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 = kzalloc(sizeof(struct btrfs_path), GFP_NOFS);
49 void btrfs_free_path(struct btrfs_path *p)
51 btrfs_release_path(p);
55 void btrfs_release_path(struct btrfs_path *p)
58 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
61 free_extent_buffer(p->nodes[i]);
63 memset(p, 0, sizeof(*p));
66 void add_root_to_dirty_list(struct btrfs_root *root)
68 if (root->track_dirty && list_empty(&root->dirty_list)) {
69 list_add(&root->dirty_list,
70 &root->fs_info->dirty_cowonly_roots);
74 int btrfs_copy_root(struct btrfs_trans_handle *trans,
75 struct btrfs_root *root,
76 struct extent_buffer *buf,
77 struct extent_buffer **cow_ret, u64 new_root_objectid)
79 struct extent_buffer *cow;
82 struct btrfs_root *new_root;
83 struct btrfs_disk_key disk_key;
85 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
89 memcpy(new_root, root, sizeof(*new_root));
90 new_root->root_key.objectid = new_root_objectid;
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);
96 level = btrfs_header_level(buf);
98 btrfs_item_key(buf, &disk_key, 0);
100 btrfs_node_key(buf, &disk_key, 0);
101 cow = btrfs_alloc_free_block(trans, new_root, buf->len,
102 new_root_objectid, &disk_key,
103 level, buf->start, 0);
109 copy_extent_buffer(cow, buf, 0, 0, cow->len);
110 btrfs_set_header_bytenr(cow, cow->start);
111 btrfs_set_header_generation(cow, trans->transid);
112 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
113 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
114 BTRFS_HEADER_FLAG_RELOC);
115 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
116 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
118 btrfs_set_header_owner(cow, new_root_objectid);
120 write_extent_buffer(cow, root->fs_info->fsid,
121 (unsigned long)btrfs_header_fsid(cow),
124 WARN_ON(btrfs_header_generation(buf) > trans->transid);
125 ret = btrfs_inc_ref(trans, new_root, cow, 0);
131 btrfs_mark_buffer_dirty(cow);
137 * check if the tree block can be shared by multiple trees
139 int btrfs_block_can_be_shared(struct btrfs_root *root,
140 struct extent_buffer *buf)
143 * Tree blocks not in refernece counted trees and tree roots
144 * are never shared. If a block was allocated after the last
145 * snapshot and the block was not allocated by tree relocation,
146 * we know the block is not shared.
148 if (root->ref_cows &&
149 buf != root->node && buf != root->commit_root &&
150 (btrfs_header_generation(buf) <=
151 btrfs_root_last_snapshot(&root->root_item) ||
152 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
154 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
155 if (root->ref_cows &&
156 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
162 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
163 struct btrfs_root *root,
164 struct extent_buffer *buf,
165 struct extent_buffer *cow)
174 * Backrefs update rules:
176 * Always use full backrefs for extent pointers in tree block
177 * allocated by tree relocation.
179 * If a shared tree block is no longer referenced by its owner
180 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
181 * use full backrefs for extent pointers in tree block.
183 * If a tree block is been relocating
184 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
185 * use full backrefs for extent pointers in tree block.
186 * The reason for this is some operations (such as drop tree)
187 * are only allowed for blocks use full backrefs.
190 if (btrfs_block_can_be_shared(root, buf)) {
191 ret = btrfs_lookup_extent_info(trans, root, buf->start,
192 btrfs_header_level(buf), 1,
198 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
199 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
200 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
205 owner = btrfs_header_owner(buf);
206 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) &&
207 owner == BTRFS_TREE_RELOC_OBJECTID);
210 if ((owner == root->root_key.objectid ||
211 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
212 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
213 ret = btrfs_inc_ref(trans, root, buf, 1);
216 if (root->root_key.objectid ==
217 BTRFS_TREE_RELOC_OBJECTID) {
218 ret = btrfs_dec_ref(trans, root, buf, 0);
220 ret = btrfs_inc_ref(trans, root, cow, 1);
223 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
226 if (root->root_key.objectid ==
227 BTRFS_TREE_RELOC_OBJECTID)
228 ret = btrfs_inc_ref(trans, root, cow, 1);
230 ret = btrfs_inc_ref(trans, root, cow, 0);
233 if (new_flags != 0) {
234 ret = btrfs_set_block_flags(trans, root, buf->start,
235 btrfs_header_level(buf),
240 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
241 if (root->root_key.objectid ==
242 BTRFS_TREE_RELOC_OBJECTID)
243 ret = btrfs_inc_ref(trans, root, cow, 1);
245 ret = btrfs_inc_ref(trans, root, cow, 0);
247 ret = btrfs_dec_ref(trans, root, buf, 1);
250 clean_tree_block(trans, root, buf);
255 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
256 struct btrfs_root *root,
257 struct extent_buffer *buf,
258 struct extent_buffer *parent, int parent_slot,
259 struct extent_buffer **cow_ret,
260 u64 search_start, u64 empty_size)
262 struct extent_buffer *cow;
263 struct btrfs_disk_key disk_key;
266 WARN_ON(root->ref_cows && trans->transid !=
267 root->fs_info->running_transaction->transid);
268 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
270 level = btrfs_header_level(buf);
273 btrfs_item_key(buf, &disk_key, 0);
275 btrfs_node_key(buf, &disk_key, 0);
277 cow = btrfs_alloc_free_block(trans, root, buf->len,
278 root->root_key.objectid, &disk_key,
279 level, search_start, empty_size);
283 copy_extent_buffer(cow, buf, 0, 0, cow->len);
284 btrfs_set_header_bytenr(cow, cow->start);
285 btrfs_set_header_generation(cow, trans->transid);
286 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
287 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
288 BTRFS_HEADER_FLAG_RELOC);
289 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
290 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
292 btrfs_set_header_owner(cow, root->root_key.objectid);
294 write_extent_buffer(cow, root->fs_info->fsid,
295 (unsigned long)btrfs_header_fsid(cow),
298 WARN_ON(btrfs_header_generation(buf) > trans->transid);
300 update_ref_for_cow(trans, root, buf, cow);
302 if (buf == root->node) {
304 extent_buffer_get(cow);
306 btrfs_free_extent(trans, root, buf->start, buf->len,
307 0, root->root_key.objectid, level, 0);
308 free_extent_buffer(buf);
309 add_root_to_dirty_list(root);
311 btrfs_set_node_blockptr(parent, parent_slot,
313 WARN_ON(trans->transid == 0);
314 btrfs_set_node_ptr_generation(parent, parent_slot,
316 btrfs_mark_buffer_dirty(parent);
317 WARN_ON(btrfs_header_generation(parent) != trans->transid);
319 btrfs_free_extent(trans, root, buf->start, buf->len,
320 0, root->root_key.objectid, level, 1);
322 free_extent_buffer(buf);
323 btrfs_mark_buffer_dirty(cow);
328 static inline int should_cow_block(struct btrfs_trans_handle *trans,
329 struct btrfs_root *root,
330 struct extent_buffer *buf)
332 if (btrfs_header_generation(buf) == trans->transid &&
333 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
334 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
335 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
340 int btrfs_cow_block(struct btrfs_trans_handle *trans,
341 struct btrfs_root *root, struct extent_buffer *buf,
342 struct extent_buffer *parent, int parent_slot,
343 struct extent_buffer **cow_ret)
348 if (trans->transaction != root->fs_info->running_transaction) {
349 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
350 root->fs_info->running_transaction->transid);
354 if (trans->transid != root->fs_info->generation) {
355 printk(KERN_CRIT "trans %llu running %llu\n",
356 (unsigned long long)trans->transid,
357 (unsigned long long)root->fs_info->generation);
360 if (!should_cow_block(trans, root, buf)) {
365 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
366 ret = __btrfs_cow_block(trans, root, buf, parent,
367 parent_slot, cow_ret, search_start, 0);
372 * compare two keys in a memcmp fashion
374 static int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
378 btrfs_disk_key_to_cpu(&k1, disk);
380 if (k1.objectid > k2->objectid)
382 if (k1.objectid < k2->objectid)
384 if (k1.type > k2->type)
386 if (k1.type < k2->type)
388 if (k1.offset > k2->offset)
390 if (k1.offset < k2->offset)
396 * The leaf data grows from end-to-front in the node.
397 * this returns the address of the start of the last item,
398 * which is the stop of the leaf data stack
400 static inline unsigned int leaf_data_end(struct btrfs_root *root,
401 struct extent_buffer *leaf)
403 u32 nr = btrfs_header_nritems(leaf);
405 return BTRFS_LEAF_DATA_SIZE(root);
406 return btrfs_item_offset_nr(leaf, nr - 1);
409 int btrfs_check_node(struct btrfs_root *root,
410 struct btrfs_disk_key *parent_key,
411 struct extent_buffer *buf)
414 struct btrfs_key cpukey;
415 struct btrfs_disk_key key;
416 u32 nritems = btrfs_header_nritems(buf);
418 if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
421 if (parent_key && parent_key->type) {
422 btrfs_node_key(buf, &key, 0);
423 if (memcmp(parent_key, &key, sizeof(key)))
426 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
427 btrfs_node_key(buf, &key, i);
428 btrfs_node_key_to_cpu(buf, &cpukey, i + 1);
429 if (btrfs_comp_keys(&key, &cpukey) >= 0)
434 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
436 btrfs_disk_key_to_cpu(&cpukey, parent_key);
438 btrfs_node_key_to_cpu(buf, &cpukey, 0);
439 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
440 buf->start, buf->len,
441 btrfs_header_level(buf));
446 int btrfs_check_leaf(struct btrfs_root *root,
447 struct btrfs_disk_key *parent_key,
448 struct extent_buffer *buf)
451 struct btrfs_key cpukey;
452 struct btrfs_disk_key key;
453 u32 nritems = btrfs_header_nritems(buf);
455 if (nritems * sizeof(struct btrfs_item) > buf->len) {
456 fprintf(stderr, "invalid number of items %llu\n",
457 (unsigned long long)buf->start);
461 if (btrfs_header_level(buf) != 0) {
462 fprintf(stderr, "leaf is not a leaf %llu\n",
463 (unsigned long long)btrfs_header_bytenr(buf));
466 if (btrfs_leaf_free_space(root, buf) < 0) {
467 fprintf(stderr, "leaf free space incorrect %llu %d\n",
468 (unsigned long long)btrfs_header_bytenr(buf),
469 btrfs_leaf_free_space(root, buf));
476 btrfs_item_key(buf, &key, 0);
477 if (parent_key && parent_key->type &&
478 memcmp(parent_key, &key, sizeof(key))) {
479 fprintf(stderr, "leaf parent key incorrect %llu\n",
480 (unsigned long long)btrfs_header_bytenr(buf));
483 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
484 btrfs_item_key(buf, &key, i);
485 btrfs_item_key_to_cpu(buf, &cpukey, i + 1);
486 if (btrfs_comp_keys(&key, &cpukey) >= 0) {
487 fprintf(stderr, "bad key ordering %d %d\n", i, i+1);
490 if (btrfs_item_offset_nr(buf, i) !=
491 btrfs_item_end_nr(buf, i + 1)) {
492 fprintf(stderr, "incorrect offsets %u %u\n",
493 btrfs_item_offset_nr(buf, i),
494 btrfs_item_end_nr(buf, i + 1));
497 if (i == 0 && btrfs_item_end_nr(buf, i) !=
498 BTRFS_LEAF_DATA_SIZE(root)) {
499 fprintf(stderr, "bad item end %u wanted %u\n",
500 btrfs_item_end_nr(buf, i),
501 (unsigned)BTRFS_LEAF_DATA_SIZE(root));
507 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
509 btrfs_disk_key_to_cpu(&cpukey, parent_key);
511 btrfs_item_key_to_cpu(buf, &cpukey, 0);
513 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
514 buf->start, buf->len, 0);
519 static int noinline check_block(struct btrfs_root *root,
520 struct btrfs_path *path, int level)
522 struct btrfs_disk_key key;
523 struct btrfs_disk_key *key_ptr = NULL;
524 struct extent_buffer *parent;
526 if (path->nodes[level + 1]) {
527 parent = path->nodes[level + 1];
528 btrfs_node_key(parent, &key, path->slots[level + 1]);
532 return btrfs_check_leaf(root, key_ptr, path->nodes[0]);
533 return btrfs_check_node(root, key_ptr, path->nodes[level]);
537 * search for key in the extent_buffer. The items start at offset p,
538 * and they are item_size apart. There are 'max' items in p.
540 * the slot in the array is returned via slot, and it points to
541 * the place where you would insert key if it is not found in
544 * slot may point to max if the key is bigger than all of the keys
546 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
547 int item_size, struct btrfs_key *key,
554 unsigned long offset;
555 struct btrfs_disk_key *tmp;
558 mid = (low + high) / 2;
559 offset = p + mid * item_size;
561 tmp = (struct btrfs_disk_key *)(eb->data + offset);
562 ret = btrfs_comp_keys(tmp, key);
578 * simple bin_search frontend that does the right thing for
581 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
582 int level, int *slot)
585 return generic_bin_search(eb,
586 offsetof(struct btrfs_leaf, items),
587 sizeof(struct btrfs_item),
588 key, btrfs_header_nritems(eb),
591 return generic_bin_search(eb,
592 offsetof(struct btrfs_node, ptrs),
593 sizeof(struct btrfs_key_ptr),
594 key, btrfs_header_nritems(eb),
598 struct extent_buffer *read_node_slot(struct btrfs_root *root,
599 struct extent_buffer *parent, int slot)
601 int level = btrfs_header_level(parent);
604 if (slot >= btrfs_header_nritems(parent))
610 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
611 btrfs_level_size(root, level - 1),
612 btrfs_node_ptr_generation(parent, slot));
615 static int balance_level(struct btrfs_trans_handle *trans,
616 struct btrfs_root *root,
617 struct btrfs_path *path, int level)
619 struct extent_buffer *right = NULL;
620 struct extent_buffer *mid;
621 struct extent_buffer *left = NULL;
622 struct extent_buffer *parent = NULL;
626 int orig_slot = path->slots[level];
632 mid = path->nodes[level];
633 WARN_ON(btrfs_header_generation(mid) != trans->transid);
635 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
637 if (level < BTRFS_MAX_LEVEL - 1) {
638 parent = path->nodes[level + 1];
639 pslot = path->slots[level + 1];
643 * deal with the case where there is only one pointer in the root
644 * by promoting the node below to a root
647 struct extent_buffer *child;
649 if (btrfs_header_nritems(mid) != 1)
652 /* promote the child to a root */
653 child = read_node_slot(root, mid, 0);
655 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
659 add_root_to_dirty_list(root);
660 path->nodes[level] = NULL;
661 clean_tree_block(trans, root, mid);
662 wait_on_tree_block_writeback(root, mid);
663 /* once for the path */
664 free_extent_buffer(mid);
666 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
667 0, root->root_key.objectid,
669 /* once for the root ptr */
670 free_extent_buffer(mid);
673 if (btrfs_header_nritems(mid) >
674 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
677 left = read_node_slot(root, parent, pslot - 1);
679 wret = btrfs_cow_block(trans, root, left,
680 parent, pslot - 1, &left);
686 right = read_node_slot(root, parent, pslot + 1);
688 wret = btrfs_cow_block(trans, root, right,
689 parent, pslot + 1, &right);
696 /* first, try to make some room in the middle buffer */
698 orig_slot += btrfs_header_nritems(left);
699 wret = push_node_left(trans, root, left, mid, 1);
705 * then try to empty the right most buffer into the middle
708 wret = push_node_left(trans, root, mid, right, 1);
709 if (wret < 0 && wret != -ENOSPC)
711 if (btrfs_header_nritems(right) == 0) {
712 u64 bytenr = right->start;
713 u32 blocksize = right->len;
715 clean_tree_block(trans, root, right);
716 wait_on_tree_block_writeback(root, right);
717 free_extent_buffer(right);
719 wret = btrfs_del_ptr(trans, root, path,
720 level + 1, pslot + 1);
723 wret = btrfs_free_extent(trans, root, bytenr,
725 root->root_key.objectid,
730 struct btrfs_disk_key right_key;
731 btrfs_node_key(right, &right_key, 0);
732 btrfs_set_node_key(parent, &right_key, pslot + 1);
733 btrfs_mark_buffer_dirty(parent);
736 if (btrfs_header_nritems(mid) == 1) {
738 * we're not allowed to leave a node with one item in the
739 * tree during a delete. A deletion from lower in the tree
740 * could try to delete the only pointer in this node.
741 * So, pull some keys from the left.
742 * There has to be a left pointer at this point because
743 * otherwise we would have pulled some pointers from the
747 wret = balance_node_right(trans, root, mid, left);
753 wret = push_node_left(trans, root, left, mid, 1);
759 if (btrfs_header_nritems(mid) == 0) {
760 /* we've managed to empty the middle node, drop it */
761 u64 bytenr = mid->start;
762 u32 blocksize = mid->len;
763 clean_tree_block(trans, root, mid);
764 wait_on_tree_block_writeback(root, mid);
765 free_extent_buffer(mid);
767 wret = btrfs_del_ptr(trans, root, path, level + 1, pslot);
770 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
771 0, root->root_key.objectid,
776 /* update the parent key to reflect our changes */
777 struct btrfs_disk_key mid_key;
778 btrfs_node_key(mid, &mid_key, 0);
779 btrfs_set_node_key(parent, &mid_key, pslot);
780 btrfs_mark_buffer_dirty(parent);
783 /* update the path */
785 if (btrfs_header_nritems(left) > orig_slot) {
786 extent_buffer_get(left);
787 path->nodes[level] = left;
788 path->slots[level + 1] -= 1;
789 path->slots[level] = orig_slot;
791 free_extent_buffer(mid);
793 orig_slot -= btrfs_header_nritems(left);
794 path->slots[level] = orig_slot;
797 /* double check we haven't messed things up */
798 check_block(root, path, level);
800 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
804 free_extent_buffer(right);
806 free_extent_buffer(left);
810 /* returns zero if the push worked, non-zero otherwise */
811 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
812 struct btrfs_root *root,
813 struct btrfs_path *path, int level)
815 struct extent_buffer *right = NULL;
816 struct extent_buffer *mid;
817 struct extent_buffer *left = NULL;
818 struct extent_buffer *parent = NULL;
822 int orig_slot = path->slots[level];
827 mid = path->nodes[level];
828 WARN_ON(btrfs_header_generation(mid) != trans->transid);
830 if (level < BTRFS_MAX_LEVEL - 1) {
831 parent = path->nodes[level + 1];
832 pslot = path->slots[level + 1];
838 left = read_node_slot(root, parent, pslot - 1);
840 /* first, try to make some room in the middle buffer */
843 left_nr = btrfs_header_nritems(left);
844 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
847 ret = btrfs_cow_block(trans, root, left, parent,
852 wret = push_node_left(trans, root,
859 struct btrfs_disk_key disk_key;
860 orig_slot += left_nr;
861 btrfs_node_key(mid, &disk_key, 0);
862 btrfs_set_node_key(parent, &disk_key, pslot);
863 btrfs_mark_buffer_dirty(parent);
864 if (btrfs_header_nritems(left) > orig_slot) {
865 path->nodes[level] = left;
866 path->slots[level + 1] -= 1;
867 path->slots[level] = orig_slot;
868 free_extent_buffer(mid);
871 btrfs_header_nritems(left);
872 path->slots[level] = orig_slot;
873 free_extent_buffer(left);
877 free_extent_buffer(left);
879 right= read_node_slot(root, parent, pslot + 1);
882 * then try to empty the right most buffer into the middle
886 right_nr = btrfs_header_nritems(right);
887 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
890 ret = btrfs_cow_block(trans, root, right,
896 wret = balance_node_right(trans, root,
903 struct btrfs_disk_key disk_key;
905 btrfs_node_key(right, &disk_key, 0);
906 btrfs_set_node_key(parent, &disk_key, pslot + 1);
907 btrfs_mark_buffer_dirty(parent);
909 if (btrfs_header_nritems(mid) <= orig_slot) {
910 path->nodes[level] = right;
911 path->slots[level + 1] += 1;
912 path->slots[level] = orig_slot -
913 btrfs_header_nritems(mid);
914 free_extent_buffer(mid);
916 free_extent_buffer(right);
920 free_extent_buffer(right);
926 * readahead one full node of leaves
928 void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
929 int level, int slot, u64 objectid)
931 struct extent_buffer *node;
932 struct btrfs_disk_key disk_key;
938 int direction = path->reada;
939 struct extent_buffer *eb;
947 if (!path->nodes[level])
950 node = path->nodes[level];
951 search = btrfs_node_blockptr(node, slot);
952 blocksize = btrfs_level_size(root, level - 1);
953 eb = btrfs_find_tree_block(root, search, blocksize);
955 free_extent_buffer(eb);
959 highest_read = search;
960 lowest_read = search;
962 nritems = btrfs_header_nritems(node);
969 } else if (direction > 0) {
974 if (path->reada < 0 && objectid) {
975 btrfs_node_key(node, &disk_key, nr);
976 if (btrfs_disk_key_objectid(&disk_key) != objectid)
979 search = btrfs_node_blockptr(node, nr);
980 if ((search >= lowest_read && search <= highest_read) ||
981 (search < lowest_read && lowest_read - search <= 32768) ||
982 (search > highest_read && search - highest_read <= 32768)) {
983 readahead_tree_block(root, search, blocksize,
984 btrfs_node_ptr_generation(node, nr));
988 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
990 if(nread > (1024 * 1024) || nscan > 128)
993 if (search < lowest_read)
994 lowest_read = search;
995 if (search > highest_read)
996 highest_read = search;
1001 * look for key in the tree. path is filled in with nodes along the way
1002 * if key is found, we return zero and you can find the item in the leaf
1003 * level of the path (level 0)
1005 * If the key isn't found, the path points to the slot where it should
1006 * be inserted, and 1 is returned. If there are other errors during the
1007 * search a negative error number is returned.
1009 * if ins_len > 0, nodes and leaves will be split as we walk down the
1010 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1013 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1014 *root, struct btrfs_key *key, struct btrfs_path *p, int
1017 struct extent_buffer *b;
1021 int should_reada = p->reada;
1022 u8 lowest_level = 0;
1024 lowest_level = p->lowest_level;
1025 WARN_ON(lowest_level && ins_len > 0);
1026 WARN_ON(p->nodes[0] != NULL);
1028 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1032 extent_buffer_get(b);
1034 level = btrfs_header_level(b);
1037 wret = btrfs_cow_block(trans, root, b,
1038 p->nodes[level + 1],
1039 p->slots[level + 1],
1042 free_extent_buffer(b);
1046 BUG_ON(!cow && ins_len);
1047 if (level != btrfs_header_level(b))
1049 level = btrfs_header_level(b);
1050 p->nodes[level] = b;
1051 ret = check_block(root, p, level);
1054 ret = bin_search(b, key, level, &slot);
1056 if (ret && slot > 0)
1058 p->slots[level] = slot;
1059 if ((p->search_for_split || ins_len > 0) &&
1060 btrfs_header_nritems(b) >=
1061 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1062 int sret = split_node(trans, root, p, level);
1066 b = p->nodes[level];
1067 slot = p->slots[level];
1068 } else if (ins_len < 0) {
1069 int sret = balance_level(trans, root, p,
1073 b = p->nodes[level];
1075 btrfs_release_path(p);
1078 slot = p->slots[level];
1079 BUG_ON(btrfs_header_nritems(b) == 1);
1081 /* this is only true while dropping a snapshot */
1082 if (level == lowest_level)
1086 reada_for_search(root, p, level, slot,
1089 b = read_node_slot(root, b, slot);
1090 if (!extent_buffer_uptodate(b))
1093 p->slots[level] = slot;
1095 ins_len > btrfs_leaf_free_space(root, b)) {
1096 int sret = split_leaf(trans, root, key,
1097 p, ins_len, ret == 0);
1109 * adjust the pointers going up the tree, starting at level
1110 * making sure the right key of each node is points to 'key'.
1111 * This is used after shifting pointers to the left, so it stops
1112 * fixing up pointers when a given leaf/node is not in slot 0 of the
1115 * If this fails to write a tree block, it returns -1, but continues
1116 * fixing up the blocks in ram so the tree is consistent.
1118 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1119 struct btrfs_root *root, struct btrfs_path *path,
1120 struct btrfs_disk_key *key, int level)
1124 struct extent_buffer *t;
1126 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1127 int tslot = path->slots[i];
1128 if (!path->nodes[i])
1131 btrfs_set_node_key(t, key, tslot);
1132 btrfs_mark_buffer_dirty(path->nodes[i]);
1142 * This function isn't completely safe. It's the caller's responsibility
1143 * that the new key won't break the order
1145 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1146 struct btrfs_root *root, struct btrfs_path *path,
1147 struct btrfs_key *new_key)
1149 struct btrfs_disk_key disk_key;
1150 struct extent_buffer *eb;
1153 eb = path->nodes[0];
1154 slot = path->slots[0];
1156 btrfs_item_key(eb, &disk_key, slot - 1);
1157 if (btrfs_comp_keys(&disk_key, new_key) >= 0)
1160 if (slot < btrfs_header_nritems(eb) - 1) {
1161 btrfs_item_key(eb, &disk_key, slot + 1);
1162 if (btrfs_comp_keys(&disk_key, new_key) <= 0)
1166 btrfs_cpu_key_to_disk(&disk_key, new_key);
1167 btrfs_set_item_key(eb, &disk_key, slot);
1168 btrfs_mark_buffer_dirty(eb);
1170 fixup_low_keys(trans, root, path, &disk_key, 1);
1175 * try to push data from one node into the next node left in the
1178 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1179 * error, and > 0 if there was no room in the left hand block.
1181 static int push_node_left(struct btrfs_trans_handle *trans,
1182 struct btrfs_root *root, struct extent_buffer *dst,
1183 struct extent_buffer *src, int empty)
1190 src_nritems = btrfs_header_nritems(src);
1191 dst_nritems = btrfs_header_nritems(dst);
1192 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1193 WARN_ON(btrfs_header_generation(src) != trans->transid);
1194 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1196 if (!empty && src_nritems <= 8)
1199 if (push_items <= 0) {
1204 push_items = min(src_nritems, push_items);
1205 if (push_items < src_nritems) {
1206 /* leave at least 8 pointers in the node if
1207 * we aren't going to empty it
1209 if (src_nritems - push_items < 8) {
1210 if (push_items <= 8)
1216 push_items = min(src_nritems - 8, push_items);
1218 copy_extent_buffer(dst, src,
1219 btrfs_node_key_ptr_offset(dst_nritems),
1220 btrfs_node_key_ptr_offset(0),
1221 push_items * sizeof(struct btrfs_key_ptr));
1223 if (push_items < src_nritems) {
1224 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1225 btrfs_node_key_ptr_offset(push_items),
1226 (src_nritems - push_items) *
1227 sizeof(struct btrfs_key_ptr));
1229 btrfs_set_header_nritems(src, src_nritems - push_items);
1230 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1231 btrfs_mark_buffer_dirty(src);
1232 btrfs_mark_buffer_dirty(dst);
1238 * try to push data from one node into the next node right in the
1241 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1242 * error, and > 0 if there was no room in the right hand block.
1244 * this will only push up to 1/2 the contents of the left node over
1246 static int balance_node_right(struct btrfs_trans_handle *trans,
1247 struct btrfs_root *root,
1248 struct extent_buffer *dst,
1249 struct extent_buffer *src)
1257 WARN_ON(btrfs_header_generation(src) != trans->transid);
1258 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1260 src_nritems = btrfs_header_nritems(src);
1261 dst_nritems = btrfs_header_nritems(dst);
1262 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1263 if (push_items <= 0) {
1267 if (src_nritems < 4) {
1271 max_push = src_nritems / 2 + 1;
1272 /* don't try to empty the node */
1273 if (max_push >= src_nritems) {
1277 if (max_push < push_items)
1278 push_items = max_push;
1280 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1281 btrfs_node_key_ptr_offset(0),
1283 sizeof(struct btrfs_key_ptr));
1285 copy_extent_buffer(dst, src,
1286 btrfs_node_key_ptr_offset(0),
1287 btrfs_node_key_ptr_offset(src_nritems - push_items),
1288 push_items * sizeof(struct btrfs_key_ptr));
1290 btrfs_set_header_nritems(src, src_nritems - push_items);
1291 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1293 btrfs_mark_buffer_dirty(src);
1294 btrfs_mark_buffer_dirty(dst);
1300 * helper function to insert a new root level in the tree.
1301 * A new node is allocated, and a single item is inserted to
1302 * point to the existing root
1304 * returns zero on success or < 0 on failure.
1306 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1307 struct btrfs_root *root,
1308 struct btrfs_path *path, int level)
1311 struct extent_buffer *lower;
1312 struct extent_buffer *c;
1313 struct extent_buffer *old;
1314 struct btrfs_disk_key lower_key;
1316 BUG_ON(path->nodes[level]);
1317 BUG_ON(path->nodes[level-1] != root->node);
1319 lower = path->nodes[level-1];
1321 btrfs_item_key(lower, &lower_key, 0);
1323 btrfs_node_key(lower, &lower_key, 0);
1325 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1326 root->root_key.objectid, &lower_key,
1327 level, root->node->start, 0);
1332 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
1333 btrfs_set_header_nritems(c, 1);
1334 btrfs_set_header_level(c, level);
1335 btrfs_set_header_bytenr(c, c->start);
1336 btrfs_set_header_generation(c, trans->transid);
1337 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
1338 btrfs_set_header_owner(c, root->root_key.objectid);
1340 write_extent_buffer(c, root->fs_info->fsid,
1341 (unsigned long)btrfs_header_fsid(c),
1344 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1345 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1348 btrfs_set_node_key(c, &lower_key, 0);
1349 btrfs_set_node_blockptr(c, 0, lower->start);
1350 lower_gen = btrfs_header_generation(lower);
1351 WARN_ON(lower_gen != trans->transid);
1353 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1355 btrfs_mark_buffer_dirty(c);
1360 /* the super has an extra ref to root->node */
1361 free_extent_buffer(old);
1363 add_root_to_dirty_list(root);
1364 extent_buffer_get(c);
1365 path->nodes[level] = c;
1366 path->slots[level] = 0;
1371 * worker function to insert a single pointer in a node.
1372 * the node should have enough room for the pointer already
1374 * slot and level indicate where you want the key to go, and
1375 * blocknr is the block the key points to.
1377 * returns zero on success and < 0 on any error
1379 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1380 *root, struct btrfs_path *path, struct btrfs_disk_key
1381 *key, u64 bytenr, int slot, int level)
1383 struct extent_buffer *lower;
1386 BUG_ON(!path->nodes[level]);
1387 lower = path->nodes[level];
1388 nritems = btrfs_header_nritems(lower);
1391 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1393 if (slot != nritems) {
1394 memmove_extent_buffer(lower,
1395 btrfs_node_key_ptr_offset(slot + 1),
1396 btrfs_node_key_ptr_offset(slot),
1397 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1399 btrfs_set_node_key(lower, key, slot);
1400 btrfs_set_node_blockptr(lower, slot, bytenr);
1401 WARN_ON(trans->transid == 0);
1402 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1403 btrfs_set_header_nritems(lower, nritems + 1);
1404 btrfs_mark_buffer_dirty(lower);
1409 * split the node at the specified level in path in two.
1410 * The path is corrected to point to the appropriate node after the split
1412 * Before splitting this tries to make some room in the node by pushing
1413 * left and right, if either one works, it returns right away.
1415 * returns 0 on success and < 0 on failure
1417 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1418 *root, struct btrfs_path *path, int level)
1420 struct extent_buffer *c;
1421 struct extent_buffer *split;
1422 struct btrfs_disk_key disk_key;
1428 c = path->nodes[level];
1429 WARN_ON(btrfs_header_generation(c) != trans->transid);
1430 if (c == root->node) {
1431 /* trying to split the root, lets make a new one */
1432 ret = insert_new_root(trans, root, path, level + 1);
1436 ret = push_nodes_for_insert(trans, root, path, level);
1437 c = path->nodes[level];
1438 if (!ret && btrfs_header_nritems(c) <
1439 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1445 c_nritems = btrfs_header_nritems(c);
1446 mid = (c_nritems + 1) / 2;
1447 btrfs_node_key(c, &disk_key, mid);
1449 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1450 root->root_key.objectid,
1451 &disk_key, level, c->start, 0);
1453 return PTR_ERR(split);
1455 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
1456 btrfs_set_header_level(split, btrfs_header_level(c));
1457 btrfs_set_header_bytenr(split, split->start);
1458 btrfs_set_header_generation(split, trans->transid);
1459 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
1460 btrfs_set_header_owner(split, root->root_key.objectid);
1461 write_extent_buffer(split, root->fs_info->fsid,
1462 (unsigned long)btrfs_header_fsid(split),
1464 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1465 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1469 copy_extent_buffer(split, c,
1470 btrfs_node_key_ptr_offset(0),
1471 btrfs_node_key_ptr_offset(mid),
1472 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1473 btrfs_set_header_nritems(split, c_nritems - mid);
1474 btrfs_set_header_nritems(c, mid);
1477 btrfs_mark_buffer_dirty(c);
1478 btrfs_mark_buffer_dirty(split);
1480 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1481 path->slots[level + 1] + 1,
1486 if (path->slots[level] >= mid) {
1487 path->slots[level] -= mid;
1488 free_extent_buffer(c);
1489 path->nodes[level] = split;
1490 path->slots[level + 1] += 1;
1492 free_extent_buffer(split);
1498 * how many bytes are required to store the items in a leaf. start
1499 * and nr indicate which items in the leaf to check. This totals up the
1500 * space used both by the item structs and the item data
1502 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1505 int nritems = btrfs_header_nritems(l);
1506 int end = min(nritems, start + nr) - 1;
1510 data_len = btrfs_item_end_nr(l, start);
1511 data_len = data_len - btrfs_item_offset_nr(l, end);
1512 data_len += sizeof(struct btrfs_item) * nr;
1513 WARN_ON(data_len < 0);
1518 * The space between the end of the leaf items and
1519 * the start of the leaf data. IOW, how much room
1520 * the leaf has left for both items and data
1522 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1524 int nritems = btrfs_header_nritems(leaf);
1526 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1528 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1529 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1530 leaf_space_used(leaf, 0, nritems), nritems);
1536 * push some data in the path leaf to the right, trying to free up at
1537 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1539 * returns 1 if the push failed because the other node didn't have enough
1540 * room, 0 if everything worked out and < 0 if there were major errors.
1542 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1543 *root, struct btrfs_path *path, int data_size,
1546 struct extent_buffer *left = path->nodes[0];
1547 struct extent_buffer *right;
1548 struct extent_buffer *upper;
1549 struct btrfs_disk_key disk_key;
1555 struct btrfs_item *item;
1563 slot = path->slots[1];
1564 if (!path->nodes[1]) {
1567 upper = path->nodes[1];
1568 if (slot >= btrfs_header_nritems(upper) - 1)
1571 right = read_node_slot(root, upper, slot + 1);
1572 free_space = btrfs_leaf_free_space(root, right);
1573 if (free_space < data_size) {
1574 free_extent_buffer(right);
1578 /* cow and double check */
1579 ret = btrfs_cow_block(trans, root, right, upper,
1582 free_extent_buffer(right);
1585 free_space = btrfs_leaf_free_space(root, right);
1586 if (free_space < data_size) {
1587 free_extent_buffer(right);
1591 left_nritems = btrfs_header_nritems(left);
1592 if (left_nritems == 0) {
1593 free_extent_buffer(right);
1602 i = left_nritems - 1;
1604 item = btrfs_item_nr(left, i);
1606 if (path->slots[0] == i)
1607 push_space += data_size + sizeof(*item);
1609 this_item_size = btrfs_item_size(left, item);
1610 if (this_item_size + sizeof(*item) + push_space > free_space)
1613 push_space += this_item_size + sizeof(*item);
1619 if (push_items == 0) {
1620 free_extent_buffer(right);
1624 if (!empty && push_items == left_nritems)
1627 /* push left to right */
1628 right_nritems = btrfs_header_nritems(right);
1630 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1631 push_space -= leaf_data_end(root, left);
1633 /* make room in the right data area */
1634 data_end = leaf_data_end(root, right);
1635 memmove_extent_buffer(right,
1636 btrfs_leaf_data(right) + data_end - push_space,
1637 btrfs_leaf_data(right) + data_end,
1638 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1640 /* copy from the left data area */
1641 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1642 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1643 btrfs_leaf_data(left) + leaf_data_end(root, left),
1646 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1647 btrfs_item_nr_offset(0),
1648 right_nritems * sizeof(struct btrfs_item));
1650 /* copy the items from left to right */
1651 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1652 btrfs_item_nr_offset(left_nritems - push_items),
1653 push_items * sizeof(struct btrfs_item));
1655 /* update the item pointers */
1656 right_nritems += push_items;
1657 btrfs_set_header_nritems(right, right_nritems);
1658 push_space = BTRFS_LEAF_DATA_SIZE(root);
1659 for (i = 0; i < right_nritems; i++) {
1660 item = btrfs_item_nr(right, i);
1661 push_space -= btrfs_item_size(right, item);
1662 btrfs_set_item_offset(right, item, push_space);
1665 left_nritems -= push_items;
1666 btrfs_set_header_nritems(left, left_nritems);
1669 btrfs_mark_buffer_dirty(left);
1670 btrfs_mark_buffer_dirty(right);
1672 btrfs_item_key(right, &disk_key, 0);
1673 btrfs_set_node_key(upper, &disk_key, slot + 1);
1674 btrfs_mark_buffer_dirty(upper);
1676 /* then fixup the leaf pointer in the path */
1677 if (path->slots[0] >= left_nritems) {
1678 path->slots[0] -= left_nritems;
1679 free_extent_buffer(path->nodes[0]);
1680 path->nodes[0] = right;
1681 path->slots[1] += 1;
1683 free_extent_buffer(right);
1688 * push some data in the path leaf to the left, trying to free up at
1689 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1691 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1692 *root, struct btrfs_path *path, int data_size,
1695 struct btrfs_disk_key disk_key;
1696 struct extent_buffer *right = path->nodes[0];
1697 struct extent_buffer *left;
1703 struct btrfs_item *item;
1704 u32 old_left_nritems;
1710 u32 old_left_item_size;
1712 slot = path->slots[1];
1715 if (!path->nodes[1])
1718 right_nritems = btrfs_header_nritems(right);
1719 if (right_nritems == 0) {
1723 left = read_node_slot(root, path->nodes[1], slot - 1);
1724 free_space = btrfs_leaf_free_space(root, left);
1725 if (free_space < data_size) {
1726 free_extent_buffer(left);
1730 /* cow and double check */
1731 ret = btrfs_cow_block(trans, root, left,
1732 path->nodes[1], slot - 1, &left);
1734 /* we hit -ENOSPC, but it isn't fatal here */
1735 free_extent_buffer(left);
1739 free_space = btrfs_leaf_free_space(root, left);
1740 if (free_space < data_size) {
1741 free_extent_buffer(left);
1748 nr = right_nritems - 1;
1750 for (i = 0; i < nr; i++) {
1751 item = btrfs_item_nr(right, i);
1753 if (path->slots[0] == i)
1754 push_space += data_size + sizeof(*item);
1756 this_item_size = btrfs_item_size(right, item);
1757 if (this_item_size + sizeof(*item) + push_space > free_space)
1761 push_space += this_item_size + sizeof(*item);
1764 if (push_items == 0) {
1765 free_extent_buffer(left);
1768 if (!empty && push_items == btrfs_header_nritems(right))
1771 /* push data from right to left */
1772 copy_extent_buffer(left, right,
1773 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1774 btrfs_item_nr_offset(0),
1775 push_items * sizeof(struct btrfs_item));
1777 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1778 btrfs_item_offset_nr(right, push_items -1);
1780 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1781 leaf_data_end(root, left) - push_space,
1782 btrfs_leaf_data(right) +
1783 btrfs_item_offset_nr(right, push_items - 1),
1785 old_left_nritems = btrfs_header_nritems(left);
1786 BUG_ON(old_left_nritems == 0);
1788 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1789 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1792 item = btrfs_item_nr(left, i);
1793 ioff = btrfs_item_offset(left, item);
1794 btrfs_set_item_offset(left, item,
1795 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1797 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1799 /* fixup right node */
1800 if (push_items > right_nritems) {
1801 printk("push items %d nr %u\n", push_items, right_nritems);
1805 if (push_items < right_nritems) {
1806 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1807 leaf_data_end(root, right);
1808 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1809 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1810 btrfs_leaf_data(right) +
1811 leaf_data_end(root, right), push_space);
1813 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1814 btrfs_item_nr_offset(push_items),
1815 (btrfs_header_nritems(right) - push_items) *
1816 sizeof(struct btrfs_item));
1818 right_nritems -= push_items;
1819 btrfs_set_header_nritems(right, right_nritems);
1820 push_space = BTRFS_LEAF_DATA_SIZE(root);
1821 for (i = 0; i < right_nritems; i++) {
1822 item = btrfs_item_nr(right, i);
1823 push_space = push_space - btrfs_item_size(right, item);
1824 btrfs_set_item_offset(right, item, push_space);
1827 btrfs_mark_buffer_dirty(left);
1829 btrfs_mark_buffer_dirty(right);
1831 btrfs_item_key(right, &disk_key, 0);
1832 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1836 /* then fixup the leaf pointer in the path */
1837 if (path->slots[0] < push_items) {
1838 path->slots[0] += old_left_nritems;
1839 free_extent_buffer(path->nodes[0]);
1840 path->nodes[0] = left;
1841 path->slots[1] -= 1;
1843 free_extent_buffer(left);
1844 path->slots[0] -= push_items;
1846 BUG_ON(path->slots[0] < 0);
1851 * split the path's leaf in two, making sure there is at least data_size
1852 * available for the resulting leaf level of the path.
1854 * returns 0 if all went well and < 0 on failure.
1856 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
1857 struct btrfs_root *root,
1858 struct btrfs_path *path,
1859 struct extent_buffer *l,
1860 struct extent_buffer *right,
1861 int slot, int mid, int nritems)
1868 struct btrfs_disk_key disk_key;
1870 nritems = nritems - mid;
1871 btrfs_set_header_nritems(right, nritems);
1872 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1874 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1875 btrfs_item_nr_offset(mid),
1876 nritems * sizeof(struct btrfs_item));
1878 copy_extent_buffer(right, l,
1879 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1880 data_copy_size, btrfs_leaf_data(l) +
1881 leaf_data_end(root, l), data_copy_size);
1883 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
1884 btrfs_item_end_nr(l, mid);
1886 for (i = 0; i < nritems; i++) {
1887 struct btrfs_item *item = btrfs_item_nr(right, i);
1888 u32 ioff = btrfs_item_offset(right, item);
1889 btrfs_set_item_offset(right, item, ioff + rt_data_off);
1892 btrfs_set_header_nritems(l, mid);
1894 btrfs_item_key(right, &disk_key, 0);
1895 wret = insert_ptr(trans, root, path, &disk_key, right->start,
1896 path->slots[1] + 1, 1);
1900 btrfs_mark_buffer_dirty(right);
1901 btrfs_mark_buffer_dirty(l);
1902 BUG_ON(path->slots[0] != slot);
1905 free_extent_buffer(path->nodes[0]);
1906 path->nodes[0] = right;
1907 path->slots[0] -= mid;
1908 path->slots[1] += 1;
1910 free_extent_buffer(right);
1913 BUG_ON(path->slots[0] < 0);
1919 * split the path's leaf in two, making sure there is at least data_size
1920 * available for the resulting leaf level of the path.
1922 * returns 0 if all went well and < 0 on failure.
1924 static noinline int split_leaf(struct btrfs_trans_handle *trans,
1925 struct btrfs_root *root,
1926 struct btrfs_key *ins_key,
1927 struct btrfs_path *path, int data_size,
1930 struct btrfs_disk_key disk_key;
1931 struct extent_buffer *l;
1935 struct extent_buffer *right;
1939 int num_doubles = 0;
1941 /* first try to make some room by pushing left and right */
1942 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
1943 wret = push_leaf_right(trans, root, path, data_size, 0);
1947 wret = push_leaf_left(trans, root, path, data_size, 0);
1953 /* did the pushes work? */
1954 if (btrfs_leaf_free_space(root, l) >= data_size)
1958 if (!path->nodes[1]) {
1959 ret = insert_new_root(trans, root, path, 1);
1966 slot = path->slots[0];
1967 nritems = btrfs_header_nritems(l);
1968 mid = (nritems + 1) / 2;
1972 leaf_space_used(l, mid, nritems - mid) + data_size >
1973 BTRFS_LEAF_DATA_SIZE(root)) {
1974 if (slot >= nritems) {
1978 if (mid != nritems &&
1979 leaf_space_used(l, mid, nritems - mid) +
1980 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
1986 if (leaf_space_used(l, 0, mid) + data_size >
1987 BTRFS_LEAF_DATA_SIZE(root)) {
1988 if (!extend && data_size && slot == 0) {
1990 } else if ((extend || !data_size) && slot == 0) {
1994 if (mid != nritems &&
1995 leaf_space_used(l, mid, nritems - mid) +
1996 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2004 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2006 btrfs_item_key(l, &disk_key, mid);
2008 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2009 root->root_key.objectid,
2010 &disk_key, 0, l->start, 0);
2011 if (IS_ERR(right)) {
2013 return PTR_ERR(right);
2016 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2017 btrfs_set_header_bytenr(right, right->start);
2018 btrfs_set_header_generation(right, trans->transid);
2019 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
2020 btrfs_set_header_owner(right, root->root_key.objectid);
2021 btrfs_set_header_level(right, 0);
2022 write_extent_buffer(right, root->fs_info->fsid,
2023 (unsigned long)btrfs_header_fsid(right),
2026 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2027 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2032 btrfs_set_header_nritems(right, 0);
2033 wret = insert_ptr(trans, root, path,
2034 &disk_key, right->start,
2035 path->slots[1] + 1, 1);
2039 free_extent_buffer(path->nodes[0]);
2040 path->nodes[0] = right;
2042 path->slots[1] += 1;
2044 btrfs_set_header_nritems(right, 0);
2045 wret = insert_ptr(trans, root, path,
2051 free_extent_buffer(path->nodes[0]);
2052 path->nodes[0] = right;
2054 if (path->slots[1] == 0) {
2055 wret = fixup_low_keys(trans, root,
2056 path, &disk_key, 1);
2061 btrfs_mark_buffer_dirty(right);
2065 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
2069 BUG_ON(num_doubles != 0);
2078 * This function splits a single item into two items,
2079 * giving 'new_key' to the new item and splitting the
2080 * old one at split_offset (from the start of the item).
2082 * The path may be released by this operation. After
2083 * the split, the path is pointing to the old item. The
2084 * new item is going to be in the same node as the old one.
2086 * Note, the item being split must be smaller enough to live alone on
2087 * a tree block with room for one extra struct btrfs_item
2089 * This allows us to split the item in place, keeping a lock on the
2090 * leaf the entire time.
2092 int btrfs_split_item(struct btrfs_trans_handle *trans,
2093 struct btrfs_root *root,
2094 struct btrfs_path *path,
2095 struct btrfs_key *new_key,
2096 unsigned long split_offset)
2099 struct extent_buffer *leaf;
2100 struct btrfs_key orig_key;
2101 struct btrfs_item *item;
2102 struct btrfs_item *new_item;
2107 struct btrfs_disk_key disk_key;
2110 leaf = path->nodes[0];
2111 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
2112 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
2115 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2116 btrfs_release_path(path);
2118 path->search_for_split = 1;
2120 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
2121 path->search_for_split = 0;
2123 /* if our item isn't there or got smaller, return now */
2124 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
2129 ret = split_leaf(trans, root, &orig_key, path, 0, 0);
2132 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
2133 leaf = path->nodes[0];
2136 item = btrfs_item_nr(leaf, path->slots[0]);
2137 orig_offset = btrfs_item_offset(leaf, item);
2138 item_size = btrfs_item_size(leaf, item);
2141 buf = kmalloc(item_size, GFP_NOFS);
2142 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
2143 path->slots[0]), item_size);
2144 slot = path->slots[0] + 1;
2145 leaf = path->nodes[0];
2147 nritems = btrfs_header_nritems(leaf);
2149 if (slot != nritems) {
2150 /* shift the items */
2151 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2152 btrfs_item_nr_offset(slot),
2153 (nritems - slot) * sizeof(struct btrfs_item));
2157 btrfs_cpu_key_to_disk(&disk_key, new_key);
2158 btrfs_set_item_key(leaf, &disk_key, slot);
2160 new_item = btrfs_item_nr(leaf, slot);
2162 btrfs_set_item_offset(leaf, new_item, orig_offset);
2163 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
2165 btrfs_set_item_offset(leaf, item,
2166 orig_offset + item_size - split_offset);
2167 btrfs_set_item_size(leaf, item, split_offset);
2169 btrfs_set_header_nritems(leaf, nritems + 1);
2171 /* write the data for the start of the original item */
2172 write_extent_buffer(leaf, buf,
2173 btrfs_item_ptr_offset(leaf, path->slots[0]),
2176 /* write the data for the new item */
2177 write_extent_buffer(leaf, buf + split_offset,
2178 btrfs_item_ptr_offset(leaf, slot),
2179 item_size - split_offset);
2180 btrfs_mark_buffer_dirty(leaf);
2183 if (btrfs_leaf_free_space(root, leaf) < 0) {
2184 btrfs_print_leaf(root, leaf);
2191 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2192 struct btrfs_root *root,
2193 struct btrfs_path *path,
2194 u32 new_size, int from_end)
2198 struct extent_buffer *leaf;
2199 struct btrfs_item *item;
2201 unsigned int data_end;
2202 unsigned int old_data_start;
2203 unsigned int old_size;
2204 unsigned int size_diff;
2207 leaf = path->nodes[0];
2208 slot = path->slots[0];
2210 old_size = btrfs_item_size_nr(leaf, slot);
2211 if (old_size == new_size)
2214 nritems = btrfs_header_nritems(leaf);
2215 data_end = leaf_data_end(root, leaf);
2217 old_data_start = btrfs_item_offset_nr(leaf, slot);
2219 size_diff = old_size - new_size;
2222 BUG_ON(slot >= nritems);
2225 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2227 /* first correct the data pointers */
2228 for (i = slot; i < nritems; i++) {
2230 item = btrfs_item_nr(leaf, i);
2231 ioff = btrfs_item_offset(leaf, item);
2232 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2235 /* shift the data */
2237 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2238 data_end + size_diff, btrfs_leaf_data(leaf) +
2239 data_end, old_data_start + new_size - data_end);
2241 struct btrfs_disk_key disk_key;
2244 btrfs_item_key(leaf, &disk_key, slot);
2246 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2248 struct btrfs_file_extent_item *fi;
2250 fi = btrfs_item_ptr(leaf, slot,
2251 struct btrfs_file_extent_item);
2252 fi = (struct btrfs_file_extent_item *)(
2253 (unsigned long)fi - size_diff);
2255 if (btrfs_file_extent_type(leaf, fi) ==
2256 BTRFS_FILE_EXTENT_INLINE) {
2257 ptr = btrfs_item_ptr_offset(leaf, slot);
2258 memmove_extent_buffer(leaf, ptr,
2260 offsetof(struct btrfs_file_extent_item,
2265 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2266 data_end + size_diff, btrfs_leaf_data(leaf) +
2267 data_end, old_data_start - data_end);
2269 offset = btrfs_disk_key_offset(&disk_key);
2270 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2271 btrfs_set_item_key(leaf, &disk_key, slot);
2273 fixup_low_keys(trans, root, path, &disk_key, 1);
2276 item = btrfs_item_nr(leaf, slot);
2277 btrfs_set_item_size(leaf, item, new_size);
2278 btrfs_mark_buffer_dirty(leaf);
2281 if (btrfs_leaf_free_space(root, leaf) < 0) {
2282 btrfs_print_leaf(root, leaf);
2288 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2289 struct btrfs_root *root, struct btrfs_path *path,
2294 struct extent_buffer *leaf;
2295 struct btrfs_item *item;
2297 unsigned int data_end;
2298 unsigned int old_data;
2299 unsigned int old_size;
2302 leaf = path->nodes[0];
2304 nritems = btrfs_header_nritems(leaf);
2305 data_end = leaf_data_end(root, leaf);
2307 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2308 btrfs_print_leaf(root, leaf);
2311 slot = path->slots[0];
2312 old_data = btrfs_item_end_nr(leaf, slot);
2315 if (slot >= nritems) {
2316 btrfs_print_leaf(root, leaf);
2317 printk("slot %d too large, nritems %d\n", slot, nritems);
2322 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2324 /* first correct the data pointers */
2325 for (i = slot; i < nritems; i++) {
2327 item = btrfs_item_nr(leaf, i);
2328 ioff = btrfs_item_offset(leaf, item);
2329 btrfs_set_item_offset(leaf, item, ioff - data_size);
2332 /* shift the data */
2333 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2334 data_end - data_size, btrfs_leaf_data(leaf) +
2335 data_end, old_data - data_end);
2337 data_end = old_data;
2338 old_size = btrfs_item_size_nr(leaf, slot);
2339 item = btrfs_item_nr(leaf, slot);
2340 btrfs_set_item_size(leaf, item, old_size + data_size);
2341 btrfs_mark_buffer_dirty(leaf);
2344 if (btrfs_leaf_free_space(root, leaf) < 0) {
2345 btrfs_print_leaf(root, leaf);
2352 * Given a key and some data, insert an item into the tree.
2353 * This does all the path init required, making room in the tree if needed.
2355 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2356 struct btrfs_root *root,
2357 struct btrfs_path *path,
2358 struct btrfs_key *cpu_key, u32 *data_size,
2361 struct extent_buffer *leaf;
2362 struct btrfs_item *item;
2369 unsigned int data_end;
2370 struct btrfs_disk_key disk_key;
2372 for (i = 0; i < nr; i++) {
2373 total_data += data_size[i];
2376 /* create a root if there isn't one */
2380 total_size = total_data + nr * sizeof(struct btrfs_item);
2381 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2388 leaf = path->nodes[0];
2390 nritems = btrfs_header_nritems(leaf);
2391 data_end = leaf_data_end(root, leaf);
2393 if (btrfs_leaf_free_space(root, leaf) < total_size) {
2394 btrfs_print_leaf(root, leaf);
2395 printk("not enough freespace need %u have %d\n",
2396 total_size, btrfs_leaf_free_space(root, leaf));
2400 slot = path->slots[0];
2403 if (slot != nritems) {
2405 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2407 if (old_data < data_end) {
2408 btrfs_print_leaf(root, leaf);
2409 printk("slot %d old_data %d data_end %d\n",
2410 slot, old_data, data_end);
2414 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2416 /* first correct the data pointers */
2417 for (i = slot; i < nritems; i++) {
2420 item = btrfs_item_nr(leaf, i);
2421 ioff = btrfs_item_offset(leaf, item);
2422 btrfs_set_item_offset(leaf, item, ioff - total_data);
2425 /* shift the items */
2426 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2427 btrfs_item_nr_offset(slot),
2428 (nritems - slot) * sizeof(struct btrfs_item));
2430 /* shift the data */
2431 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2432 data_end - total_data, btrfs_leaf_data(leaf) +
2433 data_end, old_data - data_end);
2434 data_end = old_data;
2437 /* setup the item for the new data */
2438 for (i = 0; i < nr; i++) {
2439 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2440 btrfs_set_item_key(leaf, &disk_key, slot + i);
2441 item = btrfs_item_nr(leaf, slot + i);
2442 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2443 data_end -= data_size[i];
2444 btrfs_set_item_size(leaf, item, data_size[i]);
2446 btrfs_set_header_nritems(leaf, nritems + nr);
2447 btrfs_mark_buffer_dirty(leaf);
2451 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2452 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2455 if (btrfs_leaf_free_space(root, leaf) < 0) {
2456 btrfs_print_leaf(root, leaf);
2465 * Given a key and some data, insert an item into the tree.
2466 * This does all the path init required, making room in the tree if needed.
2468 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2469 *root, struct btrfs_key *cpu_key, void *data, u32
2473 struct btrfs_path *path;
2474 struct extent_buffer *leaf;
2477 path = btrfs_alloc_path();
2479 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2481 leaf = path->nodes[0];
2482 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2483 write_extent_buffer(leaf, data, ptr, data_size);
2484 btrfs_mark_buffer_dirty(leaf);
2486 btrfs_free_path(path);
2491 * delete the pointer from a given node.
2493 * If the delete empties a node, the node is removed from the tree,
2494 * continuing all the way the root if required. The root is converted into
2495 * a leaf if all the nodes are emptied.
2497 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2498 struct btrfs_path *path, int level, int slot)
2500 struct extent_buffer *parent = path->nodes[level];
2505 nritems = btrfs_header_nritems(parent);
2506 if (slot != nritems -1) {
2507 memmove_extent_buffer(parent,
2508 btrfs_node_key_ptr_offset(slot),
2509 btrfs_node_key_ptr_offset(slot + 1),
2510 sizeof(struct btrfs_key_ptr) *
2511 (nritems - slot - 1));
2514 btrfs_set_header_nritems(parent, nritems);
2515 if (nritems == 0 && parent == root->node) {
2516 BUG_ON(btrfs_header_level(root->node) != 1);
2517 /* just turn the root into a leaf and break */
2518 btrfs_set_header_level(root->node, 0);
2519 } else if (slot == 0) {
2520 struct btrfs_disk_key disk_key;
2522 btrfs_node_key(parent, &disk_key, 0);
2523 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2527 btrfs_mark_buffer_dirty(parent);
2532 * a helper function to delete the leaf pointed to by path->slots[1] and
2535 * This deletes the pointer in path->nodes[1] and frees the leaf
2536 * block extent. zero is returned if it all worked out, < 0 otherwise.
2538 * The path must have already been setup for deleting the leaf, including
2539 * all the proper balancing. path->nodes[1] must be locked.
2541 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
2542 struct btrfs_root *root,
2543 struct btrfs_path *path,
2544 struct extent_buffer *leaf)
2548 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
2549 ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
2553 ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
2554 0, root->root_key.objectid, 0, 0);
2559 * delete the item at the leaf level in path. If that empties
2560 * the leaf, remove it from the tree
2562 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2563 struct btrfs_path *path, int slot, int nr)
2565 struct extent_buffer *leaf;
2566 struct btrfs_item *item;
2574 leaf = path->nodes[0];
2575 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2577 for (i = 0; i < nr; i++)
2578 dsize += btrfs_item_size_nr(leaf, slot + i);
2580 nritems = btrfs_header_nritems(leaf);
2582 if (slot + nr != nritems) {
2584 int data_end = leaf_data_end(root, leaf);
2586 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2588 btrfs_leaf_data(leaf) + data_end,
2589 last_off - data_end);
2591 for (i = slot + nr; i < nritems; i++) {
2594 item = btrfs_item_nr(leaf, i);
2595 ioff = btrfs_item_offset(leaf, item);
2596 btrfs_set_item_offset(leaf, item, ioff + dsize);
2599 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2600 btrfs_item_nr_offset(slot + nr),
2601 sizeof(struct btrfs_item) *
2602 (nritems - slot - nr));
2604 btrfs_set_header_nritems(leaf, nritems - nr);
2607 /* delete the leaf if we've emptied it */
2609 if (leaf == root->node) {
2610 btrfs_set_header_level(leaf, 0);
2612 clean_tree_block(trans, root, leaf);
2613 wait_on_tree_block_writeback(root, leaf);
2615 wret = btrfs_del_leaf(trans, root, path, leaf);
2621 int used = leaf_space_used(leaf, 0, nritems);
2623 struct btrfs_disk_key disk_key;
2625 btrfs_item_key(leaf, &disk_key, 0);
2626 wret = fixup_low_keys(trans, root, path,
2632 /* delete the leaf if it is mostly empty */
2633 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2634 /* push_leaf_left fixes the path.
2635 * make sure the path still points to our leaf
2636 * for possible call to del_ptr below
2638 slot = path->slots[1];
2639 extent_buffer_get(leaf);
2641 wret = push_leaf_left(trans, root, path, 1, 1);
2642 if (wret < 0 && wret != -ENOSPC)
2645 if (path->nodes[0] == leaf &&
2646 btrfs_header_nritems(leaf)) {
2647 wret = push_leaf_right(trans, root, path, 1, 1);
2648 if (wret < 0 && wret != -ENOSPC)
2652 if (btrfs_header_nritems(leaf) == 0) {
2653 clean_tree_block(trans, root, leaf);
2654 wait_on_tree_block_writeback(root, leaf);
2656 path->slots[1] = slot;
2657 ret = btrfs_del_leaf(trans, root, path, leaf);
2659 free_extent_buffer(leaf);
2662 btrfs_mark_buffer_dirty(leaf);
2663 free_extent_buffer(leaf);
2666 btrfs_mark_buffer_dirty(leaf);
2673 * walk up the tree as far as required to find the previous leaf.
2674 * returns 0 if it found something or 1 if there are no lesser leaves.
2675 * returns < 0 on io errors.
2677 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2681 struct extent_buffer *c;
2682 struct extent_buffer *next = NULL;
2684 while(level < BTRFS_MAX_LEVEL) {
2685 if (!path->nodes[level])
2688 slot = path->slots[level];
2689 c = path->nodes[level];
2692 if (level == BTRFS_MAX_LEVEL)
2698 next = read_node_slot(root, c, slot);
2701 path->slots[level] = slot;
2704 c = path->nodes[level];
2705 free_extent_buffer(c);
2706 slot = btrfs_header_nritems(next);
2709 path->nodes[level] = next;
2710 path->slots[level] = slot;
2713 next = read_node_slot(root, next, slot);
2719 * walk up the tree as far as required to find the next leaf.
2720 * returns 0 if it found something or 1 if there are no greater leaves.
2721 * returns < 0 on io errors.
2723 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2727 struct extent_buffer *c;
2728 struct extent_buffer *next = NULL;
2730 while(level < BTRFS_MAX_LEVEL) {
2731 if (!path->nodes[level])
2734 slot = path->slots[level] + 1;
2735 c = path->nodes[level];
2736 if (slot >= btrfs_header_nritems(c)) {
2738 if (level == BTRFS_MAX_LEVEL)
2744 reada_for_search(root, path, level, slot, 0);
2746 next = read_node_slot(root, c, slot);
2751 path->slots[level] = slot;
2754 c = path->nodes[level];
2755 free_extent_buffer(c);
2756 path->nodes[level] = next;
2757 path->slots[level] = 0;
2761 reada_for_search(root, path, level, 0, 0);
2762 next = read_node_slot(root, next, 0);
2769 int btrfs_previous_item(struct btrfs_root *root,
2770 struct btrfs_path *path, u64 min_objectid,
2773 struct btrfs_key found_key;
2774 struct extent_buffer *leaf;
2778 if (path->slots[0] == 0) {
2779 ret = btrfs_prev_leaf(root, path);
2785 leaf = path->nodes[0];
2786 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2787 if (found_key.type == type)