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.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size, int extend);
30 static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src);
33 static int balance_node_right(struct btrfs_trans_handle *trans,
34 struct btrfs_root *root,
35 struct extent_buffer *dst_buf,
36 struct extent_buffer *src_buf);
37 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
40 inline void btrfs_init_path(struct btrfs_path *p)
42 memset(p, 0, sizeof(*p));
45 struct btrfs_path *btrfs_alloc_path(void)
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
50 btrfs_init_path(path);
56 void btrfs_free_path(struct btrfs_path *p)
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
62 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
68 free_extent_buffer(p->nodes[i]);
70 memset(p, 0, sizeof(*p));
73 int btrfs_copy_root(struct btrfs_trans_handle *trans,
74 struct btrfs_root *root,
75 struct extent_buffer *buf,
76 struct extent_buffer **cow_ret, u64 new_root_objectid)
78 struct extent_buffer *cow;
82 struct btrfs_key first_key;
83 struct btrfs_root new_root;
85 memcpy(&new_root, root, sizeof(new_root));
86 new_root.root_key.objectid = new_root_objectid;
88 WARN_ON(root->ref_cows && trans->transid !=
89 root->fs_info->running_transaction->transid);
90 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
92 level = btrfs_header_level(buf);
93 nritems = btrfs_header_nritems(buf);
96 btrfs_item_key_to_cpu(buf, &first_key, 0);
98 btrfs_node_key_to_cpu(buf, &first_key, 0);
100 first_key.objectid = 0;
102 cow = __btrfs_alloc_free_block(trans, &new_root, buf->len,
104 trans->transid, first_key.objectid,
105 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_owner(cow, new_root_objectid);
114 WARN_ON(btrfs_header_generation(buf) > trans->transid);
115 ret = btrfs_inc_ref(trans, &new_root, buf);
119 btrfs_mark_buffer_dirty(cow);
124 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
125 struct btrfs_root *root,
126 struct extent_buffer *buf,
127 struct extent_buffer *parent, int parent_slot,
128 struct extent_buffer **cow_ret,
129 u64 search_start, u64 empty_size)
132 struct extent_buffer *cow;
135 int different_trans = 0;
137 struct btrfs_key first_key;
139 if (root->ref_cows) {
140 root_gen = trans->transid;
145 WARN_ON(root->ref_cows && trans->transid !=
146 root->fs_info->running_transaction->transid);
147 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
149 level = btrfs_header_level(buf);
150 nritems = btrfs_header_nritems(buf);
153 btrfs_item_key_to_cpu(buf, &first_key, 0);
155 btrfs_node_key_to_cpu(buf, &first_key, 0);
157 first_key.objectid = 0;
159 cow = __btrfs_alloc_free_block(trans, root, buf->len,
160 root->root_key.objectid,
161 root_gen, first_key.objectid, level,
162 search_start, empty_size);
166 copy_extent_buffer(cow, buf, 0, 0, cow->len);
167 btrfs_set_header_bytenr(cow, cow->start);
168 btrfs_set_header_generation(cow, trans->transid);
169 btrfs_set_header_owner(cow, root->root_key.objectid);
171 WARN_ON(btrfs_header_generation(buf) > trans->transid);
172 if (btrfs_header_generation(buf) != trans->transid) {
174 ret = btrfs_inc_ref(trans, root, buf);
178 clean_tree_block(trans, root, buf);
181 if (buf == root->node) {
182 root_gen = btrfs_header_generation(buf);
184 extent_buffer_get(cow);
185 if (buf != root->commit_root) {
186 btrfs_free_extent(trans, root, buf->start,
187 buf->len, root->root_key.objectid,
190 free_extent_buffer(buf);
192 root_gen = btrfs_header_generation(parent);
193 btrfs_set_node_blockptr(parent, parent_slot,
195 WARN_ON(trans->transid == 0);
196 btrfs_set_node_ptr_generation(parent, parent_slot,
198 btrfs_mark_buffer_dirty(parent);
199 WARN_ON(btrfs_header_generation(parent) != trans->transid);
200 btrfs_free_extent(trans, root, buf->start, buf->len,
201 btrfs_header_owner(parent), root_gen,
204 free_extent_buffer(buf);
205 btrfs_mark_buffer_dirty(cow);
210 int btrfs_cow_block(struct btrfs_trans_handle *trans,
211 struct btrfs_root *root, struct extent_buffer *buf,
212 struct extent_buffer *parent, int parent_slot,
213 struct extent_buffer **cow_ret)
217 if (trans->transaction != root->fs_info->running_transaction) {
218 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
219 root->fs_info->running_transaction->transid);
222 if (trans->transid != root->fs_info->generation) {
223 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
224 root->fs_info->generation);
227 if (btrfs_header_generation(buf) == trans->transid) {
232 search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
233 ret = __btrfs_cow_block(trans, root, buf, parent,
234 parent_slot, cow_ret, search_start, 0);
238 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
240 if (blocknr < other && other - (blocknr + blocksize) < 32768)
242 if (blocknr > other && blocknr - (other + blocksize) < 32768)
248 * compare two keys in a memcmp fashion
250 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
254 btrfs_disk_key_to_cpu(&k1, disk);
256 if (k1.objectid > k2->objectid)
258 if (k1.objectid < k2->objectid)
260 if (k1.type > k2->type)
262 if (k1.type < k2->type)
264 if (k1.offset > k2->offset)
266 if (k1.offset < k2->offset)
272 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
273 struct btrfs_root *root, struct extent_buffer *parent,
274 int start_slot, int cache_only, u64 *last_ret,
275 struct btrfs_key *progress)
277 struct extent_buffer *cur;
278 struct extent_buffer *tmp;
280 u64 search_start = *last_ret;
290 int progress_passed = 0;
291 struct btrfs_disk_key disk_key;
293 parent_level = btrfs_header_level(parent);
294 if (cache_only && parent_level != 1)
297 if (trans->transaction != root->fs_info->running_transaction) {
298 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
299 root->fs_info->running_transaction->transid);
302 if (trans->transid != root->fs_info->generation) {
303 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
304 root->fs_info->generation);
308 parent_nritems = btrfs_header_nritems(parent);
309 blocksize = btrfs_level_size(root, parent_level - 1);
310 end_slot = parent_nritems;
312 if (parent_nritems == 1)
315 for (i = start_slot; i < end_slot; i++) {
318 if (!parent->map_token) {
319 map_extent_buffer(parent,
320 btrfs_node_key_ptr_offset(i),
321 sizeof(struct btrfs_key_ptr),
322 &parent->map_token, &parent->kaddr,
323 &parent->map_start, &parent->map_len,
326 btrfs_node_key(parent, &disk_key, i);
327 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
331 blocknr = btrfs_node_blockptr(parent, i);
333 last_block = blocknr;
336 other = btrfs_node_blockptr(parent, i - 1);
337 close = close_blocks(blocknr, other, blocksize);
339 if (close && i < end_slot - 2) {
340 other = btrfs_node_blockptr(parent, i + 1);
341 close = close_blocks(blocknr, other, blocksize);
344 last_block = blocknr;
347 if (parent->map_token) {
348 unmap_extent_buffer(parent, parent->map_token,
350 parent->map_token = NULL;
353 cur = btrfs_find_tree_block(root, blocknr, blocksize);
355 uptodate = btrfs_buffer_uptodate(cur);
358 if (!cur || !uptodate) {
360 free_extent_buffer(cur);
364 cur = read_tree_block(root, blocknr,
366 } else if (!uptodate) {
367 btrfs_read_buffer(cur);
370 if (search_start == 0)
371 search_start = last_block;
373 err = __btrfs_cow_block(trans, root, cur, parent, i,
376 (end_slot - i) * blocksize));
378 free_extent_buffer(cur);
381 search_start = tmp->start;
382 last_block = tmp->start;
383 *last_ret = search_start;
384 if (parent_level == 1)
385 btrfs_clear_buffer_defrag(tmp);
386 free_extent_buffer(tmp);
388 if (parent->map_token) {
389 unmap_extent_buffer(parent, parent->map_token,
391 parent->map_token = NULL;
397 * The leaf data grows from end-to-front in the node.
398 * this returns the address of the start of the last item,
399 * which is the stop of the leaf data stack
401 static inline unsigned int leaf_data_end(struct btrfs_root *root,
402 struct extent_buffer *leaf)
404 u32 nr = btrfs_header_nritems(leaf);
406 return BTRFS_LEAF_DATA_SIZE(root);
407 return btrfs_item_offset_nr(leaf, nr - 1);
410 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
413 struct extent_buffer *parent = NULL;
414 struct extent_buffer *node = path->nodes[level];
415 struct btrfs_disk_key parent_key;
416 struct btrfs_disk_key node_key;
419 struct btrfs_key cpukey;
420 u32 nritems = btrfs_header_nritems(node);
422 if (path->nodes[level + 1])
423 parent = path->nodes[level + 1];
425 slot = path->slots[level];
426 BUG_ON(nritems == 0);
428 parent_slot = path->slots[level + 1];
429 btrfs_node_key(parent, &parent_key, parent_slot);
430 btrfs_node_key(node, &node_key, 0);
431 BUG_ON(memcmp(&parent_key, &node_key,
432 sizeof(struct btrfs_disk_key)));
433 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
434 btrfs_header_bytenr(node));
436 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
438 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
439 btrfs_node_key(node, &node_key, slot);
440 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
442 if (slot < nritems - 1) {
443 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
444 btrfs_node_key(node, &node_key, slot);
445 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
450 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
453 struct extent_buffer *leaf = path->nodes[level];
454 struct extent_buffer *parent = NULL;
456 struct btrfs_key cpukey;
457 struct btrfs_disk_key parent_key;
458 struct btrfs_disk_key leaf_key;
459 int slot = path->slots[0];
461 u32 nritems = btrfs_header_nritems(leaf);
463 if (path->nodes[level + 1])
464 parent = path->nodes[level + 1];
470 parent_slot = path->slots[level + 1];
471 btrfs_node_key(parent, &parent_key, parent_slot);
472 btrfs_item_key(leaf, &leaf_key, 0);
474 BUG_ON(memcmp(&parent_key, &leaf_key,
475 sizeof(struct btrfs_disk_key)));
476 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
477 btrfs_header_bytenr(leaf));
480 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
481 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
482 btrfs_item_key(leaf, &leaf_key, i);
483 if (comp_keys(&leaf_key, &cpukey) >= 0) {
484 btrfs_print_leaf(root, leaf);
485 printk("slot %d offset bad key\n", i);
488 if (btrfs_item_offset_nr(leaf, i) !=
489 btrfs_item_end_nr(leaf, i + 1)) {
490 btrfs_print_leaf(root, leaf);
491 printk("slot %d offset bad\n", i);
495 if (btrfs_item_offset_nr(leaf, i) +
496 btrfs_item_size_nr(leaf, i) !=
497 BTRFS_LEAF_DATA_SIZE(root)) {
498 btrfs_print_leaf(root, leaf);
499 printk("slot %d first offset bad\n", i);
505 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
506 btrfs_print_leaf(root, leaf);
507 printk("slot %d bad size \n", nritems - 1);
512 if (slot != 0 && slot < nritems - 1) {
513 btrfs_item_key(leaf, &leaf_key, slot);
514 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
515 if (comp_keys(&leaf_key, &cpukey) <= 0) {
516 btrfs_print_leaf(root, leaf);
517 printk("slot %d offset bad key\n", slot);
520 if (btrfs_item_offset_nr(leaf, slot - 1) !=
521 btrfs_item_end_nr(leaf, slot)) {
522 btrfs_print_leaf(root, leaf);
523 printk("slot %d offset bad\n", slot);
527 if (slot < nritems - 1) {
528 btrfs_item_key(leaf, &leaf_key, slot);
529 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
530 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
531 if (btrfs_item_offset_nr(leaf, slot) !=
532 btrfs_item_end_nr(leaf, slot + 1)) {
533 btrfs_print_leaf(root, leaf);
534 printk("slot %d offset bad\n", slot);
538 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
539 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
543 static int check_block(struct btrfs_root *root, struct btrfs_path *path,
548 struct extent_buffer *buf = path->nodes[level];
550 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
551 (unsigned long)btrfs_header_fsid(buf),
553 printk("warning bad block %Lu\n", buf->start);
558 return check_leaf(root, path, level);
559 return check_node(root, path, level);
563 * search for key in the extent_buffer. The items start at offset p,
564 * and they are item_size apart. There are 'max' items in p.
566 * the slot in the array is returned via slot, and it points to
567 * the place where you would insert key if it is not found in
570 * slot may point to max if the key is bigger than all of the keys
572 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
573 int item_size, struct btrfs_key *key,
580 struct btrfs_disk_key *tmp = NULL;
581 struct btrfs_disk_key unaligned;
582 unsigned long offset;
583 char *map_token = NULL;
585 unsigned long map_start = 0;
586 unsigned long map_len = 0;
590 mid = (low + high) / 2;
591 offset = p + mid * item_size;
593 if (!map_token || offset < map_start ||
594 (offset + sizeof(struct btrfs_disk_key)) >
595 map_start + map_len) {
597 unmap_extent_buffer(eb, map_token, KM_USER0);
600 err = map_extent_buffer(eb, offset,
601 sizeof(struct btrfs_disk_key),
603 &map_start, &map_len, KM_USER0);
606 tmp = (struct btrfs_disk_key *)(kaddr + offset -
609 read_extent_buffer(eb, &unaligned,
610 offset, sizeof(unaligned));
615 tmp = (struct btrfs_disk_key *)(kaddr + offset -
618 ret = comp_keys(tmp, key);
627 unmap_extent_buffer(eb, map_token, KM_USER0);
633 unmap_extent_buffer(eb, map_token, KM_USER0);
638 * simple bin_search frontend that does the right thing for
641 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
642 int level, int *slot)
645 return generic_bin_search(eb,
646 offsetof(struct btrfs_leaf, items),
647 sizeof(struct btrfs_item),
648 key, btrfs_header_nritems(eb),
651 return generic_bin_search(eb,
652 offsetof(struct btrfs_node, ptrs),
653 sizeof(struct btrfs_key_ptr),
654 key, btrfs_header_nritems(eb),
660 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
661 struct extent_buffer *parent, int slot)
665 if (slot >= btrfs_header_nritems(parent))
667 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
668 btrfs_level_size(root, btrfs_header_level(parent) - 1));
671 static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
672 *root, struct btrfs_path *path, int level)
674 struct extent_buffer *right = NULL;
675 struct extent_buffer *mid;
676 struct extent_buffer *left = NULL;
677 struct extent_buffer *parent = NULL;
681 int orig_slot = path->slots[level];
682 int err_on_enospc = 0;
688 mid = path->nodes[level];
689 WARN_ON(btrfs_header_generation(mid) != trans->transid);
691 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
693 if (level < BTRFS_MAX_LEVEL - 1)
694 parent = path->nodes[level + 1];
695 pslot = path->slots[level + 1];
698 * deal with the case where there is only one pointer in the root
699 * by promoting the node below to a root
702 struct extent_buffer *child;
704 if (btrfs_header_nritems(mid) != 1)
707 /* promote the child to a root */
708 child = read_node_slot(root, mid, 0);
711 path->nodes[level] = NULL;
712 clean_tree_block(trans, root, mid);
713 wait_on_tree_block_writeback(root, mid);
714 /* once for the path */
715 free_extent_buffer(mid);
716 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
717 root->root_key.objectid,
718 btrfs_header_generation(mid), 0, 0, 1);
719 /* once for the root ptr */
720 free_extent_buffer(mid);
723 if (btrfs_header_nritems(mid) >
724 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
727 if (btrfs_header_nritems(mid) < 2)
730 left = read_node_slot(root, parent, pslot - 1);
732 wret = btrfs_cow_block(trans, root, left,
733 parent, pslot - 1, &left);
739 right = read_node_slot(root, parent, pslot + 1);
741 wret = btrfs_cow_block(trans, root, right,
742 parent, pslot + 1, &right);
749 /* first, try to make some room in the middle buffer */
751 orig_slot += btrfs_header_nritems(left);
752 wret = push_node_left(trans, root, left, mid);
755 if (btrfs_header_nritems(mid) < 2)
760 * then try to empty the right most buffer into the middle
763 wret = push_node_left(trans, root, mid, right);
764 if (wret < 0 && wret != -ENOSPC)
766 if (btrfs_header_nritems(right) == 0) {
767 u64 bytenr = right->start;
768 u64 generation = btrfs_header_generation(parent);
769 u32 blocksize = right->len;
771 clean_tree_block(trans, root, right);
772 wait_on_tree_block_writeback(root, right);
773 free_extent_buffer(right);
775 wret = del_ptr(trans, root, path, level + 1, pslot +
779 wret = btrfs_free_extent(trans, root, bytenr,
781 btrfs_header_owner(parent),
782 generation, 0, 0, 1);
786 struct btrfs_disk_key right_key;
787 btrfs_node_key(right, &right_key, 0);
788 btrfs_set_node_key(parent, &right_key, pslot + 1);
789 btrfs_mark_buffer_dirty(parent);
792 if (btrfs_header_nritems(mid) == 1) {
794 * we're not allowed to leave a node with one item in the
795 * tree during a delete. A deletion from lower in the tree
796 * could try to delete the only pointer in this node.
797 * So, pull some keys from the left.
798 * There has to be a left pointer at this point because
799 * otherwise we would have pulled some pointers from the
803 wret = balance_node_right(trans, root, mid, left);
810 if (btrfs_header_nritems(mid) == 0) {
811 /* we've managed to empty the middle node, drop it */
812 u64 root_gen = btrfs_header_generation(parent);
813 u64 bytenr = mid->start;
814 u32 blocksize = mid->len;
815 clean_tree_block(trans, root, mid);
816 wait_on_tree_block_writeback(root, mid);
817 free_extent_buffer(mid);
819 wret = del_ptr(trans, root, path, level + 1, pslot);
822 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
823 btrfs_header_owner(parent),
828 /* update the parent key to reflect our changes */
829 struct btrfs_disk_key mid_key;
830 btrfs_node_key(mid, &mid_key, 0);
831 btrfs_set_node_key(parent, &mid_key, pslot);
832 btrfs_mark_buffer_dirty(parent);
835 /* update the path */
837 if (btrfs_header_nritems(left) > orig_slot) {
838 extent_buffer_get(left);
839 path->nodes[level] = left;
840 path->slots[level + 1] -= 1;
841 path->slots[level] = orig_slot;
843 free_extent_buffer(mid);
845 orig_slot -= btrfs_header_nritems(left);
846 path->slots[level] = orig_slot;
849 /* double check we haven't messed things up */
850 check_block(root, path, level);
852 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
856 free_extent_buffer(right);
858 free_extent_buffer(left);
862 /* returns zero if the push worked, non-zero otherwise */
863 static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
864 struct btrfs_root *root,
865 struct btrfs_path *path, int level)
867 struct extent_buffer *right = NULL;
868 struct extent_buffer *mid;
869 struct extent_buffer *left = NULL;
870 struct extent_buffer *parent = NULL;
874 int orig_slot = path->slots[level];
880 mid = path->nodes[level];
881 WARN_ON(btrfs_header_generation(mid) != trans->transid);
882 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
884 if (level < BTRFS_MAX_LEVEL - 1)
885 parent = path->nodes[level + 1];
886 pslot = path->slots[level + 1];
891 left = read_node_slot(root, parent, pslot - 1);
893 /* first, try to make some room in the middle buffer */
896 left_nr = btrfs_header_nritems(left);
897 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
900 ret = btrfs_cow_block(trans, root, left, parent,
905 wret = push_node_left(trans, root,
912 struct btrfs_disk_key disk_key;
913 orig_slot += left_nr;
914 btrfs_node_key(mid, &disk_key, 0);
915 btrfs_set_node_key(parent, &disk_key, pslot);
916 btrfs_mark_buffer_dirty(parent);
917 if (btrfs_header_nritems(left) > orig_slot) {
918 path->nodes[level] = left;
919 path->slots[level + 1] -= 1;
920 path->slots[level] = orig_slot;
921 free_extent_buffer(mid);
924 btrfs_header_nritems(left);
925 path->slots[level] = orig_slot;
926 free_extent_buffer(left);
930 free_extent_buffer(left);
932 right= read_node_slot(root, parent, pslot + 1);
935 * then try to empty the right most buffer into the middle
939 right_nr = btrfs_header_nritems(right);
940 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
943 ret = btrfs_cow_block(trans, root, right,
949 wret = balance_node_right(trans, root,
956 struct btrfs_disk_key disk_key;
958 btrfs_node_key(right, &disk_key, 0);
959 btrfs_set_node_key(parent, &disk_key, pslot + 1);
960 btrfs_mark_buffer_dirty(parent);
962 if (btrfs_header_nritems(mid) <= orig_slot) {
963 path->nodes[level] = right;
964 path->slots[level + 1] += 1;
965 path->slots[level] = orig_slot -
966 btrfs_header_nritems(mid);
967 free_extent_buffer(mid);
969 free_extent_buffer(right);
973 free_extent_buffer(right);
979 * readahead one full node of leaves
981 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
984 struct extent_buffer *node;
990 int direction = path->reada;
991 struct extent_buffer *eb;
999 if (!path->nodes[level])
1002 node = path->nodes[level];
1003 search = btrfs_node_blockptr(node, slot);
1004 blocksize = btrfs_level_size(root, level - 1);
1005 eb = btrfs_find_tree_block(root, search, blocksize);
1007 free_extent_buffer(eb);
1011 highest_read = search;
1012 lowest_read = search;
1014 nritems = btrfs_header_nritems(node);
1017 if (direction < 0) {
1021 } else if (direction > 0) {
1026 search = btrfs_node_blockptr(node, nr);
1027 if ((search >= lowest_read && search <= highest_read) ||
1028 (search < lowest_read && lowest_read - search <= 32768) ||
1029 (search > highest_read && search - highest_read <= 32768)) {
1030 readahead_tree_block(root, search, blocksize);
1034 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1036 if(nread > (1024 * 1024) || nscan > 128)
1039 if (search < lowest_read)
1040 lowest_read = search;
1041 if (search > highest_read)
1042 highest_read = search;
1046 * look for key in the tree. path is filled in with nodes along the way
1047 * if key is found, we return zero and you can find the item in the leaf
1048 * level of the path (level 0)
1050 * If the key isn't found, the path points to the slot where it should
1051 * be inserted, and 1 is returned. If there are other errors during the
1052 * search a negative error number is returned.
1054 * if ins_len > 0, nodes and leaves will be split as we walk down the
1055 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1058 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1059 *root, struct btrfs_key *key, struct btrfs_path *p, int
1062 struct extent_buffer *b;
1068 int should_reada = p->reada;
1069 u8 lowest_level = 0;
1071 lowest_level = p->lowest_level;
1072 WARN_ON(lowest_level && ins_len);
1073 WARN_ON(p->nodes[0] != NULL);
1074 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1077 extent_buffer_get(b);
1079 level = btrfs_header_level(b);
1082 wret = btrfs_cow_block(trans, root, b,
1083 p->nodes[level + 1],
1084 p->slots[level + 1],
1087 free_extent_buffer(b);
1091 BUG_ON(!cow && ins_len);
1092 if (level != btrfs_header_level(b))
1094 level = btrfs_header_level(b);
1095 p->nodes[level] = b;
1096 ret = check_block(root, p, level);
1099 ret = bin_search(b, key, level, &slot);
1101 if (ret && slot > 0)
1103 p->slots[level] = slot;
1104 if (ins_len > 0 && btrfs_header_nritems(b) >=
1105 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1106 int sret = split_node(trans, root, p, level);
1110 b = p->nodes[level];
1111 slot = p->slots[level];
1112 } else if (ins_len < 0) {
1113 int sret = balance_level(trans, root, p,
1117 b = p->nodes[level];
1119 btrfs_release_path(NULL, p);
1122 slot = p->slots[level];
1123 BUG_ON(btrfs_header_nritems(b) == 1);
1125 /* this is only true while dropping a snapshot */
1126 if (level == lowest_level)
1128 bytenr = btrfs_node_blockptr(b, slot);
1129 ptr_gen = btrfs_node_ptr_generation(b, slot);
1131 reada_for_search(root, p, level, slot);
1132 b = read_tree_block(root, bytenr,
1133 btrfs_level_size(root, level - 1));
1134 if (ptr_gen != btrfs_header_generation(b)) {
1135 printk("block %llu bad gen wanted %llu "
1137 (unsigned long long)b->start,
1138 (unsigned long long)ptr_gen,
1139 (unsigned long long)btrfs_header_generation(b));
1142 p->slots[level] = slot;
1143 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1144 sizeof(struct btrfs_item) + ins_len) {
1145 int sret = split_leaf(trans, root, key,
1146 p, ins_len, ret == 0);
1158 * adjust the pointers going up the tree, starting at level
1159 * making sure the right key of each node is points to 'key'.
1160 * This is used after shifting pointers to the left, so it stops
1161 * fixing up pointers when a given leaf/node is not in slot 0 of the
1164 * If this fails to write a tree block, it returns -1, but continues
1165 * fixing up the blocks in ram so the tree is consistent.
1167 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1168 struct btrfs_root *root, struct btrfs_path *path,
1169 struct btrfs_disk_key *key, int level)
1173 struct extent_buffer *t;
1175 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1176 int tslot = path->slots[i];
1177 if (!path->nodes[i])
1180 btrfs_set_node_key(t, key, tslot);
1181 btrfs_mark_buffer_dirty(path->nodes[i]);
1189 * try to push data from one node into the next node left in the
1192 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1193 * error, and > 0 if there was no room in the left hand block.
1195 static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
1196 *root, struct extent_buffer *dst,
1197 struct extent_buffer *src)
1204 src_nritems = btrfs_header_nritems(src);
1205 dst_nritems = btrfs_header_nritems(dst);
1206 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1207 WARN_ON(btrfs_header_generation(src) != trans->transid);
1208 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1210 if (push_items <= 0) {
1214 if (src_nritems < push_items)
1215 push_items = src_nritems;
1217 copy_extent_buffer(dst, src,
1218 btrfs_node_key_ptr_offset(dst_nritems),
1219 btrfs_node_key_ptr_offset(0),
1220 push_items * sizeof(struct btrfs_key_ptr));
1222 if (push_items < src_nritems) {
1223 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1224 btrfs_node_key_ptr_offset(push_items),
1225 (src_nritems - push_items) *
1226 sizeof(struct btrfs_key_ptr));
1228 btrfs_set_header_nritems(src, src_nritems - push_items);
1229 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1230 btrfs_mark_buffer_dirty(src);
1231 btrfs_mark_buffer_dirty(dst);
1236 * try to push data from one node into the next node right in the
1239 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1240 * error, and > 0 if there was no room in the right hand block.
1242 * this will only push up to 1/2 the contents of the left node over
1244 static int balance_node_right(struct btrfs_trans_handle *trans,
1245 struct btrfs_root *root,
1246 struct extent_buffer *dst,
1247 struct extent_buffer *src)
1255 WARN_ON(btrfs_header_generation(src) != trans->transid);
1256 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1258 src_nritems = btrfs_header_nritems(src);
1259 dst_nritems = btrfs_header_nritems(dst);
1260 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1261 if (push_items <= 0)
1264 max_push = src_nritems / 2 + 1;
1265 /* don't try to empty the node */
1266 if (max_push >= src_nritems)
1269 if (max_push < push_items)
1270 push_items = max_push;
1272 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1273 btrfs_node_key_ptr_offset(0),
1275 sizeof(struct btrfs_key_ptr));
1277 copy_extent_buffer(dst, src,
1278 btrfs_node_key_ptr_offset(0),
1279 btrfs_node_key_ptr_offset(src_nritems - push_items),
1280 push_items * sizeof(struct btrfs_key_ptr));
1282 btrfs_set_header_nritems(src, src_nritems - push_items);
1283 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1285 btrfs_mark_buffer_dirty(src);
1286 btrfs_mark_buffer_dirty(dst);
1291 * helper function to insert a new root level in the tree.
1292 * A new node is allocated, and a single item is inserted to
1293 * point to the existing root
1295 * returns zero on success or < 0 on failure.
1297 static int insert_new_root(struct btrfs_trans_handle *trans,
1298 struct btrfs_root *root,
1299 struct btrfs_path *path, int level)
1303 struct extent_buffer *lower;
1304 struct extent_buffer *c;
1305 struct btrfs_disk_key lower_key;
1307 BUG_ON(path->nodes[level]);
1308 BUG_ON(path->nodes[level-1] != root->node);
1311 root_gen = trans->transid;
1315 lower = path->nodes[level-1];
1317 btrfs_item_key(lower, &lower_key, 0);
1319 btrfs_node_key(lower, &lower_key, 0);
1321 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1322 root->root_key.objectid,
1323 root_gen, lower_key.objectid, level,
1324 root->node->start, 0);
1327 memset_extent_buffer(c, 0, 0, root->nodesize);
1328 btrfs_set_header_nritems(c, 1);
1329 btrfs_set_header_level(c, level);
1330 btrfs_set_header_bytenr(c, c->start);
1331 btrfs_set_header_generation(c, trans->transid);
1332 btrfs_set_header_owner(c, root->root_key.objectid);
1334 write_extent_buffer(c, root->fs_info->fsid,
1335 (unsigned long)btrfs_header_fsid(c),
1337 btrfs_set_node_key(c, &lower_key, 0);
1338 btrfs_set_node_blockptr(c, 0, lower->start);
1339 lower_gen = btrfs_header_generation(lower);
1340 WARN_ON(lower_gen == 0);
1342 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1344 btrfs_mark_buffer_dirty(c);
1346 /* the super has an extra ref to root->node */
1347 free_extent_buffer(root->node);
1349 extent_buffer_get(c);
1350 path->nodes[level] = c;
1351 path->slots[level] = 0;
1353 if (root->ref_cows && lower_gen != trans->transid) {
1354 struct btrfs_path *back_path = btrfs_alloc_path();
1356 ret = btrfs_insert_extent_backref(trans,
1357 root->fs_info->extent_root,
1359 root->root_key.objectid,
1360 trans->transid, 0, 0);
1362 btrfs_free_path(back_path);
1368 * worker function to insert a single pointer in a node.
1369 * the node should have enough room for the pointer already
1371 * slot and level indicate where you want the key to go, and
1372 * blocknr is the block the key points to.
1374 * returns zero on success and < 0 on any error
1376 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1377 *root, struct btrfs_path *path, struct btrfs_disk_key
1378 *key, u64 bytenr, int slot, int level)
1380 struct extent_buffer *lower;
1383 BUG_ON(!path->nodes[level]);
1384 lower = path->nodes[level];
1385 nritems = btrfs_header_nritems(lower);
1388 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1390 if (slot != nritems) {
1391 memmove_extent_buffer(lower,
1392 btrfs_node_key_ptr_offset(slot + 1),
1393 btrfs_node_key_ptr_offset(slot),
1394 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1396 btrfs_set_node_key(lower, key, slot);
1397 btrfs_set_node_blockptr(lower, slot, bytenr);
1398 WARN_ON(trans->transid == 0);
1399 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1400 btrfs_set_header_nritems(lower, nritems + 1);
1401 btrfs_mark_buffer_dirty(lower);
1406 * split the node at the specified level in path in two.
1407 * The path is corrected to point to the appropriate node after the split
1409 * Before splitting this tries to make some room in the node by pushing
1410 * left and right, if either one works, it returns right away.
1412 * returns 0 on success and < 0 on failure
1414 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1415 *root, struct btrfs_path *path, int level)
1418 struct extent_buffer *c;
1419 struct extent_buffer *split;
1420 struct btrfs_disk_key disk_key;
1426 c = path->nodes[level];
1427 WARN_ON(btrfs_header_generation(c) != trans->transid);
1428 if (c == root->node) {
1429 /* trying to split the root, lets make a new one */
1430 ret = insert_new_root(trans, root, path, level + 1);
1434 ret = push_nodes_for_insert(trans, root, path, level);
1435 c = path->nodes[level];
1436 if (!ret && btrfs_header_nritems(c) <
1437 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1443 c_nritems = btrfs_header_nritems(c);
1445 root_gen = trans->transid;
1449 btrfs_node_key(c, &disk_key, 0);
1450 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1451 root->root_key.objectid,
1453 btrfs_disk_key_objectid(&disk_key),
1454 level, c->start, 0);
1456 return PTR_ERR(split);
1458 btrfs_set_header_flags(split, btrfs_header_flags(c));
1459 btrfs_set_header_level(split, btrfs_header_level(c));
1460 btrfs_set_header_bytenr(split, split->start);
1461 btrfs_set_header_generation(split, trans->transid);
1462 btrfs_set_header_owner(split, root->root_key.objectid);
1463 write_extent_buffer(split, root->fs_info->fsid,
1464 (unsigned long)btrfs_header_fsid(split),
1467 mid = (c_nritems + 1) / 2;
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 btrfs_node_key(split, &disk_key, 0);
1481 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1482 path->slots[level + 1] + 1,
1487 if (path->slots[level] >= mid) {
1488 path->slots[level] -= mid;
1489 free_extent_buffer(c);
1490 path->nodes[level] = split;
1491 path->slots[level + 1] += 1;
1493 free_extent_buffer(split);
1499 * how many bytes are required to store the items in a leaf. start
1500 * and nr indicate which items in the leaf to check. This totals up the
1501 * space used both by the item structs and the item data
1503 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1506 int nritems = btrfs_header_nritems(l);
1507 int end = min(nritems, start + nr) - 1;
1511 data_len = btrfs_item_end_nr(l, start);
1512 data_len = data_len - btrfs_item_offset_nr(l, end);
1513 data_len += sizeof(struct btrfs_item) * nr;
1514 WARN_ON(data_len < 0);
1519 * The space between the end of the leaf items and
1520 * the start of the leaf data. IOW, how much room
1521 * the leaf has left for both items and data
1523 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1525 int nritems = btrfs_header_nritems(leaf);
1527 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1529 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1530 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1531 leaf_space_used(leaf, 0, nritems), nritems);
1537 * push some data in the path leaf to the right, trying to free up at
1538 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1540 * returns 1 if the push failed because the other node didn't have enough
1541 * room, 0 if everything worked out and < 0 if there were major errors.
1543 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1544 *root, struct btrfs_path *path, int data_size,
1547 struct extent_buffer *left = path->nodes[0];
1548 struct extent_buffer *right;
1549 struct extent_buffer *upper;
1550 struct btrfs_disk_key disk_key;
1556 struct btrfs_item *item;
1564 slot = path->slots[1];
1565 if (!path->nodes[1]) {
1568 upper = path->nodes[1];
1569 if (slot >= btrfs_header_nritems(upper) - 1)
1572 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1574 free_space = btrfs_leaf_free_space(root, right);
1575 if (free_space < data_size + sizeof(struct btrfs_item)) {
1576 free_extent_buffer(right);
1580 /* cow and double check */
1581 ret = btrfs_cow_block(trans, root, right, upper,
1584 free_extent_buffer(right);
1587 free_space = btrfs_leaf_free_space(root, right);
1588 if (free_space < data_size + sizeof(struct btrfs_item)) {
1589 free_extent_buffer(right);
1593 left_nritems = btrfs_header_nritems(left);
1594 if (left_nritems == 0) {
1595 free_extent_buffer(right);
1604 i = left_nritems - 1;
1606 item = btrfs_item_nr(left, i);
1608 if (path->slots[0] == i)
1609 push_space += data_size + sizeof(*item);
1611 if (!left->map_token) {
1612 map_extent_buffer(left, (unsigned long)item,
1613 sizeof(struct btrfs_item),
1614 &left->map_token, &left->kaddr,
1615 &left->map_start, &left->map_len,
1619 this_item_size = btrfs_item_size(left, item);
1620 if (this_item_size + sizeof(*item) + push_space > free_space)
1623 push_space += this_item_size + sizeof(*item);
1628 if (left->map_token) {
1629 unmap_extent_buffer(left, left->map_token, KM_USER1);
1630 left->map_token = NULL;
1633 if (push_items == 0) {
1634 free_extent_buffer(right);
1638 if (!empty && push_items == left_nritems)
1641 /* push left to right */
1642 right_nritems = btrfs_header_nritems(right);
1644 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1645 push_space -= leaf_data_end(root, left);
1647 /* make room in the right data area */
1648 data_end = leaf_data_end(root, right);
1649 memmove_extent_buffer(right,
1650 btrfs_leaf_data(right) + data_end - push_space,
1651 btrfs_leaf_data(right) + data_end,
1652 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1654 /* copy from the left data area */
1655 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1656 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1657 btrfs_leaf_data(left) + leaf_data_end(root, left),
1660 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1661 btrfs_item_nr_offset(0),
1662 right_nritems * sizeof(struct btrfs_item));
1664 /* copy the items from left to right */
1665 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1666 btrfs_item_nr_offset(left_nritems - push_items),
1667 push_items * sizeof(struct btrfs_item));
1669 /* update the item pointers */
1670 right_nritems += push_items;
1671 btrfs_set_header_nritems(right, right_nritems);
1672 push_space = BTRFS_LEAF_DATA_SIZE(root);
1673 for (i = 0; i < right_nritems; i++) {
1674 item = btrfs_item_nr(right, i);
1675 if (!right->map_token) {
1676 map_extent_buffer(right, (unsigned long)item,
1677 sizeof(struct btrfs_item),
1678 &right->map_token, &right->kaddr,
1679 &right->map_start, &right->map_len,
1682 push_space -= btrfs_item_size(right, item);
1683 btrfs_set_item_offset(right, item, push_space);
1686 if (right->map_token) {
1687 unmap_extent_buffer(right, right->map_token, KM_USER1);
1688 right->map_token = NULL;
1690 left_nritems -= push_items;
1691 btrfs_set_header_nritems(left, left_nritems);
1694 btrfs_mark_buffer_dirty(left);
1695 btrfs_mark_buffer_dirty(right);
1697 btrfs_item_key(right, &disk_key, 0);
1698 btrfs_set_node_key(upper, &disk_key, slot + 1);
1699 btrfs_mark_buffer_dirty(upper);
1701 /* then fixup the leaf pointer in the path */
1702 if (path->slots[0] >= left_nritems) {
1703 path->slots[0] -= left_nritems;
1704 free_extent_buffer(path->nodes[0]);
1705 path->nodes[0] = right;
1706 path->slots[1] += 1;
1708 free_extent_buffer(right);
1713 * push some data in the path leaf to the left, trying to free up at
1714 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1716 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1717 *root, struct btrfs_path *path, int data_size,
1720 struct btrfs_disk_key disk_key;
1721 struct extent_buffer *right = path->nodes[0];
1722 struct extent_buffer *left;
1728 struct btrfs_item *item;
1729 u32 old_left_nritems;
1735 u32 old_left_item_size;
1737 slot = path->slots[1];
1740 if (!path->nodes[1])
1743 right_nritems = btrfs_header_nritems(right);
1744 if (right_nritems == 0) {
1748 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1749 slot - 1), root->leafsize);
1750 free_space = btrfs_leaf_free_space(root, left);
1751 if (free_space < data_size + sizeof(struct btrfs_item)) {
1752 free_extent_buffer(left);
1756 /* cow and double check */
1757 ret = btrfs_cow_block(trans, root, left,
1758 path->nodes[1], slot - 1, &left);
1760 /* we hit -ENOSPC, but it isn't fatal here */
1761 free_extent_buffer(left);
1765 free_space = btrfs_leaf_free_space(root, left);
1766 if (free_space < data_size + sizeof(struct btrfs_item)) {
1767 free_extent_buffer(left);
1774 nr = right_nritems - 1;
1776 for (i = 0; i < nr; i++) {
1777 item = btrfs_item_nr(right, i);
1778 if (!right->map_token) {
1779 map_extent_buffer(right, (unsigned long)item,
1780 sizeof(struct btrfs_item),
1781 &right->map_token, &right->kaddr,
1782 &right->map_start, &right->map_len,
1786 if (path->slots[0] == i)
1787 push_space += data_size + sizeof(*item);
1789 this_item_size = btrfs_item_size(right, item);
1790 if (this_item_size + sizeof(*item) + push_space > free_space)
1794 push_space += this_item_size + sizeof(*item);
1797 if (right->map_token) {
1798 unmap_extent_buffer(right, right->map_token, KM_USER1);
1799 right->map_token = NULL;
1802 if (push_items == 0) {
1803 free_extent_buffer(left);
1806 if (!empty && push_items == btrfs_header_nritems(right))
1809 /* push data from right to left */
1810 copy_extent_buffer(left, right,
1811 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1812 btrfs_item_nr_offset(0),
1813 push_items * sizeof(struct btrfs_item));
1815 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1816 btrfs_item_offset_nr(right, push_items -1);
1818 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1819 leaf_data_end(root, left) - push_space,
1820 btrfs_leaf_data(right) +
1821 btrfs_item_offset_nr(right, push_items - 1),
1823 old_left_nritems = btrfs_header_nritems(left);
1824 BUG_ON(old_left_nritems < 0);
1826 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1827 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1830 item = btrfs_item_nr(left, i);
1831 if (!left->map_token) {
1832 map_extent_buffer(left, (unsigned long)item,
1833 sizeof(struct btrfs_item),
1834 &left->map_token, &left->kaddr,
1835 &left->map_start, &left->map_len,
1839 ioff = btrfs_item_offset(left, item);
1840 btrfs_set_item_offset(left, item,
1841 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1843 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1844 if (left->map_token) {
1845 unmap_extent_buffer(left, left->map_token, KM_USER1);
1846 left->map_token = NULL;
1849 /* fixup right node */
1850 if (push_items > right_nritems) {
1851 printk("push items %d nr %u\n", push_items, right_nritems);
1855 if (push_items < right_nritems) {
1856 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1857 leaf_data_end(root, right);
1858 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1859 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1860 btrfs_leaf_data(right) +
1861 leaf_data_end(root, right), push_space);
1863 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1864 btrfs_item_nr_offset(push_items),
1865 (btrfs_header_nritems(right) - push_items) *
1866 sizeof(struct btrfs_item));
1868 right_nritems -= push_items;
1869 btrfs_set_header_nritems(right, right_nritems);
1870 push_space = BTRFS_LEAF_DATA_SIZE(root);
1871 for (i = 0; i < right_nritems; i++) {
1872 item = btrfs_item_nr(right, i);
1874 if (!right->map_token) {
1875 map_extent_buffer(right, (unsigned long)item,
1876 sizeof(struct btrfs_item),
1877 &right->map_token, &right->kaddr,
1878 &right->map_start, &right->map_len,
1882 push_space = push_space - btrfs_item_size(right, item);
1883 btrfs_set_item_offset(right, item, push_space);
1885 if (right->map_token) {
1886 unmap_extent_buffer(right, right->map_token, KM_USER1);
1887 right->map_token = NULL;
1890 btrfs_mark_buffer_dirty(left);
1892 btrfs_mark_buffer_dirty(right);
1894 btrfs_item_key(right, &disk_key, 0);
1895 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1899 /* then fixup the leaf pointer in the path */
1900 if (path->slots[0] < push_items) {
1901 path->slots[0] += old_left_nritems;
1902 free_extent_buffer(path->nodes[0]);
1903 path->nodes[0] = left;
1904 path->slots[1] -= 1;
1906 free_extent_buffer(left);
1907 path->slots[0] -= push_items;
1909 BUG_ON(path->slots[0] < 0);
1914 * split the path's leaf in two, making sure there is at least data_size
1915 * available for the resulting leaf level of the path.
1917 * returns 0 if all went well and < 0 on failure.
1919 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1920 *root, struct btrfs_key *ins_key,
1921 struct btrfs_path *path, int data_size, int extend)
1924 struct extent_buffer *l;
1928 struct extent_buffer *right;
1929 int space_needed = data_size + sizeof(struct btrfs_item);
1936 int num_doubles = 0;
1937 struct btrfs_disk_key disk_key;
1940 space_needed = data_size;
1943 root_gen = trans->transid;
1947 /* first try to make some room by pushing left and right */
1948 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1949 wret = push_leaf_right(trans, root, path, data_size, 0);
1954 wret = push_leaf_left(trans, root, path, data_size, 0);
1960 /* did the pushes work? */
1961 if (btrfs_leaf_free_space(root, l) >= space_needed)
1965 if (!path->nodes[1]) {
1966 ret = insert_new_root(trans, root, path, 1);
1973 slot = path->slots[0];
1974 nritems = btrfs_header_nritems(l);
1975 mid = (nritems + 1)/ 2;
1977 btrfs_item_key(l, &disk_key, 0);
1979 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
1980 root->root_key.objectid,
1981 root_gen, disk_key.objectid, 0,
1984 return PTR_ERR(right);
1986 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1987 btrfs_set_header_bytenr(right, right->start);
1988 btrfs_set_header_generation(right, trans->transid);
1989 btrfs_set_header_owner(right, root->root_key.objectid);
1990 btrfs_set_header_level(right, 0);
1991 write_extent_buffer(right, root->fs_info->fsid,
1992 (unsigned long)btrfs_header_fsid(right),
1996 leaf_space_used(l, mid, nritems - mid) + space_needed >
1997 BTRFS_LEAF_DATA_SIZE(root)) {
1998 if (slot >= nritems) {
1999 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2000 btrfs_set_header_nritems(right, 0);
2001 wret = insert_ptr(trans, root, path,
2002 &disk_key, right->start,
2003 path->slots[1] + 1, 1);
2006 free_extent_buffer(path->nodes[0]);
2007 path->nodes[0] = right;
2009 path->slots[1] += 1;
2013 if (mid != nritems &&
2014 leaf_space_used(l, mid, nritems - mid) +
2015 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2020 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2021 BTRFS_LEAF_DATA_SIZE(root)) {
2022 if (!extend && slot == 0) {
2023 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2024 btrfs_set_header_nritems(right, 0);
2025 wret = insert_ptr(trans, root, path,
2031 free_extent_buffer(path->nodes[0]);
2032 path->nodes[0] = right;
2034 if (path->slots[1] == 0) {
2035 wret = fixup_low_keys(trans, root,
2036 path, &disk_key, 1);
2041 } else if (extend && slot == 0) {
2045 if (mid != nritems &&
2046 leaf_space_used(l, mid, nritems - mid) +
2047 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2053 nritems = nritems - mid;
2054 btrfs_set_header_nritems(right, nritems);
2055 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2057 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2058 btrfs_item_nr_offset(mid),
2059 nritems * sizeof(struct btrfs_item));
2061 copy_extent_buffer(right, l,
2062 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2063 data_copy_size, btrfs_leaf_data(l) +
2064 leaf_data_end(root, l), data_copy_size);
2066 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2067 btrfs_item_end_nr(l, mid);
2069 for (i = 0; i < nritems; i++) {
2070 struct btrfs_item *item = btrfs_item_nr(right, i);
2073 if (!right->map_token) {
2074 map_extent_buffer(right, (unsigned long)item,
2075 sizeof(struct btrfs_item),
2076 &right->map_token, &right->kaddr,
2077 &right->map_start, &right->map_len,
2081 ioff = btrfs_item_offset(right, item);
2082 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2085 if (right->map_token) {
2086 unmap_extent_buffer(right, right->map_token, KM_USER1);
2087 right->map_token = NULL;
2090 btrfs_set_header_nritems(l, mid);
2092 btrfs_item_key(right, &disk_key, 0);
2093 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2094 path->slots[1] + 1, 1);
2098 btrfs_mark_buffer_dirty(right);
2099 btrfs_mark_buffer_dirty(l);
2100 BUG_ON(path->slots[0] != slot);
2103 free_extent_buffer(path->nodes[0]);
2104 path->nodes[0] = right;
2105 path->slots[0] -= mid;
2106 path->slots[1] += 1;
2108 free_extent_buffer(right);
2110 BUG_ON(path->slots[0] < 0);
2113 BUG_ON(num_doubles != 0);
2120 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2121 struct btrfs_root *root,
2122 struct btrfs_path *path,
2123 u32 new_size, int from_end)
2128 struct extent_buffer *leaf;
2129 struct btrfs_item *item;
2131 unsigned int data_end;
2132 unsigned int old_data_start;
2133 unsigned int old_size;
2134 unsigned int size_diff;
2137 slot_orig = path->slots[0];
2138 leaf = path->nodes[0];
2139 slot = path->slots[0];
2141 old_size = btrfs_item_size_nr(leaf, slot);
2142 if (old_size == new_size)
2145 nritems = btrfs_header_nritems(leaf);
2146 data_end = leaf_data_end(root, leaf);
2148 old_data_start = btrfs_item_offset_nr(leaf, slot);
2150 size_diff = old_size - new_size;
2153 BUG_ON(slot >= nritems);
2156 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2158 /* first correct the data pointers */
2159 for (i = slot; i < nritems; i++) {
2161 item = btrfs_item_nr(leaf, i);
2163 if (!leaf->map_token) {
2164 map_extent_buffer(leaf, (unsigned long)item,
2165 sizeof(struct btrfs_item),
2166 &leaf->map_token, &leaf->kaddr,
2167 &leaf->map_start, &leaf->map_len,
2171 ioff = btrfs_item_offset(leaf, item);
2172 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2175 if (leaf->map_token) {
2176 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2177 leaf->map_token = NULL;
2180 /* shift the data */
2182 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2183 data_end + size_diff, btrfs_leaf_data(leaf) +
2184 data_end, old_data_start + new_size - data_end);
2186 struct btrfs_disk_key disk_key;
2189 btrfs_item_key(leaf, &disk_key, slot);
2191 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2193 struct btrfs_file_extent_item *fi;
2195 fi = btrfs_item_ptr(leaf, slot,
2196 struct btrfs_file_extent_item);
2197 fi = (struct btrfs_file_extent_item *)(
2198 (unsigned long)fi - size_diff);
2200 if (btrfs_file_extent_type(leaf, fi) ==
2201 BTRFS_FILE_EXTENT_INLINE) {
2202 ptr = btrfs_item_ptr_offset(leaf, slot);
2203 memmove_extent_buffer(leaf, ptr,
2205 offsetof(struct btrfs_file_extent_item,
2210 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2211 data_end + size_diff, btrfs_leaf_data(leaf) +
2212 data_end, old_data_start - data_end);
2214 offset = btrfs_disk_key_offset(&disk_key);
2215 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2216 btrfs_set_item_key(leaf, &disk_key, slot);
2218 fixup_low_keys(trans, root, path, &disk_key, 1);
2221 item = btrfs_item_nr(leaf, slot);
2222 btrfs_set_item_size(leaf, item, new_size);
2223 btrfs_mark_buffer_dirty(leaf);
2226 if (btrfs_leaf_free_space(root, leaf) < 0) {
2227 btrfs_print_leaf(root, leaf);
2233 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2234 struct btrfs_root *root, struct btrfs_path *path,
2240 struct extent_buffer *leaf;
2241 struct btrfs_item *item;
2243 unsigned int data_end;
2244 unsigned int old_data;
2245 unsigned int old_size;
2248 slot_orig = path->slots[0];
2249 leaf = path->nodes[0];
2251 nritems = btrfs_header_nritems(leaf);
2252 data_end = leaf_data_end(root, leaf);
2254 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2255 btrfs_print_leaf(root, leaf);
2258 slot = path->slots[0];
2259 old_data = btrfs_item_end_nr(leaf, slot);
2262 if (slot >= nritems) {
2263 btrfs_print_leaf(root, leaf);
2264 printk("slot %d too large, nritems %d\n", slot, nritems);
2269 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2271 /* first correct the data pointers */
2272 for (i = slot; i < nritems; i++) {
2274 item = btrfs_item_nr(leaf, i);
2276 if (!leaf->map_token) {
2277 map_extent_buffer(leaf, (unsigned long)item,
2278 sizeof(struct btrfs_item),
2279 &leaf->map_token, &leaf->kaddr,
2280 &leaf->map_start, &leaf->map_len,
2283 ioff = btrfs_item_offset(leaf, item);
2284 btrfs_set_item_offset(leaf, item, ioff - data_size);
2287 if (leaf->map_token) {
2288 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2289 leaf->map_token = NULL;
2292 /* shift the data */
2293 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2294 data_end - data_size, btrfs_leaf_data(leaf) +
2295 data_end, old_data - data_end);
2297 data_end = old_data;
2298 old_size = btrfs_item_size_nr(leaf, slot);
2299 item = btrfs_item_nr(leaf, slot);
2300 btrfs_set_item_size(leaf, item, old_size + data_size);
2301 btrfs_mark_buffer_dirty(leaf);
2304 if (btrfs_leaf_free_space(root, leaf) < 0) {
2305 btrfs_print_leaf(root, leaf);
2312 * Given a key and some data, insert an item into the tree.
2313 * This does all the path init required, making room in the tree if needed.
2315 int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
2316 struct btrfs_root *root,
2317 struct btrfs_path *path,
2318 struct btrfs_key *cpu_key, u32 data_size)
2320 struct extent_buffer *leaf;
2321 struct btrfs_item *item;
2326 unsigned int data_end;
2327 struct btrfs_disk_key disk_key;
2329 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2331 /* create a root if there isn't one */
2335 ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
2342 slot_orig = path->slots[0];
2343 leaf = path->nodes[0];
2345 nritems = btrfs_header_nritems(leaf);
2346 data_end = leaf_data_end(root, leaf);
2348 if (btrfs_leaf_free_space(root, leaf) <
2349 sizeof(struct btrfs_item) + data_size) {
2350 btrfs_print_leaf(root, leaf);
2351 printk("not enough freespace need %u have %d\n",
2352 data_size, btrfs_leaf_free_space(root, leaf));
2356 slot = path->slots[0];
2359 if (slot != nritems) {
2361 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2363 if (old_data < data_end) {
2364 btrfs_print_leaf(root, leaf);
2365 printk("slot %d old_data %d data_end %d\n",
2366 slot, old_data, data_end);
2370 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2372 /* first correct the data pointers */
2373 WARN_ON(leaf->map_token);
2374 for (i = slot; i < nritems; i++) {
2377 item = btrfs_item_nr(leaf, i);
2378 if (!leaf->map_token) {
2379 map_extent_buffer(leaf, (unsigned long)item,
2380 sizeof(struct btrfs_item),
2381 &leaf->map_token, &leaf->kaddr,
2382 &leaf->map_start, &leaf->map_len,
2386 ioff = btrfs_item_offset(leaf, item);
2387 btrfs_set_item_offset(leaf, item, ioff - data_size);
2389 if (leaf->map_token) {
2390 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2391 leaf->map_token = NULL;
2394 /* shift the items */
2395 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2396 btrfs_item_nr_offset(slot),
2397 (nritems - slot) * sizeof(struct btrfs_item));
2399 /* shift the data */
2400 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2401 data_end - data_size, btrfs_leaf_data(leaf) +
2402 data_end, old_data - data_end);
2403 data_end = old_data;
2406 /* setup the item for the new data */
2407 btrfs_set_item_key(leaf, &disk_key, slot);
2408 item = btrfs_item_nr(leaf, slot);
2409 btrfs_set_item_offset(leaf, item, data_end - data_size);
2410 btrfs_set_item_size(leaf, item, data_size);
2411 btrfs_set_header_nritems(leaf, nritems + 1);
2412 btrfs_mark_buffer_dirty(leaf);
2416 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2418 if (btrfs_leaf_free_space(root, leaf) < 0) {
2419 btrfs_print_leaf(root, leaf);
2427 * Given a key and some data, insert an item into the tree.
2428 * This does all the path init required, making room in the tree if needed.
2430 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2431 *root, struct btrfs_key *cpu_key, void *data, u32
2435 struct btrfs_path *path;
2436 struct extent_buffer *leaf;
2439 path = btrfs_alloc_path();
2441 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2443 leaf = path->nodes[0];
2444 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2445 write_extent_buffer(leaf, data, ptr, data_size);
2446 btrfs_mark_buffer_dirty(leaf);
2448 btrfs_free_path(path);
2453 * delete the pointer from a given node.
2455 * If the delete empties a node, the node is removed from the tree,
2456 * continuing all the way the root if required. The root is converted into
2457 * a leaf if all the nodes are emptied.
2459 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2460 struct btrfs_path *path, int level, int slot)
2462 struct extent_buffer *parent = path->nodes[level];
2467 nritems = btrfs_header_nritems(parent);
2468 if (slot != nritems -1) {
2469 memmove_extent_buffer(parent,
2470 btrfs_node_key_ptr_offset(slot),
2471 btrfs_node_key_ptr_offset(slot + 1),
2472 sizeof(struct btrfs_key_ptr) *
2473 (nritems - slot - 1));
2476 btrfs_set_header_nritems(parent, nritems);
2477 if (nritems == 0 && parent == root->node) {
2478 BUG_ON(btrfs_header_level(root->node) != 1);
2479 /* just turn the root into a leaf and break */
2480 btrfs_set_header_level(root->node, 0);
2481 } else if (slot == 0) {
2482 struct btrfs_disk_key disk_key;
2484 btrfs_node_key(parent, &disk_key, 0);
2485 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2489 btrfs_mark_buffer_dirty(parent);
2494 * delete the item at the leaf level in path. If that empties
2495 * the leaf, remove it from the tree
2497 int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2498 struct btrfs_path *path)
2501 struct extent_buffer *leaf;
2502 struct btrfs_item *item;
2509 leaf = path->nodes[0];
2510 slot = path->slots[0];
2511 doff = btrfs_item_offset_nr(leaf, slot);
2512 dsize = btrfs_item_size_nr(leaf, slot);
2513 nritems = btrfs_header_nritems(leaf);
2515 if (slot != nritems - 1) {
2517 int data_end = leaf_data_end(root, leaf);
2519 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2521 btrfs_leaf_data(leaf) + data_end,
2524 for (i = slot + 1; i < nritems; i++) {
2527 item = btrfs_item_nr(leaf, i);
2528 if (!leaf->map_token) {
2529 map_extent_buffer(leaf, (unsigned long)item,
2530 sizeof(struct btrfs_item),
2531 &leaf->map_token, &leaf->kaddr,
2532 &leaf->map_start, &leaf->map_len,
2535 ioff = btrfs_item_offset(leaf, item);
2536 btrfs_set_item_offset(leaf, item, ioff + dsize);
2539 if (leaf->map_token) {
2540 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2541 leaf->map_token = NULL;
2544 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2545 btrfs_item_nr_offset(slot + 1),
2546 sizeof(struct btrfs_item) *
2547 (nritems - slot - 1));
2549 btrfs_set_header_nritems(leaf, nritems - 1);
2552 /* delete the leaf if we've emptied it */
2554 if (leaf == root->node) {
2555 btrfs_set_header_level(leaf, 0);
2557 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2558 clean_tree_block(trans, root, leaf);
2559 wait_on_tree_block_writeback(root, leaf);
2560 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2563 wret = btrfs_free_extent(trans, root,
2564 leaf->start, leaf->len,
2565 btrfs_header_owner(path->nodes[1]),
2571 int used = leaf_space_used(leaf, 0, nritems);
2573 struct btrfs_disk_key disk_key;
2575 btrfs_item_key(leaf, &disk_key, 0);
2576 wret = fixup_low_keys(trans, root, path,
2582 /* delete the leaf if it is mostly empty */
2583 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
2584 /* push_leaf_left fixes the path.
2585 * make sure the path still points to our leaf
2586 * for possible call to del_ptr below
2588 slot = path->slots[1];
2589 extent_buffer_get(leaf);
2591 wret = push_leaf_right(trans, root, path, 1, 1);
2592 if (wret < 0 && wret != -ENOSPC)
2595 if (path->nodes[0] == leaf &&
2596 btrfs_header_nritems(leaf)) {
2597 wret = push_leaf_left(trans, root, path, 1, 1);
2598 if (wret < 0 && wret != -ENOSPC)
2602 if (btrfs_header_nritems(leaf) == 0) {
2604 u64 bytenr = leaf->start;
2605 u32 blocksize = leaf->len;
2607 root_gen = btrfs_header_generation(
2610 clean_tree_block(trans, root, leaf);
2611 wait_on_tree_block_writeback(root, leaf);
2613 wret = del_ptr(trans, root, path, 1, slot);
2617 free_extent_buffer(leaf);
2618 wret = btrfs_free_extent(trans, root, bytenr,
2620 btrfs_header_owner(path->nodes[1]),
2625 btrfs_mark_buffer_dirty(leaf);
2626 free_extent_buffer(leaf);
2629 btrfs_mark_buffer_dirty(leaf);
2636 * walk up the tree as far as required to find the previous leaf.
2637 * returns 0 if it found something or 1 if there are no lesser leaves.
2638 * returns < 0 on io errors.
2640 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2645 struct extent_buffer *c;
2646 struct extent_buffer *next = NULL;
2648 while(level < BTRFS_MAX_LEVEL) {
2649 if (!path->nodes[level])
2652 slot = path->slots[level];
2653 c = path->nodes[level];
2656 if (level == BTRFS_MAX_LEVEL)
2662 bytenr = btrfs_node_blockptr(c, slot);
2664 free_extent_buffer(next);
2666 if (path->reada < 0)
2667 reada_for_search(root, path, level, slot);
2669 next = read_tree_block(root, bytenr,
2670 btrfs_level_size(root, level - 1));
2673 path->slots[level] = slot;
2676 c = path->nodes[level];
2677 free_extent_buffer(c);
2678 path->nodes[level] = next;
2679 path->slots[level] = 0;
2683 reada_for_search(root, path, level, 0);
2684 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2685 btrfs_level_size(root, level - 1));
2691 * walk up the tree as far as required to find the next leaf.
2692 * returns 0 if it found something or 1 if there are no greater leaves.
2693 * returns < 0 on io errors.
2695 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2700 struct extent_buffer *c;
2701 struct extent_buffer *next = NULL;
2703 while(level < BTRFS_MAX_LEVEL) {
2704 if (!path->nodes[level])
2707 slot = path->slots[level] + 1;
2708 c = path->nodes[level];
2709 if (slot >= btrfs_header_nritems(c)) {
2711 if (level == BTRFS_MAX_LEVEL)
2716 bytenr = btrfs_node_blockptr(c, slot);
2718 free_extent_buffer(next);
2721 reada_for_search(root, path, level, slot);
2723 next = read_tree_block(root, bytenr,
2724 btrfs_level_size(root, level -1));
2727 path->slots[level] = slot;
2730 c = path->nodes[level];
2731 free_extent_buffer(c);
2732 path->nodes[level] = next;
2733 path->slots[level] = 0;
2737 reada_for_search(root, path, level, 0);
2738 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2739 btrfs_level_size(root, level - 1));