2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include "transaction.h"
21 #include "print-tree.h"
24 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
25 *root, struct btrfs_path *path, int level);
26 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_key *ins_key,
28 struct btrfs_path *path, int data_size, int extend);
29 static int push_node_left(struct btrfs_trans_handle *trans,
30 struct btrfs_root *root, struct extent_buffer *dst,
31 struct extent_buffer *src, int empty);
32 static int balance_node_right(struct btrfs_trans_handle *trans,
33 struct btrfs_root *root,
34 struct extent_buffer *dst_buf,
35 struct extent_buffer *src_buf);
37 inline void btrfs_init_path(struct btrfs_path *p)
39 memset(p, 0, sizeof(*p));
42 struct btrfs_path *btrfs_alloc_path(void)
44 struct btrfs_path *path;
45 path = kzalloc(sizeof(struct btrfs_path), GFP_NOFS);
49 void btrfs_free_path(struct btrfs_path *p)
51 btrfs_release_path(p);
55 void btrfs_release_path(struct btrfs_path *p)
58 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
61 free_extent_buffer(p->nodes[i]);
63 memset(p, 0, sizeof(*p));
66 void add_root_to_dirty_list(struct btrfs_root *root)
68 if (root->track_dirty && list_empty(&root->dirty_list)) {
69 list_add(&root->dirty_list,
70 &root->fs_info->dirty_cowonly_roots);
74 int btrfs_copy_root(struct btrfs_trans_handle *trans,
75 struct btrfs_root *root,
76 struct extent_buffer *buf,
77 struct extent_buffer **cow_ret, u64 new_root_objectid)
79 struct extent_buffer *cow;
82 struct btrfs_root *new_root;
83 struct btrfs_disk_key disk_key;
85 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
89 memcpy(new_root, root, sizeof(*new_root));
90 new_root->root_key.objectid = new_root_objectid;
92 WARN_ON(root->ref_cows && trans->transid !=
93 root->fs_info->running_transaction->transid);
94 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
96 level = btrfs_header_level(buf);
98 btrfs_item_key(buf, &disk_key, 0);
100 btrfs_node_key(buf, &disk_key, 0);
101 cow = btrfs_alloc_free_block(trans, new_root, buf->len,
102 new_root_objectid, &disk_key,
103 level, buf->start, 0);
109 copy_extent_buffer(cow, buf, 0, 0, cow->len);
110 btrfs_set_header_bytenr(cow, cow->start);
111 btrfs_set_header_generation(cow, trans->transid);
112 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
113 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
114 BTRFS_HEADER_FLAG_RELOC);
115 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
116 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
118 btrfs_set_header_owner(cow, new_root_objectid);
120 write_extent_buffer(cow, root->fs_info->fsid,
121 btrfs_header_fsid(), BTRFS_FSID_SIZE);
123 WARN_ON(btrfs_header_generation(buf) > trans->transid);
124 ret = btrfs_inc_ref(trans, new_root, cow, 0);
130 btrfs_mark_buffer_dirty(cow);
136 * check if the tree block can be shared by multiple trees
138 static int btrfs_block_can_be_shared(struct btrfs_root *root,
139 struct extent_buffer *buf)
142 * Tree blocks not in refernece counted trees and tree roots
143 * are never shared. If a block was allocated after the last
144 * snapshot and the block was not allocated by tree relocation,
145 * we know the block is not shared.
147 if (root->ref_cows &&
148 buf != root->node && buf != root->commit_root &&
149 (btrfs_header_generation(buf) <=
150 btrfs_root_last_snapshot(&root->root_item) ||
151 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
153 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
154 if (root->ref_cows &&
155 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
161 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
162 struct btrfs_root *root,
163 struct extent_buffer *buf,
164 struct extent_buffer *cow)
173 * Backrefs update rules:
175 * Always use full backrefs for extent pointers in tree block
176 * allocated by tree relocation.
178 * If a shared tree block is no longer referenced by its owner
179 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
180 * use full backrefs for extent pointers in tree block.
182 * If a tree block is been relocating
183 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
184 * use full backrefs for extent pointers in tree block.
185 * The reason for this is some operations (such as drop tree)
186 * are only allowed for blocks use full backrefs.
189 if (btrfs_block_can_be_shared(root, buf)) {
190 ret = btrfs_lookup_extent_info(trans, root, buf->start,
191 btrfs_header_level(buf), 1,
197 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
198 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
199 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
204 owner = btrfs_header_owner(buf);
205 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) &&
206 owner == BTRFS_TREE_RELOC_OBJECTID);
209 if ((owner == root->root_key.objectid ||
210 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
211 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
212 ret = btrfs_inc_ref(trans, root, buf, 1);
215 if (root->root_key.objectid ==
216 BTRFS_TREE_RELOC_OBJECTID) {
217 ret = btrfs_dec_ref(trans, root, buf, 0);
219 ret = btrfs_inc_ref(trans, root, cow, 1);
222 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
225 if (root->root_key.objectid ==
226 BTRFS_TREE_RELOC_OBJECTID)
227 ret = btrfs_inc_ref(trans, root, cow, 1);
229 ret = btrfs_inc_ref(trans, root, cow, 0);
232 if (new_flags != 0) {
233 ret = btrfs_set_block_flags(trans, root, buf->start,
234 btrfs_header_level(buf),
239 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
240 if (root->root_key.objectid ==
241 BTRFS_TREE_RELOC_OBJECTID)
242 ret = btrfs_inc_ref(trans, root, cow, 1);
244 ret = btrfs_inc_ref(trans, root, cow, 0);
246 ret = btrfs_dec_ref(trans, root, buf, 1);
249 clean_tree_block(trans, root, buf);
254 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
255 struct btrfs_root *root,
256 struct extent_buffer *buf,
257 struct extent_buffer *parent, int parent_slot,
258 struct extent_buffer **cow_ret,
259 u64 search_start, u64 empty_size)
261 struct extent_buffer *cow;
262 struct btrfs_disk_key disk_key;
265 WARN_ON(root->ref_cows && trans->transid !=
266 root->fs_info->running_transaction->transid);
267 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
269 level = btrfs_header_level(buf);
272 btrfs_item_key(buf, &disk_key, 0);
274 btrfs_node_key(buf, &disk_key, 0);
276 cow = btrfs_alloc_free_block(trans, root, buf->len,
277 root->root_key.objectid, &disk_key,
278 level, search_start, empty_size);
282 copy_extent_buffer(cow, buf, 0, 0, cow->len);
283 btrfs_set_header_bytenr(cow, cow->start);
284 btrfs_set_header_generation(cow, trans->transid);
285 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
286 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
287 BTRFS_HEADER_FLAG_RELOC);
288 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
289 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
291 btrfs_set_header_owner(cow, root->root_key.objectid);
293 write_extent_buffer(cow, root->fs_info->fsid,
294 btrfs_header_fsid(), BTRFS_FSID_SIZE);
296 WARN_ON(!(buf->flags & EXTENT_BAD_TRANSID) &&
297 btrfs_header_generation(buf) > trans->transid);
299 update_ref_for_cow(trans, root, buf, cow);
301 if (buf == root->node) {
303 extent_buffer_get(cow);
305 btrfs_free_extent(trans, root, buf->start, buf->len,
306 0, root->root_key.objectid, level, 0);
307 free_extent_buffer(buf);
308 add_root_to_dirty_list(root);
310 btrfs_set_node_blockptr(parent, parent_slot,
312 WARN_ON(trans->transid == 0);
313 btrfs_set_node_ptr_generation(parent, parent_slot,
315 btrfs_mark_buffer_dirty(parent);
316 WARN_ON(btrfs_header_generation(parent) != trans->transid);
318 btrfs_free_extent(trans, root, buf->start, buf->len,
319 0, root->root_key.objectid, level, 1);
321 if (!list_empty(&buf->recow)) {
322 list_del_init(&buf->recow);
323 free_extent_buffer(buf);
325 free_extent_buffer(buf);
326 btrfs_mark_buffer_dirty(cow);
331 static inline int should_cow_block(struct btrfs_trans_handle *trans,
332 struct btrfs_root *root,
333 struct extent_buffer *buf)
335 if (btrfs_header_generation(buf) == trans->transid &&
336 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
337 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
338 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
343 int btrfs_cow_block(struct btrfs_trans_handle *trans,
344 struct btrfs_root *root, struct extent_buffer *buf,
345 struct extent_buffer *parent, int parent_slot,
346 struct extent_buffer **cow_ret)
351 if (trans->transaction != root->fs_info->running_transaction) {
352 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
353 root->fs_info->running_transaction->transid);
357 if (trans->transid != root->fs_info->generation) {
358 printk(KERN_CRIT "trans %llu running %llu\n",
359 (unsigned long long)trans->transid,
360 (unsigned long long)root->fs_info->generation);
363 if (!should_cow_block(trans, root, buf)) {
368 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
369 ret = __btrfs_cow_block(trans, root, buf, parent,
370 parent_slot, cow_ret, search_start, 0);
375 * compare two keys in a memcmp fashion
377 static int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
381 btrfs_disk_key_to_cpu(&k1, disk);
383 if (k1.objectid > k2->objectid)
385 if (k1.objectid < k2->objectid)
387 if (k1.type > k2->type)
389 if (k1.type < k2->type)
391 if (k1.offset > k2->offset)
393 if (k1.offset < k2->offset)
399 * The leaf data grows from end-to-front in the node.
400 * this returns the address of the start of the last item,
401 * which is the stop of the leaf data stack
403 static inline unsigned int leaf_data_end(struct btrfs_root *root,
404 struct extent_buffer *leaf)
406 u32 nr = btrfs_header_nritems(leaf);
408 return BTRFS_LEAF_DATA_SIZE(root);
409 return btrfs_item_offset_nr(leaf, nr - 1);
412 int btrfs_check_node(struct btrfs_root *root,
413 struct btrfs_disk_key *parent_key,
414 struct extent_buffer *buf)
417 struct btrfs_key cpukey;
418 struct btrfs_disk_key key;
419 u32 nritems = btrfs_header_nritems(buf);
421 if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
424 if (parent_key && parent_key->type) {
425 btrfs_node_key(buf, &key, 0);
426 if (memcmp(parent_key, &key, sizeof(key)))
429 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
430 btrfs_node_key(buf, &key, i);
431 btrfs_node_key_to_cpu(buf, &cpukey, i + 1);
432 if (btrfs_comp_keys(&key, &cpukey) >= 0)
437 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
439 btrfs_disk_key_to_cpu(&cpukey, parent_key);
441 btrfs_node_key_to_cpu(buf, &cpukey, 0);
442 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
443 buf->start, buf->len,
444 btrfs_header_level(buf));
449 int btrfs_check_leaf(struct btrfs_root *root,
450 struct btrfs_disk_key *parent_key,
451 struct extent_buffer *buf)
454 struct btrfs_key cpukey;
455 struct btrfs_disk_key key;
456 u32 nritems = btrfs_header_nritems(buf);
458 if (nritems * sizeof(struct btrfs_item) > buf->len) {
459 fprintf(stderr, "invalid number of items %llu\n",
460 (unsigned long long)buf->start);
464 if (btrfs_header_level(buf) != 0) {
465 fprintf(stderr, "leaf is not a leaf %llu\n",
466 (unsigned long long)btrfs_header_bytenr(buf));
469 if (btrfs_leaf_free_space(root, buf) < 0) {
470 fprintf(stderr, "leaf free space incorrect %llu %d\n",
471 (unsigned long long)btrfs_header_bytenr(buf),
472 btrfs_leaf_free_space(root, buf));
479 btrfs_item_key(buf, &key, 0);
480 if (parent_key && parent_key->type &&
481 memcmp(parent_key, &key, sizeof(key))) {
482 fprintf(stderr, "leaf parent key incorrect %llu\n",
483 (unsigned long long)btrfs_header_bytenr(buf));
486 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
487 btrfs_item_key(buf, &key, i);
488 btrfs_item_key_to_cpu(buf, &cpukey, i + 1);
489 if (btrfs_comp_keys(&key, &cpukey) >= 0) {
490 fprintf(stderr, "bad key ordering %d %d\n", i, i+1);
493 if (btrfs_item_offset_nr(buf, i) !=
494 btrfs_item_end_nr(buf, i + 1)) {
495 fprintf(stderr, "incorrect offsets %u %u\n",
496 btrfs_item_offset_nr(buf, i),
497 btrfs_item_end_nr(buf, i + 1));
500 if (i == 0 && btrfs_item_end_nr(buf, i) !=
501 BTRFS_LEAF_DATA_SIZE(root)) {
502 fprintf(stderr, "bad item end %u wanted %u\n",
503 btrfs_item_end_nr(buf, i),
504 (unsigned)BTRFS_LEAF_DATA_SIZE(root));
510 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
512 btrfs_disk_key_to_cpu(&cpukey, parent_key);
514 btrfs_item_key_to_cpu(buf, &cpukey, 0);
516 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
517 buf->start, buf->len, 0);
522 static int noinline check_block(struct btrfs_root *root,
523 struct btrfs_path *path, int level)
525 struct btrfs_disk_key key;
526 struct btrfs_disk_key *key_ptr = NULL;
527 struct extent_buffer *parent;
529 if (path->nodes[level + 1]) {
530 parent = path->nodes[level + 1];
531 btrfs_node_key(parent, &key, path->slots[level + 1]);
535 return btrfs_check_leaf(root, key_ptr, path->nodes[0]);
536 return btrfs_check_node(root, key_ptr, path->nodes[level]);
540 * search for key in the extent_buffer. The items start at offset p,
541 * and they are item_size apart. There are 'max' items in p.
543 * the slot in the array is returned via slot, and it points to
544 * the place where you would insert key if it is not found in
547 * slot may point to max if the key is bigger than all of the keys
549 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
550 int item_size, struct btrfs_key *key,
557 unsigned long offset;
558 struct btrfs_disk_key *tmp;
561 mid = (low + high) / 2;
562 offset = p + mid * item_size;
564 tmp = (struct btrfs_disk_key *)(eb->data + offset);
565 ret = btrfs_comp_keys(tmp, key);
581 * simple bin_search frontend that does the right thing for
584 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
585 int level, int *slot)
588 return generic_bin_search(eb,
589 offsetof(struct btrfs_leaf, items),
590 sizeof(struct btrfs_item),
591 key, btrfs_header_nritems(eb),
594 return generic_bin_search(eb,
595 offsetof(struct btrfs_node, ptrs),
596 sizeof(struct btrfs_key_ptr),
597 key, btrfs_header_nritems(eb),
601 struct extent_buffer *read_node_slot(struct btrfs_root *root,
602 struct extent_buffer *parent, int slot)
604 int level = btrfs_header_level(parent);
607 if (slot >= btrfs_header_nritems(parent))
613 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
614 btrfs_level_size(root, level - 1),
615 btrfs_node_ptr_generation(parent, slot));
618 static int balance_level(struct btrfs_trans_handle *trans,
619 struct btrfs_root *root,
620 struct btrfs_path *path, int level)
622 struct extent_buffer *right = NULL;
623 struct extent_buffer *mid;
624 struct extent_buffer *left = NULL;
625 struct extent_buffer *parent = NULL;
629 int orig_slot = path->slots[level];
635 mid = path->nodes[level];
636 WARN_ON(btrfs_header_generation(mid) != trans->transid);
638 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
640 if (level < BTRFS_MAX_LEVEL - 1) {
641 parent = path->nodes[level + 1];
642 pslot = path->slots[level + 1];
646 * deal with the case where there is only one pointer in the root
647 * by promoting the node below to a root
650 struct extent_buffer *child;
652 if (btrfs_header_nritems(mid) != 1)
655 /* promote the child to a root */
656 child = read_node_slot(root, mid, 0);
658 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
662 add_root_to_dirty_list(root);
663 path->nodes[level] = NULL;
664 clean_tree_block(trans, root, mid);
665 wait_on_tree_block_writeback(root, mid);
666 /* once for the path */
667 free_extent_buffer(mid);
669 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
670 0, root->root_key.objectid,
672 /* once for the root ptr */
673 free_extent_buffer(mid);
676 if (btrfs_header_nritems(mid) >
677 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
680 left = read_node_slot(root, parent, pslot - 1);
682 wret = btrfs_cow_block(trans, root, left,
683 parent, pslot - 1, &left);
689 right = read_node_slot(root, parent, pslot + 1);
691 wret = btrfs_cow_block(trans, root, right,
692 parent, pslot + 1, &right);
699 /* first, try to make some room in the middle buffer */
701 orig_slot += btrfs_header_nritems(left);
702 wret = push_node_left(trans, root, left, mid, 1);
708 * then try to empty the right most buffer into the middle
711 wret = push_node_left(trans, root, mid, right, 1);
712 if (wret < 0 && wret != -ENOSPC)
714 if (btrfs_header_nritems(right) == 0) {
715 u64 bytenr = right->start;
716 u32 blocksize = right->len;
718 clean_tree_block(trans, root, right);
719 wait_on_tree_block_writeback(root, right);
720 free_extent_buffer(right);
722 wret = btrfs_del_ptr(trans, root, path,
723 level + 1, pslot + 1);
726 wret = btrfs_free_extent(trans, root, bytenr,
728 root->root_key.objectid,
733 struct btrfs_disk_key right_key;
734 btrfs_node_key(right, &right_key, 0);
735 btrfs_set_node_key(parent, &right_key, pslot + 1);
736 btrfs_mark_buffer_dirty(parent);
739 if (btrfs_header_nritems(mid) == 1) {
741 * we're not allowed to leave a node with one item in the
742 * tree during a delete. A deletion from lower in the tree
743 * could try to delete the only pointer in this node.
744 * So, pull some keys from the left.
745 * There has to be a left pointer at this point because
746 * otherwise we would have pulled some pointers from the
750 wret = balance_node_right(trans, root, mid, left);
756 wret = push_node_left(trans, root, left, mid, 1);
762 if (btrfs_header_nritems(mid) == 0) {
763 /* we've managed to empty the middle node, drop it */
764 u64 bytenr = mid->start;
765 u32 blocksize = mid->len;
766 clean_tree_block(trans, root, mid);
767 wait_on_tree_block_writeback(root, mid);
768 free_extent_buffer(mid);
770 wret = btrfs_del_ptr(trans, root, path, level + 1, pslot);
773 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
774 0, root->root_key.objectid,
779 /* update the parent key to reflect our changes */
780 struct btrfs_disk_key mid_key;
781 btrfs_node_key(mid, &mid_key, 0);
782 btrfs_set_node_key(parent, &mid_key, pslot);
783 btrfs_mark_buffer_dirty(parent);
786 /* update the path */
788 if (btrfs_header_nritems(left) > orig_slot) {
789 extent_buffer_get(left);
790 path->nodes[level] = left;
791 path->slots[level + 1] -= 1;
792 path->slots[level] = orig_slot;
794 free_extent_buffer(mid);
796 orig_slot -= btrfs_header_nritems(left);
797 path->slots[level] = orig_slot;
800 /* double check we haven't messed things up */
801 check_block(root, path, level);
803 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
807 free_extent_buffer(right);
809 free_extent_buffer(left);
813 /* returns zero if the push worked, non-zero otherwise */
814 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
815 struct btrfs_root *root,
816 struct btrfs_path *path, int level)
818 struct extent_buffer *right = NULL;
819 struct extent_buffer *mid;
820 struct extent_buffer *left = NULL;
821 struct extent_buffer *parent = NULL;
825 int orig_slot = path->slots[level];
830 mid = path->nodes[level];
831 WARN_ON(btrfs_header_generation(mid) != trans->transid);
833 if (level < BTRFS_MAX_LEVEL - 1) {
834 parent = path->nodes[level + 1];
835 pslot = path->slots[level + 1];
841 left = read_node_slot(root, parent, pslot - 1);
843 /* first, try to make some room in the middle buffer */
846 left_nr = btrfs_header_nritems(left);
847 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
850 ret = btrfs_cow_block(trans, root, left, parent,
855 wret = push_node_left(trans, root,
862 struct btrfs_disk_key disk_key;
863 orig_slot += left_nr;
864 btrfs_node_key(mid, &disk_key, 0);
865 btrfs_set_node_key(parent, &disk_key, pslot);
866 btrfs_mark_buffer_dirty(parent);
867 if (btrfs_header_nritems(left) > orig_slot) {
868 path->nodes[level] = left;
869 path->slots[level + 1] -= 1;
870 path->slots[level] = orig_slot;
871 free_extent_buffer(mid);
874 btrfs_header_nritems(left);
875 path->slots[level] = orig_slot;
876 free_extent_buffer(left);
880 free_extent_buffer(left);
882 right= read_node_slot(root, parent, pslot + 1);
885 * then try to empty the right most buffer into the middle
889 right_nr = btrfs_header_nritems(right);
890 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
893 ret = btrfs_cow_block(trans, root, right,
899 wret = balance_node_right(trans, root,
906 struct btrfs_disk_key disk_key;
908 btrfs_node_key(right, &disk_key, 0);
909 btrfs_set_node_key(parent, &disk_key, pslot + 1);
910 btrfs_mark_buffer_dirty(parent);
912 if (btrfs_header_nritems(mid) <= orig_slot) {
913 path->nodes[level] = right;
914 path->slots[level + 1] += 1;
915 path->slots[level] = orig_slot -
916 btrfs_header_nritems(mid);
917 free_extent_buffer(mid);
919 free_extent_buffer(right);
923 free_extent_buffer(right);
929 * readahead one full node of leaves
931 void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
932 int level, int slot, u64 objectid)
934 struct extent_buffer *node;
935 struct btrfs_disk_key disk_key;
941 int direction = path->reada;
942 struct extent_buffer *eb;
950 if (!path->nodes[level])
953 node = path->nodes[level];
954 search = btrfs_node_blockptr(node, slot);
955 blocksize = btrfs_level_size(root, level - 1);
956 eb = btrfs_find_tree_block(root, search, blocksize);
958 free_extent_buffer(eb);
962 highest_read = search;
963 lowest_read = search;
965 nritems = btrfs_header_nritems(node);
972 } else if (direction > 0) {
977 if (path->reada < 0 && objectid) {
978 btrfs_node_key(node, &disk_key, nr);
979 if (btrfs_disk_key_objectid(&disk_key) != objectid)
982 search = btrfs_node_blockptr(node, nr);
983 if ((search >= lowest_read && search <= highest_read) ||
984 (search < lowest_read && lowest_read - search <= 32768) ||
985 (search > highest_read && search - highest_read <= 32768)) {
986 readahead_tree_block(root, search, blocksize,
987 btrfs_node_ptr_generation(node, nr));
991 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
993 if(nread > (1024 * 1024) || nscan > 128)
996 if (search < lowest_read)
997 lowest_read = search;
998 if (search > highest_read)
999 highest_read = search;
1004 * look for key in the tree. path is filled in with nodes along the way
1005 * if key is found, we return zero and you can find the item in the leaf
1006 * level of the path (level 0)
1008 * If the key isn't found, the path points to the slot where it should
1009 * be inserted, and 1 is returned. If there are other errors during the
1010 * search a negative error number is returned.
1012 * if ins_len > 0, nodes and leaves will be split as we walk down the
1013 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1016 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1017 *root, struct btrfs_key *key, struct btrfs_path *p, int
1020 struct extent_buffer *b;
1024 int should_reada = p->reada;
1025 u8 lowest_level = 0;
1027 lowest_level = p->lowest_level;
1028 WARN_ON(lowest_level && ins_len > 0);
1029 WARN_ON(p->nodes[0] != NULL);
1031 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1035 extent_buffer_get(b);
1037 level = btrfs_header_level(b);
1040 wret = btrfs_cow_block(trans, root, b,
1041 p->nodes[level + 1],
1042 p->slots[level + 1],
1045 free_extent_buffer(b);
1049 BUG_ON(!cow && ins_len);
1050 if (level != btrfs_header_level(b))
1052 level = btrfs_header_level(b);
1053 p->nodes[level] = b;
1054 ret = check_block(root, p, level);
1057 ret = bin_search(b, key, level, &slot);
1059 if (ret && slot > 0)
1061 p->slots[level] = slot;
1062 if ((p->search_for_split || ins_len > 0) &&
1063 btrfs_header_nritems(b) >=
1064 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1065 int sret = split_node(trans, root, p, level);
1069 b = p->nodes[level];
1070 slot = p->slots[level];
1071 } else if (ins_len < 0) {
1072 int sret = balance_level(trans, root, p,
1076 b = p->nodes[level];
1078 btrfs_release_path(p);
1081 slot = p->slots[level];
1082 BUG_ON(btrfs_header_nritems(b) == 1);
1084 /* this is only true while dropping a snapshot */
1085 if (level == lowest_level)
1089 reada_for_search(root, p, level, slot,
1092 b = read_node_slot(root, b, slot);
1093 if (!extent_buffer_uptodate(b))
1096 p->slots[level] = slot;
1098 ins_len > btrfs_leaf_free_space(root, b)) {
1099 int sret = split_leaf(trans, root, key,
1100 p, ins_len, ret == 0);
1112 * adjust the pointers going up the tree, starting at level
1113 * making sure the right key of each node is points to 'key'.
1114 * This is used after shifting pointers to the left, so it stops
1115 * fixing up pointers when a given leaf/node is not in slot 0 of the
1118 * If this fails to write a tree block, it returns -1, but continues
1119 * fixing up the blocks in ram so the tree is consistent.
1121 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1122 struct btrfs_root *root, struct btrfs_path *path,
1123 struct btrfs_disk_key *key, int level)
1127 struct extent_buffer *t;
1129 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1130 int tslot = path->slots[i];
1131 if (!path->nodes[i])
1134 btrfs_set_node_key(t, key, tslot);
1135 btrfs_mark_buffer_dirty(path->nodes[i]);
1145 * This function isn't completely safe. It's the caller's responsibility
1146 * that the new key won't break the order
1148 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1149 struct btrfs_root *root, struct btrfs_path *path,
1150 struct btrfs_key *new_key)
1152 struct btrfs_disk_key disk_key;
1153 struct extent_buffer *eb;
1156 eb = path->nodes[0];
1157 slot = path->slots[0];
1159 btrfs_item_key(eb, &disk_key, slot - 1);
1160 if (btrfs_comp_keys(&disk_key, new_key) >= 0)
1163 if (slot < btrfs_header_nritems(eb) - 1) {
1164 btrfs_item_key(eb, &disk_key, slot + 1);
1165 if (btrfs_comp_keys(&disk_key, new_key) <= 0)
1169 btrfs_cpu_key_to_disk(&disk_key, new_key);
1170 btrfs_set_item_key(eb, &disk_key, slot);
1171 btrfs_mark_buffer_dirty(eb);
1173 fixup_low_keys(trans, root, path, &disk_key, 1);
1178 * try to push data from one node into the next node left in the
1181 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1182 * error, and > 0 if there was no room in the left hand block.
1184 static int push_node_left(struct btrfs_trans_handle *trans,
1185 struct btrfs_root *root, struct extent_buffer *dst,
1186 struct extent_buffer *src, int empty)
1193 src_nritems = btrfs_header_nritems(src);
1194 dst_nritems = btrfs_header_nritems(dst);
1195 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1196 WARN_ON(btrfs_header_generation(src) != trans->transid);
1197 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1199 if (!empty && src_nritems <= 8)
1202 if (push_items <= 0) {
1207 push_items = min(src_nritems, push_items);
1208 if (push_items < src_nritems) {
1209 /* leave at least 8 pointers in the node if
1210 * we aren't going to empty it
1212 if (src_nritems - push_items < 8) {
1213 if (push_items <= 8)
1219 push_items = min(src_nritems - 8, push_items);
1221 copy_extent_buffer(dst, src,
1222 btrfs_node_key_ptr_offset(dst_nritems),
1223 btrfs_node_key_ptr_offset(0),
1224 push_items * sizeof(struct btrfs_key_ptr));
1226 if (push_items < src_nritems) {
1227 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1228 btrfs_node_key_ptr_offset(push_items),
1229 (src_nritems - push_items) *
1230 sizeof(struct btrfs_key_ptr));
1232 btrfs_set_header_nritems(src, src_nritems - push_items);
1233 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1234 btrfs_mark_buffer_dirty(src);
1235 btrfs_mark_buffer_dirty(dst);
1241 * try to push data from one node into the next node right in the
1244 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1245 * error, and > 0 if there was no room in the right hand block.
1247 * this will only push up to 1/2 the contents of the left node over
1249 static int balance_node_right(struct btrfs_trans_handle *trans,
1250 struct btrfs_root *root,
1251 struct extent_buffer *dst,
1252 struct extent_buffer *src)
1260 WARN_ON(btrfs_header_generation(src) != trans->transid);
1261 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1263 src_nritems = btrfs_header_nritems(src);
1264 dst_nritems = btrfs_header_nritems(dst);
1265 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1266 if (push_items <= 0) {
1270 if (src_nritems < 4) {
1274 max_push = src_nritems / 2 + 1;
1275 /* don't try to empty the node */
1276 if (max_push >= src_nritems) {
1280 if (max_push < push_items)
1281 push_items = max_push;
1283 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1284 btrfs_node_key_ptr_offset(0),
1286 sizeof(struct btrfs_key_ptr));
1288 copy_extent_buffer(dst, src,
1289 btrfs_node_key_ptr_offset(0),
1290 btrfs_node_key_ptr_offset(src_nritems - push_items),
1291 push_items * sizeof(struct btrfs_key_ptr));
1293 btrfs_set_header_nritems(src, src_nritems - push_items);
1294 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1296 btrfs_mark_buffer_dirty(src);
1297 btrfs_mark_buffer_dirty(dst);
1303 * helper function to insert a new root level in the tree.
1304 * A new node is allocated, and a single item is inserted to
1305 * point to the existing root
1307 * returns zero on success or < 0 on failure.
1309 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1310 struct btrfs_root *root,
1311 struct btrfs_path *path, int level)
1314 struct extent_buffer *lower;
1315 struct extent_buffer *c;
1316 struct extent_buffer *old;
1317 struct btrfs_disk_key lower_key;
1319 BUG_ON(path->nodes[level]);
1320 BUG_ON(path->nodes[level-1] != root->node);
1322 lower = path->nodes[level-1];
1324 btrfs_item_key(lower, &lower_key, 0);
1326 btrfs_node_key(lower, &lower_key, 0);
1328 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1329 root->root_key.objectid, &lower_key,
1330 level, root->node->start, 0);
1335 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
1336 btrfs_set_header_nritems(c, 1);
1337 btrfs_set_header_level(c, level);
1338 btrfs_set_header_bytenr(c, c->start);
1339 btrfs_set_header_generation(c, trans->transid);
1340 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
1341 btrfs_set_header_owner(c, root->root_key.objectid);
1343 write_extent_buffer(c, root->fs_info->fsid,
1344 btrfs_header_fsid(), BTRFS_FSID_SIZE);
1346 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1347 btrfs_header_chunk_tree_uuid(c),
1350 btrfs_set_node_key(c, &lower_key, 0);
1351 btrfs_set_node_blockptr(c, 0, lower->start);
1352 lower_gen = btrfs_header_generation(lower);
1353 WARN_ON(lower_gen != trans->transid);
1355 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1357 btrfs_mark_buffer_dirty(c);
1362 /* the super has an extra ref to root->node */
1363 free_extent_buffer(old);
1365 add_root_to_dirty_list(root);
1366 extent_buffer_get(c);
1367 path->nodes[level] = c;
1368 path->slots[level] = 0;
1373 * worker function to insert a single pointer in a node.
1374 * the node should have enough room for the pointer already
1376 * slot and level indicate where you want the key to go, and
1377 * blocknr is the block the key points to.
1379 * returns zero on success and < 0 on any error
1381 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1382 *root, struct btrfs_path *path, struct btrfs_disk_key
1383 *key, u64 bytenr, int slot, int level)
1385 struct extent_buffer *lower;
1388 BUG_ON(!path->nodes[level]);
1389 lower = path->nodes[level];
1390 nritems = btrfs_header_nritems(lower);
1393 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1395 if (slot != nritems) {
1396 memmove_extent_buffer(lower,
1397 btrfs_node_key_ptr_offset(slot + 1),
1398 btrfs_node_key_ptr_offset(slot),
1399 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1401 btrfs_set_node_key(lower, key, slot);
1402 btrfs_set_node_blockptr(lower, slot, bytenr);
1403 WARN_ON(trans->transid == 0);
1404 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1405 btrfs_set_header_nritems(lower, nritems + 1);
1406 btrfs_mark_buffer_dirty(lower);
1411 * split the node at the specified level in path in two.
1412 * The path is corrected to point to the appropriate node after the split
1414 * Before splitting this tries to make some room in the node by pushing
1415 * left and right, if either one works, it returns right away.
1417 * returns 0 on success and < 0 on failure
1419 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1420 *root, struct btrfs_path *path, int level)
1422 struct extent_buffer *c;
1423 struct extent_buffer *split;
1424 struct btrfs_disk_key disk_key;
1430 c = path->nodes[level];
1431 WARN_ON(btrfs_header_generation(c) != trans->transid);
1432 if (c == root->node) {
1433 /* trying to split the root, lets make a new one */
1434 ret = insert_new_root(trans, root, path, level + 1);
1438 ret = push_nodes_for_insert(trans, root, path, level);
1439 c = path->nodes[level];
1440 if (!ret && btrfs_header_nritems(c) <
1441 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1447 c_nritems = btrfs_header_nritems(c);
1448 mid = (c_nritems + 1) / 2;
1449 btrfs_node_key(c, &disk_key, mid);
1451 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1452 root->root_key.objectid,
1453 &disk_key, level, c->start, 0);
1455 return PTR_ERR(split);
1457 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
1458 btrfs_set_header_level(split, btrfs_header_level(c));
1459 btrfs_set_header_bytenr(split, split->start);
1460 btrfs_set_header_generation(split, trans->transid);
1461 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
1462 btrfs_set_header_owner(split, root->root_key.objectid);
1463 write_extent_buffer(split, root->fs_info->fsid,
1464 btrfs_header_fsid(), BTRFS_FSID_SIZE);
1465 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1466 btrfs_header_chunk_tree_uuid(split),
1470 copy_extent_buffer(split, c,
1471 btrfs_node_key_ptr_offset(0),
1472 btrfs_node_key_ptr_offset(mid),
1473 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1474 btrfs_set_header_nritems(split, c_nritems - mid);
1475 btrfs_set_header_nritems(c, mid);
1478 btrfs_mark_buffer_dirty(c);
1479 btrfs_mark_buffer_dirty(split);
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_node_slot(root, upper, slot + 1);
1573 free_space = btrfs_leaf_free_space(root, right);
1574 if (free_space < data_size) {
1575 free_extent_buffer(right);
1579 /* cow and double check */
1580 ret = btrfs_cow_block(trans, root, right, upper,
1583 free_extent_buffer(right);
1586 free_space = btrfs_leaf_free_space(root, right);
1587 if (free_space < data_size) {
1588 free_extent_buffer(right);
1592 left_nritems = btrfs_header_nritems(left);
1593 if (left_nritems == 0) {
1594 free_extent_buffer(right);
1603 i = left_nritems - 1;
1605 item = btrfs_item_nr(i);
1607 if (path->slots[0] == i)
1608 push_space += data_size + sizeof(*item);
1610 this_item_size = btrfs_item_size(left, item);
1611 if (this_item_size + sizeof(*item) + push_space > free_space)
1614 push_space += this_item_size + sizeof(*item);
1620 if (push_items == 0) {
1621 free_extent_buffer(right);
1625 if (!empty && push_items == left_nritems)
1628 /* push left to right */
1629 right_nritems = btrfs_header_nritems(right);
1631 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1632 push_space -= leaf_data_end(root, left);
1634 /* make room in the right data area */
1635 data_end = leaf_data_end(root, right);
1636 memmove_extent_buffer(right,
1637 btrfs_leaf_data(right) + data_end - push_space,
1638 btrfs_leaf_data(right) + data_end,
1639 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1641 /* copy from the left data area */
1642 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1643 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1644 btrfs_leaf_data(left) + leaf_data_end(root, left),
1647 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1648 btrfs_item_nr_offset(0),
1649 right_nritems * sizeof(struct btrfs_item));
1651 /* copy the items from left to right */
1652 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1653 btrfs_item_nr_offset(left_nritems - push_items),
1654 push_items * sizeof(struct btrfs_item));
1656 /* update the item pointers */
1657 right_nritems += push_items;
1658 btrfs_set_header_nritems(right, right_nritems);
1659 push_space = BTRFS_LEAF_DATA_SIZE(root);
1660 for (i = 0; i < right_nritems; i++) {
1661 item = btrfs_item_nr(i);
1662 push_space -= btrfs_item_size(right, item);
1663 btrfs_set_item_offset(right, item, push_space);
1666 left_nritems -= push_items;
1667 btrfs_set_header_nritems(left, left_nritems);
1670 btrfs_mark_buffer_dirty(left);
1671 btrfs_mark_buffer_dirty(right);
1673 btrfs_item_key(right, &disk_key, 0);
1674 btrfs_set_node_key(upper, &disk_key, slot + 1);
1675 btrfs_mark_buffer_dirty(upper);
1677 /* then fixup the leaf pointer in the path */
1678 if (path->slots[0] >= left_nritems) {
1679 path->slots[0] -= left_nritems;
1680 free_extent_buffer(path->nodes[0]);
1681 path->nodes[0] = right;
1682 path->slots[1] += 1;
1684 free_extent_buffer(right);
1689 * push some data in the path leaf to the left, trying to free up at
1690 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1692 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1693 *root, struct btrfs_path *path, int data_size,
1696 struct btrfs_disk_key disk_key;
1697 struct extent_buffer *right = path->nodes[0];
1698 struct extent_buffer *left;
1704 struct btrfs_item *item;
1705 u32 old_left_nritems;
1711 u32 old_left_item_size;
1713 slot = path->slots[1];
1716 if (!path->nodes[1])
1719 right_nritems = btrfs_header_nritems(right);
1720 if (right_nritems == 0) {
1724 left = read_node_slot(root, path->nodes[1], slot - 1);
1725 free_space = btrfs_leaf_free_space(root, left);
1726 if (free_space < data_size) {
1727 free_extent_buffer(left);
1731 /* cow and double check */
1732 ret = btrfs_cow_block(trans, root, left,
1733 path->nodes[1], slot - 1, &left);
1735 /* we hit -ENOSPC, but it isn't fatal here */
1736 free_extent_buffer(left);
1740 free_space = btrfs_leaf_free_space(root, left);
1741 if (free_space < data_size) {
1742 free_extent_buffer(left);
1749 nr = right_nritems - 1;
1751 for (i = 0; i < nr; i++) {
1752 item = btrfs_item_nr(i);
1754 if (path->slots[0] == i)
1755 push_space += data_size + sizeof(*item);
1757 this_item_size = btrfs_item_size(right, item);
1758 if (this_item_size + sizeof(*item) + push_space > free_space)
1762 push_space += this_item_size + sizeof(*item);
1765 if (push_items == 0) {
1766 free_extent_buffer(left);
1769 if (!empty && push_items == btrfs_header_nritems(right))
1772 /* push data from right to left */
1773 copy_extent_buffer(left, right,
1774 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1775 btrfs_item_nr_offset(0),
1776 push_items * sizeof(struct btrfs_item));
1778 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1779 btrfs_item_offset_nr(right, push_items -1);
1781 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1782 leaf_data_end(root, left) - push_space,
1783 btrfs_leaf_data(right) +
1784 btrfs_item_offset_nr(right, push_items - 1),
1786 old_left_nritems = btrfs_header_nritems(left);
1787 BUG_ON(old_left_nritems == 0);
1789 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1790 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1793 item = btrfs_item_nr(i);
1794 ioff = btrfs_item_offset(left, item);
1795 btrfs_set_item_offset(left, item,
1796 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1798 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1800 /* fixup right node */
1801 if (push_items > right_nritems) {
1802 printk("push items %d nr %u\n", push_items, right_nritems);
1806 if (push_items < right_nritems) {
1807 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1808 leaf_data_end(root, right);
1809 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1810 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1811 btrfs_leaf_data(right) +
1812 leaf_data_end(root, right), push_space);
1814 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1815 btrfs_item_nr_offset(push_items),
1816 (btrfs_header_nritems(right) - push_items) *
1817 sizeof(struct btrfs_item));
1819 right_nritems -= push_items;
1820 btrfs_set_header_nritems(right, right_nritems);
1821 push_space = BTRFS_LEAF_DATA_SIZE(root);
1822 for (i = 0; i < right_nritems; i++) {
1823 item = btrfs_item_nr(i);
1824 push_space = push_space - btrfs_item_size(right, item);
1825 btrfs_set_item_offset(right, item, push_space);
1828 btrfs_mark_buffer_dirty(left);
1830 btrfs_mark_buffer_dirty(right);
1832 btrfs_item_key(right, &disk_key, 0);
1833 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1837 /* then fixup the leaf pointer in the path */
1838 if (path->slots[0] < push_items) {
1839 path->slots[0] += old_left_nritems;
1840 free_extent_buffer(path->nodes[0]);
1841 path->nodes[0] = left;
1842 path->slots[1] -= 1;
1844 free_extent_buffer(left);
1845 path->slots[0] -= push_items;
1847 BUG_ON(path->slots[0] < 0);
1852 * split the path's leaf in two, making sure there is at least data_size
1853 * available for the resulting leaf level of the path.
1855 * returns 0 if all went well and < 0 on failure.
1857 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
1858 struct btrfs_root *root,
1859 struct btrfs_path *path,
1860 struct extent_buffer *l,
1861 struct extent_buffer *right,
1862 int slot, int mid, int nritems)
1869 struct btrfs_disk_key disk_key;
1871 nritems = nritems - mid;
1872 btrfs_set_header_nritems(right, nritems);
1873 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1875 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1876 btrfs_item_nr_offset(mid),
1877 nritems * sizeof(struct btrfs_item));
1879 copy_extent_buffer(right, l,
1880 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1881 data_copy_size, btrfs_leaf_data(l) +
1882 leaf_data_end(root, l), data_copy_size);
1884 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
1885 btrfs_item_end_nr(l, mid);
1887 for (i = 0; i < nritems; i++) {
1888 struct btrfs_item *item = btrfs_item_nr(i);
1889 u32 ioff = btrfs_item_offset(right, item);
1890 btrfs_set_item_offset(right, item, ioff + rt_data_off);
1893 btrfs_set_header_nritems(l, mid);
1895 btrfs_item_key(right, &disk_key, 0);
1896 wret = insert_ptr(trans, root, path, &disk_key, right->start,
1897 path->slots[1] + 1, 1);
1901 btrfs_mark_buffer_dirty(right);
1902 btrfs_mark_buffer_dirty(l);
1903 BUG_ON(path->slots[0] != slot);
1906 free_extent_buffer(path->nodes[0]);
1907 path->nodes[0] = right;
1908 path->slots[0] -= mid;
1909 path->slots[1] += 1;
1911 free_extent_buffer(right);
1914 BUG_ON(path->slots[0] < 0);
1920 * split the path's leaf in two, making sure there is at least data_size
1921 * available for the resulting leaf level of the path.
1923 * returns 0 if all went well and < 0 on failure.
1925 static noinline int split_leaf(struct btrfs_trans_handle *trans,
1926 struct btrfs_root *root,
1927 struct btrfs_key *ins_key,
1928 struct btrfs_path *path, int data_size,
1931 struct btrfs_disk_key disk_key;
1932 struct extent_buffer *l;
1936 struct extent_buffer *right;
1940 int num_doubles = 0;
1942 /* first try to make some room by pushing left and right */
1943 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
1944 wret = push_leaf_right(trans, root, path, data_size, 0);
1948 wret = push_leaf_left(trans, root, path, data_size, 0);
1954 /* did the pushes work? */
1955 if (btrfs_leaf_free_space(root, l) >= data_size)
1959 if (!path->nodes[1]) {
1960 ret = insert_new_root(trans, root, path, 1);
1967 slot = path->slots[0];
1968 nritems = btrfs_header_nritems(l);
1969 mid = (nritems + 1) / 2;
1973 leaf_space_used(l, mid, nritems - mid) + data_size >
1974 BTRFS_LEAF_DATA_SIZE(root)) {
1975 if (slot >= nritems) {
1979 if (mid != nritems &&
1980 leaf_space_used(l, mid, nritems - mid) +
1981 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
1987 if (leaf_space_used(l, 0, mid) + data_size >
1988 BTRFS_LEAF_DATA_SIZE(root)) {
1989 if (!extend && data_size && slot == 0) {
1991 } else if ((extend || !data_size) && slot == 0) {
1995 if (mid != nritems &&
1996 leaf_space_used(l, mid, nritems - mid) +
1997 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2005 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2007 btrfs_item_key(l, &disk_key, mid);
2009 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2010 root->root_key.objectid,
2011 &disk_key, 0, l->start, 0);
2012 if (IS_ERR(right)) {
2014 return PTR_ERR(right);
2017 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2018 btrfs_set_header_bytenr(right, right->start);
2019 btrfs_set_header_generation(right, trans->transid);
2020 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
2021 btrfs_set_header_owner(right, root->root_key.objectid);
2022 btrfs_set_header_level(right, 0);
2023 write_extent_buffer(right, root->fs_info->fsid,
2024 btrfs_header_fsid(), BTRFS_FSID_SIZE);
2026 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2027 btrfs_header_chunk_tree_uuid(right),
2032 btrfs_set_header_nritems(right, 0);
2033 wret = insert_ptr(trans, root, path,
2034 &disk_key, right->start,
2035 path->slots[1] + 1, 1);
2039 free_extent_buffer(path->nodes[0]);
2040 path->nodes[0] = right;
2042 path->slots[1] += 1;
2044 btrfs_set_header_nritems(right, 0);
2045 wret = insert_ptr(trans, root, path,
2051 free_extent_buffer(path->nodes[0]);
2052 path->nodes[0] = right;
2054 if (path->slots[1] == 0) {
2055 wret = fixup_low_keys(trans, root,
2056 path, &disk_key, 1);
2061 btrfs_mark_buffer_dirty(right);
2065 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
2069 BUG_ON(num_doubles != 0);
2078 * This function splits a single item into two items,
2079 * giving 'new_key' to the new item and splitting the
2080 * old one at split_offset (from the start of the item).
2082 * The path may be released by this operation. After
2083 * the split, the path is pointing to the old item. The
2084 * new item is going to be in the same node as the old one.
2086 * Note, the item being split must be smaller enough to live alone on
2087 * a tree block with room for one extra struct btrfs_item
2089 * This allows us to split the item in place, keeping a lock on the
2090 * leaf the entire time.
2092 int btrfs_split_item(struct btrfs_trans_handle *trans,
2093 struct btrfs_root *root,
2094 struct btrfs_path *path,
2095 struct btrfs_key *new_key,
2096 unsigned long split_offset)
2099 struct extent_buffer *leaf;
2100 struct btrfs_key orig_key;
2101 struct btrfs_item *item;
2102 struct btrfs_item *new_item;
2107 struct btrfs_disk_key disk_key;
2110 leaf = path->nodes[0];
2111 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
2112 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
2115 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2116 btrfs_release_path(path);
2118 path->search_for_split = 1;
2120 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
2121 path->search_for_split = 0;
2123 /* if our item isn't there or got smaller, return now */
2124 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
2129 ret = split_leaf(trans, root, &orig_key, path, 0, 0);
2132 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
2133 leaf = path->nodes[0];
2136 item = btrfs_item_nr(path->slots[0]);
2137 orig_offset = btrfs_item_offset(leaf, item);
2138 item_size = btrfs_item_size(leaf, item);
2141 buf = kmalloc(item_size, GFP_NOFS);
2142 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
2143 path->slots[0]), item_size);
2144 slot = path->slots[0] + 1;
2145 leaf = path->nodes[0];
2147 nritems = btrfs_header_nritems(leaf);
2149 if (slot != nritems) {
2150 /* shift the items */
2151 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2152 btrfs_item_nr_offset(slot),
2153 (nritems - slot) * sizeof(struct btrfs_item));
2157 btrfs_cpu_key_to_disk(&disk_key, new_key);
2158 btrfs_set_item_key(leaf, &disk_key, slot);
2160 new_item = btrfs_item_nr(slot);
2162 btrfs_set_item_offset(leaf, new_item, orig_offset);
2163 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
2165 btrfs_set_item_offset(leaf, item,
2166 orig_offset + item_size - split_offset);
2167 btrfs_set_item_size(leaf, item, split_offset);
2169 btrfs_set_header_nritems(leaf, nritems + 1);
2171 /* write the data for the start of the original item */
2172 write_extent_buffer(leaf, buf,
2173 btrfs_item_ptr_offset(leaf, path->slots[0]),
2176 /* write the data for the new item */
2177 write_extent_buffer(leaf, buf + split_offset,
2178 btrfs_item_ptr_offset(leaf, slot),
2179 item_size - split_offset);
2180 btrfs_mark_buffer_dirty(leaf);
2183 if (btrfs_leaf_free_space(root, leaf) < 0) {
2184 btrfs_print_leaf(root, leaf);
2191 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2192 struct btrfs_root *root,
2193 struct btrfs_path *path,
2194 u32 new_size, int from_end)
2198 struct extent_buffer *leaf;
2199 struct btrfs_item *item;
2201 unsigned int data_end;
2202 unsigned int old_data_start;
2203 unsigned int old_size;
2204 unsigned int size_diff;
2207 leaf = path->nodes[0];
2208 slot = path->slots[0];
2210 old_size = btrfs_item_size_nr(leaf, slot);
2211 if (old_size == new_size)
2214 nritems = btrfs_header_nritems(leaf);
2215 data_end = leaf_data_end(root, leaf);
2217 old_data_start = btrfs_item_offset_nr(leaf, slot);
2219 size_diff = old_size - new_size;
2222 BUG_ON(slot >= nritems);
2225 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2227 /* first correct the data pointers */
2228 for (i = slot; i < nritems; i++) {
2230 item = btrfs_item_nr(i);
2231 ioff = btrfs_item_offset(leaf, item);
2232 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2235 /* shift the data */
2237 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2238 data_end + size_diff, btrfs_leaf_data(leaf) +
2239 data_end, old_data_start + new_size - data_end);
2241 struct btrfs_disk_key disk_key;
2244 btrfs_item_key(leaf, &disk_key, slot);
2246 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2248 struct btrfs_file_extent_item *fi;
2250 fi = btrfs_item_ptr(leaf, slot,
2251 struct btrfs_file_extent_item);
2252 fi = (struct btrfs_file_extent_item *)(
2253 (unsigned long)fi - size_diff);
2255 if (btrfs_file_extent_type(leaf, fi) ==
2256 BTRFS_FILE_EXTENT_INLINE) {
2257 ptr = btrfs_item_ptr_offset(leaf, slot);
2258 memmove_extent_buffer(leaf, ptr,
2260 offsetof(struct btrfs_file_extent_item,
2265 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2266 data_end + size_diff, btrfs_leaf_data(leaf) +
2267 data_end, old_data_start - data_end);
2269 offset = btrfs_disk_key_offset(&disk_key);
2270 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2271 btrfs_set_item_key(leaf, &disk_key, slot);
2273 fixup_low_keys(trans, root, path, &disk_key, 1);
2276 item = btrfs_item_nr(slot);
2277 btrfs_set_item_size(leaf, item, new_size);
2278 btrfs_mark_buffer_dirty(leaf);
2281 if (btrfs_leaf_free_space(root, leaf) < 0) {
2282 btrfs_print_leaf(root, leaf);
2288 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2289 struct btrfs_root *root, struct btrfs_path *path,
2294 struct extent_buffer *leaf;
2295 struct btrfs_item *item;
2297 unsigned int data_end;
2298 unsigned int old_data;
2299 unsigned int old_size;
2302 leaf = path->nodes[0];
2304 nritems = btrfs_header_nritems(leaf);
2305 data_end = leaf_data_end(root, leaf);
2307 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2308 btrfs_print_leaf(root, leaf);
2311 slot = path->slots[0];
2312 old_data = btrfs_item_end_nr(leaf, slot);
2315 if (slot >= nritems) {
2316 btrfs_print_leaf(root, leaf);
2317 printk("slot %d too large, nritems %d\n", slot, nritems);
2322 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2324 /* first correct the data pointers */
2325 for (i = slot; i < nritems; i++) {
2327 item = btrfs_item_nr(i);
2328 ioff = btrfs_item_offset(leaf, item);
2329 btrfs_set_item_offset(leaf, item, ioff - data_size);
2332 /* shift the data */
2333 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2334 data_end - data_size, btrfs_leaf_data(leaf) +
2335 data_end, old_data - data_end);
2337 data_end = old_data;
2338 old_size = btrfs_item_size_nr(leaf, slot);
2339 item = btrfs_item_nr(slot);
2340 btrfs_set_item_size(leaf, item, old_size + data_size);
2341 btrfs_mark_buffer_dirty(leaf);
2344 if (btrfs_leaf_free_space(root, leaf) < 0) {
2345 btrfs_print_leaf(root, leaf);
2352 * Given a key and some data, insert an item into the tree.
2353 * This does all the path init required, making room in the tree if needed.
2355 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2356 struct btrfs_root *root,
2357 struct btrfs_path *path,
2358 struct btrfs_key *cpu_key, u32 *data_size,
2361 struct extent_buffer *leaf;
2362 struct btrfs_item *item;
2369 unsigned int data_end;
2370 struct btrfs_disk_key disk_key;
2372 for (i = 0; i < nr; i++) {
2373 total_data += data_size[i];
2376 /* create a root if there isn't one */
2380 total_size = total_data + nr * sizeof(struct btrfs_item);
2381 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2388 leaf = path->nodes[0];
2390 nritems = btrfs_header_nritems(leaf);
2391 data_end = leaf_data_end(root, leaf);
2393 if (btrfs_leaf_free_space(root, leaf) < total_size) {
2394 btrfs_print_leaf(root, leaf);
2395 printk("not enough freespace need %u have %d\n",
2396 total_size, btrfs_leaf_free_space(root, leaf));
2400 slot = path->slots[0];
2403 if (slot != nritems) {
2404 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2406 if (old_data < data_end) {
2407 btrfs_print_leaf(root, leaf);
2408 printk("slot %d old_data %d data_end %d\n",
2409 slot, old_data, data_end);
2413 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2415 /* first correct the data pointers */
2416 for (i = slot; i < nritems; i++) {
2419 item = btrfs_item_nr(i);
2420 ioff = btrfs_item_offset(leaf, item);
2421 btrfs_set_item_offset(leaf, item, ioff - total_data);
2424 /* shift the items */
2425 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2426 btrfs_item_nr_offset(slot),
2427 (nritems - slot) * sizeof(struct btrfs_item));
2429 /* shift the data */
2430 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2431 data_end - total_data, btrfs_leaf_data(leaf) +
2432 data_end, old_data - data_end);
2433 data_end = old_data;
2436 /* setup the item for the new data */
2437 for (i = 0; i < nr; i++) {
2438 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2439 btrfs_set_item_key(leaf, &disk_key, slot + i);
2440 item = btrfs_item_nr(slot + i);
2441 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2442 data_end -= data_size[i];
2443 btrfs_set_item_size(leaf, item, data_size[i]);
2445 btrfs_set_header_nritems(leaf, nritems + nr);
2446 btrfs_mark_buffer_dirty(leaf);
2450 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2451 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2454 if (btrfs_leaf_free_space(root, leaf) < 0) {
2455 btrfs_print_leaf(root, leaf);
2464 * Given a key and some data, insert an item into the tree.
2465 * This does all the path init required, making room in the tree if needed.
2467 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2468 *root, struct btrfs_key *cpu_key, void *data, u32
2472 struct btrfs_path *path;
2473 struct extent_buffer *leaf;
2476 path = btrfs_alloc_path();
2478 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2480 leaf = path->nodes[0];
2481 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2482 write_extent_buffer(leaf, data, ptr, data_size);
2483 btrfs_mark_buffer_dirty(leaf);
2485 btrfs_free_path(path);
2490 * delete the pointer from a given node.
2492 * If the delete empties a node, the node is removed from the tree,
2493 * continuing all the way the root if required. The root is converted into
2494 * a leaf if all the nodes are emptied.
2496 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2497 struct btrfs_path *path, int level, int slot)
2499 struct extent_buffer *parent = path->nodes[level];
2504 nritems = btrfs_header_nritems(parent);
2505 if (slot != nritems -1) {
2506 memmove_extent_buffer(parent,
2507 btrfs_node_key_ptr_offset(slot),
2508 btrfs_node_key_ptr_offset(slot + 1),
2509 sizeof(struct btrfs_key_ptr) *
2510 (nritems - slot - 1));
2513 btrfs_set_header_nritems(parent, nritems);
2514 if (nritems == 0 && parent == root->node) {
2515 BUG_ON(btrfs_header_level(root->node) != 1);
2516 /* just turn the root into a leaf and break */
2517 btrfs_set_header_level(root->node, 0);
2518 } else if (slot == 0) {
2519 struct btrfs_disk_key disk_key;
2521 btrfs_node_key(parent, &disk_key, 0);
2522 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2526 btrfs_mark_buffer_dirty(parent);
2531 * a helper function to delete the leaf pointed to by path->slots[1] and
2534 * This deletes the pointer in path->nodes[1] and frees the leaf
2535 * block extent. zero is returned if it all worked out, < 0 otherwise.
2537 * The path must have already been setup for deleting the leaf, including
2538 * all the proper balancing. path->nodes[1] must be locked.
2540 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
2541 struct btrfs_root *root,
2542 struct btrfs_path *path,
2543 struct extent_buffer *leaf)
2547 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
2548 ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
2552 ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
2553 0, root->root_key.objectid, 0, 0);
2558 * delete the item at the leaf level in path. If that empties
2559 * the leaf, remove it from the tree
2561 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2562 struct btrfs_path *path, int slot, int nr)
2564 struct extent_buffer *leaf;
2565 struct btrfs_item *item;
2573 leaf = path->nodes[0];
2574 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2576 for (i = 0; i < nr; i++)
2577 dsize += btrfs_item_size_nr(leaf, slot + i);
2579 nritems = btrfs_header_nritems(leaf);
2581 if (slot + nr != nritems) {
2582 int data_end = leaf_data_end(root, leaf);
2584 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2586 btrfs_leaf_data(leaf) + data_end,
2587 last_off - data_end);
2589 for (i = slot + nr; i < nritems; i++) {
2592 item = btrfs_item_nr(i);
2593 ioff = btrfs_item_offset(leaf, item);
2594 btrfs_set_item_offset(leaf, item, ioff + dsize);
2597 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2598 btrfs_item_nr_offset(slot + nr),
2599 sizeof(struct btrfs_item) *
2600 (nritems - slot - nr));
2602 btrfs_set_header_nritems(leaf, nritems - nr);
2605 /* delete the leaf if we've emptied it */
2607 if (leaf == root->node) {
2608 btrfs_set_header_level(leaf, 0);
2610 clean_tree_block(trans, root, leaf);
2611 wait_on_tree_block_writeback(root, leaf);
2613 wret = btrfs_del_leaf(trans, root, path, leaf);
2619 int used = leaf_space_used(leaf, 0, nritems);
2621 struct btrfs_disk_key disk_key;
2623 btrfs_item_key(leaf, &disk_key, 0);
2624 wret = fixup_low_keys(trans, root, path,
2630 /* delete the leaf if it is mostly empty */
2631 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2632 /* push_leaf_left fixes the path.
2633 * make sure the path still points to our leaf
2634 * for possible call to del_ptr below
2636 slot = path->slots[1];
2637 extent_buffer_get(leaf);
2639 wret = push_leaf_left(trans, root, path, 1, 1);
2640 if (wret < 0 && wret != -ENOSPC)
2643 if (path->nodes[0] == leaf &&
2644 btrfs_header_nritems(leaf)) {
2645 wret = push_leaf_right(trans, root, path, 1, 1);
2646 if (wret < 0 && wret != -ENOSPC)
2650 if (btrfs_header_nritems(leaf) == 0) {
2651 clean_tree_block(trans, root, leaf);
2652 wait_on_tree_block_writeback(root, leaf);
2654 path->slots[1] = slot;
2655 ret = btrfs_del_leaf(trans, root, path, leaf);
2657 free_extent_buffer(leaf);
2660 btrfs_mark_buffer_dirty(leaf);
2661 free_extent_buffer(leaf);
2664 btrfs_mark_buffer_dirty(leaf);
2671 * walk up the tree as far as required to find the previous leaf.
2672 * returns 0 if it found something or 1 if there are no lesser leaves.
2673 * returns < 0 on io errors.
2675 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2679 struct extent_buffer *c;
2680 struct extent_buffer *next = NULL;
2682 while(level < BTRFS_MAX_LEVEL) {
2683 if (!path->nodes[level])
2686 slot = path->slots[level];
2687 c = path->nodes[level];
2690 if (level == BTRFS_MAX_LEVEL)
2696 next = read_node_slot(root, c, slot);
2699 path->slots[level] = slot;
2702 c = path->nodes[level];
2703 free_extent_buffer(c);
2704 slot = btrfs_header_nritems(next);
2707 path->nodes[level] = next;
2708 path->slots[level] = slot;
2711 next = read_node_slot(root, next, slot);
2717 * walk up the tree as far as required to find the next leaf.
2718 * returns 0 if it found something or 1 if there are no greater leaves.
2719 * returns < 0 on io errors.
2721 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2725 struct extent_buffer *c;
2726 struct extent_buffer *next = NULL;
2728 while(level < BTRFS_MAX_LEVEL) {
2729 if (!path->nodes[level])
2732 slot = path->slots[level] + 1;
2733 c = path->nodes[level];
2734 if (slot >= btrfs_header_nritems(c)) {
2736 if (level == BTRFS_MAX_LEVEL)
2742 reada_for_search(root, path, level, slot, 0);
2744 next = read_node_slot(root, c, slot);
2749 path->slots[level] = slot;
2752 c = path->nodes[level];
2753 free_extent_buffer(c);
2754 path->nodes[level] = next;
2755 path->slots[level] = 0;
2759 reada_for_search(root, path, level, 0, 0);
2760 next = read_node_slot(root, next, 0);
2767 int btrfs_previous_item(struct btrfs_root *root,
2768 struct btrfs_path *path, u64 min_objectid,
2771 struct btrfs_key found_key;
2772 struct extent_buffer *leaf;
2776 if (path->slots[0] == 0) {
2777 ret = btrfs_prev_leaf(root, path);
2783 leaf = path->nodes[0];
2784 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2785 if (found_key.type == type)