2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
20 #include "transaction.h"
21 #include "print-tree.h"
24 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
25 *root, struct btrfs_path *path, int level);
26 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_key *ins_key,
28 struct btrfs_path *path, int data_size, int extend);
29 static int push_node_left(struct btrfs_trans_handle *trans,
30 struct btrfs_root *root, struct extent_buffer *dst,
31 struct extent_buffer *src, int empty);
32 static int balance_node_right(struct btrfs_trans_handle *trans,
33 struct btrfs_root *root,
34 struct extent_buffer *dst_buf,
35 struct extent_buffer *src_buf);
37 inline void btrfs_init_path(struct btrfs_path *p)
39 memset(p, 0, sizeof(*p));
42 struct btrfs_path *btrfs_alloc_path(void)
44 struct btrfs_path *path;
45 path = kmalloc(sizeof(struct btrfs_path), GFP_NOFS);
47 btrfs_init_path(path);
53 void btrfs_free_path(struct btrfs_path *p)
55 btrfs_release_path(NULL, p);
59 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
62 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
65 free_extent_buffer(p->nodes[i]);
67 memset(p, 0, sizeof(*p));
70 static void add_root_to_dirty_list(struct btrfs_root *root)
72 if (root->track_dirty && list_empty(&root->dirty_list)) {
73 list_add(&root->dirty_list,
74 &root->fs_info->dirty_cowonly_roots);
78 int btrfs_copy_root(struct btrfs_trans_handle *trans,
79 struct btrfs_root *root,
80 struct extent_buffer *buf,
81 struct extent_buffer **cow_ret, u64 new_root_objectid)
83 struct extent_buffer *cow;
86 struct btrfs_root *new_root;
87 struct btrfs_disk_key disk_key;
89 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
93 memcpy(new_root, root, sizeof(*new_root));
94 new_root->root_key.objectid = new_root_objectid;
96 WARN_ON(root->ref_cows && trans->transid !=
97 root->fs_info->running_transaction->transid);
98 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
100 level = btrfs_header_level(buf);
102 btrfs_item_key(buf, &disk_key, 0);
104 btrfs_node_key(buf, &disk_key, 0);
105 cow = btrfs_alloc_free_block(trans, new_root, buf->len,
106 new_root_objectid, &disk_key,
107 level, buf->start, 0);
113 copy_extent_buffer(cow, buf, 0, 0, cow->len);
114 btrfs_set_header_bytenr(cow, cow->start);
115 btrfs_set_header_generation(cow, trans->transid);
116 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
117 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
118 BTRFS_HEADER_FLAG_RELOC);
119 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
120 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
122 btrfs_set_header_owner(cow, new_root_objectid);
124 write_extent_buffer(cow, root->fs_info->fsid,
125 (unsigned long)btrfs_header_fsid(cow),
128 WARN_ON(btrfs_header_generation(buf) > trans->transid);
129 ret = btrfs_inc_ref(trans, new_root, cow, 0);
135 btrfs_mark_buffer_dirty(cow);
140 int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
141 struct btrfs_root *root, int overwrite)
143 struct extent_buffer *c;
144 struct extent_buffer *old = root->node;
146 struct btrfs_disk_key disk_key = {0,0,0};
152 extent_buffer_get(c);
155 c = btrfs_alloc_free_block(trans, root,
156 btrfs_level_size(root, 0),
157 root->root_key.objectid,
158 &disk_key, level, 0, 0);
161 extent_buffer_get(c);
164 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
165 btrfs_set_header_level(c, level);
166 btrfs_set_header_bytenr(c, c->start);
167 btrfs_set_header_generation(c, trans->transid);
168 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
169 btrfs_set_header_owner(c, root->root_key.objectid);
171 write_extent_buffer(c, root->fs_info->fsid,
172 (unsigned long)btrfs_header_fsid(c),
175 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
176 (unsigned long)btrfs_header_chunk_tree_uuid(c),
179 btrfs_mark_buffer_dirty(c);
181 free_extent_buffer(old);
183 add_root_to_dirty_list(root);
188 * check if the tree block can be shared by multiple trees
190 int btrfs_block_can_be_shared(struct btrfs_root *root,
191 struct extent_buffer *buf)
194 * Tree blocks not in refernece counted trees and tree roots
195 * are never shared. If a block was allocated after the last
196 * snapshot and the block was not allocated by tree relocation,
197 * we know the block is not shared.
199 if (root->ref_cows &&
200 buf != root->node && buf != root->commit_root &&
201 (btrfs_header_generation(buf) <=
202 btrfs_root_last_snapshot(&root->root_item) ||
203 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
205 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
206 if (root->ref_cows &&
207 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
213 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
214 struct btrfs_root *root,
215 struct extent_buffer *buf,
216 struct extent_buffer *cow)
225 * Backrefs update rules:
227 * Always use full backrefs for extent pointers in tree block
228 * allocated by tree relocation.
230 * If a shared tree block is no longer referenced by its owner
231 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
232 * use full backrefs for extent pointers in tree block.
234 * If a tree block is been relocating
235 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
236 * use full backrefs for extent pointers in tree block.
237 * The reason for this is some operations (such as drop tree)
238 * are only allowed for blocks use full backrefs.
241 if (btrfs_block_can_be_shared(root, buf)) {
242 ret = btrfs_lookup_extent_info(trans, root, buf->start,
243 btrfs_header_level(buf), 1,
249 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
250 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
251 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
256 owner = btrfs_header_owner(buf);
257 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) &&
258 owner == BTRFS_TREE_RELOC_OBJECTID);
261 if ((owner == root->root_key.objectid ||
262 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
263 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
264 ret = btrfs_inc_ref(trans, root, buf, 1);
267 if (root->root_key.objectid ==
268 BTRFS_TREE_RELOC_OBJECTID) {
269 ret = btrfs_dec_ref(trans, root, buf, 0);
271 ret = btrfs_inc_ref(trans, root, cow, 1);
274 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
277 if (root->root_key.objectid ==
278 BTRFS_TREE_RELOC_OBJECTID)
279 ret = btrfs_inc_ref(trans, root, cow, 1);
281 ret = btrfs_inc_ref(trans, root, cow, 0);
284 if (new_flags != 0) {
285 ret = btrfs_set_block_flags(trans, root, buf->start,
286 btrfs_header_level(buf),
291 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
292 if (root->root_key.objectid ==
293 BTRFS_TREE_RELOC_OBJECTID)
294 ret = btrfs_inc_ref(trans, root, cow, 1);
296 ret = btrfs_inc_ref(trans, root, cow, 0);
298 ret = btrfs_dec_ref(trans, root, buf, 1);
301 clean_tree_block(trans, root, buf);
306 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
307 struct btrfs_root *root,
308 struct extent_buffer *buf,
309 struct extent_buffer *parent, int parent_slot,
310 struct extent_buffer **cow_ret,
311 u64 search_start, u64 empty_size)
313 struct extent_buffer *cow;
314 struct btrfs_disk_key disk_key;
317 WARN_ON(root->ref_cows && trans->transid !=
318 root->fs_info->running_transaction->transid);
319 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
321 level = btrfs_header_level(buf);
324 btrfs_item_key(buf, &disk_key, 0);
326 btrfs_node_key(buf, &disk_key, 0);
328 cow = btrfs_alloc_free_block(trans, root, buf->len,
329 root->root_key.objectid, &disk_key,
330 level, search_start, empty_size);
334 copy_extent_buffer(cow, buf, 0, 0, cow->len);
335 btrfs_set_header_bytenr(cow, cow->start);
336 btrfs_set_header_generation(cow, trans->transid);
337 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
338 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
339 BTRFS_HEADER_FLAG_RELOC);
340 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
341 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
343 btrfs_set_header_owner(cow, root->root_key.objectid);
345 write_extent_buffer(cow, root->fs_info->fsid,
346 (unsigned long)btrfs_header_fsid(cow),
349 WARN_ON(btrfs_header_generation(buf) > trans->transid);
351 update_ref_for_cow(trans, root, buf, cow);
353 if (buf == root->node) {
355 extent_buffer_get(cow);
357 btrfs_free_extent(trans, root, buf->start, buf->len,
358 0, root->root_key.objectid, level, 0);
359 free_extent_buffer(buf);
360 add_root_to_dirty_list(root);
362 btrfs_set_node_blockptr(parent, parent_slot,
364 WARN_ON(trans->transid == 0);
365 btrfs_set_node_ptr_generation(parent, parent_slot,
367 btrfs_mark_buffer_dirty(parent);
368 WARN_ON(btrfs_header_generation(parent) != trans->transid);
370 btrfs_free_extent(trans, root, buf->start, buf->len,
371 0, root->root_key.objectid, level, 1);
373 free_extent_buffer(buf);
374 btrfs_mark_buffer_dirty(cow);
379 static inline int should_cow_block(struct btrfs_trans_handle *trans,
380 struct btrfs_root *root,
381 struct extent_buffer *buf)
383 if (btrfs_header_generation(buf) == trans->transid &&
384 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
385 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
386 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
391 int btrfs_cow_block(struct btrfs_trans_handle *trans,
392 struct btrfs_root *root, struct extent_buffer *buf,
393 struct extent_buffer *parent, int parent_slot,
394 struct extent_buffer **cow_ret)
399 if (trans->transaction != root->fs_info->running_transaction) {
400 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
401 root->fs_info->running_transaction->transid);
405 if (trans->transid != root->fs_info->generation) {
406 printk(KERN_CRIT "trans %llu running %llu\n",
407 (unsigned long long)trans->transid,
408 (unsigned long long)root->fs_info->generation);
411 if (!should_cow_block(trans, root, buf)) {
416 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
417 ret = __btrfs_cow_block(trans, root, buf, parent,
418 parent_slot, cow_ret, search_start, 0);
423 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
425 if (blocknr < other && other - (blocknr + blocksize) < 32768)
427 if (blocknr > other && blocknr - (other + blocksize) < 32768)
434 * compare two keys in a memcmp fashion
436 int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
440 btrfs_disk_key_to_cpu(&k1, disk);
442 if (k1.objectid > k2->objectid)
444 if (k1.objectid < k2->objectid)
446 if (k1.type > k2->type)
448 if (k1.type < k2->type)
450 if (k1.offset > k2->offset)
452 if (k1.offset < k2->offset)
459 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
460 struct btrfs_root *root, struct extent_buffer *parent,
461 int start_slot, int cache_only, u64 *last_ret,
462 struct btrfs_key *progress)
464 struct extent_buffer *cur;
465 struct extent_buffer *tmp;
468 u64 search_start = *last_ret;
478 int progress_passed = 0;
479 struct btrfs_disk_key disk_key;
481 parent_level = btrfs_header_level(parent);
482 if (cache_only && parent_level != 1)
485 if (trans->transaction != root->fs_info->running_transaction) {
486 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
487 root->fs_info->running_transaction->transid);
490 if (trans->transid != root->fs_info->generation) {
491 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
492 root->fs_info->generation);
496 parent_nritems = btrfs_header_nritems(parent);
497 blocksize = btrfs_level_size(root, parent_level - 1);
498 end_slot = parent_nritems;
500 if (parent_nritems == 1)
503 for (i = start_slot; i < end_slot; i++) {
506 if (!parent->map_token) {
507 map_extent_buffer(parent,
508 btrfs_node_key_ptr_offset(i),
509 sizeof(struct btrfs_key_ptr),
510 &parent->map_token, &parent->kaddr,
511 &parent->map_start, &parent->map_len,
514 btrfs_node_key(parent, &disk_key, i);
515 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
519 blocknr = btrfs_node_blockptr(parent, i);
520 gen = btrfs_node_ptr_generation(parent, i);
522 last_block = blocknr;
525 other = btrfs_node_blockptr(parent, i - 1);
526 close = close_blocks(blocknr, other, blocksize);
528 if (close && i < end_slot - 2) {
529 other = btrfs_node_blockptr(parent, i + 1);
530 close = close_blocks(blocknr, other, blocksize);
533 last_block = blocknr;
536 if (parent->map_token) {
537 unmap_extent_buffer(parent, parent->map_token,
539 parent->map_token = NULL;
542 cur = btrfs_find_tree_block(root, blocknr, blocksize);
544 uptodate = btrfs_buffer_uptodate(cur, gen);
547 if (!cur || !uptodate) {
549 free_extent_buffer(cur);
553 cur = read_tree_block(root, blocknr,
555 } else if (!uptodate) {
556 btrfs_read_buffer(cur, gen);
559 if (search_start == 0)
560 search_start = last_block;
562 err = __btrfs_cow_block(trans, root, cur, parent, i,
565 (end_slot - i) * blocksize));
567 free_extent_buffer(cur);
570 search_start = tmp->start;
571 last_block = tmp->start;
572 *last_ret = search_start;
573 if (parent_level == 1)
574 btrfs_clear_buffer_defrag(tmp);
575 free_extent_buffer(tmp);
577 if (parent->map_token) {
578 unmap_extent_buffer(parent, parent->map_token,
580 parent->map_token = NULL;
587 * The leaf data grows from end-to-front in the node.
588 * this returns the address of the start of the last item,
589 * which is the stop of the leaf data stack
591 static inline unsigned int leaf_data_end(struct btrfs_root *root,
592 struct extent_buffer *leaf)
594 u32 nr = btrfs_header_nritems(leaf);
596 return BTRFS_LEAF_DATA_SIZE(root);
597 return btrfs_item_offset_nr(leaf, nr - 1);
600 int btrfs_check_node(struct btrfs_root *root,
601 struct btrfs_disk_key *parent_key,
602 struct extent_buffer *buf)
605 struct btrfs_key cpukey;
606 struct btrfs_disk_key key;
607 u32 nritems = btrfs_header_nritems(buf);
609 if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
612 if (parent_key && parent_key->type) {
613 btrfs_node_key(buf, &key, 0);
614 if (memcmp(parent_key, &key, sizeof(key)))
617 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
618 btrfs_node_key(buf, &key, i);
619 btrfs_node_key_to_cpu(buf, &cpukey, i + 1);
620 if (btrfs_comp_keys(&key, &cpukey) >= 0)
625 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
627 btrfs_disk_key_to_cpu(&cpukey, parent_key);
629 btrfs_node_key_to_cpu(buf, &cpukey, 0);
630 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
631 buf->start, buf->len,
632 btrfs_header_level(buf));
637 int btrfs_check_leaf(struct btrfs_root *root,
638 struct btrfs_disk_key *parent_key,
639 struct extent_buffer *buf)
642 struct btrfs_key cpukey;
643 struct btrfs_disk_key key;
644 u32 nritems = btrfs_header_nritems(buf);
646 if (nritems * sizeof(struct btrfs_item) > buf->len) {
647 fprintf(stderr, "invalid number of items %llu\n",
648 (unsigned long long)buf->start);
652 if (btrfs_header_level(buf) != 0) {
653 fprintf(stderr, "leaf is not a leaf %llu\n",
654 (unsigned long long)btrfs_header_bytenr(buf));
657 if (btrfs_leaf_free_space(root, buf) < 0) {
658 fprintf(stderr, "leaf free space incorrect %llu %d\n",
659 (unsigned long long)btrfs_header_bytenr(buf),
660 btrfs_leaf_free_space(root, buf));
667 btrfs_item_key(buf, &key, 0);
668 if (parent_key && parent_key->type &&
669 memcmp(parent_key, &key, sizeof(key))) {
670 fprintf(stderr, "leaf parent key incorrect %llu\n",
671 (unsigned long long)btrfs_header_bytenr(buf));
674 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
675 btrfs_item_key(buf, &key, i);
676 btrfs_item_key_to_cpu(buf, &cpukey, i + 1);
677 if (btrfs_comp_keys(&key, &cpukey) >= 0) {
678 fprintf(stderr, "bad key ordering %d %d\n", i, i+1);
681 if (btrfs_item_offset_nr(buf, i) !=
682 btrfs_item_end_nr(buf, i + 1)) {
683 fprintf(stderr, "incorrect offsets %u %u\n",
684 btrfs_item_offset_nr(buf, i),
685 btrfs_item_end_nr(buf, i + 1));
688 if (i == 0 && btrfs_item_end_nr(buf, i) !=
689 BTRFS_LEAF_DATA_SIZE(root)) {
690 fprintf(stderr, "bad item end %u wanted %u\n",
691 btrfs_item_end_nr(buf, i),
692 (unsigned)BTRFS_LEAF_DATA_SIZE(root));
698 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
700 btrfs_disk_key_to_cpu(&cpukey, parent_key);
702 btrfs_item_key_to_cpu(buf, &cpukey, 0);
704 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
705 buf->start, buf->len, 0);
710 static int noinline check_block(struct btrfs_root *root,
711 struct btrfs_path *path, int level)
713 struct btrfs_disk_key key;
714 struct btrfs_disk_key *key_ptr = NULL;
715 struct extent_buffer *parent;
717 if (path->nodes[level + 1]) {
718 parent = path->nodes[level + 1];
719 btrfs_node_key(parent, &key, path->slots[level + 1]);
723 return btrfs_check_leaf(root, key_ptr, path->nodes[0]);
724 return btrfs_check_node(root, key_ptr, path->nodes[level]);
728 * search for key in the extent_buffer. The items start at offset p,
729 * and they are item_size apart. There are 'max' items in p.
731 * the slot in the array is returned via slot, and it points to
732 * the place where you would insert key if it is not found in
735 * slot may point to max if the key is bigger than all of the keys
737 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
738 int item_size, struct btrfs_key *key,
745 unsigned long offset;
746 struct btrfs_disk_key *tmp;
749 mid = (low + high) / 2;
750 offset = p + mid * item_size;
752 tmp = (struct btrfs_disk_key *)(eb->data + offset);
753 ret = btrfs_comp_keys(tmp, key);
769 * simple bin_search frontend that does the right thing for
772 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
773 int level, int *slot)
776 return generic_bin_search(eb,
777 offsetof(struct btrfs_leaf, items),
778 sizeof(struct btrfs_item),
779 key, btrfs_header_nritems(eb),
782 return generic_bin_search(eb,
783 offsetof(struct btrfs_node, ptrs),
784 sizeof(struct btrfs_key_ptr),
785 key, btrfs_header_nritems(eb),
791 struct extent_buffer *read_node_slot(struct btrfs_root *root,
792 struct extent_buffer *parent, int slot)
794 int level = btrfs_header_level(parent);
797 if (slot >= btrfs_header_nritems(parent))
803 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
804 btrfs_level_size(root, level - 1),
805 btrfs_node_ptr_generation(parent, slot));
808 static int balance_level(struct btrfs_trans_handle *trans,
809 struct btrfs_root *root,
810 struct btrfs_path *path, int level)
812 struct extent_buffer *right = NULL;
813 struct extent_buffer *mid;
814 struct extent_buffer *left = NULL;
815 struct extent_buffer *parent = NULL;
819 int orig_slot = path->slots[level];
825 mid = path->nodes[level];
826 WARN_ON(btrfs_header_generation(mid) != trans->transid);
828 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
830 if (level < BTRFS_MAX_LEVEL - 1) {
831 parent = path->nodes[level + 1];
832 pslot = path->slots[level + 1];
836 * deal with the case where there is only one pointer in the root
837 * by promoting the node below to a root
840 struct extent_buffer *child;
842 if (btrfs_header_nritems(mid) != 1)
845 /* promote the child to a root */
846 child = read_node_slot(root, mid, 0);
848 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
852 add_root_to_dirty_list(root);
853 path->nodes[level] = NULL;
854 clean_tree_block(trans, root, mid);
855 wait_on_tree_block_writeback(root, mid);
856 /* once for the path */
857 free_extent_buffer(mid);
859 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
860 0, root->root_key.objectid,
862 /* once for the root ptr */
863 free_extent_buffer(mid);
866 if (btrfs_header_nritems(mid) >
867 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
870 left = read_node_slot(root, parent, pslot - 1);
872 wret = btrfs_cow_block(trans, root, left,
873 parent, pslot - 1, &left);
879 right = read_node_slot(root, parent, pslot + 1);
881 wret = btrfs_cow_block(trans, root, right,
882 parent, pslot + 1, &right);
889 /* first, try to make some room in the middle buffer */
891 orig_slot += btrfs_header_nritems(left);
892 wret = push_node_left(trans, root, left, mid, 1);
898 * then try to empty the right most buffer into the middle
901 wret = push_node_left(trans, root, mid, right, 1);
902 if (wret < 0 && wret != -ENOSPC)
904 if (btrfs_header_nritems(right) == 0) {
905 u64 bytenr = right->start;
906 u32 blocksize = right->len;
908 clean_tree_block(trans, root, right);
909 wait_on_tree_block_writeback(root, right);
910 free_extent_buffer(right);
912 wret = btrfs_del_ptr(trans, root, path,
913 level + 1, pslot + 1);
916 wret = btrfs_free_extent(trans, root, bytenr,
918 root->root_key.objectid,
923 struct btrfs_disk_key right_key;
924 btrfs_node_key(right, &right_key, 0);
925 btrfs_set_node_key(parent, &right_key, pslot + 1);
926 btrfs_mark_buffer_dirty(parent);
929 if (btrfs_header_nritems(mid) == 1) {
931 * we're not allowed to leave a node with one item in the
932 * tree during a delete. A deletion from lower in the tree
933 * could try to delete the only pointer in this node.
934 * So, pull some keys from the left.
935 * There has to be a left pointer at this point because
936 * otherwise we would have pulled some pointers from the
940 wret = balance_node_right(trans, root, mid, left);
946 wret = push_node_left(trans, root, left, mid, 1);
952 if (btrfs_header_nritems(mid) == 0) {
953 /* we've managed to empty the middle node, drop it */
954 u64 bytenr = mid->start;
955 u32 blocksize = mid->len;
956 clean_tree_block(trans, root, mid);
957 wait_on_tree_block_writeback(root, mid);
958 free_extent_buffer(mid);
960 wret = btrfs_del_ptr(trans, root, path, level + 1, pslot);
963 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
964 0, root->root_key.objectid,
969 /* update the parent key to reflect our changes */
970 struct btrfs_disk_key mid_key;
971 btrfs_node_key(mid, &mid_key, 0);
972 btrfs_set_node_key(parent, &mid_key, pslot);
973 btrfs_mark_buffer_dirty(parent);
976 /* update the path */
978 if (btrfs_header_nritems(left) > orig_slot) {
979 extent_buffer_get(left);
980 path->nodes[level] = left;
981 path->slots[level + 1] -= 1;
982 path->slots[level] = orig_slot;
984 free_extent_buffer(mid);
986 orig_slot -= btrfs_header_nritems(left);
987 path->slots[level] = orig_slot;
990 /* double check we haven't messed things up */
991 check_block(root, path, level);
993 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
997 free_extent_buffer(right);
999 free_extent_buffer(left);
1003 /* returns zero if the push worked, non-zero otherwise */
1004 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
1005 struct btrfs_root *root,
1006 struct btrfs_path *path, int level)
1008 struct extent_buffer *right = NULL;
1009 struct extent_buffer *mid;
1010 struct extent_buffer *left = NULL;
1011 struct extent_buffer *parent = NULL;
1015 int orig_slot = path->slots[level];
1020 mid = path->nodes[level];
1021 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1023 if (level < BTRFS_MAX_LEVEL - 1) {
1024 parent = path->nodes[level + 1];
1025 pslot = path->slots[level + 1];
1031 left = read_node_slot(root, parent, pslot - 1);
1033 /* first, try to make some room in the middle buffer */
1036 left_nr = btrfs_header_nritems(left);
1037 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1040 ret = btrfs_cow_block(trans, root, left, parent,
1045 wret = push_node_left(trans, root,
1052 struct btrfs_disk_key disk_key;
1053 orig_slot += left_nr;
1054 btrfs_node_key(mid, &disk_key, 0);
1055 btrfs_set_node_key(parent, &disk_key, pslot);
1056 btrfs_mark_buffer_dirty(parent);
1057 if (btrfs_header_nritems(left) > orig_slot) {
1058 path->nodes[level] = left;
1059 path->slots[level + 1] -= 1;
1060 path->slots[level] = orig_slot;
1061 free_extent_buffer(mid);
1064 btrfs_header_nritems(left);
1065 path->slots[level] = orig_slot;
1066 free_extent_buffer(left);
1070 free_extent_buffer(left);
1072 right= read_node_slot(root, parent, pslot + 1);
1075 * then try to empty the right most buffer into the middle
1079 right_nr = btrfs_header_nritems(right);
1080 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1083 ret = btrfs_cow_block(trans, root, right,
1089 wret = balance_node_right(trans, root,
1096 struct btrfs_disk_key disk_key;
1098 btrfs_node_key(right, &disk_key, 0);
1099 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1100 btrfs_mark_buffer_dirty(parent);
1102 if (btrfs_header_nritems(mid) <= orig_slot) {
1103 path->nodes[level] = right;
1104 path->slots[level + 1] += 1;
1105 path->slots[level] = orig_slot -
1106 btrfs_header_nritems(mid);
1107 free_extent_buffer(mid);
1109 free_extent_buffer(right);
1113 free_extent_buffer(right);
1119 * readahead one full node of leaves
1121 void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1122 int level, int slot, u64 objectid)
1124 struct extent_buffer *node;
1125 struct btrfs_disk_key disk_key;
1131 int direction = path->reada;
1132 struct extent_buffer *eb;
1140 if (!path->nodes[level])
1143 node = path->nodes[level];
1144 search = btrfs_node_blockptr(node, slot);
1145 blocksize = btrfs_level_size(root, level - 1);
1146 eb = btrfs_find_tree_block(root, search, blocksize);
1148 free_extent_buffer(eb);
1152 highest_read = search;
1153 lowest_read = search;
1155 nritems = btrfs_header_nritems(node);
1158 if (direction < 0) {
1162 } else if (direction > 0) {
1167 if (path->reada < 0 && objectid) {
1168 btrfs_node_key(node, &disk_key, nr);
1169 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1172 search = btrfs_node_blockptr(node, nr);
1173 if ((search >= lowest_read && search <= highest_read) ||
1174 (search < lowest_read && lowest_read - search <= 32768) ||
1175 (search > highest_read && search - highest_read <= 32768)) {
1176 readahead_tree_block(root, search, blocksize,
1177 btrfs_node_ptr_generation(node, nr));
1181 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1183 if(nread > (1024 * 1024) || nscan > 128)
1186 if (search < lowest_read)
1187 lowest_read = search;
1188 if (search > highest_read)
1189 highest_read = search;
1194 * look for key in the tree. path is filled in with nodes along the way
1195 * if key is found, we return zero and you can find the item in the leaf
1196 * level of the path (level 0)
1198 * If the key isn't found, the path points to the slot where it should
1199 * be inserted, and 1 is returned. If there are other errors during the
1200 * search a negative error number is returned.
1202 * if ins_len > 0, nodes and leaves will be split as we walk down the
1203 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1206 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1207 *root, struct btrfs_key *key, struct btrfs_path *p, int
1210 struct extent_buffer *b;
1214 int should_reada = p->reada;
1215 u8 lowest_level = 0;
1217 lowest_level = p->lowest_level;
1218 WARN_ON(lowest_level && ins_len > 0);
1219 WARN_ON(p->nodes[0] != NULL);
1221 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1225 extent_buffer_get(b);
1227 level = btrfs_header_level(b);
1230 wret = btrfs_cow_block(trans, root, b,
1231 p->nodes[level + 1],
1232 p->slots[level + 1],
1235 free_extent_buffer(b);
1239 BUG_ON(!cow && ins_len);
1240 if (level != btrfs_header_level(b))
1242 level = btrfs_header_level(b);
1243 p->nodes[level] = b;
1244 ret = check_block(root, p, level);
1247 ret = bin_search(b, key, level, &slot);
1249 if (ret && slot > 0)
1251 p->slots[level] = slot;
1252 if ((p->search_for_split || ins_len > 0) &&
1253 btrfs_header_nritems(b) >=
1254 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1255 int sret = split_node(trans, root, p, level);
1259 b = p->nodes[level];
1260 slot = p->slots[level];
1261 } else if (ins_len < 0) {
1262 int sret = balance_level(trans, root, p,
1266 b = p->nodes[level];
1268 btrfs_release_path(NULL, p);
1271 slot = p->slots[level];
1272 BUG_ON(btrfs_header_nritems(b) == 1);
1274 /* this is only true while dropping a snapshot */
1275 if (level == lowest_level)
1279 reada_for_search(root, p, level, slot,
1282 b = read_node_slot(root, b, slot);
1283 if (!extent_buffer_uptodate(b))
1286 p->slots[level] = slot;
1288 ins_len > btrfs_leaf_free_space(root, b)) {
1289 int sret = split_leaf(trans, root, key,
1290 p, ins_len, ret == 0);
1302 * adjust the pointers going up the tree, starting at level
1303 * making sure the right key of each node is points to 'key'.
1304 * This is used after shifting pointers to the left, so it stops
1305 * fixing up pointers when a given leaf/node is not in slot 0 of the
1308 * If this fails to write a tree block, it returns -1, but continues
1309 * fixing up the blocks in ram so the tree is consistent.
1311 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1312 struct btrfs_root *root, struct btrfs_path *path,
1313 struct btrfs_disk_key *key, int level)
1317 struct extent_buffer *t;
1319 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1320 int tslot = path->slots[i];
1321 if (!path->nodes[i])
1324 btrfs_set_node_key(t, key, tslot);
1325 btrfs_mark_buffer_dirty(path->nodes[i]);
1335 * This function isn't completely safe. It's the caller's responsibility
1336 * that the new key won't break the order
1338 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1339 struct btrfs_root *root, struct btrfs_path *path,
1340 struct btrfs_key *new_key)
1342 struct btrfs_disk_key disk_key;
1343 struct extent_buffer *eb;
1346 eb = path->nodes[0];
1347 slot = path->slots[0];
1349 btrfs_item_key(eb, &disk_key, slot - 1);
1350 if (btrfs_comp_keys(&disk_key, new_key) >= 0)
1353 if (slot < btrfs_header_nritems(eb) - 1) {
1354 btrfs_item_key(eb, &disk_key, slot + 1);
1355 if (btrfs_comp_keys(&disk_key, new_key) <= 0)
1359 btrfs_cpu_key_to_disk(&disk_key, new_key);
1360 btrfs_set_item_key(eb, &disk_key, slot);
1361 btrfs_mark_buffer_dirty(eb);
1363 fixup_low_keys(trans, root, path, &disk_key, 1);
1368 * try to push data from one node into the next node left in the
1371 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1372 * error, and > 0 if there was no room in the left hand block.
1374 static int push_node_left(struct btrfs_trans_handle *trans,
1375 struct btrfs_root *root, struct extent_buffer *dst,
1376 struct extent_buffer *src, int empty)
1383 src_nritems = btrfs_header_nritems(src);
1384 dst_nritems = btrfs_header_nritems(dst);
1385 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1386 WARN_ON(btrfs_header_generation(src) != trans->transid);
1387 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1389 if (!empty && src_nritems <= 8)
1392 if (push_items <= 0) {
1397 push_items = min(src_nritems, push_items);
1398 if (push_items < src_nritems) {
1399 /* leave at least 8 pointers in the node if
1400 * we aren't going to empty it
1402 if (src_nritems - push_items < 8) {
1403 if (push_items <= 8)
1409 push_items = min(src_nritems - 8, push_items);
1411 copy_extent_buffer(dst, src,
1412 btrfs_node_key_ptr_offset(dst_nritems),
1413 btrfs_node_key_ptr_offset(0),
1414 push_items * sizeof(struct btrfs_key_ptr));
1416 if (push_items < src_nritems) {
1417 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1418 btrfs_node_key_ptr_offset(push_items),
1419 (src_nritems - push_items) *
1420 sizeof(struct btrfs_key_ptr));
1422 btrfs_set_header_nritems(src, src_nritems - push_items);
1423 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1424 btrfs_mark_buffer_dirty(src);
1425 btrfs_mark_buffer_dirty(dst);
1431 * try to push data from one node into the next node right in the
1434 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1435 * error, and > 0 if there was no room in the right hand block.
1437 * this will only push up to 1/2 the contents of the left node over
1439 static int balance_node_right(struct btrfs_trans_handle *trans,
1440 struct btrfs_root *root,
1441 struct extent_buffer *dst,
1442 struct extent_buffer *src)
1450 WARN_ON(btrfs_header_generation(src) != trans->transid);
1451 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1453 src_nritems = btrfs_header_nritems(src);
1454 dst_nritems = btrfs_header_nritems(dst);
1455 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1456 if (push_items <= 0) {
1460 if (src_nritems < 4) {
1464 max_push = src_nritems / 2 + 1;
1465 /* don't try to empty the node */
1466 if (max_push >= src_nritems) {
1470 if (max_push < push_items)
1471 push_items = max_push;
1473 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1474 btrfs_node_key_ptr_offset(0),
1476 sizeof(struct btrfs_key_ptr));
1478 copy_extent_buffer(dst, src,
1479 btrfs_node_key_ptr_offset(0),
1480 btrfs_node_key_ptr_offset(src_nritems - push_items),
1481 push_items * sizeof(struct btrfs_key_ptr));
1483 btrfs_set_header_nritems(src, src_nritems - push_items);
1484 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1486 btrfs_mark_buffer_dirty(src);
1487 btrfs_mark_buffer_dirty(dst);
1493 * helper function to insert a new root level in the tree.
1494 * A new node is allocated, and a single item is inserted to
1495 * point to the existing root
1497 * returns zero on success or < 0 on failure.
1499 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1500 struct btrfs_root *root,
1501 struct btrfs_path *path, int level)
1504 struct extent_buffer *lower;
1505 struct extent_buffer *c;
1506 struct extent_buffer *old;
1507 struct btrfs_disk_key lower_key;
1509 BUG_ON(path->nodes[level]);
1510 BUG_ON(path->nodes[level-1] != root->node);
1512 lower = path->nodes[level-1];
1514 btrfs_item_key(lower, &lower_key, 0);
1516 btrfs_node_key(lower, &lower_key, 0);
1518 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1519 root->root_key.objectid, &lower_key,
1520 level, root->node->start, 0);
1525 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
1526 btrfs_set_header_nritems(c, 1);
1527 btrfs_set_header_level(c, level);
1528 btrfs_set_header_bytenr(c, c->start);
1529 btrfs_set_header_generation(c, trans->transid);
1530 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
1531 btrfs_set_header_owner(c, root->root_key.objectid);
1533 write_extent_buffer(c, root->fs_info->fsid,
1534 (unsigned long)btrfs_header_fsid(c),
1537 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1538 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1541 btrfs_set_node_key(c, &lower_key, 0);
1542 btrfs_set_node_blockptr(c, 0, lower->start);
1543 lower_gen = btrfs_header_generation(lower);
1544 WARN_ON(lower_gen != trans->transid);
1546 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1548 btrfs_mark_buffer_dirty(c);
1553 /* the super has an extra ref to root->node */
1554 free_extent_buffer(old);
1556 add_root_to_dirty_list(root);
1557 extent_buffer_get(c);
1558 path->nodes[level] = c;
1559 path->slots[level] = 0;
1564 * worker function to insert a single pointer in a node.
1565 * the node should have enough room for the pointer already
1567 * slot and level indicate where you want the key to go, and
1568 * blocknr is the block the key points to.
1570 * returns zero on success and < 0 on any error
1572 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1573 *root, struct btrfs_path *path, struct btrfs_disk_key
1574 *key, u64 bytenr, int slot, int level)
1576 struct extent_buffer *lower;
1579 BUG_ON(!path->nodes[level]);
1580 lower = path->nodes[level];
1581 nritems = btrfs_header_nritems(lower);
1584 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1586 if (slot != nritems) {
1587 memmove_extent_buffer(lower,
1588 btrfs_node_key_ptr_offset(slot + 1),
1589 btrfs_node_key_ptr_offset(slot),
1590 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1592 btrfs_set_node_key(lower, key, slot);
1593 btrfs_set_node_blockptr(lower, slot, bytenr);
1594 WARN_ON(trans->transid == 0);
1595 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1596 btrfs_set_header_nritems(lower, nritems + 1);
1597 btrfs_mark_buffer_dirty(lower);
1602 * split the node at the specified level in path in two.
1603 * The path is corrected to point to the appropriate node after the split
1605 * Before splitting this tries to make some room in the node by pushing
1606 * left and right, if either one works, it returns right away.
1608 * returns 0 on success and < 0 on failure
1610 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1611 *root, struct btrfs_path *path, int level)
1613 struct extent_buffer *c;
1614 struct extent_buffer *split;
1615 struct btrfs_disk_key disk_key;
1621 c = path->nodes[level];
1622 WARN_ON(btrfs_header_generation(c) != trans->transid);
1623 if (c == root->node) {
1624 /* trying to split the root, lets make a new one */
1625 ret = insert_new_root(trans, root, path, level + 1);
1629 ret = push_nodes_for_insert(trans, root, path, level);
1630 c = path->nodes[level];
1631 if (!ret && btrfs_header_nritems(c) <
1632 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1638 c_nritems = btrfs_header_nritems(c);
1639 mid = (c_nritems + 1) / 2;
1640 btrfs_node_key(c, &disk_key, mid);
1642 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1643 root->root_key.objectid,
1644 &disk_key, level, c->start, 0);
1646 return PTR_ERR(split);
1648 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
1649 btrfs_set_header_level(split, btrfs_header_level(c));
1650 btrfs_set_header_bytenr(split, split->start);
1651 btrfs_set_header_generation(split, trans->transid);
1652 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
1653 btrfs_set_header_owner(split, root->root_key.objectid);
1654 write_extent_buffer(split, root->fs_info->fsid,
1655 (unsigned long)btrfs_header_fsid(split),
1657 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1658 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1662 copy_extent_buffer(split, c,
1663 btrfs_node_key_ptr_offset(0),
1664 btrfs_node_key_ptr_offset(mid),
1665 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1666 btrfs_set_header_nritems(split, c_nritems - mid);
1667 btrfs_set_header_nritems(c, mid);
1670 btrfs_mark_buffer_dirty(c);
1671 btrfs_mark_buffer_dirty(split);
1673 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1674 path->slots[level + 1] + 1,
1679 if (path->slots[level] >= mid) {
1680 path->slots[level] -= mid;
1681 free_extent_buffer(c);
1682 path->nodes[level] = split;
1683 path->slots[level + 1] += 1;
1685 free_extent_buffer(split);
1691 * how many bytes are required to store the items in a leaf. start
1692 * and nr indicate which items in the leaf to check. This totals up the
1693 * space used both by the item structs and the item data
1695 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1698 int nritems = btrfs_header_nritems(l);
1699 int end = min(nritems, start + nr) - 1;
1703 data_len = btrfs_item_end_nr(l, start);
1704 data_len = data_len - btrfs_item_offset_nr(l, end);
1705 data_len += sizeof(struct btrfs_item) * nr;
1706 WARN_ON(data_len < 0);
1711 * The space between the end of the leaf items and
1712 * the start of the leaf data. IOW, how much room
1713 * the leaf has left for both items and data
1715 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1717 int nritems = btrfs_header_nritems(leaf);
1719 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1721 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1722 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1723 leaf_space_used(leaf, 0, nritems), nritems);
1729 * push some data in the path leaf to the right, trying to free up at
1730 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1732 * returns 1 if the push failed because the other node didn't have enough
1733 * room, 0 if everything worked out and < 0 if there were major errors.
1735 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1736 *root, struct btrfs_path *path, int data_size,
1739 struct extent_buffer *left = path->nodes[0];
1740 struct extent_buffer *right;
1741 struct extent_buffer *upper;
1742 struct btrfs_disk_key disk_key;
1748 struct btrfs_item *item;
1756 slot = path->slots[1];
1757 if (!path->nodes[1]) {
1760 upper = path->nodes[1];
1761 if (slot >= btrfs_header_nritems(upper) - 1)
1764 right = read_node_slot(root, upper, slot + 1);
1765 free_space = btrfs_leaf_free_space(root, right);
1766 if (free_space < data_size) {
1767 free_extent_buffer(right);
1771 /* cow and double check */
1772 ret = btrfs_cow_block(trans, root, right, upper,
1775 free_extent_buffer(right);
1778 free_space = btrfs_leaf_free_space(root, right);
1779 if (free_space < data_size) {
1780 free_extent_buffer(right);
1784 left_nritems = btrfs_header_nritems(left);
1785 if (left_nritems == 0) {
1786 free_extent_buffer(right);
1795 i = left_nritems - 1;
1797 item = btrfs_item_nr(left, i);
1799 if (path->slots[0] == i)
1800 push_space += data_size + sizeof(*item);
1802 this_item_size = btrfs_item_size(left, item);
1803 if (this_item_size + sizeof(*item) + push_space > free_space)
1806 push_space += this_item_size + sizeof(*item);
1812 if (push_items == 0) {
1813 free_extent_buffer(right);
1817 if (!empty && push_items == left_nritems)
1820 /* push left to right */
1821 right_nritems = btrfs_header_nritems(right);
1823 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1824 push_space -= leaf_data_end(root, left);
1826 /* make room in the right data area */
1827 data_end = leaf_data_end(root, right);
1828 memmove_extent_buffer(right,
1829 btrfs_leaf_data(right) + data_end - push_space,
1830 btrfs_leaf_data(right) + data_end,
1831 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1833 /* copy from the left data area */
1834 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1835 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1836 btrfs_leaf_data(left) + leaf_data_end(root, left),
1839 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1840 btrfs_item_nr_offset(0),
1841 right_nritems * sizeof(struct btrfs_item));
1843 /* copy the items from left to right */
1844 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1845 btrfs_item_nr_offset(left_nritems - push_items),
1846 push_items * sizeof(struct btrfs_item));
1848 /* update the item pointers */
1849 right_nritems += push_items;
1850 btrfs_set_header_nritems(right, right_nritems);
1851 push_space = BTRFS_LEAF_DATA_SIZE(root);
1852 for (i = 0; i < right_nritems; i++) {
1853 item = btrfs_item_nr(right, i);
1854 push_space -= btrfs_item_size(right, item);
1855 btrfs_set_item_offset(right, item, push_space);
1858 left_nritems -= push_items;
1859 btrfs_set_header_nritems(left, left_nritems);
1862 btrfs_mark_buffer_dirty(left);
1863 btrfs_mark_buffer_dirty(right);
1865 btrfs_item_key(right, &disk_key, 0);
1866 btrfs_set_node_key(upper, &disk_key, slot + 1);
1867 btrfs_mark_buffer_dirty(upper);
1869 /* then fixup the leaf pointer in the path */
1870 if (path->slots[0] >= left_nritems) {
1871 path->slots[0] -= left_nritems;
1872 free_extent_buffer(path->nodes[0]);
1873 path->nodes[0] = right;
1874 path->slots[1] += 1;
1876 free_extent_buffer(right);
1881 * push some data in the path leaf to the left, trying to free up at
1882 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1884 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1885 *root, struct btrfs_path *path, int data_size,
1888 struct btrfs_disk_key disk_key;
1889 struct extent_buffer *right = path->nodes[0];
1890 struct extent_buffer *left;
1896 struct btrfs_item *item;
1897 u32 old_left_nritems;
1903 u32 old_left_item_size;
1905 slot = path->slots[1];
1908 if (!path->nodes[1])
1911 right_nritems = btrfs_header_nritems(right);
1912 if (right_nritems == 0) {
1916 left = read_node_slot(root, path->nodes[1], slot - 1);
1917 free_space = btrfs_leaf_free_space(root, left);
1918 if (free_space < data_size) {
1919 free_extent_buffer(left);
1923 /* cow and double check */
1924 ret = btrfs_cow_block(trans, root, left,
1925 path->nodes[1], slot - 1, &left);
1927 /* we hit -ENOSPC, but it isn't fatal here */
1928 free_extent_buffer(left);
1932 free_space = btrfs_leaf_free_space(root, left);
1933 if (free_space < data_size) {
1934 free_extent_buffer(left);
1941 nr = right_nritems - 1;
1943 for (i = 0; i < nr; i++) {
1944 item = btrfs_item_nr(right, i);
1946 if (path->slots[0] == i)
1947 push_space += data_size + sizeof(*item);
1949 this_item_size = btrfs_item_size(right, item);
1950 if (this_item_size + sizeof(*item) + push_space > free_space)
1954 push_space += this_item_size + sizeof(*item);
1957 if (push_items == 0) {
1958 free_extent_buffer(left);
1961 if (!empty && push_items == btrfs_header_nritems(right))
1964 /* push data from right to left */
1965 copy_extent_buffer(left, right,
1966 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1967 btrfs_item_nr_offset(0),
1968 push_items * sizeof(struct btrfs_item));
1970 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1971 btrfs_item_offset_nr(right, push_items -1);
1973 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1974 leaf_data_end(root, left) - push_space,
1975 btrfs_leaf_data(right) +
1976 btrfs_item_offset_nr(right, push_items - 1),
1978 old_left_nritems = btrfs_header_nritems(left);
1979 BUG_ON(old_left_nritems == 0);
1981 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1982 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1985 item = btrfs_item_nr(left, i);
1986 ioff = btrfs_item_offset(left, item);
1987 btrfs_set_item_offset(left, item,
1988 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1990 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1992 /* fixup right node */
1993 if (push_items > right_nritems) {
1994 printk("push items %d nr %u\n", push_items, right_nritems);
1998 if (push_items < right_nritems) {
1999 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2000 leaf_data_end(root, right);
2001 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2002 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2003 btrfs_leaf_data(right) +
2004 leaf_data_end(root, right), push_space);
2006 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2007 btrfs_item_nr_offset(push_items),
2008 (btrfs_header_nritems(right) - push_items) *
2009 sizeof(struct btrfs_item));
2011 right_nritems -= push_items;
2012 btrfs_set_header_nritems(right, right_nritems);
2013 push_space = BTRFS_LEAF_DATA_SIZE(root);
2014 for (i = 0; i < right_nritems; i++) {
2015 item = btrfs_item_nr(right, i);
2016 push_space = push_space - btrfs_item_size(right, item);
2017 btrfs_set_item_offset(right, item, push_space);
2020 btrfs_mark_buffer_dirty(left);
2022 btrfs_mark_buffer_dirty(right);
2024 btrfs_item_key(right, &disk_key, 0);
2025 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2029 /* then fixup the leaf pointer in the path */
2030 if (path->slots[0] < push_items) {
2031 path->slots[0] += old_left_nritems;
2032 free_extent_buffer(path->nodes[0]);
2033 path->nodes[0] = left;
2034 path->slots[1] -= 1;
2036 free_extent_buffer(left);
2037 path->slots[0] -= push_items;
2039 BUG_ON(path->slots[0] < 0);
2044 * split the path's leaf in two, making sure there is at least data_size
2045 * available for the resulting leaf level of the path.
2047 * returns 0 if all went well and < 0 on failure.
2049 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
2050 struct btrfs_root *root,
2051 struct btrfs_path *path,
2052 struct extent_buffer *l,
2053 struct extent_buffer *right,
2054 int slot, int mid, int nritems)
2061 struct btrfs_disk_key disk_key;
2063 nritems = nritems - mid;
2064 btrfs_set_header_nritems(right, nritems);
2065 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2067 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2068 btrfs_item_nr_offset(mid),
2069 nritems * sizeof(struct btrfs_item));
2071 copy_extent_buffer(right, l,
2072 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2073 data_copy_size, btrfs_leaf_data(l) +
2074 leaf_data_end(root, l), data_copy_size);
2076 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2077 btrfs_item_end_nr(l, mid);
2079 for (i = 0; i < nritems; i++) {
2080 struct btrfs_item *item = btrfs_item_nr(right, i);
2081 u32 ioff = btrfs_item_offset(right, item);
2082 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2085 btrfs_set_header_nritems(l, mid);
2087 btrfs_item_key(right, &disk_key, 0);
2088 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2089 path->slots[1] + 1, 1);
2093 btrfs_mark_buffer_dirty(right);
2094 btrfs_mark_buffer_dirty(l);
2095 BUG_ON(path->slots[0] != slot);
2098 free_extent_buffer(path->nodes[0]);
2099 path->nodes[0] = right;
2100 path->slots[0] -= mid;
2101 path->slots[1] += 1;
2103 free_extent_buffer(right);
2106 BUG_ON(path->slots[0] < 0);
2112 * split the path's leaf in two, making sure there is at least data_size
2113 * available for the resulting leaf level of the path.
2115 * returns 0 if all went well and < 0 on failure.
2117 static noinline int split_leaf(struct btrfs_trans_handle *trans,
2118 struct btrfs_root *root,
2119 struct btrfs_key *ins_key,
2120 struct btrfs_path *path, int data_size,
2123 struct btrfs_disk_key disk_key;
2124 struct extent_buffer *l;
2128 struct extent_buffer *right;
2132 int num_doubles = 0;
2134 /* first try to make some room by pushing left and right */
2135 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
2136 wret = push_leaf_right(trans, root, path, data_size, 0);
2140 wret = push_leaf_left(trans, root, path, data_size, 0);
2146 /* did the pushes work? */
2147 if (btrfs_leaf_free_space(root, l) >= data_size)
2151 if (!path->nodes[1]) {
2152 ret = insert_new_root(trans, root, path, 1);
2159 slot = path->slots[0];
2160 nritems = btrfs_header_nritems(l);
2161 mid = (nritems + 1) / 2;
2165 leaf_space_used(l, mid, nritems - mid) + data_size >
2166 BTRFS_LEAF_DATA_SIZE(root)) {
2167 if (slot >= nritems) {
2171 if (mid != nritems &&
2172 leaf_space_used(l, mid, nritems - mid) +
2173 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2179 if (leaf_space_used(l, 0, mid) + data_size >
2180 BTRFS_LEAF_DATA_SIZE(root)) {
2181 if (!extend && data_size && slot == 0) {
2183 } else if ((extend || !data_size) && slot == 0) {
2187 if (mid != nritems &&
2188 leaf_space_used(l, mid, nritems - mid) +
2189 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2197 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2199 btrfs_item_key(l, &disk_key, mid);
2201 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2202 root->root_key.objectid,
2203 &disk_key, 0, l->start, 0);
2204 if (IS_ERR(right)) {
2206 return PTR_ERR(right);
2209 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2210 btrfs_set_header_bytenr(right, right->start);
2211 btrfs_set_header_generation(right, trans->transid);
2212 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
2213 btrfs_set_header_owner(right, root->root_key.objectid);
2214 btrfs_set_header_level(right, 0);
2215 write_extent_buffer(right, root->fs_info->fsid,
2216 (unsigned long)btrfs_header_fsid(right),
2219 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2220 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2225 btrfs_set_header_nritems(right, 0);
2226 wret = insert_ptr(trans, root, path,
2227 &disk_key, right->start,
2228 path->slots[1] + 1, 1);
2232 free_extent_buffer(path->nodes[0]);
2233 path->nodes[0] = right;
2235 path->slots[1] += 1;
2237 btrfs_set_header_nritems(right, 0);
2238 wret = insert_ptr(trans, root, path,
2244 free_extent_buffer(path->nodes[0]);
2245 path->nodes[0] = right;
2247 if (path->slots[1] == 0) {
2248 wret = fixup_low_keys(trans, root,
2249 path, &disk_key, 1);
2254 btrfs_mark_buffer_dirty(right);
2258 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
2262 BUG_ON(num_doubles != 0);
2271 * This function splits a single item into two items,
2272 * giving 'new_key' to the new item and splitting the
2273 * old one at split_offset (from the start of the item).
2275 * The path may be released by this operation. After
2276 * the split, the path is pointing to the old item. The
2277 * new item is going to be in the same node as the old one.
2279 * Note, the item being split must be smaller enough to live alone on
2280 * a tree block with room for one extra struct btrfs_item
2282 * This allows us to split the item in place, keeping a lock on the
2283 * leaf the entire time.
2285 int btrfs_split_item(struct btrfs_trans_handle *trans,
2286 struct btrfs_root *root,
2287 struct btrfs_path *path,
2288 struct btrfs_key *new_key,
2289 unsigned long split_offset)
2292 struct extent_buffer *leaf;
2293 struct btrfs_key orig_key;
2294 struct btrfs_item *item;
2295 struct btrfs_item *new_item;
2300 struct btrfs_disk_key disk_key;
2303 leaf = path->nodes[0];
2304 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
2305 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
2308 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2309 btrfs_release_path(root, path);
2311 path->search_for_split = 1;
2313 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
2314 path->search_for_split = 0;
2316 /* if our item isn't there or got smaller, return now */
2317 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
2322 ret = split_leaf(trans, root, &orig_key, path, 0, 0);
2325 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
2326 leaf = path->nodes[0];
2329 item = btrfs_item_nr(leaf, path->slots[0]);
2330 orig_offset = btrfs_item_offset(leaf, item);
2331 item_size = btrfs_item_size(leaf, item);
2334 buf = kmalloc(item_size, GFP_NOFS);
2335 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
2336 path->slots[0]), item_size);
2337 slot = path->slots[0] + 1;
2338 leaf = path->nodes[0];
2340 nritems = btrfs_header_nritems(leaf);
2342 if (slot != nritems) {
2343 /* shift the items */
2344 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2345 btrfs_item_nr_offset(slot),
2346 (nritems - slot) * sizeof(struct btrfs_item));
2350 btrfs_cpu_key_to_disk(&disk_key, new_key);
2351 btrfs_set_item_key(leaf, &disk_key, slot);
2353 new_item = btrfs_item_nr(leaf, slot);
2355 btrfs_set_item_offset(leaf, new_item, orig_offset);
2356 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
2358 btrfs_set_item_offset(leaf, item,
2359 orig_offset + item_size - split_offset);
2360 btrfs_set_item_size(leaf, item, split_offset);
2362 btrfs_set_header_nritems(leaf, nritems + 1);
2364 /* write the data for the start of the original item */
2365 write_extent_buffer(leaf, buf,
2366 btrfs_item_ptr_offset(leaf, path->slots[0]),
2369 /* write the data for the new item */
2370 write_extent_buffer(leaf, buf + split_offset,
2371 btrfs_item_ptr_offset(leaf, slot),
2372 item_size - split_offset);
2373 btrfs_mark_buffer_dirty(leaf);
2376 if (btrfs_leaf_free_space(root, leaf) < 0) {
2377 btrfs_print_leaf(root, leaf);
2384 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2385 struct btrfs_root *root,
2386 struct btrfs_path *path,
2387 u32 new_size, int from_end)
2391 struct extent_buffer *leaf;
2392 struct btrfs_item *item;
2394 unsigned int data_end;
2395 unsigned int old_data_start;
2396 unsigned int old_size;
2397 unsigned int size_diff;
2400 leaf = path->nodes[0];
2401 slot = path->slots[0];
2403 old_size = btrfs_item_size_nr(leaf, slot);
2404 if (old_size == new_size)
2407 nritems = btrfs_header_nritems(leaf);
2408 data_end = leaf_data_end(root, leaf);
2410 old_data_start = btrfs_item_offset_nr(leaf, slot);
2412 size_diff = old_size - new_size;
2415 BUG_ON(slot >= nritems);
2418 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2420 /* first correct the data pointers */
2421 for (i = slot; i < nritems; i++) {
2423 item = btrfs_item_nr(leaf, i);
2424 ioff = btrfs_item_offset(leaf, item);
2425 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2428 /* shift the data */
2430 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2431 data_end + size_diff, btrfs_leaf_data(leaf) +
2432 data_end, old_data_start + new_size - data_end);
2434 struct btrfs_disk_key disk_key;
2437 btrfs_item_key(leaf, &disk_key, slot);
2439 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2441 struct btrfs_file_extent_item *fi;
2443 fi = btrfs_item_ptr(leaf, slot,
2444 struct btrfs_file_extent_item);
2445 fi = (struct btrfs_file_extent_item *)(
2446 (unsigned long)fi - size_diff);
2448 if (btrfs_file_extent_type(leaf, fi) ==
2449 BTRFS_FILE_EXTENT_INLINE) {
2450 ptr = btrfs_item_ptr_offset(leaf, slot);
2451 memmove_extent_buffer(leaf, ptr,
2453 offsetof(struct btrfs_file_extent_item,
2458 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2459 data_end + size_diff, btrfs_leaf_data(leaf) +
2460 data_end, old_data_start - data_end);
2462 offset = btrfs_disk_key_offset(&disk_key);
2463 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2464 btrfs_set_item_key(leaf, &disk_key, slot);
2466 fixup_low_keys(trans, root, path, &disk_key, 1);
2469 item = btrfs_item_nr(leaf, slot);
2470 btrfs_set_item_size(leaf, item, new_size);
2471 btrfs_mark_buffer_dirty(leaf);
2474 if (btrfs_leaf_free_space(root, leaf) < 0) {
2475 btrfs_print_leaf(root, leaf);
2481 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2482 struct btrfs_root *root, struct btrfs_path *path,
2487 struct extent_buffer *leaf;
2488 struct btrfs_item *item;
2490 unsigned int data_end;
2491 unsigned int old_data;
2492 unsigned int old_size;
2495 leaf = path->nodes[0];
2497 nritems = btrfs_header_nritems(leaf);
2498 data_end = leaf_data_end(root, leaf);
2500 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2501 btrfs_print_leaf(root, leaf);
2504 slot = path->slots[0];
2505 old_data = btrfs_item_end_nr(leaf, slot);
2508 if (slot >= nritems) {
2509 btrfs_print_leaf(root, leaf);
2510 printk("slot %d too large, nritems %d\n", slot, nritems);
2515 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2517 /* first correct the data pointers */
2518 for (i = slot; i < nritems; i++) {
2520 item = btrfs_item_nr(leaf, i);
2521 ioff = btrfs_item_offset(leaf, item);
2522 btrfs_set_item_offset(leaf, item, ioff - data_size);
2525 /* shift the data */
2526 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2527 data_end - data_size, btrfs_leaf_data(leaf) +
2528 data_end, old_data - data_end);
2530 data_end = old_data;
2531 old_size = btrfs_item_size_nr(leaf, slot);
2532 item = btrfs_item_nr(leaf, slot);
2533 btrfs_set_item_size(leaf, item, old_size + data_size);
2534 btrfs_mark_buffer_dirty(leaf);
2537 if (btrfs_leaf_free_space(root, leaf) < 0) {
2538 btrfs_print_leaf(root, leaf);
2545 * Given a key and some data, insert an item into the tree.
2546 * This does all the path init required, making room in the tree if needed.
2548 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2549 struct btrfs_root *root,
2550 struct btrfs_path *path,
2551 struct btrfs_key *cpu_key, u32 *data_size,
2554 struct extent_buffer *leaf;
2555 struct btrfs_item *item;
2562 unsigned int data_end;
2563 struct btrfs_disk_key disk_key;
2565 for (i = 0; i < nr; i++) {
2566 total_data += data_size[i];
2569 /* create a root if there isn't one */
2573 total_size = total_data + nr * sizeof(struct btrfs_item);
2574 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2581 leaf = path->nodes[0];
2583 nritems = btrfs_header_nritems(leaf);
2584 data_end = leaf_data_end(root, leaf);
2586 if (btrfs_leaf_free_space(root, leaf) < total_size) {
2587 btrfs_print_leaf(root, leaf);
2588 printk("not enough freespace need %u have %d\n",
2589 total_size, btrfs_leaf_free_space(root, leaf));
2593 slot = path->slots[0];
2596 if (slot != nritems) {
2598 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2600 if (old_data < data_end) {
2601 btrfs_print_leaf(root, leaf);
2602 printk("slot %d old_data %d data_end %d\n",
2603 slot, old_data, data_end);
2607 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2609 /* first correct the data pointers */
2610 for (i = slot; i < nritems; i++) {
2613 item = btrfs_item_nr(leaf, i);
2614 ioff = btrfs_item_offset(leaf, item);
2615 btrfs_set_item_offset(leaf, item, ioff - total_data);
2618 /* shift the items */
2619 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2620 btrfs_item_nr_offset(slot),
2621 (nritems - slot) * sizeof(struct btrfs_item));
2623 /* shift the data */
2624 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2625 data_end - total_data, btrfs_leaf_data(leaf) +
2626 data_end, old_data - data_end);
2627 data_end = old_data;
2630 /* setup the item for the new data */
2631 for (i = 0; i < nr; i++) {
2632 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2633 btrfs_set_item_key(leaf, &disk_key, slot + i);
2634 item = btrfs_item_nr(leaf, slot + i);
2635 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2636 data_end -= data_size[i];
2637 btrfs_set_item_size(leaf, item, data_size[i]);
2639 btrfs_set_header_nritems(leaf, nritems + nr);
2640 btrfs_mark_buffer_dirty(leaf);
2644 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2645 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2648 if (btrfs_leaf_free_space(root, leaf) < 0) {
2649 btrfs_print_leaf(root, leaf);
2658 * Given a key and some data, insert an item into the tree.
2659 * This does all the path init required, making room in the tree if needed.
2661 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2662 *root, struct btrfs_key *cpu_key, void *data, u32
2666 struct btrfs_path *path;
2667 struct extent_buffer *leaf;
2670 path = btrfs_alloc_path();
2672 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2674 leaf = path->nodes[0];
2675 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2676 write_extent_buffer(leaf, data, ptr, data_size);
2677 btrfs_mark_buffer_dirty(leaf);
2679 btrfs_free_path(path);
2684 * delete the pointer from a given node.
2686 * If the delete empties a node, the node is removed from the tree,
2687 * continuing all the way the root if required. The root is converted into
2688 * a leaf if all the nodes are emptied.
2690 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2691 struct btrfs_path *path, int level, int slot)
2693 struct extent_buffer *parent = path->nodes[level];
2698 nritems = btrfs_header_nritems(parent);
2699 if (slot != nritems -1) {
2700 memmove_extent_buffer(parent,
2701 btrfs_node_key_ptr_offset(slot),
2702 btrfs_node_key_ptr_offset(slot + 1),
2703 sizeof(struct btrfs_key_ptr) *
2704 (nritems - slot - 1));
2707 btrfs_set_header_nritems(parent, nritems);
2708 if (nritems == 0 && parent == root->node) {
2709 BUG_ON(btrfs_header_level(root->node) != 1);
2710 /* just turn the root into a leaf and break */
2711 btrfs_set_header_level(root->node, 0);
2712 } else if (slot == 0) {
2713 struct btrfs_disk_key disk_key;
2715 btrfs_node_key(parent, &disk_key, 0);
2716 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2720 btrfs_mark_buffer_dirty(parent);
2725 * a helper function to delete the leaf pointed to by path->slots[1] and
2728 * This deletes the pointer in path->nodes[1] and frees the leaf
2729 * block extent. zero is returned if it all worked out, < 0 otherwise.
2731 * The path must have already been setup for deleting the leaf, including
2732 * all the proper balancing. path->nodes[1] must be locked.
2734 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
2735 struct btrfs_root *root,
2736 struct btrfs_path *path,
2737 struct extent_buffer *leaf)
2741 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
2742 ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
2746 ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
2747 0, root->root_key.objectid, 0, 0);
2752 * delete the item at the leaf level in path. If that empties
2753 * the leaf, remove it from the tree
2755 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2756 struct btrfs_path *path, int slot, int nr)
2758 struct extent_buffer *leaf;
2759 struct btrfs_item *item;
2767 leaf = path->nodes[0];
2768 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2770 for (i = 0; i < nr; i++)
2771 dsize += btrfs_item_size_nr(leaf, slot + i);
2773 nritems = btrfs_header_nritems(leaf);
2775 if (slot + nr != nritems) {
2777 int data_end = leaf_data_end(root, leaf);
2779 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2781 btrfs_leaf_data(leaf) + data_end,
2782 last_off - data_end);
2784 for (i = slot + nr; i < nritems; i++) {
2787 item = btrfs_item_nr(leaf, i);
2788 ioff = btrfs_item_offset(leaf, item);
2789 btrfs_set_item_offset(leaf, item, ioff + dsize);
2792 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2793 btrfs_item_nr_offset(slot + nr),
2794 sizeof(struct btrfs_item) *
2795 (nritems - slot - nr));
2797 btrfs_set_header_nritems(leaf, nritems - nr);
2800 /* delete the leaf if we've emptied it */
2802 if (leaf == root->node) {
2803 btrfs_set_header_level(leaf, 0);
2805 clean_tree_block(trans, root, leaf);
2806 wait_on_tree_block_writeback(root, leaf);
2808 wret = btrfs_del_leaf(trans, root, path, leaf);
2814 int used = leaf_space_used(leaf, 0, nritems);
2816 struct btrfs_disk_key disk_key;
2818 btrfs_item_key(leaf, &disk_key, 0);
2819 wret = fixup_low_keys(trans, root, path,
2825 /* delete the leaf if it is mostly empty */
2826 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2827 /* push_leaf_left fixes the path.
2828 * make sure the path still points to our leaf
2829 * for possible call to del_ptr below
2831 slot = path->slots[1];
2832 extent_buffer_get(leaf);
2834 wret = push_leaf_left(trans, root, path, 1, 1);
2835 if (wret < 0 && wret != -ENOSPC)
2838 if (path->nodes[0] == leaf &&
2839 btrfs_header_nritems(leaf)) {
2840 wret = push_leaf_right(trans, root, path, 1, 1);
2841 if (wret < 0 && wret != -ENOSPC)
2845 if (btrfs_header_nritems(leaf) == 0) {
2846 clean_tree_block(trans, root, leaf);
2847 wait_on_tree_block_writeback(root, leaf);
2849 path->slots[1] = slot;
2850 ret = btrfs_del_leaf(trans, root, path, leaf);
2852 free_extent_buffer(leaf);
2855 btrfs_mark_buffer_dirty(leaf);
2856 free_extent_buffer(leaf);
2859 btrfs_mark_buffer_dirty(leaf);
2866 * walk up the tree as far as required to find the previous leaf.
2867 * returns 0 if it found something or 1 if there are no lesser leaves.
2868 * returns < 0 on io errors.
2870 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2874 struct extent_buffer *c;
2875 struct extent_buffer *next = NULL;
2877 while(level < BTRFS_MAX_LEVEL) {
2878 if (!path->nodes[level])
2881 slot = path->slots[level];
2882 c = path->nodes[level];
2885 if (level == BTRFS_MAX_LEVEL)
2891 next = read_node_slot(root, c, slot);
2894 path->slots[level] = slot;
2897 c = path->nodes[level];
2898 free_extent_buffer(c);
2899 slot = btrfs_header_nritems(next);
2902 path->nodes[level] = next;
2903 path->slots[level] = slot;
2906 next = read_node_slot(root, next, slot);
2912 * walk up the tree as far as required to find the next leaf.
2913 * returns 0 if it found something or 1 if there are no greater leaves.
2914 * returns < 0 on io errors.
2916 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2920 struct extent_buffer *c;
2921 struct extent_buffer *next = NULL;
2923 while(level < BTRFS_MAX_LEVEL) {
2924 if (!path->nodes[level])
2927 slot = path->slots[level] + 1;
2928 c = path->nodes[level];
2929 if (slot >= btrfs_header_nritems(c)) {
2931 if (level == BTRFS_MAX_LEVEL)
2937 reada_for_search(root, path, level, slot, 0);
2939 next = read_node_slot(root, c, slot);
2944 path->slots[level] = slot;
2947 c = path->nodes[level];
2948 free_extent_buffer(c);
2949 path->nodes[level] = next;
2950 path->slots[level] = 0;
2954 reada_for_search(root, path, level, 0, 0);
2955 next = read_node_slot(root, next, 0);
2962 int btrfs_previous_item(struct btrfs_root *root,
2963 struct btrfs_path *path, u64 min_objectid,
2966 struct btrfs_key found_key;
2967 struct extent_buffer *leaf;
2971 if (path->slots[0] == 0) {
2972 ret = btrfs_prev_leaf(root, path);
2978 leaf = path->nodes[0];
2979 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2980 if (found_key.type == type)