0, nritems), nritems);
1552 }
1553 return ret;
1554 }
1555
1556 /*
1557 * push some data in the path leaf to the right, trying to free up at
1558 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1559 *
1560 * returns 1 if the push failed because the other node didn't have enough
1561 * room, 0 if everything worked out and < 0 if there were major errors.
1562 */
1563 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1564 *root, struct btrfs_path *path, int data_size,
1565 int empty)
1566 {
1567 struct extent_buffer *left = path->nodes[0];
1568 struct extent_buffer *right;
1569 struct extent_buffer *upper;
1570 struct btrfs_disk_key disk_key;
1571 int slot;
1572 u32 i;
1573 int free_space;
1574 int push_space = 0;
1575 int push_items = 0;
1576 struct btrfs_item *item;
1577 u32 left_nritems;
1578 u32 nr;
1579 u32 right_nritems;
1580 u32 data_end;
1581 u32 this_item_size;
1582 int ret;
1583
1584 slot = path->slots[1];
1585 if (!path->nodes[1]) {
1586 return 1;
1587 }
1588 upper = path->nodes[1];
1589 if (slot >= btrfs_header_nritems(upper) - 1)
1590 return 1;
1591
1592 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1593 root->leafsize);
1594 free_space = btrfs_leaf_free_space(root, right);
1595 if (free_space < data_size + sizeof(struct btrfs_item)) {
1596 free_extent_buffer(right);
1597 return 1;
1598 }
1599
1600 /* cow and double check */
1601 ret = btrfs_cow_block(trans, root, right, upper,
1602 slot + 1, &right);
1603 if (ret) {
1604 free_extent_buffer(right);
1605 return 1;
1606 }
1607 free_space = btrfs_leaf_free_space(root, right);
1608 if (free_space < data_size + sizeof(struct btrfs_item)) {
1609 free_extent_buffer(right);
1610 return 1;
1611 }
1612
1613 left_nritems = btrfs_header_nritems(left);
1614 if (left_nritems == 0) {
1615 free_extent_buffer(right);
1616 return 1;
1617 }
1618
1619 if (empty)
1620 nr = 0;
1621 else
1622 nr = 1;
1623
1624 i = left_nritems - 1;
1625 while (i >= nr) {
1626 item = btrfs_item_nr(left, i);
1627
1628 if (path->slots[0] == i)
1629 push_space += data_size + sizeof(*item);
1630
1631 if (!left->map_token) {
1632 map_extent_buffer(left, (unsigned long)item,
1633 sizeof(struct btrfs_item),
1634 &left->map_token, &left->kaddr,
1635 &left->map_start, &left->map_len,
1636 KM_USER1);
1637 }
1638
1639 this_item_size = btrfs_item_size(left, item);
1640 if (this_item_size + sizeof(*item) + push_space > free_space)
1641 break;
1642 push_items++;
1643 push_space += this_item_size + sizeof(*item);
1644 if (i == 0)
1645 break;
1646 i--;
1647 }
1648 if (left->map_token) {
1649 unmap_extent_buffer(left, left->map_token, KM_USER1);
1650 left->map_token = NULL;
1651 }
1652
1653 if (push_items == 0) {
1654 free_extent_buffer(right);
1655 return 1;
1656 }
1657
1658 if (!empty && push_items == left_nritems)
1659 WARN_ON(1);
1660
1661 /* push left to right */
1662 right_nritems = btrfs_header_nritems(right);
1663
1664 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1665 push_space -= leaf_data_end(root, left);
1666
1667 /* make room in the right data area */
1668 data_end = leaf_data_end(root, right);
1669 memmove_extent_buffer(right,
1670 btrfs_leaf_data(right) + data_end - push_space,
1671 btrfs_leaf_data(right) + data_end,
1672 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1673
1674 /* copy from the left data area */
1675 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1676 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1677 btrfs_leaf_data(left) + leaf_data_end(root, left),
1678 push_space);
1679
1680 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1681 btrfs_item_nr_offset(0),
1682 right_nritems * sizeof(struct btrfs_item));
1683
1684 /* copy the items from left to right */
1685 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1686 btrfs_item_nr_offset(left_nritems - push_items),
1687 push_items * sizeof(struct btrfs_item));
1688
1689 /* update the item pointers */
1690 right_nritems += push_items;
1691 btrfs_set_header_nritems(right, right_nritems);
1692 push_space = BTRFS_LEAF_DATA_SIZE(root);
1693 for (i = 0; i < right_nritems; i++) {
1694 item = btrfs_item_nr(right, i);
1695 if (!right->map_token) {
1696 map_extent_buffer(right, (unsigned long)item,
1697 sizeof(struct btrfs_item),
1698 &right->map_token, &right->kaddr,
1699 &right->map_start, &right->map_len,
1700 KM_USER1);
1701 }
1702 push_space -= btrfs_item_size(right, item);
1703 btrfs_set_item_offset(right, item, push_space);
1704 }
1705
1706 if (right->map_token) {
1707 unmap_extent_buffer(right, right->map_token, KM_USER1);
1708 right->map_token = NULL;
1709 }
1710 left_nritems -= push_items;
1711 btrfs_set_header_nritems(left, left_nritems);
1712
1713 if (left_nritems)
1714 btrfs_mark_buffer_dirty(left);
1715 btrfs_mark_buffer_dirty(right);
1716
1717 btrfs_item_key(right, &disk_key, 0);
1718 btrfs_set_node_key(upper, &disk_key, slot + 1);
1719 btrfs_mark_buffer_dirty(upper);
1720
1721 /* then fixup the leaf pointer in the path */
1722 if (path->slots[0] >= left_nritems) {
1723 path->slots[0] -= left_nritems;
1724 free_extent_buffer(path->nodes[0]);
1725 path->nodes[0] = right;
1726 path->slots[1] += 1;
1727 } else {
1728 free_extent_buffer(right);
1729 }
1730 return 0;
1731 }
1732 /*
1733 * push some data in the path leaf to the left, trying to free up at
1734 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1735 */
1736 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1737 *root, struct btrfs_path *path, int data_size,
1738 int empty)
1739 {
1740 struct btrfs_disk_key disk_key;
1741 struct extent_buffer *right = path->nodes[0];
1742 struct extent_buffer *left;
1743 int slot;
1744 int i;
1745 int free_space;
1746 int push_space = 0;
1747 int push_items = 0;
1748 struct btrfs_item *item;
1749 u32 old_left_nritems;
1750 u32 right_nritems;
1751 u32 nr;
1752 int ret = 0;
1753 int wret;
1754 u32 this_item_size;
1755 u32 old_left_item_size;
1756
1757 slot = path->slots[1];
1758 if (slot == 0)
1759 return 1;
1760 if (!path->nodes[1])
1761 return 1;
1762
1763 right_nritems = btrfs_header_nritems(right);
1764 if (right_nritems == 0) {
1765 return 1;
1766 }
1767
1768 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1769 slot - 1), root->leafsize);
1770 free_space = btrfs_leaf_free_space(root, left);
1771 if (free_space < data_size + sizeof(struct btrfs_item)) {
1772 free_extent_buffer(left);
1773 return 1;
1774 }
1775
1776 /* cow and double check */
1777 ret = btrfs_cow_block(trans, root, left,
1778 path->nodes[1], slot - 1, &left);
1779 if (ret) {
1780 /* we hit -ENOSPC, but it isn't fatal here */
1781 free_extent_buffer(left);
1782 return 1;
1783 }
1784
1785 free_space = btrfs_leaf_free_space(root, left);
1786 if (free_space < data_size + sizeof(struct btrfs_item)) {
1787 free_extent_buffer(left);
1788 return 1;
1789 }
1790
1791 if (empty)
1792 nr = right_nritems;
1793 else
1794 nr = right_nritems - 1;
1795
1796 for (i = 0; i < nr; i++) {
1797 item = btrfs_item_nr(right, i);
1798 if (!right->map_token) {
1799 map_extent_buffer(right, (unsigned long)item,
1800 sizeof(struct btrfs_item),
1801 &right->map_token, &right->kaddr,
1802 &right->map_start, &right->map_len,
1803 KM_USER1);
1804 }
1805
1806 if (path->slots[0] == i)
1807 push_space += data_size + sizeof(*item);
1808
1809 this_item_size = btrfs_item_size(right, item);
1810 if (this_item_size + sizeof(*item) + push_space > free_space)
1811 break;
1812
1813 push_items++;
1814 push_space += this_item_size + sizeof(*item);
1815 }
1816
1817 if (right->map_token) {
1818 unmap_extent_buffer(right, right->map_token, KM_USER1);
1819 right->map_token = NULL;
1820 }
1821
1822 if (push_items == 0) {
1823 free_extent_buffer(left);
1824 return 1;
1825 }
1826 if (!empty && push_items == btrfs_header_nritems(right))
1827 WARN_ON(1);
1828
1829 /* push data from right to left */
1830 copy_extent_buffer(left, right,
1831 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1832 btrfs_item_nr_offset(0),
1833 push_items * sizeof(struct btrfs_item));
1834
1835 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1836 btrfs_item_offset_nr(right, push_items -1);
1837
1838 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1839 leaf_data_end(root, left) - push_space,
1840 btrfs_leaf_data(right) +
1841 btrfs_item_offset_nr(right, push_items - 1),
1842 push_space);
1843 old_left_nritems = btrfs_header_nritems(left);
1844 BUG_ON(old_left_nritems < 0);
1845
1846 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1847 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1848 u32 ioff;
1849
1850 item = btrfs_item_nr(left, i);
1851 if (!left->map_token) {
1852 map_extent_buffer(left, (unsigned long)item,
1853 sizeof(struct btrfs_item),
1854 &left->map_token, &left->kaddr,
1855 &left->map_start, &left->map_len,
1856 KM_USER1);
1857 }
1858
1859 ioff = btrfs_item_offset(left, item);
1860 btrfs_set_item_offset(left, item,
1861 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1862 }
1863 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1864 if (left->map_token) {
1865 unmap_extent_buffer(left, left->map_token, KM_USER1);
1866 left->map_token = NULL;
1867 }
1868
1869 /* fixup right node */
1870 if (push_items > right_nritems) {
1871 printk("push items %d nr %u\n", push_items, right_nritems);
1872 WARN_ON(1);
1873 }
1874
1875 if (push_items < right_nritems) {
1876 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1877 leaf_data_end(root, right);
1878 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1879 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1880 btrfs_leaf_data(right) +
1881 leaf_data_end(root, right), push_space);
1882
1883 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1884 btrfs_item_nr_offset(push_items),
1885 (btrfs_header_nritems(right) - push_items) *
1886 sizeof(struct btrfs_item));
1887 }
1888 right_nritems -= push_items;
1889 btrfs_set_header_nritems(right, right_nritems);
1890 push_space = BTRFS_LEAF_DATA_SIZE(root);
1891 for (i = 0; i < right_nritems; i++) {
1892 item = btrfs_item_nr(right, i);
1893
1894 if (!right->map_token) {
1895 map_extent_buffer(right, (unsigned long)item,
1896 sizeof(struct btrfs_item),
1897 &right->map_token, &right->kaddr,
1898 &right->map_start, &right->map_len,
1899 KM_USER1);
1900 }
1901
1902 push_space = push_space - btrfs_item_size(right, item);
1903 btrfs_set_item_offset(right, item, push_space);
1904 }
1905 if (right->map_token) {
1906 unmap_extent_buffer(right, right->map_token, KM_USER1);
1907 right->map_token = NULL;
1908 }
1909
1910 btrfs_mark_buffer_dirty(left);
1911 if (right_nritems)
1912 btrfs_mark_buffer_dirty(right);
1913
1914 btrfs_item_key(right, &disk_key, 0);
1915 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1916 if (wret)
1917 ret = wret;
1918
1919 /* then fixup the leaf pointer in the path */
1920 if (path->slots[0] < push_items) {
1921 path->slots[0] += old_left_nritems;
1922 free_extent_buffer(path->nodes[0]);
1923 path->nodes[0] = left;
1924 path->slots[1] -= 1;
1925 } else {
1926 free_extent_buffer(left);
1927 path->slots[0] -= push_items;
1928 }
1929 BUG_ON(path->slots[0] < 0);
1930 return ret;
1931 }
1932
1933 /*
1934 * split the path's leaf in two, making sure there is at least data_size
1935 * available for the resulting leaf level of the path.
1936 *
1937 * returns 0 if all went well and < 0 on failure.
1938 */
1939 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1940 *root, struct btrfs_key *ins_key,
1941 struct btrfs_path *path, int data_size, int extend)
1942 {
1943 u64 root_gen;
1944 struct extent_buffer *l;
1945 u32 nritems;
1946 int mid;
1947 int slot;
1948 struct extent_buffer *right;
1949 int space_needed = data_size + sizeof(struct btrfs_item);
1950 int data_copy_size;
1951 int rt_data_off;
1952 int i;
1953 int ret = 0;
1954 int wret;
1955 int double_split;
1956 int num_doubles = 0;
1957 struct btrfs_disk_key disk_key;
1958
1959 if (extend)
1960 space_needed = data_size;
1961
1962 if (root->ref_cows)
1963 root_gen = trans->transid;
1964 else
1965 root_gen = 0;
1966
1967 /* first try to make some room by pushing left and right */
1968 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1969 wret = push_leaf_right(trans, root, path, data_size, 0);
1970 if (wret < 0) {
1971 return wret;
1972 }
1973 if (wret) {
1974 wret = push_leaf_left(trans, root, path, data_size, 0);
1975 if (wret < 0)
1976 return wret;
1977 }
1978 l = path->nodes[0];
1979
1980 /* did the pushes work? */
1981 if (btrfs_leaf_free_space(root, l) >= space_needed)
1982 return 0;
1983 }
1984
1985 if (!path->nodes[1]) {
1986 ret = insert_new_root(trans, root, path, 1);
1987 if (ret)
1988 return ret;
1989 }
1990 again:
1991 double_split = 0;
1992 l = path->nodes[0];
1993 slot = path->slots[0];
1994 nritems = btrfs_header_nritems(l);
1995 mid = (nritems + 1)/ 2;
1996
1997 btrfs_item_key(l, &disk_key, 0);
1998
1999 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
2000 root->root_key.objectid,
2001 root_gen, disk_key.objectid, 0,
2002 l->start, 0);
2003 if (IS_ERR(right))
2004 return PTR_ERR(right);
2005
2006 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2007 btrfs_set_header_bytenr(right, right->start);
2008 btrfs_set_header_generation(right, trans->transid);
2009 btrfs_set_header_owner(right, root->root_key.objectid);
2010 btrfs_set_header_level(right, 0);
2011 write_extent_buffer(right, root->fs_info->fsid,
2012 (unsigned long)btrfs_header_fsid(right),
2013 BTRFS_FSID_SIZE);
2014 if (mid <= slot) {
2015 if (nritems == 1 ||
2016 leaf_space_used(l, mid, nritems - mid) + space_needed >
2017 BTRFS_LEAF_DATA_SIZE(root)) {
2018 if (slot >= nritems) {
2019 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2020 btrfs_set_header_nritems(right, 0);
2021 wret = insert_ptr(trans, root, path,
2022 &disk_key, right->start,
2023 path->slots[1] + 1, 1);
2024 if (wret)
2025 ret = wret;
2026 free_extent_buffer(path->nodes[0]);
2027 path->nodes[0] = right;
2028 path->slots[0] = 0;
2029 path->slots[1] += 1;
2030 return ret;
2031 }
2032 mid = slot;
2033 if (mid != nritems &&
2034 leaf_space_used(l, mid, nritems - mid) +
2035 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2036 double_split = 1;
2037 }
2038 }
2039 } else {
2040 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2041 BTRFS_LEAF_DATA_SIZE(root)) {
2042 if (!extend && slot == 0) {
2043 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2044 btrfs_set_header_nritems(right, 0);
2045 wret = insert_ptr(trans, root, path,
2046 &disk_key,
2047 right->start,
2048 path->slots[1], 1);
2049 if (wret)
2050 ret = wret;
2051 free_extent_buffer(path->nodes[0]);
2052 path->nodes[0] = right;
2053 path->slots[0] = 0;
2054 if (path->slots[1] == 0) {
2055 wret = fixup_low_keys(trans, root,
2056 path, &disk_key, 1);
2057 if (wret)
2058 ret = wret;
2059 }
2060 return ret;
2061 } else if (extend && slot == 0) {
2062 mid = 1;
2063 } else {
2064 mid = slot;
2065 if (mid != nritems &&
2066 leaf_space_used(l, mid, nritems - mid) +
2067 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2068 double_split = 1;
2069 }
2070 }
2071 }
2072 }
2073 nritems = nritems - mid;
2074 btrfs_set_header_nritems(right, nritems);
2075 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2076
2077 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2078 btrfs_item_nr_offset(mid),
2079 nritems * sizeof(struct btrfs_item));
2080
2081 copy_extent_buffer(right, l,
2082 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2083 data_copy_size, btrfs_leaf_data(l) +
2084 leaf_data_end(root, l), data_copy_size);
2085
2086 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2087 btrfs_item_end_nr(l, mid);
2088
2089 for (i = 0; i < nritems; i++) {
2090 struct btrfs_item *item = btrfs_item_nr(right, i);
2091 u32 ioff;
2092
2093 if (!right->map_token) {
2094 map_extent_buffer(right, (unsigned long)item,
2095 sizeof(struct btrfs_item),
2096 &right->map_token, &right->kaddr,
2097 &right->map_start, &right->map_len,
2098 KM_USER1);
2099 }
2100
2101 ioff = btrfs_item_offset(right, item);
2102 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2103 }
2104
2105 if (right->map_token) {
2106 unmap_extent_buffer(right, right->map_token, KM_USER1);
2107 right->map_token = NULL;
2108 }
2109
2110 btrfs_set_header_nritems(l, mid);
2111 ret = 0;
2112 btrfs_item_key(right, &disk_key, 0);
2113 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2114 path->slots[1] + 1, 1);
2115 if (wret)
2116 ret = wret;
2117
2118 btrfs_mark_buffer_dirty(right);
2119 btrfs_mark_buffer_dirty(l);
2120 BUG_ON(path->slots[0] != slot);
2121
2122 if (mid <= slot) {
2123 free_extent_buffer(path->nodes[0]);
2124 path->nodes[0] = right;
2125 path->slots[0] -= mid;
2126 path->slots[1] += 1;
2127 } else
2128 free_extent_buffer(right);
2129
2130 BUG_ON(path->slots[0] < 0);
2131
2132 if (double_split) {
2133 BUG_ON(num_doubles != 0);
2134 num_doubles++;
2135 goto again;
2136 }
2137 return ret;
2138 }
2139
2140 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2141 struct btrfs_root *root,
2142 struct btrfs_path *path,
2143 u32 new_size, int from_end)
2144 {
2145 int ret = 0;
2146 int slot;
2147 int slot_orig;
2148 struct extent_buffer *leaf;
2149 struct btrfs_item *item;
2150 u32 nritems;
2151 unsigned int data_end;
2152 unsigned int old_data_start;
2153 unsigned int old_size;
2154 unsigned int size_diff;
2155 int i;
2156
2157 slot_orig = path->slots[0];
2158 leaf = path->nodes[0];
2159 slot = path->slots[0];
2160
2161 old_size = btrfs_item_size_nr(leaf, slot);
2162 if (old_size == new_size)
2163 return 0;
2164
2165 nritems = btrfs_header_nritems(leaf);
2166 data_end = leaf_data_end(root, leaf);
2167
2168 old_data_start = btrfs_item_offset_nr(leaf, slot);
2169
2170 size_diff = old_size - new_size;
2171
2172 BUG_ON(slot < 0);
2173 BUG_ON(slot >= nritems);
2174
2175 /*
2176 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2177 */
2178 /* first correct the data pointers */
2179 for (i = slot; i < nritems; i++) {
2180 u32 ioff;
2181 item = btrfs_item_nr(leaf, i);
2182
2183 if (!leaf->map_token) {
2184 map_extent_buffer(leaf, (unsigned long)item,
2185 sizeof(struct btrfs_item),
2186 &leaf->map_token, &leaf->kaddr,
2187 &leaf->map_start, &leaf->map_len,
2188 KM_USER1);
2189 }
2190
2191 ioff = btrfs_item_offset(leaf, item);
2192 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2193 }
2194
2195 if (leaf->map_token) {
2196 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2197 leaf->map_token = NULL;
2198 }
2199
2200 /* shift the data */
2201 if (from_end) {
2202 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2203 data_end + size_diff, btrfs_leaf_data(leaf) +
2204 data_end, old_data_start + new_size - data_end);
2205 } else {
2206 struct btrfs_disk_key disk_key;
2207 u64 offset;
2208
2209 btrfs_item_key(leaf, &disk_key, slot);
2210
2211 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2212 unsigned long ptr;
2213 struct btrfs_file_extent_item *fi;
2214
2215 fi = btrfs_item_ptr(leaf, slot,
2216 struct btrfs_file_extent_item);
2217 fi = (struct btrfs_file_extent_item *)(
2218 (unsigned long)fi - size_diff);
2219
2220 if (btrfs_file_extent_type(leaf, fi) ==
2221 BTRFS_FILE_EXTENT_INLINE) {
2222 ptr = btrfs_item_ptr_offset(leaf, slot);
2223 memmove_extent_buffer(leaf, ptr,
2224 (unsigned long)fi,
2225 offsetof(struct btrfs_file_extent_item,
2226 disk_bytenr));
2227 }
2228 }
2229
2230 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2231 data_end + size_diff, btrfs_leaf_data(leaf) +
2232 data_end, old_data_start - data_end);
2233
2234 offset = btrfs_disk_key_offset(&disk_key);
2235 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2236 btrfs_set_item_key(leaf, &disk_key, slot);
2237 if (slot == 0)
2238 fixup_low_keys(trans, root, path, &disk_key, 1);
2239 }
2240
2241 item = btrfs_item_nr(leaf, slot);
2242 btrfs_set_item_size(leaf, item, new_size);
2243 btrfs_mark_buffer_dirty(leaf);
2244
2245 ret = 0;
2246 if (btrfs_leaf_free_space(root, leaf) < 0) {
2247 btrfs_print_leaf(root, leaf);
2248 BUG();
2249 }
2250 return ret;
2251 }
2252
2253 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2254 struct btrfs_root *root, struct btrfs_path *path,
2255 u32 data_size)
2256 {
2257 int ret = 0;
2258 int slot;
2259 int slot_orig;
2260 struct extent_buffer *leaf;
2261 struct btrfs_item *item;
2262 u32 nritems;
2263 unsigned int data_end;
2264 unsigned int old_data;
2265 unsigned int old_size;
2266 int i;
2267
2268 slot_orig = path->slots[0];
2269 leaf = path->nodes[0];
2270
2271 nritems = btrfs_header_nritems(leaf);
2272 data_end = leaf_data_end(root, leaf);
2273
2274 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2275 btrfs_print_leaf(root, leaf);
2276 BUG();
2277 }
2278 slot = path->slots[0];
2279 old_data = btrfs_item_end_nr(leaf, slot);
2280
2281 BUG_ON(slot < 0);
2282 if (slot >= nritems) {
2283 btrfs_print_leaf(root, leaf);
2284 printk("slot %d too large, nritems %d\n", slot, nritems);
2285 BUG_ON(1);
2286 }
2287
2288 /*
2289 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2290 */
2291 /* first correct the data pointers */
2292 for (i = slot; i < nritems; i++) {
2293 u32 ioff;
2294 item = btrfs_item_nr(leaf, i);
2295
2296 if (!leaf->map_token) {
2297 map_extent_buffer(leaf, (unsigned long)item,
2298 sizeof(struct btrfs_item),
2299 &leaf->map_token, &leaf->kaddr,
2300 &leaf->map_start, &leaf->map_len,
2301 KM_USER1);
2302 }
2303 ioff = btrfs_item_offset(leaf, item);
2304 btrfs_set_item_offset(leaf, item, ioff - data_size);
2305 }
2306
2307 if (leaf->map_token) {
2308 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2309 leaf->map_token = NULL;
2310 }
2311
2312 /* shift the data */
2313 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2314 data_end - data_size, btrfs_leaf_data(leaf) +
2315 data_end, old_data - data_end);
2316
2317 data_end = old_data;
2318 old_size = btrfs_item_size_nr(leaf, slot);
2319 item = btrfs_item_nr(leaf, slot);
2320 btrfs_set_item_size(leaf, item, old_size + data_size);
2321 btrfs_mark_buffer_dirty(leaf);
2322
2323 ret = 0;
2324 if (btrfs_leaf_free_space(root, leaf) < 0) {
2325 btrfs_print_leaf(root, leaf);
2326 BUG();
2327 }
2328 return ret;
2329 }
2330
2331 /*
2332 * Given a key and some data, insert an item into the tree.
2333 * This does all the path init required, making room in the tree if needed.
2334 */
2335 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2336 struct btrfs_root *root,
2337 struct btrfs_path *path,
2338 struct btrfs_key *cpu_key, u32 *data_size,
2339 int nr)
2340 {
2341 struct extent_buffer *leaf;
2342 struct btrfs_item *item;
2343 int ret = 0;
2344 int slot;
2345 int slot_orig;
2346 int i;
2347 u32 nritems;
2348 u32 total_size = 0;
2349 u32 total_data = 0;
2350 unsigned int data_end;
2351 struct btrfs_disk_key disk_key;
2352
2353 for (i = 0; i < nr; i++) {
2354 total_data += data_size[i];
2355 }
2356
2357 /* create a root if there isn't one */
2358 if (!root->node)
2359 BUG();
2360
2361 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2362 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2363 if (ret == 0) {
2364 return -EEXIST;
2365 }
2366 if (ret < 0)
2367 goto out;
2368
2369 slot_orig = path->slots[0];
2370 leaf = path->nodes[0];
2371
2372 nritems = btrfs_header_nritems(leaf);
2373 data_end = leaf_data_end(root, leaf);
2374
2375 if (btrfs_leaf_free_space(root, leaf) <
2376 sizeof(struct btrfs_item) + total_size) {
2377 btrfs_print_leaf(root, leaf);
2378 printk("not enough freespace need %u have %d\n",
2379 total_size, btrfs_leaf_free_space(root, leaf));
2380 BUG();
2381 }
2382
2383 slot = path->slots[0];
2384 BUG_ON(slot < 0);
2385
2386 if (slot != nritems) {
2387 int i;
2388 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2389
2390 if (old_data < data_end) {
2391 btrfs_print_leaf(root, leaf);
2392 printk("slot %d old_data %d data_end %d\n",
2393 slot, old_data, data_end);
2394 BUG_ON(1);
2395 }
2396 /*
2397 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2398 */
2399 /* first correct the data pointers */
2400 WARN_ON(leaf->map_token);
2401 for (i = slot; i < nritems; i++) {
2402 u32 ioff;
2403
2404 item = btrfs_item_nr(leaf, i);
2405 if (!leaf->map_token) {
2406 map_extent_buffer(leaf, (unsigned long)item,
2407 sizeof(struct btrfs_item),
2408 &leaf->map_token, &leaf->kaddr,
2409 &leaf->map_start, &leaf->map_len,
2410 KM_USER1);
2411 }
2412
2413 ioff = btrfs_item_offset(leaf, item);
2414 btrfs_set_item_offset(leaf, item, ioff - total_data);
2415 }
2416 if (leaf->map_token) {
2417 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2418 leaf->map_token = NULL;
2419 }
2420
2421 /* shift the items */
2422 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2423 btrfs_item_nr_offset(slot),
2424 (nritems - slot) * sizeof(struct btrfs_item));
2425
2426 /* shift the data */
2427 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2428 data_end - total_data, btrfs_leaf_data(leaf) +
2429 data_end, old_data - data_end);
2430 data_end = old_data;
2431 }
2432
2433 /* setup the item for the new data */
2434 for (i = 0; i < nr; i++) {
2435 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2436 btrfs_set_item_key(leaf, &disk_key, slot + i);
2437 item = btrfs_item_nr(leaf, slot + i);
2438 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2439 data_end -= data_size[i];
2440 btrfs_set_item_size(leaf, item, data_size[i]);
2441 }
2442 btrfs_set_header_nritems(leaf, nritems + nr);
2443 btrfs_mark_buffer_dirty(leaf);
2444
2445 ret = 0;
2446 if (slot == 0) {
2447 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2448 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2449 }
2450
2451 if (btrfs_leaf_free_space(root, leaf) < 0) {
2452 btrfs_print_leaf(root, leaf);
2453 BUG();
2454 }
2455
2456 out:
2457 return ret;
2458 }
2459
2460 /*
2461 * Given a key and some data, insert an item into the tree.
2462 * This does all the path init required, making room in the tree if needed.
2463 */
2464 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2465 *root, struct btrfs_key *cpu_key, void *data, u32
2466 data_size)
2467 {
2468 int ret = 0;
2469 struct btrfs_path *path;
2470 struct extent_buffer *leaf;
2471 unsigned long ptr;
2472
2473 path = btrfs_alloc_path();
2474 BUG_ON(!path);
2475 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2476 if (!ret) {
2477 leaf = path->nodes[0];
2478 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2479 write_extent_buffer(leaf, data, ptr, data_size);
2480 btrfs_mark_buffer_dirty(leaf);
2481 }
2482 btrfs_free_path(path);
2483 return ret;
2484 }
2485
2486 /*
2487 * delete the pointer from a given node.
2488 *
2489 * If the delete empties a node, the node is removed from the tree,
2490 * continuing all the way the root if required. The root is converted into
2491 * a leaf if all the nodes are emptied.
2492 */
2493 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2494 struct btrfs_path *path, int level, int slot)
2495 {
2496 struct extent_buffer *parent = path->nodes[level];
2497 u32 nritems;
2498 int ret = 0;
2499 int wret;
2500
2501 nritems = btrfs_header_nritems(parent);
2502 if (slot != nritems -1) {
2503 memmove_extent_buffer(parent,
2504 btrfs_node_key_ptr_offset(slot),
2505 btrfs_node_key_ptr_offset(slot + 1),
2506 sizeof(struct btrfs_key_ptr) *
2507 (nritems - slot - 1));
2508 }
2509 nritems--;
2510 btrfs_set_header_nritems(parent, nritems);
2511 if (nritems == 0 && parent == root->node) {
2512 BUG_ON(btrfs_header_level(root->node) != 1);
2513 /* just turn the root into a leaf and break */
2514 btrfs_set_header_level(root->node, 0);
2515 } else if (slot == 0) {
2516 struct btrfs_disk_key disk_key;
2517
2518 btrfs_node_key(parent, &disk_key, 0);
2519 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2520 if (wret)
2521 ret = wret;
2522 }
2523 btrfs_mark_buffer_dirty(parent);
2524 return ret;
2525 }
2526
2527 /*
2528 * delete the item at the leaf level in path. If that empties
2529 * the leaf, remove it from the tree
2530 */
2531 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2532 struct btrfs_path *path, int slot, int nr)
2533 {
2534 struct extent_buffer *leaf;
2535 struct btrfs_item *item;
2536 int last_off;
2537 int dsize = 0;
2538 int ret = 0;
2539 int wret;
2540 int i;
2541 u32 nritems;
2542
2543 leaf = path->nodes[0];
2544 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2545
2546 for (i = 0; i < nr; i++)
2547 dsize += btrfs_item_size_nr(leaf, slot + i);
2548
2549 nritems = btrfs_header_nritems(leaf);
2550
2551 if (slot + nr != nritems) {
2552 int i;
2553 int data_end = leaf_data_end(root, leaf);
2554
2555 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2556 data_end + dsize,
2557 btrfs_leaf_data(leaf) + data_end,
2558 last_off - data_end);
2559
2560 for (i = slot + nr; i < nritems; i++) {
2561 u32 ioff;
2562
2563 item = btrfs_item_nr(leaf, i);
2564 if (!leaf->map_token) {
2565 map_extent_buffer(leaf, (unsigned long)item,
2566 sizeof(struct btrfs_item),
2567 &leaf->map_token, &leaf->kaddr,
2568 &leaf->map_start, &leaf->map_len,
2569 KM_USER1);
2570 }
2571 ioff = btrfs_item_offset(leaf, item);
2572 btrfs_set_item_offset(leaf, item, ioff + dsize);
2573 }
2574
2575 if (leaf->map_token) {
2576 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2577 leaf->map_token = NULL;
2578 }
2579
2580 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2581 btrfs_item_nr_offset(slot + nr),
2582 sizeof(struct btrfs_item) *
2583 (nritems - slot - nr));
2584 }
2585 btrfs_set_header_nritems(leaf, nritems - nr);
2586 nritems -= nr;
2587
2588 /* delete the leaf if we've emptied it */
2589 if (nritems == 0) {
2590 if (leaf == root->node) {
2591 btrfs_set_header_level(leaf, 0);
2592 } else {
2593 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2594 clean_tree_block(trans, root, leaf);
2595 wait_on_tree_block_writeback(root, leaf);
2596 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2597 if (wret)
2598 ret = wret;
2599 wret = btrfs_free_extent(trans, root,
2600 leaf->start, leaf->len,
2601 btrfs_header_owner(path->nodes[1]),
2602 root_gen, 0, 0, 1);
2603 if (wret)
2604 ret = wret;
2605 }
2606 } else {
2607 int used = leaf_space_used(leaf, 0, nritems);
2608 if (slot == 0) {
2609 struct btrfs_disk_key disk_key;
2610
2611 btrfs_item_key(leaf, &disk_key, 0);
2612 wret = fixup_low_keys(trans, root, path,
2613 &disk_key, 1);
2614 if (wret)
2615 ret = wret;
2616 }
2617
2618 /* delete the leaf if it is mostly empty */
2619 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2620 /* push_leaf_left fixes the path.
2621 * make sure the path still points to our leaf
2622 * for possible call to del_ptr below
2623 */
2624 slot = path->slots[1];
2625 extent_buffer_get(leaf);
2626
2627 wret = push_leaf_left(trans, root, path, 1, 1);
2628 if (wret < 0 && wret != -ENOSPC)
2629 ret = wret;
2630
2631 if (path->nodes[0] == leaf &&
2632 btrfs_header_nritems(leaf)) {
2633 wret = push_leaf_right(trans, root, path, 1, 1);
2634 if (wret < 0 && wret != -ENOSPC)
2635 ret = wret;
2636 }
2637
2638 if (btrfs_header_nritems(leaf) == 0) {
2639 u64 root_gen;
2640 u64 bytenr = leaf->start;
2641 u32 blocksize = leaf->len;
2642
2643 root_gen = btrfs_header_generation(
2644 path->nodes[1]);
2645
2646 clean_tree_block(trans, root, leaf);
2647 wait_on_tree_block_writeback(root, leaf);
2648
2649 wret = del_ptr(trans, root, path, 1, slot);
2650 if (wret)
2651 ret = wret;
2652
2653 free_extent_buffer(leaf);
2654 wret = btrfs_free_extent(trans, root, bytenr,
2655 blocksize,
2656 btrfs_header_owner(path->nodes[1]),
2657 root_gen, 0, 0, 1);
2658 if (wret)
2659 ret = wret;
2660 } else {
2661 btrfs_mark_buffer_dirty(leaf);
2662 free_extent_buffer(leaf);
2663 }
2664 } else {
2665 btrfs_mark_buffer_dirty(leaf);
2666 }
2667 }
2668 return ret;
2669 }
2670
2671 /*
2672 * walk up the tree as far as required to find the previous leaf.
2673 * returns 0 if it found something or 1 if there are no lesser leaves.
2674 * returns < 0 on io errors.
2675 */
2676 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2677 {
2678 u64 bytenr;
2679 int slot;
2680 int level = 1;
2681 struct extent_buffer *c;
2682 struct extent_buffer *next = NULL;
2683
2684 while(level < BTRFS_MAX_LEVEL) {
2685 if (!path->nodes[level])
2686 return 1;
2687
2688 slot = path->slots[level];
2689 c = path->nodes[level];
2690 if (slot == 0) {
2691 level++;
2692 if (level == BTRFS_MAX_LEVEL)
2693 return 1;
2694 continue;
2695 }
2696 slot--;
2697
2698 bytenr = btrfs_node_blockptr(c, slot);
2699 if (next)
2700 free_extent_buffer(next);
2701
2702 next = read_tree_block(root, bytenr,
2703 btrfs_level_size(root, level - 1));
2704 break;
2705 }
2706 path->slots[level] = slot;
2707 while(1) {
2708 level--;
2709 c = path->nodes[level];
2710 free_extent_buffer(c);
2711 slot = btrfs_header_nritems(next);
2712 if (slot != 0)
2713 slot--;
2714 path->nodes[level] = next;
2715 path->slots[level] = slot;
2716 if (!level)
2717 break;
2718 next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2719 btrfs_level_size(root, level - 1));
2720 }
2721 return 0;
2722 }
2723
2724 /*
2725 * walk up the tree as far as required to find the next leaf.
2726 * returns 0 if it found something or 1 if there are no greater leaves.
2727 * returns < 0 on io errors.
2728 */
2729 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2730 {
2731 int slot;
2732 int level = 1;
2733 u64 bytenr;
2734 struct extent_buffer *c;
2735 struct extent_buffer *next = NULL;
2736
2737 while(level < BTRFS_MAX_LEVEL) {
2738 if (!path->nodes[level])
2739 return 1;
2740
2741 slot = path->slots[level] + 1;
2742 c = path->nodes[level];
2743 if (slot >= btrfs_header_nritems(c)) {
2744 level++;
2745 if (level == BTRFS_MAX_LEVEL)
2746 return 1;
2747 continue;
2748 }
2749
2750 bytenr = btrfs_node_blockptr(c, slot);
2751 if (next)
2752 free_extent_buffer(next);
2753
2754 if (path->reada)
2755 reada_for_search(root, path, level, slot, 0);
2756
2757 next = read_tree_block(root, bytenr,
2758 btrfs_level_size(root, level -1));
2759 break;
2760 }
2761 path->slots[level] = slot;
2762 while(1) {
2763 level--;
2764 c = path->nodes[level];
2765 free_extent_buffer(c);
2766 path->nodes[level] = next;
2767 path->slots[level] = 0;
2768 if (!level)
2769 break;
2770 if (path->reada)
2771 reada_for_search(root, path, level, 0, 0);
2772 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2773 btrfs_level_size(root, level - 1));
2774 }
2775 return 0;
2776 }
ubuntu-zesty-kernel mirror