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 static void add_root_to_dirty_list(struct btrfs_root *root)
75 if (root->track_dirty && list_empty(&root->dirty_list)) {
76 list_add(&root->dirty_list,
77 &root->fs_info->dirty_cowonly_roots);
81 int btrfs_copy_root(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root,
83 struct extent_buffer *buf,
84 struct extent_buffer **cow_ret, u64 new_root_objectid)
86 struct extent_buffer *cow;
90 struct btrfs_key first_key;
91 struct btrfs_root *new_root;
93 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
97 memcpy(new_root, root, sizeof(*new_root));
98 new_root->root_key.objectid = new_root_objectid;
100 WARN_ON(root->ref_cows && trans->transid !=
101 root->fs_info->running_transaction->transid);
102 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
104 level = btrfs_header_level(buf);
105 nritems = btrfs_header_nritems(buf);
108 btrfs_item_key_to_cpu(buf, &first_key, 0);
110 btrfs_node_key_to_cpu(buf, &first_key, 0);
112 first_key.objectid = 0;
114 cow = __btrfs_alloc_free_block(trans, new_root, buf->len,
116 trans->transid, first_key.objectid,
117 level, buf->start, 0);
123 copy_extent_buffer(cow, buf, 0, 0, cow->len);
124 btrfs_set_header_bytenr(cow, cow->start);
125 btrfs_set_header_generation(cow, trans->transid);
126 btrfs_set_header_owner(cow, new_root_objectid);
127 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
129 WARN_ON(btrfs_header_generation(buf) > trans->transid);
130 ret = btrfs_inc_ref(trans, new_root, buf);
136 btrfs_mark_buffer_dirty(cow);
141 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
142 struct btrfs_root *root,
143 struct extent_buffer *buf,
144 struct extent_buffer *parent, int parent_slot,
145 struct extent_buffer **cow_ret,
146 u64 search_start, u64 empty_size)
149 struct extent_buffer *cow;
152 int different_trans = 0;
154 struct btrfs_key first_key;
156 if (root->ref_cows) {
157 root_gen = trans->transid;
161 if (!(buf->flags & EXTENT_CSUM))
164 WARN_ON(root->ref_cows && trans->transid !=
165 root->fs_info->running_transaction->transid);
166 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
168 level = btrfs_header_level(buf);
169 nritems = btrfs_header_nritems(buf);
172 btrfs_item_key_to_cpu(buf, &first_key, 0);
174 btrfs_node_key_to_cpu(buf, &first_key, 0);
176 first_key.objectid = 0;
178 cow = __btrfs_alloc_free_block(trans, root, buf->len,
179 root->root_key.objectid,
180 root_gen, first_key.objectid, level,
181 search_start, empty_size);
185 copy_extent_buffer(cow, buf, 0, 0, cow->len);
186 btrfs_set_header_bytenr(cow, cow->start);
187 btrfs_set_header_generation(cow, trans->transid);
188 btrfs_set_header_owner(cow, root->root_key.objectid);
189 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
191 WARN_ON(btrfs_header_generation(buf) > trans->transid);
192 if (btrfs_header_generation(buf) != trans->transid) {
194 ret = btrfs_inc_ref(trans, root, buf);
198 clean_tree_block(trans, root, buf);
201 if (buf == root->node) {
202 root_gen = btrfs_header_generation(buf);
204 extent_buffer_get(cow);
205 if (buf != root->commit_root) {
206 btrfs_free_extent(trans, root, buf->start,
207 buf->len, root->root_key.objectid,
210 free_extent_buffer(buf);
211 add_root_to_dirty_list(root);
213 root_gen = btrfs_header_generation(parent);
214 btrfs_set_node_blockptr(parent, parent_slot,
216 WARN_ON(trans->transid == 0);
217 btrfs_set_node_ptr_generation(parent, parent_slot,
219 btrfs_mark_buffer_dirty(parent);
220 WARN_ON(btrfs_header_generation(parent) != trans->transid);
221 btrfs_free_extent(trans, root, buf->start, buf->len,
222 btrfs_header_owner(parent), root_gen,
225 free_extent_buffer(buf);
226 btrfs_mark_buffer_dirty(cow);
231 int btrfs_cow_block(struct btrfs_trans_handle *trans,
232 struct btrfs_root *root, struct extent_buffer *buf,
233 struct extent_buffer *parent, int parent_slot,
234 struct extent_buffer **cow_ret)
240 if (trans->transaction != root->fs_info->running_transaction) {
241 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
242 root->fs_info->running_transaction->transid);
245 if (trans->transid != root->fs_info->generation) {
246 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
247 root->fs_info->generation);
250 if (!(buf->flags & EXTENT_CSUM))
253 header_trans = btrfs_header_generation(buf);
254 spin_lock(&root->fs_info->hash_lock);
255 if (header_trans == trans->transid &&
256 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
258 spin_unlock(&root->fs_info->hash_lock);
261 spin_unlock(&root->fs_info->hash_lock);
262 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
263 ret = __btrfs_cow_block(trans, root, buf, parent,
264 parent_slot, cow_ret, search_start, 0);
268 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
270 if (blocknr < other && other - (blocknr + blocksize) < 32768)
272 if (blocknr > other && blocknr - (other + blocksize) < 32768)
278 * compare two keys in a memcmp fashion
280 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
284 btrfs_disk_key_to_cpu(&k1, disk);
286 if (k1.objectid > k2->objectid)
288 if (k1.objectid < k2->objectid)
290 if (k1.type > k2->type)
292 if (k1.type < k2->type)
294 if (k1.offset > k2->offset)
296 if (k1.offset < k2->offset)
302 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
303 struct btrfs_root *root, struct extent_buffer *parent,
304 int start_slot, int cache_only, u64 *last_ret,
305 struct btrfs_key *progress)
307 struct extent_buffer *cur;
308 struct extent_buffer *tmp;
310 u64 search_start = *last_ret;
320 int progress_passed = 0;
321 struct btrfs_disk_key disk_key;
323 parent_level = btrfs_header_level(parent);
324 if (cache_only && parent_level != 1)
327 if (trans->transaction != root->fs_info->running_transaction) {
328 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
329 root->fs_info->running_transaction->transid);
332 if (trans->transid != root->fs_info->generation) {
333 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
334 root->fs_info->generation);
338 parent_nritems = btrfs_header_nritems(parent);
339 blocksize = btrfs_level_size(root, parent_level - 1);
340 end_slot = parent_nritems;
342 if (parent_nritems == 1)
345 for (i = start_slot; i < end_slot; i++) {
348 if (!parent->map_token) {
349 map_extent_buffer(parent,
350 btrfs_node_key_ptr_offset(i),
351 sizeof(struct btrfs_key_ptr),
352 &parent->map_token, &parent->kaddr,
353 &parent->map_start, &parent->map_len,
356 btrfs_node_key(parent, &disk_key, i);
357 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
361 blocknr = btrfs_node_blockptr(parent, i);
363 last_block = blocknr;
366 other = btrfs_node_blockptr(parent, i - 1);
367 close = close_blocks(blocknr, other, blocksize);
369 if (close && i < end_slot - 2) {
370 other = btrfs_node_blockptr(parent, i + 1);
371 close = close_blocks(blocknr, other, blocksize);
374 last_block = blocknr;
377 if (parent->map_token) {
378 unmap_extent_buffer(parent, parent->map_token,
380 parent->map_token = NULL;
383 cur = btrfs_find_tree_block(root, blocknr, blocksize);
385 uptodate = btrfs_buffer_uptodate(cur);
388 if (!cur || !uptodate) {
390 free_extent_buffer(cur);
394 cur = read_tree_block(root, blocknr,
396 } else if (!uptodate) {
397 btrfs_read_buffer(cur);
400 if (search_start == 0)
401 search_start = last_block;
403 btrfs_verify_block_csum(root, cur);
404 err = __btrfs_cow_block(trans, root, cur, parent, i,
407 (end_slot - i) * blocksize));
409 free_extent_buffer(cur);
412 search_start = tmp->start;
413 last_block = tmp->start;
414 *last_ret = search_start;
415 if (parent_level == 1)
416 btrfs_clear_buffer_defrag(tmp);
417 free_extent_buffer(tmp);
419 if (parent->map_token) {
420 unmap_extent_buffer(parent, parent->map_token,
422 parent->map_token = NULL;
428 * The leaf data grows from end-to-front in the node.
429 * this returns the address of the start of the last item,
430 * which is the stop of the leaf data stack
432 static inline unsigned int leaf_data_end(struct btrfs_root *root,
433 struct extent_buffer *leaf)
435 u32 nr = btrfs_header_nritems(leaf);
437 return BTRFS_LEAF_DATA_SIZE(root);
438 return btrfs_item_offset_nr(leaf, nr - 1);
441 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
444 struct extent_buffer *parent = NULL;
445 struct extent_buffer *node = path->nodes[level];
446 struct btrfs_disk_key parent_key;
447 struct btrfs_disk_key node_key;
450 struct btrfs_key cpukey;
451 u32 nritems = btrfs_header_nritems(node);
453 if (path->nodes[level + 1])
454 parent = path->nodes[level + 1];
456 slot = path->slots[level];
457 BUG_ON(nritems == 0);
459 parent_slot = path->slots[level + 1];
460 btrfs_node_key(parent, &parent_key, parent_slot);
461 btrfs_node_key(node, &node_key, 0);
462 BUG_ON(memcmp(&parent_key, &node_key,
463 sizeof(struct btrfs_disk_key)));
464 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
465 btrfs_header_bytenr(node));
467 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
469 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
470 btrfs_node_key(node, &node_key, slot);
471 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
473 if (slot < nritems - 1) {
474 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
475 btrfs_node_key(node, &node_key, slot);
476 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
481 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
484 struct extent_buffer *leaf = path->nodes[level];
485 struct extent_buffer *parent = NULL;
487 struct btrfs_key cpukey;
488 struct btrfs_disk_key parent_key;
489 struct btrfs_disk_key leaf_key;
490 int slot = path->slots[0];
492 u32 nritems = btrfs_header_nritems(leaf);
494 if (path->nodes[level + 1])
495 parent = path->nodes[level + 1];
501 parent_slot = path->slots[level + 1];
502 btrfs_node_key(parent, &parent_key, parent_slot);
503 btrfs_item_key(leaf, &leaf_key, 0);
505 BUG_ON(memcmp(&parent_key, &leaf_key,
506 sizeof(struct btrfs_disk_key)));
507 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
508 btrfs_header_bytenr(leaf));
511 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
512 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
513 btrfs_item_key(leaf, &leaf_key, i);
514 if (comp_keys(&leaf_key, &cpukey) >= 0) {
515 btrfs_print_leaf(root, leaf);
516 printk("slot %d offset bad key\n", i);
519 if (btrfs_item_offset_nr(leaf, i) !=
520 btrfs_item_end_nr(leaf, i + 1)) {
521 btrfs_print_leaf(root, leaf);
522 printk("slot %d offset bad\n", i);
526 if (btrfs_item_offset_nr(leaf, i) +
527 btrfs_item_size_nr(leaf, i) !=
528 BTRFS_LEAF_DATA_SIZE(root)) {
529 btrfs_print_leaf(root, leaf);
530 printk("slot %d first offset bad\n", i);
536 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
537 btrfs_print_leaf(root, leaf);
538 printk("slot %d bad size \n", nritems - 1);
543 if (slot != 0 && slot < nritems - 1) {
544 btrfs_item_key(leaf, &leaf_key, slot);
545 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
546 if (comp_keys(&leaf_key, &cpukey) <= 0) {
547 btrfs_print_leaf(root, leaf);
548 printk("slot %d offset bad key\n", slot);
551 if (btrfs_item_offset_nr(leaf, slot - 1) !=
552 btrfs_item_end_nr(leaf, slot)) {
553 btrfs_print_leaf(root, leaf);
554 printk("slot %d offset bad\n", slot);
558 if (slot < nritems - 1) {
559 btrfs_item_key(leaf, &leaf_key, slot);
560 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
561 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
562 if (btrfs_item_offset_nr(leaf, slot) !=
563 btrfs_item_end_nr(leaf, slot + 1)) {
564 btrfs_print_leaf(root, leaf);
565 printk("slot %d offset bad\n", slot);
569 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
570 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
574 static int noinline check_block(struct btrfs_root *root,
575 struct btrfs_path *path, int level)
579 struct extent_buffer *buf = path->nodes[level];
581 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
582 (unsigned long)btrfs_header_fsid(buf),
584 printk("warning bad block %Lu\n", buf->start);
589 return check_leaf(root, path, level);
590 return check_node(root, path, level);
594 * search for key in the extent_buffer. The items start at offset p,
595 * and they are item_size apart. There are 'max' items in p.
597 * the slot in the array is returned via slot, and it points to
598 * the place where you would insert key if it is not found in
601 * slot may point to max if the key is bigger than all of the keys
603 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
604 int item_size, struct btrfs_key *key,
611 struct btrfs_disk_key *tmp = NULL;
612 struct btrfs_disk_key unaligned;
613 unsigned long offset;
614 char *map_token = NULL;
616 unsigned long map_start = 0;
617 unsigned long map_len = 0;
621 mid = (low + high) / 2;
622 offset = p + mid * item_size;
624 if (!map_token || offset < map_start ||
625 (offset + sizeof(struct btrfs_disk_key)) >
626 map_start + map_len) {
628 unmap_extent_buffer(eb, map_token, KM_USER0);
631 err = map_extent_buffer(eb, offset,
632 sizeof(struct btrfs_disk_key),
634 &map_start, &map_len, KM_USER0);
637 tmp = (struct btrfs_disk_key *)(kaddr + offset -
640 read_extent_buffer(eb, &unaligned,
641 offset, sizeof(unaligned));
646 tmp = (struct btrfs_disk_key *)(kaddr + offset -
649 ret = comp_keys(tmp, key);
658 unmap_extent_buffer(eb, map_token, KM_USER0);
664 unmap_extent_buffer(eb, map_token, KM_USER0);
669 * simple bin_search frontend that does the right thing for
672 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
673 int level, int *slot)
676 return generic_bin_search(eb,
677 offsetof(struct btrfs_leaf, items),
678 sizeof(struct btrfs_item),
679 key, btrfs_header_nritems(eb),
682 return generic_bin_search(eb,
683 offsetof(struct btrfs_node, ptrs),
684 sizeof(struct btrfs_key_ptr),
685 key, btrfs_header_nritems(eb),
691 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
692 struct extent_buffer *parent, int slot)
696 if (slot >= btrfs_header_nritems(parent))
698 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
699 btrfs_level_size(root, btrfs_header_level(parent) - 1));
702 static int balance_level(struct btrfs_trans_handle *trans,
703 struct btrfs_root *root,
704 struct btrfs_path *path, int level)
706 struct extent_buffer *right = NULL;
707 struct extent_buffer *mid;
708 struct extent_buffer *left = NULL;
709 struct extent_buffer *parent = NULL;
713 int orig_slot = path->slots[level];
714 int err_on_enospc = 0;
720 mid = path->nodes[level];
721 WARN_ON(btrfs_header_generation(mid) != trans->transid);
723 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
725 if (level < BTRFS_MAX_LEVEL - 1)
726 parent = path->nodes[level + 1];
727 pslot = path->slots[level + 1];
730 * deal with the case where there is only one pointer in the root
731 * by promoting the node below to a root
734 struct extent_buffer *child;
736 if (btrfs_header_nritems(mid) != 1)
739 /* promote the child to a root */
740 child = read_node_slot(root, mid, 0);
742 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
746 add_root_to_dirty_list(root);
747 path->nodes[level] = NULL;
748 clean_tree_block(trans, root, mid);
749 wait_on_tree_block_writeback(root, mid);
750 /* once for the path */
751 free_extent_buffer(mid);
752 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
753 root->root_key.objectid,
754 btrfs_header_generation(mid), 0, 0, 1);
755 /* once for the root ptr */
756 free_extent_buffer(mid);
759 if (btrfs_header_nritems(mid) >
760 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
763 if (btrfs_header_nritems(mid) < 2)
766 left = read_node_slot(root, parent, pslot - 1);
768 wret = btrfs_cow_block(trans, root, left,
769 parent, pslot - 1, &left);
775 right = read_node_slot(root, parent, pslot + 1);
777 wret = btrfs_cow_block(trans, root, right,
778 parent, pslot + 1, &right);
785 /* first, try to make some room in the middle buffer */
787 orig_slot += btrfs_header_nritems(left);
788 wret = push_node_left(trans, root, left, mid);
791 if (btrfs_header_nritems(mid) < 2)
796 * then try to empty the right most buffer into the middle
799 wret = push_node_left(trans, root, mid, right);
800 if (wret < 0 && wret != -ENOSPC)
802 if (btrfs_header_nritems(right) == 0) {
803 u64 bytenr = right->start;
804 u64 generation = btrfs_header_generation(parent);
805 u32 blocksize = right->len;
807 clean_tree_block(trans, root, right);
808 wait_on_tree_block_writeback(root, right);
809 free_extent_buffer(right);
811 wret = del_ptr(trans, root, path, level + 1, pslot +
815 wret = btrfs_free_extent(trans, root, bytenr,
817 btrfs_header_owner(parent),
818 generation, 0, 0, 1);
822 struct btrfs_disk_key right_key;
823 btrfs_node_key(right, &right_key, 0);
824 btrfs_set_node_key(parent, &right_key, pslot + 1);
825 btrfs_mark_buffer_dirty(parent);
828 if (btrfs_header_nritems(mid) == 1) {
830 * we're not allowed to leave a node with one item in the
831 * tree during a delete. A deletion from lower in the tree
832 * could try to delete the only pointer in this node.
833 * So, pull some keys from the left.
834 * There has to be a left pointer at this point because
835 * otherwise we would have pulled some pointers from the
839 wret = balance_node_right(trans, root, mid, left);
846 if (btrfs_header_nritems(mid) == 0) {
847 /* we've managed to empty the middle node, drop it */
848 u64 root_gen = btrfs_header_generation(parent);
849 u64 bytenr = mid->start;
850 u32 blocksize = mid->len;
851 clean_tree_block(trans, root, mid);
852 wait_on_tree_block_writeback(root, mid);
853 free_extent_buffer(mid);
855 wret = del_ptr(trans, root, path, level + 1, pslot);
858 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
859 btrfs_header_owner(parent),
864 /* update the parent key to reflect our changes */
865 struct btrfs_disk_key mid_key;
866 btrfs_node_key(mid, &mid_key, 0);
867 btrfs_set_node_key(parent, &mid_key, pslot);
868 btrfs_mark_buffer_dirty(parent);
871 /* update the path */
873 if (btrfs_header_nritems(left) > orig_slot) {
874 extent_buffer_get(left);
875 path->nodes[level] = left;
876 path->slots[level + 1] -= 1;
877 path->slots[level] = orig_slot;
879 free_extent_buffer(mid);
881 orig_slot -= btrfs_header_nritems(left);
882 path->slots[level] = orig_slot;
885 /* double check we haven't messed things up */
886 check_block(root, path, level);
888 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
892 free_extent_buffer(right);
894 free_extent_buffer(left);
898 /* returns zero if the push worked, non-zero otherwise */
899 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
900 struct btrfs_root *root,
901 struct btrfs_path *path, int level)
903 struct extent_buffer *right = NULL;
904 struct extent_buffer *mid;
905 struct extent_buffer *left = NULL;
906 struct extent_buffer *parent = NULL;
910 int orig_slot = path->slots[level];
916 mid = path->nodes[level];
917 WARN_ON(btrfs_header_generation(mid) != trans->transid);
918 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
920 if (level < BTRFS_MAX_LEVEL - 1)
921 parent = path->nodes[level + 1];
922 pslot = path->slots[level + 1];
927 left = read_node_slot(root, parent, pslot - 1);
929 /* first, try to make some room in the middle buffer */
932 left_nr = btrfs_header_nritems(left);
933 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
936 ret = btrfs_cow_block(trans, root, left, parent,
941 wret = push_node_left(trans, root,
948 struct btrfs_disk_key disk_key;
949 orig_slot += left_nr;
950 btrfs_node_key(mid, &disk_key, 0);
951 btrfs_set_node_key(parent, &disk_key, pslot);
952 btrfs_mark_buffer_dirty(parent);
953 if (btrfs_header_nritems(left) > orig_slot) {
954 path->nodes[level] = left;
955 path->slots[level + 1] -= 1;
956 path->slots[level] = orig_slot;
957 free_extent_buffer(mid);
960 btrfs_header_nritems(left);
961 path->slots[level] = orig_slot;
962 free_extent_buffer(left);
966 free_extent_buffer(left);
968 right= read_node_slot(root, parent, pslot + 1);
971 * then try to empty the right most buffer into the middle
975 right_nr = btrfs_header_nritems(right);
976 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
979 ret = btrfs_cow_block(trans, root, right,
985 wret = balance_node_right(trans, root,
992 struct btrfs_disk_key disk_key;
994 btrfs_node_key(right, &disk_key, 0);
995 btrfs_set_node_key(parent, &disk_key, pslot + 1);
996 btrfs_mark_buffer_dirty(parent);
998 if (btrfs_header_nritems(mid) <= orig_slot) {
999 path->nodes[level] = right;
1000 path->slots[level + 1] += 1;
1001 path->slots[level] = orig_slot -
1002 btrfs_header_nritems(mid);
1003 free_extent_buffer(mid);
1005 free_extent_buffer(right);
1009 free_extent_buffer(right);
1015 * readahead one full node of leaves
1017 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1018 int level, int slot, u64 objectid)
1020 struct extent_buffer *node;
1021 struct btrfs_disk_key disk_key;
1027 int direction = path->reada;
1028 struct extent_buffer *eb;
1036 if (!path->nodes[level])
1039 node = path->nodes[level];
1040 search = btrfs_node_blockptr(node, slot);
1041 blocksize = btrfs_level_size(root, level - 1);
1042 eb = btrfs_find_tree_block(root, search, blocksize);
1044 free_extent_buffer(eb);
1048 highest_read = search;
1049 lowest_read = search;
1051 nritems = btrfs_header_nritems(node);
1054 if (direction < 0) {
1058 } else if (direction > 0) {
1063 if (path->reada < 0 && objectid) {
1064 btrfs_node_key(node, &disk_key, nr);
1065 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1068 search = btrfs_node_blockptr(node, nr);
1069 if ((search >= lowest_read && search <= highest_read) ||
1070 (search < lowest_read && lowest_read - search <= 32768) ||
1071 (search > highest_read && search - highest_read <= 32768)) {
1072 readahead_tree_block(root, search, blocksize);
1076 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1078 if(nread > (1024 * 1024) || nscan > 128)
1081 if (search < lowest_read)
1082 lowest_read = search;
1083 if (search > highest_read)
1084 highest_read = search;
1088 * look for key in the tree. path is filled in with nodes along the way
1089 * if key is found, we return zero and you can find the item in the leaf
1090 * level of the path (level 0)
1092 * If the key isn't found, the path points to the slot where it should
1093 * be inserted, and 1 is returned. If there are other errors during the
1094 * search a negative error number is returned.
1096 * if ins_len > 0, nodes and leaves will be split as we walk down the
1097 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1100 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1101 *root, struct btrfs_key *key, struct btrfs_path *p, int
1104 struct extent_buffer *b;
1110 int should_reada = p->reada;
1111 u8 lowest_level = 0;
1113 lowest_level = p->lowest_level;
1114 WARN_ON(lowest_level && ins_len);
1115 WARN_ON(p->nodes[0] != NULL);
1116 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1119 extent_buffer_get(b);
1121 level = btrfs_header_level(b);
1124 wret = btrfs_cow_block(trans, root, b,
1125 p->nodes[level + 1],
1126 p->slots[level + 1],
1129 free_extent_buffer(b);
1133 BUG_ON(!cow && ins_len);
1134 if (level != btrfs_header_level(b))
1136 level = btrfs_header_level(b);
1137 p->nodes[level] = b;
1138 ret = check_block(root, p, level);
1141 ret = bin_search(b, key, level, &slot);
1143 if (ret && slot > 0)
1145 p->slots[level] = slot;
1146 if (ins_len > 0 && btrfs_header_nritems(b) >=
1147 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1148 int sret = split_node(trans, root, p, level);
1152 b = p->nodes[level];
1153 slot = p->slots[level];
1154 } else if (ins_len < 0) {
1155 int sret = balance_level(trans, root, p,
1159 b = p->nodes[level];
1161 btrfs_release_path(NULL, p);
1164 slot = p->slots[level];
1165 BUG_ON(btrfs_header_nritems(b) == 1);
1167 /* this is only true while dropping a snapshot */
1168 if (level == lowest_level)
1170 bytenr = btrfs_node_blockptr(b, slot);
1171 ptr_gen = btrfs_node_ptr_generation(b, slot);
1173 reada_for_search(root, p, level, slot,
1175 b = read_tree_block(root, bytenr,
1176 btrfs_level_size(root, level - 1));
1177 if (ptr_gen != btrfs_header_generation(b)) {
1178 printk("block %llu bad gen wanted %llu "
1180 (unsigned long long)b->start,
1181 (unsigned long long)ptr_gen,
1182 (unsigned long long)btrfs_header_generation(b));
1185 p->slots[level] = slot;
1186 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1187 sizeof(struct btrfs_item) + ins_len) {
1188 int sret = split_leaf(trans, root, key,
1189 p, ins_len, ret == 0);
1201 * adjust the pointers going up the tree, starting at level
1202 * making sure the right key of each node is points to 'key'.
1203 * This is used after shifting pointers to the left, so it stops
1204 * fixing up pointers when a given leaf/node is not in slot 0 of the
1207 * If this fails to write a tree block, it returns -1, but continues
1208 * fixing up the blocks in ram so the tree is consistent.
1210 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1211 struct btrfs_root *root, struct btrfs_path *path,
1212 struct btrfs_disk_key *key, int level)
1216 struct extent_buffer *t;
1218 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1219 int tslot = path->slots[i];
1220 if (!path->nodes[i])
1223 btrfs_set_node_key(t, key, tslot);
1224 btrfs_mark_buffer_dirty(path->nodes[i]);
1232 * try to push data from one node into the next node left in the
1235 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1236 * error, and > 0 if there was no room in the left hand block.
1238 static int push_node_left(struct btrfs_trans_handle *trans,
1239 struct btrfs_root *root, struct extent_buffer *dst,
1240 struct extent_buffer *src)
1247 src_nritems = btrfs_header_nritems(src);
1248 dst_nritems = btrfs_header_nritems(dst);
1249 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1250 WARN_ON(btrfs_header_generation(src) != trans->transid);
1251 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1253 if (push_items <= 0) {
1257 if (src_nritems < push_items)
1258 push_items = src_nritems;
1260 copy_extent_buffer(dst, src,
1261 btrfs_node_key_ptr_offset(dst_nritems),
1262 btrfs_node_key_ptr_offset(0),
1263 push_items * sizeof(struct btrfs_key_ptr));
1265 if (push_items < src_nritems) {
1266 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1267 btrfs_node_key_ptr_offset(push_items),
1268 (src_nritems - push_items) *
1269 sizeof(struct btrfs_key_ptr));
1271 btrfs_set_header_nritems(src, src_nritems - push_items);
1272 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1273 btrfs_mark_buffer_dirty(src);
1274 btrfs_mark_buffer_dirty(dst);
1279 * try to push data from one node into the next node right in the
1282 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1283 * error, and > 0 if there was no room in the right hand block.
1285 * this will only push up to 1/2 the contents of the left node over
1287 static int balance_node_right(struct btrfs_trans_handle *trans,
1288 struct btrfs_root *root,
1289 struct extent_buffer *dst,
1290 struct extent_buffer *src)
1298 WARN_ON(btrfs_header_generation(src) != trans->transid);
1299 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1301 src_nritems = btrfs_header_nritems(src);
1302 dst_nritems = btrfs_header_nritems(dst);
1303 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1304 if (push_items <= 0)
1307 max_push = src_nritems / 2 + 1;
1308 /* don't try to empty the node */
1309 if (max_push >= src_nritems)
1312 if (max_push < push_items)
1313 push_items = max_push;
1315 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1316 btrfs_node_key_ptr_offset(0),
1318 sizeof(struct btrfs_key_ptr));
1320 copy_extent_buffer(dst, src,
1321 btrfs_node_key_ptr_offset(0),
1322 btrfs_node_key_ptr_offset(src_nritems - push_items),
1323 push_items * sizeof(struct btrfs_key_ptr));
1325 btrfs_set_header_nritems(src, src_nritems - push_items);
1326 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1328 btrfs_mark_buffer_dirty(src);
1329 btrfs_mark_buffer_dirty(dst);
1334 * helper function to insert a new root level in the tree.
1335 * A new node is allocated, and a single item is inserted to
1336 * point to the existing root
1338 * returns zero on success or < 0 on failure.
1340 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1341 struct btrfs_root *root,
1342 struct btrfs_path *path, int level)
1346 struct extent_buffer *lower;
1347 struct extent_buffer *c;
1348 struct btrfs_disk_key lower_key;
1350 BUG_ON(path->nodes[level]);
1351 BUG_ON(path->nodes[level-1] != root->node);
1354 root_gen = trans->transid;
1358 lower = path->nodes[level-1];
1360 btrfs_item_key(lower, &lower_key, 0);
1362 btrfs_node_key(lower, &lower_key, 0);
1364 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1365 root->root_key.objectid,
1366 root_gen, lower_key.objectid, level,
1367 root->node->start, 0);
1370 memset_extent_buffer(c, 0, 0, root->nodesize);
1371 btrfs_set_header_nritems(c, 1);
1372 btrfs_set_header_level(c, level);
1373 btrfs_set_header_bytenr(c, c->start);
1374 btrfs_set_header_generation(c, trans->transid);
1375 btrfs_set_header_owner(c, root->root_key.objectid);
1377 write_extent_buffer(c, root->fs_info->fsid,
1378 (unsigned long)btrfs_header_fsid(c),
1380 btrfs_set_node_key(c, &lower_key, 0);
1381 btrfs_set_node_blockptr(c, 0, lower->start);
1382 lower_gen = btrfs_header_generation(lower);
1383 WARN_ON(lower_gen == 0);
1385 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1387 btrfs_mark_buffer_dirty(c);
1389 /* the super has an extra ref to root->node */
1390 free_extent_buffer(root->node);
1392 add_root_to_dirty_list(root);
1393 extent_buffer_get(c);
1394 path->nodes[level] = c;
1395 path->slots[level] = 0;
1397 if (root->ref_cows && lower_gen != trans->transid) {
1398 struct btrfs_path *back_path = btrfs_alloc_path();
1400 ret = btrfs_insert_extent_backref(trans,
1401 root->fs_info->extent_root,
1403 root->root_key.objectid,
1404 trans->transid, 0, 0);
1406 btrfs_free_path(back_path);
1412 * worker function to insert a single pointer in a node.
1413 * the node should have enough room for the pointer already
1415 * slot and level indicate where you want the key to go, and
1416 * blocknr is the block the key points to.
1418 * returns zero on success and < 0 on any error
1420 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1421 *root, struct btrfs_path *path, struct btrfs_disk_key
1422 *key, u64 bytenr, int slot, int level)
1424 struct extent_buffer *lower;
1427 BUG_ON(!path->nodes[level]);
1428 lower = path->nodes[level];
1429 nritems = btrfs_header_nritems(lower);
1432 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1434 if (slot != nritems) {
1435 memmove_extent_buffer(lower,
1436 btrfs_node_key_ptr_offset(slot + 1),
1437 btrfs_node_key_ptr_offset(slot),
1438 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1440 btrfs_set_node_key(lower, key, slot);
1441 btrfs_set_node_blockptr(lower, slot, bytenr);
1442 WARN_ON(trans->transid == 0);
1443 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1444 btrfs_set_header_nritems(lower, nritems + 1);
1445 btrfs_mark_buffer_dirty(lower);
1450 * split the node at the specified level in path in two.
1451 * The path is corrected to point to the appropriate node after the split
1453 * Before splitting this tries to make some room in the node by pushing
1454 * left and right, if either one works, it returns right away.
1456 * returns 0 on success and < 0 on failure
1458 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1459 *root, struct btrfs_path *path, int level)
1462 struct extent_buffer *c;
1463 struct extent_buffer *split;
1464 struct btrfs_disk_key disk_key;
1470 c = path->nodes[level];
1471 WARN_ON(btrfs_header_generation(c) != trans->transid);
1472 if (c == root->node) {
1473 /* trying to split the root, lets make a new one */
1474 ret = insert_new_root(trans, root, path, level + 1);
1478 ret = push_nodes_for_insert(trans, root, path, level);
1479 c = path->nodes[level];
1480 if (!ret && btrfs_header_nritems(c) <
1481 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1487 c_nritems = btrfs_header_nritems(c);
1489 root_gen = trans->transid;
1493 btrfs_node_key(c, &disk_key, 0);
1494 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1495 root->root_key.objectid,
1497 btrfs_disk_key_objectid(&disk_key),
1498 level, c->start, 0);
1500 return PTR_ERR(split);
1502 btrfs_set_header_flags(split, btrfs_header_flags(c));
1503 btrfs_set_header_level(split, btrfs_header_level(c));
1504 btrfs_set_header_bytenr(split, split->start);
1505 btrfs_set_header_generation(split, trans->transid);
1506 btrfs_set_header_owner(split, root->root_key.objectid);
1507 btrfs_set_header_flags(split, 0);
1508 write_extent_buffer(split, root->fs_info->fsid,
1509 (unsigned long)btrfs_header_fsid(split),
1512 mid = (c_nritems + 1) / 2;
1514 copy_extent_buffer(split, c,
1515 btrfs_node_key_ptr_offset(0),
1516 btrfs_node_key_ptr_offset(mid),
1517 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1518 btrfs_set_header_nritems(split, c_nritems - mid);
1519 btrfs_set_header_nritems(c, mid);
1522 btrfs_mark_buffer_dirty(c);
1523 btrfs_mark_buffer_dirty(split);
1525 btrfs_node_key(split, &disk_key, 0);
1526 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1527 path->slots[level + 1] + 1,
1532 if (path->slots[level] >= mid) {
1533 path->slots[level] -= mid;
1534 free_extent_buffer(c);
1535 path->nodes[level] = split;
1536 path->slots[level + 1] += 1;
1538 free_extent_buffer(split);
1544 * how many bytes are required to store the items in a leaf. start
1545 * and nr indicate which items in the leaf to check. This totals up the
1546 * space used both by the item structs and the item data
1548 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1551 int nritems = btrfs_header_nritems(l);
1552 int end = min(nritems, start + nr) - 1;
1556 data_len = btrfs_item_end_nr(l, start);
1557 data_len = data_len - btrfs_item_offset_nr(l, end);
1558 data_len += sizeof(struct btrfs_item) * nr;
1559 WARN_ON(data_len < 0);
1564 * The space between the end of the leaf items and
1565 * the start of the leaf data. IOW, how much room
1566 * the leaf has left for both items and data
1568 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1570 int nritems = btrfs_header_nritems(leaf);
1572 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1574 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1575 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1576 leaf_space_used(leaf, 0, nritems), nritems);
1582 * push some data in the path leaf to the right, trying to free up at
1583 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1585 * returns 1 if the push failed because the other node didn't have enough
1586 * room, 0 if everything worked out and < 0 if there were major errors.
1588 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1589 *root, struct btrfs_path *path, int data_size,
1592 struct extent_buffer *left = path->nodes[0];
1593 struct extent_buffer *right;
1594 struct extent_buffer *upper;
1595 struct btrfs_disk_key disk_key;
1601 struct btrfs_item *item;
1609 slot = path->slots[1];
1610 if (!path->nodes[1]) {
1613 upper = path->nodes[1];
1614 if (slot >= btrfs_header_nritems(upper) - 1)
1617 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1619 free_space = btrfs_leaf_free_space(root, right);
1620 if (free_space < data_size + sizeof(struct btrfs_item)) {
1621 free_extent_buffer(right);
1625 /* cow and double check */
1626 ret = btrfs_cow_block(trans, root, right, upper,
1629 free_extent_buffer(right);
1632 free_space = btrfs_leaf_free_space(root, right);
1633 if (free_space < data_size + sizeof(struct btrfs_item)) {
1634 free_extent_buffer(right);
1638 left_nritems = btrfs_header_nritems(left);
1639 if (left_nritems == 0) {
1640 free_extent_buffer(right);
1649 i = left_nritems - 1;
1651 item = btrfs_item_nr(left, i);
1653 if (path->slots[0] == i)
1654 push_space += data_size + sizeof(*item);
1656 if (!left->map_token) {
1657 map_extent_buffer(left, (unsigned long)item,
1658 sizeof(struct btrfs_item),
1659 &left->map_token, &left->kaddr,
1660 &left->map_start, &left->map_len,
1664 this_item_size = btrfs_item_size(left, item);
1665 if (this_item_size + sizeof(*item) + push_space > free_space)
1668 push_space += this_item_size + sizeof(*item);
1673 if (left->map_token) {
1674 unmap_extent_buffer(left, left->map_token, KM_USER1);
1675 left->map_token = NULL;
1678 if (push_items == 0) {
1679 free_extent_buffer(right);
1683 if (!empty && push_items == left_nritems)
1686 /* push left to right */
1687 right_nritems = btrfs_header_nritems(right);
1689 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1690 push_space -= leaf_data_end(root, left);
1692 /* make room in the right data area */
1693 data_end = leaf_data_end(root, right);
1694 memmove_extent_buffer(right,
1695 btrfs_leaf_data(right) + data_end - push_space,
1696 btrfs_leaf_data(right) + data_end,
1697 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1699 /* copy from the left data area */
1700 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1701 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1702 btrfs_leaf_data(left) + leaf_data_end(root, left),
1705 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1706 btrfs_item_nr_offset(0),
1707 right_nritems * sizeof(struct btrfs_item));
1709 /* copy the items from left to right */
1710 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1711 btrfs_item_nr_offset(left_nritems - push_items),
1712 push_items * sizeof(struct btrfs_item));
1714 /* update the item pointers */
1715 right_nritems += push_items;
1716 btrfs_set_header_nritems(right, right_nritems);
1717 push_space = BTRFS_LEAF_DATA_SIZE(root);
1718 for (i = 0; i < right_nritems; i++) {
1719 item = btrfs_item_nr(right, i);
1720 if (!right->map_token) {
1721 map_extent_buffer(right, (unsigned long)item,
1722 sizeof(struct btrfs_item),
1723 &right->map_token, &right->kaddr,
1724 &right->map_start, &right->map_len,
1727 push_space -= btrfs_item_size(right, item);
1728 btrfs_set_item_offset(right, item, push_space);
1731 if (right->map_token) {
1732 unmap_extent_buffer(right, right->map_token, KM_USER1);
1733 right->map_token = NULL;
1735 left_nritems -= push_items;
1736 btrfs_set_header_nritems(left, left_nritems);
1739 btrfs_mark_buffer_dirty(left);
1740 btrfs_mark_buffer_dirty(right);
1742 btrfs_item_key(right, &disk_key, 0);
1743 btrfs_set_node_key(upper, &disk_key, slot + 1);
1744 btrfs_mark_buffer_dirty(upper);
1746 /* then fixup the leaf pointer in the path */
1747 if (path->slots[0] >= left_nritems) {
1748 path->slots[0] -= left_nritems;
1749 free_extent_buffer(path->nodes[0]);
1750 path->nodes[0] = right;
1751 path->slots[1] += 1;
1753 free_extent_buffer(right);
1758 * push some data in the path leaf to the left, trying to free up at
1759 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1761 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1762 *root, struct btrfs_path *path, int data_size,
1765 struct btrfs_disk_key disk_key;
1766 struct extent_buffer *right = path->nodes[0];
1767 struct extent_buffer *left;
1773 struct btrfs_item *item;
1774 u32 old_left_nritems;
1780 u32 old_left_item_size;
1782 slot = path->slots[1];
1785 if (!path->nodes[1])
1788 right_nritems = btrfs_header_nritems(right);
1789 if (right_nritems == 0) {
1793 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1794 slot - 1), root->leafsize);
1795 free_space = btrfs_leaf_free_space(root, left);
1796 if (free_space < data_size + sizeof(struct btrfs_item)) {
1797 free_extent_buffer(left);
1801 /* cow and double check */
1802 ret = btrfs_cow_block(trans, root, left,
1803 path->nodes[1], slot - 1, &left);
1805 /* we hit -ENOSPC, but it isn't fatal here */
1806 free_extent_buffer(left);
1810 free_space = btrfs_leaf_free_space(root, left);
1811 if (free_space < data_size + sizeof(struct btrfs_item)) {
1812 free_extent_buffer(left);
1819 nr = right_nritems - 1;
1821 for (i = 0; i < nr; i++) {
1822 item = btrfs_item_nr(right, i);
1823 if (!right->map_token) {
1824 map_extent_buffer(right, (unsigned long)item,
1825 sizeof(struct btrfs_item),
1826 &right->map_token, &right->kaddr,
1827 &right->map_start, &right->map_len,
1831 if (path->slots[0] == i)
1832 push_space += data_size + sizeof(*item);
1834 this_item_size = btrfs_item_size(right, item);
1835 if (this_item_size + sizeof(*item) + push_space > free_space)
1839 push_space += this_item_size + sizeof(*item);
1842 if (right->map_token) {
1843 unmap_extent_buffer(right, right->map_token, KM_USER1);
1844 right->map_token = NULL;
1847 if (push_items == 0) {
1848 free_extent_buffer(left);
1851 if (!empty && push_items == btrfs_header_nritems(right))
1854 /* push data from right to left */
1855 copy_extent_buffer(left, right,
1856 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1857 btrfs_item_nr_offset(0),
1858 push_items * sizeof(struct btrfs_item));
1860 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1861 btrfs_item_offset_nr(right, push_items -1);
1863 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1864 leaf_data_end(root, left) - push_space,
1865 btrfs_leaf_data(right) +
1866 btrfs_item_offset_nr(right, push_items - 1),
1868 old_left_nritems = btrfs_header_nritems(left);
1869 BUG_ON(old_left_nritems < 0);
1871 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1872 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1875 item = btrfs_item_nr(left, i);
1876 if (!left->map_token) {
1877 map_extent_buffer(left, (unsigned long)item,
1878 sizeof(struct btrfs_item),
1879 &left->map_token, &left->kaddr,
1880 &left->map_start, &left->map_len,
1884 ioff = btrfs_item_offset(left, item);
1885 btrfs_set_item_offset(left, item,
1886 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1888 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1889 if (left->map_token) {
1890 unmap_extent_buffer(left, left->map_token, KM_USER1);
1891 left->map_token = NULL;
1894 /* fixup right node */
1895 if (push_items > right_nritems) {
1896 printk("push items %d nr %u\n", push_items, right_nritems);
1900 if (push_items < right_nritems) {
1901 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1902 leaf_data_end(root, right);
1903 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1904 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1905 btrfs_leaf_data(right) +
1906 leaf_data_end(root, right), push_space);
1908 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1909 btrfs_item_nr_offset(push_items),
1910 (btrfs_header_nritems(right) - push_items) *
1911 sizeof(struct btrfs_item));
1913 right_nritems -= push_items;
1914 btrfs_set_header_nritems(right, right_nritems);
1915 push_space = BTRFS_LEAF_DATA_SIZE(root);
1916 for (i = 0; i < right_nritems; i++) {
1917 item = btrfs_item_nr(right, i);
1919 if (!right->map_token) {
1920 map_extent_buffer(right, (unsigned long)item,
1921 sizeof(struct btrfs_item),
1922 &right->map_token, &right->kaddr,
1923 &right->map_start, &right->map_len,
1927 push_space = push_space - btrfs_item_size(right, item);
1928 btrfs_set_item_offset(right, item, push_space);
1930 if (right->map_token) {
1931 unmap_extent_buffer(right, right->map_token, KM_USER1);
1932 right->map_token = NULL;
1935 btrfs_mark_buffer_dirty(left);
1937 btrfs_mark_buffer_dirty(right);
1939 btrfs_item_key(right, &disk_key, 0);
1940 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1944 /* then fixup the leaf pointer in the path */
1945 if (path->slots[0] < push_items) {
1946 path->slots[0] += old_left_nritems;
1947 free_extent_buffer(path->nodes[0]);
1948 path->nodes[0] = left;
1949 path->slots[1] -= 1;
1951 free_extent_buffer(left);
1952 path->slots[0] -= push_items;
1954 BUG_ON(path->slots[0] < 0);
1959 * split the path's leaf in two, making sure there is at least data_size
1960 * available for the resulting leaf level of the path.
1962 * returns 0 if all went well and < 0 on failure.
1964 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1965 *root, struct btrfs_key *ins_key,
1966 struct btrfs_path *path, int data_size, int extend)
1969 struct extent_buffer *l;
1973 struct extent_buffer *right;
1974 int space_needed = data_size + sizeof(struct btrfs_item);
1981 int num_doubles = 0;
1982 struct btrfs_disk_key disk_key;
1985 space_needed = data_size;
1988 root_gen = trans->transid;
1992 /* first try to make some room by pushing left and right */
1993 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1994 wret = push_leaf_right(trans, root, path, data_size, 0);
1999 wret = push_leaf_left(trans, root, path, data_size, 0);
2005 /* did the pushes work? */
2006 if (btrfs_leaf_free_space(root, l) >= space_needed)
2010 if (!path->nodes[1]) {
2011 ret = insert_new_root(trans, root, path, 1);
2018 slot = path->slots[0];
2019 nritems = btrfs_header_nritems(l);
2020 mid = (nritems + 1)/ 2;
2022 btrfs_item_key(l, &disk_key, 0);
2024 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
2025 root->root_key.objectid,
2026 root_gen, disk_key.objectid, 0,
2029 return PTR_ERR(right);
2031 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2032 btrfs_set_header_bytenr(right, right->start);
2033 btrfs_set_header_generation(right, trans->transid);
2034 btrfs_set_header_owner(right, root->root_key.objectid);
2035 btrfs_set_header_level(right, 0);
2036 write_extent_buffer(right, root->fs_info->fsid,
2037 (unsigned long)btrfs_header_fsid(right),
2041 leaf_space_used(l, mid, nritems - mid) + space_needed >
2042 BTRFS_LEAF_DATA_SIZE(root)) {
2043 if (slot >= nritems) {
2044 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2045 btrfs_set_header_nritems(right, 0);
2046 wret = insert_ptr(trans, root, path,
2047 &disk_key, right->start,
2048 path->slots[1] + 1, 1);
2051 free_extent_buffer(path->nodes[0]);
2052 path->nodes[0] = right;
2054 path->slots[1] += 1;
2055 btrfs_mark_buffer_dirty(right);
2059 if (mid != nritems &&
2060 leaf_space_used(l, mid, nritems - mid) +
2061 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2066 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2067 BTRFS_LEAF_DATA_SIZE(root)) {
2068 if (!extend && slot == 0) {
2069 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2070 btrfs_set_header_nritems(right, 0);
2071 wret = insert_ptr(trans, root, path,
2077 free_extent_buffer(path->nodes[0]);
2078 path->nodes[0] = right;
2080 if (path->slots[1] == 0) {
2081 wret = fixup_low_keys(trans, root,
2082 path, &disk_key, 1);
2086 btrfs_mark_buffer_dirty(right);
2088 } else if (extend && slot == 0) {
2092 if (mid != nritems &&
2093 leaf_space_used(l, mid, nritems - mid) +
2094 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2100 nritems = nritems - mid;
2101 btrfs_set_header_nritems(right, nritems);
2102 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2104 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2105 btrfs_item_nr_offset(mid),
2106 nritems * sizeof(struct btrfs_item));
2108 copy_extent_buffer(right, l,
2109 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2110 data_copy_size, btrfs_leaf_data(l) +
2111 leaf_data_end(root, l), data_copy_size);
2113 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2114 btrfs_item_end_nr(l, mid);
2116 for (i = 0; i < nritems; i++) {
2117 struct btrfs_item *item = btrfs_item_nr(right, i);
2120 if (!right->map_token) {
2121 map_extent_buffer(right, (unsigned long)item,
2122 sizeof(struct btrfs_item),
2123 &right->map_token, &right->kaddr,
2124 &right->map_start, &right->map_len,
2128 ioff = btrfs_item_offset(right, item);
2129 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2132 if (right->map_token) {
2133 unmap_extent_buffer(right, right->map_token, KM_USER1);
2134 right->map_token = NULL;
2137 btrfs_set_header_nritems(l, mid);
2139 btrfs_item_key(right, &disk_key, 0);
2140 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2141 path->slots[1] + 1, 1);
2145 btrfs_mark_buffer_dirty(right);
2146 btrfs_mark_buffer_dirty(l);
2147 BUG_ON(path->slots[0] != slot);
2150 free_extent_buffer(path->nodes[0]);
2151 path->nodes[0] = right;
2152 path->slots[0] -= mid;
2153 path->slots[1] += 1;
2155 free_extent_buffer(right);
2157 BUG_ON(path->slots[0] < 0);
2160 BUG_ON(num_doubles != 0);
2167 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2168 struct btrfs_root *root,
2169 struct btrfs_path *path,
2170 u32 new_size, int from_end)
2175 struct extent_buffer *leaf;
2176 struct btrfs_item *item;
2178 unsigned int data_end;
2179 unsigned int old_data_start;
2180 unsigned int old_size;
2181 unsigned int size_diff;
2184 slot_orig = path->slots[0];
2185 leaf = path->nodes[0];
2186 slot = path->slots[0];
2188 old_size = btrfs_item_size_nr(leaf, slot);
2189 if (old_size == new_size)
2192 nritems = btrfs_header_nritems(leaf);
2193 data_end = leaf_data_end(root, leaf);
2195 old_data_start = btrfs_item_offset_nr(leaf, slot);
2197 size_diff = old_size - new_size;
2200 BUG_ON(slot >= nritems);
2203 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2205 /* first correct the data pointers */
2206 for (i = slot; i < nritems; i++) {
2208 item = btrfs_item_nr(leaf, i);
2210 if (!leaf->map_token) {
2211 map_extent_buffer(leaf, (unsigned long)item,
2212 sizeof(struct btrfs_item),
2213 &leaf->map_token, &leaf->kaddr,
2214 &leaf->map_start, &leaf->map_len,
2218 ioff = btrfs_item_offset(leaf, item);
2219 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2222 if (leaf->map_token) {
2223 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2224 leaf->map_token = NULL;
2227 /* shift the data */
2229 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2230 data_end + size_diff, btrfs_leaf_data(leaf) +
2231 data_end, old_data_start + new_size - data_end);
2233 struct btrfs_disk_key disk_key;
2236 btrfs_item_key(leaf, &disk_key, slot);
2238 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2240 struct btrfs_file_extent_item *fi;
2242 fi = btrfs_item_ptr(leaf, slot,
2243 struct btrfs_file_extent_item);
2244 fi = (struct btrfs_file_extent_item *)(
2245 (unsigned long)fi - size_diff);
2247 if (btrfs_file_extent_type(leaf, fi) ==
2248 BTRFS_FILE_EXTENT_INLINE) {
2249 ptr = btrfs_item_ptr_offset(leaf, slot);
2250 memmove_extent_buffer(leaf, ptr,
2252 offsetof(struct btrfs_file_extent_item,
2257 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2258 data_end + size_diff, btrfs_leaf_data(leaf) +
2259 data_end, old_data_start - data_end);
2261 offset = btrfs_disk_key_offset(&disk_key);
2262 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2263 btrfs_set_item_key(leaf, &disk_key, slot);
2265 fixup_low_keys(trans, root, path, &disk_key, 1);
2268 item = btrfs_item_nr(leaf, slot);
2269 btrfs_set_item_size(leaf, item, new_size);
2270 btrfs_mark_buffer_dirty(leaf);
2273 if (btrfs_leaf_free_space(root, leaf) < 0) {
2274 btrfs_print_leaf(root, leaf);
2280 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2281 struct btrfs_root *root, struct btrfs_path *path,
2287 struct extent_buffer *leaf;
2288 struct btrfs_item *item;
2290 unsigned int data_end;
2291 unsigned int old_data;
2292 unsigned int old_size;
2295 slot_orig = path->slots[0];
2296 leaf = path->nodes[0];
2298 nritems = btrfs_header_nritems(leaf);
2299 data_end = leaf_data_end(root, leaf);
2301 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2302 btrfs_print_leaf(root, leaf);
2305 slot = path->slots[0];
2306 old_data = btrfs_item_end_nr(leaf, slot);
2309 if (slot >= nritems) {
2310 btrfs_print_leaf(root, leaf);
2311 printk("slot %d too large, nritems %d\n", slot, nritems);
2316 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2318 /* first correct the data pointers */
2319 for (i = slot; i < nritems; i++) {
2321 item = btrfs_item_nr(leaf, i);
2323 if (!leaf->map_token) {
2324 map_extent_buffer(leaf, (unsigned long)item,
2325 sizeof(struct btrfs_item),
2326 &leaf->map_token, &leaf->kaddr,
2327 &leaf->map_start, &leaf->map_len,
2330 ioff = btrfs_item_offset(leaf, item);
2331 btrfs_set_item_offset(leaf, item, ioff - data_size);
2334 if (leaf->map_token) {
2335 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2336 leaf->map_token = NULL;
2339 /* shift the data */
2340 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2341 data_end - data_size, btrfs_leaf_data(leaf) +
2342 data_end, old_data - data_end);
2344 data_end = old_data;
2345 old_size = btrfs_item_size_nr(leaf, slot);
2346 item = btrfs_item_nr(leaf, slot);
2347 btrfs_set_item_size(leaf, item, old_size + data_size);
2348 btrfs_mark_buffer_dirty(leaf);
2351 if (btrfs_leaf_free_space(root, leaf) < 0) {
2352 btrfs_print_leaf(root, leaf);
2359 * Given a key and some data, insert an item into the tree.
2360 * This does all the path init required, making room in the tree if needed.
2362 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2363 struct btrfs_root *root,
2364 struct btrfs_path *path,
2365 struct btrfs_key *cpu_key, u32 *data_size,
2368 struct extent_buffer *leaf;
2369 struct btrfs_item *item;
2377 unsigned int data_end;
2378 struct btrfs_disk_key disk_key;
2380 for (i = 0; i < nr; i++) {
2381 total_data += data_size[i];
2384 /* create a root if there isn't one */
2388 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2389 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2396 slot_orig = path->slots[0];
2397 leaf = path->nodes[0];
2399 nritems = btrfs_header_nritems(leaf);
2400 data_end = leaf_data_end(root, leaf);
2402 if (btrfs_leaf_free_space(root, leaf) <
2403 sizeof(struct btrfs_item) + total_size) {
2404 btrfs_print_leaf(root, leaf);
2405 printk("not enough freespace need %u have %d\n",
2406 total_size, btrfs_leaf_free_space(root, leaf));
2410 slot = path->slots[0];
2413 if (slot != nritems) {
2415 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2417 if (old_data < data_end) {
2418 btrfs_print_leaf(root, leaf);
2419 printk("slot %d old_data %d data_end %d\n",
2420 slot, old_data, data_end);
2424 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2426 /* first correct the data pointers */
2427 WARN_ON(leaf->map_token);
2428 for (i = slot; i < nritems; i++) {
2431 item = btrfs_item_nr(leaf, i);
2432 if (!leaf->map_token) {
2433 map_extent_buffer(leaf, (unsigned long)item,
2434 sizeof(struct btrfs_item),
2435 &leaf->map_token, &leaf->kaddr,
2436 &leaf->map_start, &leaf->map_len,
2440 ioff = btrfs_item_offset(leaf, item);
2441 btrfs_set_item_offset(leaf, item, ioff - total_data);
2443 if (leaf->map_token) {
2444 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2445 leaf->map_token = NULL;
2448 /* shift the items */
2449 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2450 btrfs_item_nr_offset(slot),
2451 (nritems - slot) * sizeof(struct btrfs_item));
2453 /* shift the data */
2454 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2455 data_end - total_data, btrfs_leaf_data(leaf) +
2456 data_end, old_data - data_end);
2457 data_end = old_data;
2460 /* setup the item for the new data */
2461 for (i = 0; i < nr; i++) {
2462 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2463 btrfs_set_item_key(leaf, &disk_key, slot + i);
2464 item = btrfs_item_nr(leaf, slot + i);
2465 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2466 data_end -= data_size[i];
2467 btrfs_set_item_size(leaf, item, data_size[i]);
2469 btrfs_set_header_nritems(leaf, nritems + nr);
2470 btrfs_mark_buffer_dirty(leaf);
2474 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2475 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2478 if (btrfs_leaf_free_space(root, leaf) < 0) {
2479 btrfs_print_leaf(root, leaf);
2488 * Given a key and some data, insert an item into the tree.
2489 * This does all the path init required, making room in the tree if needed.
2491 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2492 *root, struct btrfs_key *cpu_key, void *data, u32
2496 struct btrfs_path *path;
2497 struct extent_buffer *leaf;
2500 path = btrfs_alloc_path();
2502 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2504 leaf = path->nodes[0];
2505 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2506 write_extent_buffer(leaf, data, ptr, data_size);
2507 btrfs_mark_buffer_dirty(leaf);
2509 btrfs_free_path(path);
2514 * delete the pointer from a given node.
2516 * If the delete empties a node, the node is removed from the tree,
2517 * continuing all the way the root if required. The root is converted into
2518 * a leaf if all the nodes are emptied.
2520 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2521 struct btrfs_path *path, int level, int slot)
2523 struct extent_buffer *parent = path->nodes[level];
2528 nritems = btrfs_header_nritems(parent);
2529 if (slot != nritems -1) {
2530 memmove_extent_buffer(parent,
2531 btrfs_node_key_ptr_offset(slot),
2532 btrfs_node_key_ptr_offset(slot + 1),
2533 sizeof(struct btrfs_key_ptr) *
2534 (nritems - slot - 1));
2537 btrfs_set_header_nritems(parent, nritems);
2538 if (nritems == 0 && parent == root->node) {
2539 BUG_ON(btrfs_header_level(root->node) != 1);
2540 /* just turn the root into a leaf and break */
2541 btrfs_set_header_level(root->node, 0);
2542 } else if (slot == 0) {
2543 struct btrfs_disk_key disk_key;
2545 btrfs_node_key(parent, &disk_key, 0);
2546 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2550 btrfs_mark_buffer_dirty(parent);
2555 * delete the item at the leaf level in path. If that empties
2556 * the leaf, remove it from the tree
2558 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2559 struct btrfs_path *path, int slot, int nr)
2561 struct extent_buffer *leaf;
2562 struct btrfs_item *item;
2570 leaf = path->nodes[0];
2571 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2573 for (i = 0; i < nr; i++)
2574 dsize += btrfs_item_size_nr(leaf, slot + i);
2576 nritems = btrfs_header_nritems(leaf);
2578 if (slot + nr != nritems) {
2580 int data_end = leaf_data_end(root, leaf);
2582 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2584 btrfs_leaf_data(leaf) + data_end,
2585 last_off - data_end);
2587 for (i = slot + nr; i < nritems; i++) {
2590 item = btrfs_item_nr(leaf, i);
2591 if (!leaf->map_token) {
2592 map_extent_buffer(leaf, (unsigned long)item,
2593 sizeof(struct btrfs_item),
2594 &leaf->map_token, &leaf->kaddr,
2595 &leaf->map_start, &leaf->map_len,
2598 ioff = btrfs_item_offset(leaf, item);
2599 btrfs_set_item_offset(leaf, item, ioff + dsize);
2602 if (leaf->map_token) {
2603 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2604 leaf->map_token = NULL;
2607 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2608 btrfs_item_nr_offset(slot + nr),
2609 sizeof(struct btrfs_item) *
2610 (nritems - slot - nr));
2612 btrfs_set_header_nritems(leaf, nritems - nr);
2615 /* delete the leaf if we've emptied it */
2617 if (leaf == root->node) {
2618 btrfs_set_header_level(leaf, 0);
2620 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2621 clean_tree_block(trans, root, leaf);
2622 wait_on_tree_block_writeback(root, leaf);
2623 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2626 wret = btrfs_free_extent(trans, root,
2627 leaf->start, leaf->len,
2628 btrfs_header_owner(path->nodes[1]),
2634 int used = leaf_space_used(leaf, 0, nritems);
2636 struct btrfs_disk_key disk_key;
2638 btrfs_item_key(leaf, &disk_key, 0);
2639 wret = fixup_low_keys(trans, root, path,
2645 /* delete the leaf if it is mostly empty */
2646 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2647 /* push_leaf_left fixes the path.
2648 * make sure the path still points to our leaf
2649 * for possible call to del_ptr below
2651 slot = path->slots[1];
2652 extent_buffer_get(leaf);
2654 wret = push_leaf_left(trans, root, path, 1, 1);
2655 if (wret < 0 && wret != -ENOSPC)
2658 if (path->nodes[0] == leaf &&
2659 btrfs_header_nritems(leaf)) {
2660 wret = push_leaf_right(trans, root, path, 1, 1);
2661 if (wret < 0 && wret != -ENOSPC)
2665 if (btrfs_header_nritems(leaf) == 0) {
2667 u64 bytenr = leaf->start;
2668 u32 blocksize = leaf->len;
2670 root_gen = btrfs_header_generation(
2673 clean_tree_block(trans, root, leaf);
2674 wait_on_tree_block_writeback(root, leaf);
2676 wret = del_ptr(trans, root, path, 1, slot);
2680 free_extent_buffer(leaf);
2681 wret = btrfs_free_extent(trans, root, bytenr,
2683 btrfs_header_owner(path->nodes[1]),
2688 btrfs_mark_buffer_dirty(leaf);
2689 free_extent_buffer(leaf);
2692 btrfs_mark_buffer_dirty(leaf);
2699 * walk up the tree as far as required to find the previous leaf.
2700 * returns 0 if it found something or 1 if there are no lesser leaves.
2701 * returns < 0 on io errors.
2703 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2708 struct extent_buffer *c;
2709 struct extent_buffer *next = NULL;
2711 while(level < BTRFS_MAX_LEVEL) {
2712 if (!path->nodes[level])
2715 slot = path->slots[level];
2716 c = path->nodes[level];
2719 if (level == BTRFS_MAX_LEVEL)
2725 bytenr = btrfs_node_blockptr(c, slot);
2727 free_extent_buffer(next);
2729 next = read_tree_block(root, bytenr,
2730 btrfs_level_size(root, level - 1));
2733 path->slots[level] = slot;
2736 c = path->nodes[level];
2737 free_extent_buffer(c);
2738 slot = btrfs_header_nritems(next);
2741 path->nodes[level] = next;
2742 path->slots[level] = slot;
2745 next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2746 btrfs_level_size(root, level - 1));
2752 * walk up the tree as far as required to find the next leaf.
2753 * returns 0 if it found something or 1 if there are no greater leaves.
2754 * returns < 0 on io errors.
2756 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2761 struct extent_buffer *c;
2762 struct extent_buffer *next = NULL;
2764 while(level < BTRFS_MAX_LEVEL) {
2765 if (!path->nodes[level])
2768 slot = path->slots[level] + 1;
2769 c = path->nodes[level];
2770 if (slot >= btrfs_header_nritems(c)) {
2772 if (level == BTRFS_MAX_LEVEL)
2777 bytenr = btrfs_node_blockptr(c, slot);
2779 free_extent_buffer(next);
2782 reada_for_search(root, path, level, slot, 0);
2784 next = read_tree_block(root, bytenr,
2785 btrfs_level_size(root, level -1));
2788 path->slots[level] = slot;
2791 c = path->nodes[level];
2792 free_extent_buffer(c);
2793 path->nodes[level] = next;
2794 path->slots[level] = 0;
2798 reada_for_search(root, path, level, 0, 0);
2799 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2800 btrfs_level_size(root, level - 1));
2805 int btrfs_previous_item(struct btrfs_root *root,
2806 struct btrfs_path *path, u64 min_objectid,
2809 struct btrfs_key found_key;
2810 struct extent_buffer *leaf;
2814 if (path->slots[0] == 0) {
2815 ret = btrfs_prev_leaf(root, path);
2821 leaf = path->nodes[0];
2822 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2823 if (found_key.type == type)