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);
374 int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
376 if (k1->objectid > k2->objectid)
378 if (k1->objectid < k2->objectid)
380 if (k1->type > k2->type)
382 if (k1->type < k2->type)
384 if (k1->offset > k2->offset)
386 if (k1->offset < k2->offset)
392 * compare two keys in a memcmp fashion
394 static int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
398 btrfs_disk_key_to_cpu(&k1, disk);
399 return btrfs_comp_cpu_keys(&k1, k2);
403 * The leaf data grows from end-to-front in the node.
404 * this returns the address of the start of the last item,
405 * which is the stop of the leaf data stack
407 static inline unsigned int leaf_data_end(struct btrfs_root *root,
408 struct extent_buffer *leaf)
410 u32 nr = btrfs_header_nritems(leaf);
412 return BTRFS_LEAF_DATA_SIZE(root);
413 return btrfs_item_offset_nr(leaf, nr - 1);
416 enum btrfs_tree_block_status
417 btrfs_check_node(struct btrfs_root *root, struct btrfs_disk_key *parent_key,
418 struct extent_buffer *buf)
421 struct btrfs_key cpukey;
422 struct btrfs_disk_key key;
423 u32 nritems = btrfs_header_nritems(buf);
424 enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;
426 if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root))
429 ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY;
430 if (parent_key && parent_key->type) {
431 btrfs_node_key(buf, &key, 0);
432 if (memcmp(parent_key, &key, sizeof(key)))
435 ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
436 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
437 btrfs_node_key(buf, &key, i);
438 btrfs_node_key_to_cpu(buf, &cpukey, i + 1);
439 if (btrfs_comp_keys(&key, &cpukey) >= 0)
442 return BTRFS_TREE_BLOCK_CLEAN;
444 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
446 btrfs_disk_key_to_cpu(&cpukey, parent_key);
448 btrfs_node_key_to_cpu(buf, &cpukey, 0);
449 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
450 buf->start, buf->len,
451 btrfs_header_level(buf));
456 enum btrfs_tree_block_status
457 btrfs_check_leaf(struct btrfs_root *root, struct btrfs_disk_key *parent_key,
458 struct extent_buffer *buf)
461 struct btrfs_key cpukey;
462 struct btrfs_disk_key key;
463 u32 nritems = btrfs_header_nritems(buf);
464 enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;
466 if (nritems * sizeof(struct btrfs_item) > buf->len) {
467 fprintf(stderr, "invalid number of items %llu\n",
468 (unsigned long long)buf->start);
472 if (btrfs_header_level(buf) != 0) {
473 ret = BTRFS_TREE_BLOCK_INVALID_LEVEL;
474 fprintf(stderr, "leaf is not a leaf %llu\n",
475 (unsigned long long)btrfs_header_bytenr(buf));
478 if (btrfs_leaf_free_space(root, buf) < 0) {
479 ret = BTRFS_TREE_BLOCK_INVALID_FREE_SPACE;
480 fprintf(stderr, "leaf free space incorrect %llu %d\n",
481 (unsigned long long)btrfs_header_bytenr(buf),
482 btrfs_leaf_free_space(root, buf));
487 return BTRFS_TREE_BLOCK_CLEAN;
489 btrfs_item_key(buf, &key, 0);
490 if (parent_key && parent_key->type &&
491 memcmp(parent_key, &key, sizeof(key))) {
492 ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY;
493 fprintf(stderr, "leaf parent key incorrect %llu\n",
494 (unsigned long long)btrfs_header_bytenr(buf));
497 for (i = 0; nritems > 1 && i < nritems - 1; i++) {
498 btrfs_item_key(buf, &key, i);
499 btrfs_item_key_to_cpu(buf, &cpukey, i + 1);
500 if (btrfs_comp_keys(&key, &cpukey) >= 0) {
501 ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
502 fprintf(stderr, "bad key ordering %d %d\n", i, i+1);
505 if (btrfs_item_offset_nr(buf, i) !=
506 btrfs_item_end_nr(buf, i + 1)) {
507 ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
508 fprintf(stderr, "incorrect offsets %u %u\n",
509 btrfs_item_offset_nr(buf, i),
510 btrfs_item_end_nr(buf, i + 1));
513 if (i == 0 && btrfs_item_end_nr(buf, i) !=
514 BTRFS_LEAF_DATA_SIZE(root)) {
515 ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
516 fprintf(stderr, "bad item end %u wanted %u\n",
517 btrfs_item_end_nr(buf, i),
518 (unsigned)BTRFS_LEAF_DATA_SIZE(root));
522 return BTRFS_TREE_BLOCK_CLEAN;
524 if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
526 btrfs_disk_key_to_cpu(&cpukey, parent_key);
528 btrfs_item_key_to_cpu(buf, &cpukey, 0);
530 btrfs_add_corrupt_extent_record(root->fs_info, &cpukey,
531 buf->start, buf->len, 0);
536 static int noinline check_block(struct btrfs_root *root,
537 struct btrfs_path *path, int level)
539 struct btrfs_disk_key key;
540 struct btrfs_disk_key *key_ptr = NULL;
541 struct extent_buffer *parent;
542 enum btrfs_tree_block_status ret;
544 if (path->skip_check_block)
546 if (path->nodes[level + 1]) {
547 parent = path->nodes[level + 1];
548 btrfs_node_key(parent, &key, path->slots[level + 1]);
552 ret = btrfs_check_leaf(root, key_ptr, path->nodes[0]);
554 ret = btrfs_check_node(root, key_ptr, path->nodes[level]);
555 if (ret == BTRFS_TREE_BLOCK_CLEAN)
561 * search for key in the extent_buffer. The items start at offset p,
562 * and they are item_size apart. There are 'max' items in p.
564 * the slot in the array is returned via slot, and it points to
565 * the place where you would insert key if it is not found in
568 * slot may point to max if the key is bigger than all of the keys
570 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
571 int item_size, struct btrfs_key *key,
578 unsigned long offset;
579 struct btrfs_disk_key *tmp;
582 mid = (low + high) / 2;
583 offset = p + mid * item_size;
585 tmp = (struct btrfs_disk_key *)(eb->data + offset);
586 ret = btrfs_comp_keys(tmp, key);
602 * simple bin_search frontend that does the right thing for
605 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
606 int level, int *slot)
609 return generic_bin_search(eb,
610 offsetof(struct btrfs_leaf, items),
611 sizeof(struct btrfs_item),
612 key, btrfs_header_nritems(eb),
615 return generic_bin_search(eb,
616 offsetof(struct btrfs_node, ptrs),
617 sizeof(struct btrfs_key_ptr),
618 key, btrfs_header_nritems(eb),
622 struct extent_buffer *read_node_slot(struct btrfs_root *root,
623 struct extent_buffer *parent, int slot)
625 int level = btrfs_header_level(parent);
628 if (slot >= btrfs_header_nritems(parent))
634 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
635 btrfs_level_size(root, level - 1),
636 btrfs_node_ptr_generation(parent, slot));
639 static int balance_level(struct btrfs_trans_handle *trans,
640 struct btrfs_root *root,
641 struct btrfs_path *path, int level)
643 struct extent_buffer *right = NULL;
644 struct extent_buffer *mid;
645 struct extent_buffer *left = NULL;
646 struct extent_buffer *parent = NULL;
650 int orig_slot = path->slots[level];
656 mid = path->nodes[level];
657 WARN_ON(btrfs_header_generation(mid) != trans->transid);
659 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
661 if (level < BTRFS_MAX_LEVEL - 1) {
662 parent = path->nodes[level + 1];
663 pslot = path->slots[level + 1];
667 * deal with the case where there is only one pointer in the root
668 * by promoting the node below to a root
671 struct extent_buffer *child;
673 if (btrfs_header_nritems(mid) != 1)
676 /* promote the child to a root */
677 child = read_node_slot(root, mid, 0);
679 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
683 add_root_to_dirty_list(root);
684 path->nodes[level] = NULL;
685 clean_tree_block(trans, root, mid);
686 wait_on_tree_block_writeback(root, mid);
687 /* once for the path */
688 free_extent_buffer(mid);
690 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
691 0, root->root_key.objectid,
693 /* once for the root ptr */
694 free_extent_buffer(mid);
697 if (btrfs_header_nritems(mid) >
698 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
701 left = read_node_slot(root, parent, pslot - 1);
703 wret = btrfs_cow_block(trans, root, left,
704 parent, pslot - 1, &left);
710 right = read_node_slot(root, parent, pslot + 1);
712 wret = btrfs_cow_block(trans, root, right,
713 parent, pslot + 1, &right);
720 /* first, try to make some room in the middle buffer */
722 orig_slot += btrfs_header_nritems(left);
723 wret = push_node_left(trans, root, left, mid, 1);
729 * then try to empty the right most buffer into the middle
732 wret = push_node_left(trans, root, mid, right, 1);
733 if (wret < 0 && wret != -ENOSPC)
735 if (btrfs_header_nritems(right) == 0) {
736 u64 bytenr = right->start;
737 u32 blocksize = right->len;
739 clean_tree_block(trans, root, right);
740 wait_on_tree_block_writeback(root, right);
741 free_extent_buffer(right);
743 wret = btrfs_del_ptr(trans, root, path,
744 level + 1, pslot + 1);
747 wret = btrfs_free_extent(trans, root, bytenr,
749 root->root_key.objectid,
754 struct btrfs_disk_key right_key;
755 btrfs_node_key(right, &right_key, 0);
756 btrfs_set_node_key(parent, &right_key, pslot + 1);
757 btrfs_mark_buffer_dirty(parent);
760 if (btrfs_header_nritems(mid) == 1) {
762 * we're not allowed to leave a node with one item in the
763 * tree during a delete. A deletion from lower in the tree
764 * could try to delete the only pointer in this node.
765 * So, pull some keys from the left.
766 * There has to be a left pointer at this point because
767 * otherwise we would have pulled some pointers from the
771 wret = balance_node_right(trans, root, mid, left);
777 wret = push_node_left(trans, root, left, mid, 1);
783 if (btrfs_header_nritems(mid) == 0) {
784 /* we've managed to empty the middle node, drop it */
785 u64 bytenr = mid->start;
786 u32 blocksize = mid->len;
787 clean_tree_block(trans, root, mid);
788 wait_on_tree_block_writeback(root, mid);
789 free_extent_buffer(mid);
791 wret = btrfs_del_ptr(trans, root, path, level + 1, pslot);
794 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
795 0, root->root_key.objectid,
800 /* update the parent key to reflect our changes */
801 struct btrfs_disk_key mid_key;
802 btrfs_node_key(mid, &mid_key, 0);
803 btrfs_set_node_key(parent, &mid_key, pslot);
804 btrfs_mark_buffer_dirty(parent);
807 /* update the path */
809 if (btrfs_header_nritems(left) > orig_slot) {
810 extent_buffer_get(left);
811 path->nodes[level] = left;
812 path->slots[level + 1] -= 1;
813 path->slots[level] = orig_slot;
815 free_extent_buffer(mid);
817 orig_slot -= btrfs_header_nritems(left);
818 path->slots[level] = orig_slot;
821 /* double check we haven't messed things up */
822 check_block(root, path, level);
824 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
828 free_extent_buffer(right);
830 free_extent_buffer(left);
834 /* returns zero if the push worked, non-zero otherwise */
835 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
836 struct btrfs_root *root,
837 struct btrfs_path *path, int level)
839 struct extent_buffer *right = NULL;
840 struct extent_buffer *mid;
841 struct extent_buffer *left = NULL;
842 struct extent_buffer *parent = NULL;
846 int orig_slot = path->slots[level];
851 mid = path->nodes[level];
852 WARN_ON(btrfs_header_generation(mid) != trans->transid);
854 if (level < BTRFS_MAX_LEVEL - 1) {
855 parent = path->nodes[level + 1];
856 pslot = path->slots[level + 1];
862 left = read_node_slot(root, parent, pslot - 1);
864 /* first, try to make some room in the middle buffer */
867 left_nr = btrfs_header_nritems(left);
868 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
871 ret = btrfs_cow_block(trans, root, left, parent,
876 wret = push_node_left(trans, root,
883 struct btrfs_disk_key disk_key;
884 orig_slot += left_nr;
885 btrfs_node_key(mid, &disk_key, 0);
886 btrfs_set_node_key(parent, &disk_key, pslot);
887 btrfs_mark_buffer_dirty(parent);
888 if (btrfs_header_nritems(left) > orig_slot) {
889 path->nodes[level] = left;
890 path->slots[level + 1] -= 1;
891 path->slots[level] = orig_slot;
892 free_extent_buffer(mid);
895 btrfs_header_nritems(left);
896 path->slots[level] = orig_slot;
897 free_extent_buffer(left);
901 free_extent_buffer(left);
903 right= read_node_slot(root, parent, pslot + 1);
906 * then try to empty the right most buffer into the middle
910 right_nr = btrfs_header_nritems(right);
911 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
914 ret = btrfs_cow_block(trans, root, right,
920 wret = balance_node_right(trans, root,
927 struct btrfs_disk_key disk_key;
929 btrfs_node_key(right, &disk_key, 0);
930 btrfs_set_node_key(parent, &disk_key, pslot + 1);
931 btrfs_mark_buffer_dirty(parent);
933 if (btrfs_header_nritems(mid) <= orig_slot) {
934 path->nodes[level] = right;
935 path->slots[level + 1] += 1;
936 path->slots[level] = orig_slot -
937 btrfs_header_nritems(mid);
938 free_extent_buffer(mid);
940 free_extent_buffer(right);
944 free_extent_buffer(right);
950 * readahead one full node of leaves
952 void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
953 int level, int slot, u64 objectid)
955 struct extent_buffer *node;
956 struct btrfs_disk_key disk_key;
962 int direction = path->reada;
963 struct extent_buffer *eb;
971 if (!path->nodes[level])
974 node = path->nodes[level];
975 search = btrfs_node_blockptr(node, slot);
976 blocksize = btrfs_level_size(root, level - 1);
977 eb = btrfs_find_tree_block(root, search, blocksize);
979 free_extent_buffer(eb);
983 highest_read = search;
984 lowest_read = search;
986 nritems = btrfs_header_nritems(node);
993 } else if (direction > 0) {
998 if (path->reada < 0 && objectid) {
999 btrfs_node_key(node, &disk_key, nr);
1000 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1003 search = btrfs_node_blockptr(node, nr);
1004 if ((search >= lowest_read && search <= highest_read) ||
1005 (search < lowest_read && lowest_read - search <= 32768) ||
1006 (search > highest_read && search - highest_read <= 32768)) {
1007 readahead_tree_block(root, search, blocksize,
1008 btrfs_node_ptr_generation(node, nr));
1012 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1014 if(nread > (1024 * 1024) || nscan > 128)
1017 if (search < lowest_read)
1018 lowest_read = search;
1019 if (search > highest_read)
1020 highest_read = search;
1024 int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
1025 u64 iobjectid, u64 ioff, u8 key_type,
1026 struct btrfs_key *found_key)
1029 struct btrfs_key key;
1030 struct extent_buffer *eb;
1031 struct btrfs_path *path;
1033 key.type = key_type;
1034 key.objectid = iobjectid;
1037 if (found_path == NULL) {
1038 path = btrfs_alloc_path();
1044 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1045 if ((ret < 0) || (found_key == NULL)) {
1046 if (path != found_path)
1047 btrfs_free_path(path);
1051 eb = path->nodes[0];
1052 if (ret && path->slots[0] >= btrfs_header_nritems(eb)) {
1053 ret = btrfs_next_leaf(fs_root, path);
1056 eb = path->nodes[0];
1059 btrfs_item_key_to_cpu(eb, found_key, path->slots[0]);
1060 if (found_key->type != key.type ||
1061 found_key->objectid != key.objectid)
1068 * look for key in the tree. path is filled in with nodes along the way
1069 * if key is found, we return zero and you can find the item in the leaf
1070 * level of the path (level 0)
1072 * If the key isn't found, the path points to the slot where it should
1073 * be inserted, and 1 is returned. If there are other errors during the
1074 * search a negative error number is returned.
1076 * if ins_len > 0, nodes and leaves will be split as we walk down the
1077 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1080 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1081 *root, struct btrfs_key *key, struct btrfs_path *p, int
1084 struct extent_buffer *b;
1088 int should_reada = p->reada;
1089 u8 lowest_level = 0;
1091 lowest_level = p->lowest_level;
1092 WARN_ON(lowest_level && ins_len > 0);
1093 WARN_ON(p->nodes[0] != NULL);
1095 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1099 extent_buffer_get(b);
1101 level = btrfs_header_level(b);
1104 wret = btrfs_cow_block(trans, root, b,
1105 p->nodes[level + 1],
1106 p->slots[level + 1],
1109 free_extent_buffer(b);
1113 BUG_ON(!cow && ins_len);
1114 if (level != btrfs_header_level(b))
1116 level = btrfs_header_level(b);
1117 p->nodes[level] = b;
1118 ret = check_block(root, p, level);
1121 ret = bin_search(b, key, level, &slot);
1123 if (ret && slot > 0)
1125 p->slots[level] = slot;
1126 if ((p->search_for_split || ins_len > 0) &&
1127 btrfs_header_nritems(b) >=
1128 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1129 int sret = split_node(trans, root, p, level);
1133 b = p->nodes[level];
1134 slot = p->slots[level];
1135 } else if (ins_len < 0) {
1136 int sret = balance_level(trans, root, p,
1140 b = p->nodes[level];
1142 btrfs_release_path(p);
1145 slot = p->slots[level];
1146 BUG_ON(btrfs_header_nritems(b) == 1);
1148 /* this is only true while dropping a snapshot */
1149 if (level == lowest_level)
1153 reada_for_search(root, p, level, slot,
1156 b = read_node_slot(root, b, slot);
1157 if (!extent_buffer_uptodate(b))
1160 p->slots[level] = slot;
1162 ins_len > btrfs_leaf_free_space(root, b)) {
1163 int sret = split_leaf(trans, root, key,
1164 p, ins_len, ret == 0);
1176 * adjust the pointers going up the tree, starting at level
1177 * making sure the right key of each node is points to 'key'.
1178 * This is used after shifting pointers to the left, so it stops
1179 * fixing up pointers when a given leaf/node is not in slot 0 of the
1182 void btrfs_fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path,
1183 struct btrfs_disk_key *key, int level)
1186 struct extent_buffer *t;
1188 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1189 int tslot = path->slots[i];
1190 if (!path->nodes[i])
1193 btrfs_set_node_key(t, key, tslot);
1194 btrfs_mark_buffer_dirty(path->nodes[i]);
1203 * This function isn't completely safe. It's the caller's responsibility
1204 * that the new key won't break the order
1206 int btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path,
1207 struct btrfs_key *new_key)
1209 struct btrfs_disk_key disk_key;
1210 struct extent_buffer *eb;
1213 eb = path->nodes[0];
1214 slot = path->slots[0];
1216 btrfs_item_key(eb, &disk_key, slot - 1);
1217 if (btrfs_comp_keys(&disk_key, new_key) >= 0)
1220 if (slot < btrfs_header_nritems(eb) - 1) {
1221 btrfs_item_key(eb, &disk_key, slot + 1);
1222 if (btrfs_comp_keys(&disk_key, new_key) <= 0)
1226 btrfs_cpu_key_to_disk(&disk_key, new_key);
1227 btrfs_set_item_key(eb, &disk_key, slot);
1228 btrfs_mark_buffer_dirty(eb);
1230 btrfs_fixup_low_keys(root, path, &disk_key, 1);
1235 * update an item key without the safety checks. This is meant to be called by
1238 void btrfs_set_item_key_unsafe(struct btrfs_root *root,
1239 struct btrfs_path *path,
1240 struct btrfs_key *new_key)
1242 struct btrfs_disk_key disk_key;
1243 struct extent_buffer *eb;
1246 eb = path->nodes[0];
1247 slot = path->slots[0];
1249 btrfs_cpu_key_to_disk(&disk_key, new_key);
1250 btrfs_set_item_key(eb, &disk_key, slot);
1251 btrfs_mark_buffer_dirty(eb);
1253 btrfs_fixup_low_keys(root, path, &disk_key, 1);
1257 * try to push data from one node into the next node left in the
1260 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1261 * error, and > 0 if there was no room in the left hand block.
1263 static int push_node_left(struct btrfs_trans_handle *trans,
1264 struct btrfs_root *root, struct extent_buffer *dst,
1265 struct extent_buffer *src, int empty)
1272 src_nritems = btrfs_header_nritems(src);
1273 dst_nritems = btrfs_header_nritems(dst);
1274 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1275 WARN_ON(btrfs_header_generation(src) != trans->transid);
1276 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1278 if (!empty && src_nritems <= 8)
1281 if (push_items <= 0) {
1286 push_items = min(src_nritems, push_items);
1287 if (push_items < src_nritems) {
1288 /* leave at least 8 pointers in the node if
1289 * we aren't going to empty it
1291 if (src_nritems - push_items < 8) {
1292 if (push_items <= 8)
1298 push_items = min(src_nritems - 8, push_items);
1300 copy_extent_buffer(dst, src,
1301 btrfs_node_key_ptr_offset(dst_nritems),
1302 btrfs_node_key_ptr_offset(0),
1303 push_items * sizeof(struct btrfs_key_ptr));
1305 if (push_items < src_nritems) {
1306 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1307 btrfs_node_key_ptr_offset(push_items),
1308 (src_nritems - push_items) *
1309 sizeof(struct btrfs_key_ptr));
1311 btrfs_set_header_nritems(src, src_nritems - push_items);
1312 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1313 btrfs_mark_buffer_dirty(src);
1314 btrfs_mark_buffer_dirty(dst);
1320 * try to push data from one node into the next node right in the
1323 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1324 * error, and > 0 if there was no room in the right hand block.
1326 * this will only push up to 1/2 the contents of the left node over
1328 static int balance_node_right(struct btrfs_trans_handle *trans,
1329 struct btrfs_root *root,
1330 struct extent_buffer *dst,
1331 struct extent_buffer *src)
1339 WARN_ON(btrfs_header_generation(src) != trans->transid);
1340 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1342 src_nritems = btrfs_header_nritems(src);
1343 dst_nritems = btrfs_header_nritems(dst);
1344 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1345 if (push_items <= 0) {
1349 if (src_nritems < 4) {
1353 max_push = src_nritems / 2 + 1;
1354 /* don't try to empty the node */
1355 if (max_push >= src_nritems) {
1359 if (max_push < push_items)
1360 push_items = max_push;
1362 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1363 btrfs_node_key_ptr_offset(0),
1365 sizeof(struct btrfs_key_ptr));
1367 copy_extent_buffer(dst, src,
1368 btrfs_node_key_ptr_offset(0),
1369 btrfs_node_key_ptr_offset(src_nritems - push_items),
1370 push_items * sizeof(struct btrfs_key_ptr));
1372 btrfs_set_header_nritems(src, src_nritems - push_items);
1373 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1375 btrfs_mark_buffer_dirty(src);
1376 btrfs_mark_buffer_dirty(dst);
1382 * helper function to insert a new root level in the tree.
1383 * A new node is allocated, and a single item is inserted to
1384 * point to the existing root
1386 * returns zero on success or < 0 on failure.
1388 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1389 struct btrfs_root *root,
1390 struct btrfs_path *path, int level)
1393 struct extent_buffer *lower;
1394 struct extent_buffer *c;
1395 struct extent_buffer *old;
1396 struct btrfs_disk_key lower_key;
1398 BUG_ON(path->nodes[level]);
1399 BUG_ON(path->nodes[level-1] != root->node);
1401 lower = path->nodes[level-1];
1403 btrfs_item_key(lower, &lower_key, 0);
1405 btrfs_node_key(lower, &lower_key, 0);
1407 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1408 root->root_key.objectid, &lower_key,
1409 level, root->node->start, 0);
1414 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
1415 btrfs_set_header_nritems(c, 1);
1416 btrfs_set_header_level(c, level);
1417 btrfs_set_header_bytenr(c, c->start);
1418 btrfs_set_header_generation(c, trans->transid);
1419 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
1420 btrfs_set_header_owner(c, root->root_key.objectid);
1422 write_extent_buffer(c, root->fs_info->fsid,
1423 btrfs_header_fsid(), BTRFS_FSID_SIZE);
1425 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1426 btrfs_header_chunk_tree_uuid(c),
1429 btrfs_set_node_key(c, &lower_key, 0);
1430 btrfs_set_node_blockptr(c, 0, lower->start);
1431 lower_gen = btrfs_header_generation(lower);
1432 WARN_ON(lower_gen != trans->transid);
1434 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1436 btrfs_mark_buffer_dirty(c);
1441 /* the super has an extra ref to root->node */
1442 free_extent_buffer(old);
1444 add_root_to_dirty_list(root);
1445 extent_buffer_get(c);
1446 path->nodes[level] = c;
1447 path->slots[level] = 0;
1452 * worker function to insert a single pointer in a node.
1453 * the node should have enough room for the pointer already
1455 * slot and level indicate where you want the key to go, and
1456 * blocknr is the block the key points to.
1458 * returns zero on success and < 0 on any error
1460 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1461 *root, struct btrfs_path *path, struct btrfs_disk_key
1462 *key, u64 bytenr, int slot, int level)
1464 struct extent_buffer *lower;
1467 BUG_ON(!path->nodes[level]);
1468 lower = path->nodes[level];
1469 nritems = btrfs_header_nritems(lower);
1472 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1474 if (slot != nritems) {
1475 memmove_extent_buffer(lower,
1476 btrfs_node_key_ptr_offset(slot + 1),
1477 btrfs_node_key_ptr_offset(slot),
1478 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1480 btrfs_set_node_key(lower, key, slot);
1481 btrfs_set_node_blockptr(lower, slot, bytenr);
1482 WARN_ON(trans->transid == 0);
1483 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1484 btrfs_set_header_nritems(lower, nritems + 1);
1485 btrfs_mark_buffer_dirty(lower);
1490 * split the node at the specified level in path in two.
1491 * The path is corrected to point to the appropriate node after the split
1493 * Before splitting this tries to make some room in the node by pushing
1494 * left and right, if either one works, it returns right away.
1496 * returns 0 on success and < 0 on failure
1498 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1499 *root, struct btrfs_path *path, int level)
1501 struct extent_buffer *c;
1502 struct extent_buffer *split;
1503 struct btrfs_disk_key disk_key;
1509 c = path->nodes[level];
1510 WARN_ON(btrfs_header_generation(c) != trans->transid);
1511 if (c == root->node) {
1512 /* trying to split the root, lets make a new one */
1513 ret = insert_new_root(trans, root, path, level + 1);
1517 ret = push_nodes_for_insert(trans, root, path, level);
1518 c = path->nodes[level];
1519 if (!ret && btrfs_header_nritems(c) <
1520 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1526 c_nritems = btrfs_header_nritems(c);
1527 mid = (c_nritems + 1) / 2;
1528 btrfs_node_key(c, &disk_key, mid);
1530 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1531 root->root_key.objectid,
1532 &disk_key, level, c->start, 0);
1534 return PTR_ERR(split);
1536 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
1537 btrfs_set_header_level(split, btrfs_header_level(c));
1538 btrfs_set_header_bytenr(split, split->start);
1539 btrfs_set_header_generation(split, trans->transid);
1540 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
1541 btrfs_set_header_owner(split, root->root_key.objectid);
1542 write_extent_buffer(split, root->fs_info->fsid,
1543 btrfs_header_fsid(), BTRFS_FSID_SIZE);
1544 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1545 btrfs_header_chunk_tree_uuid(split),
1549 copy_extent_buffer(split, c,
1550 btrfs_node_key_ptr_offset(0),
1551 btrfs_node_key_ptr_offset(mid),
1552 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1553 btrfs_set_header_nritems(split, c_nritems - mid);
1554 btrfs_set_header_nritems(c, mid);
1557 btrfs_mark_buffer_dirty(c);
1558 btrfs_mark_buffer_dirty(split);
1560 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1561 path->slots[level + 1] + 1,
1566 if (path->slots[level] >= mid) {
1567 path->slots[level] -= mid;
1568 free_extent_buffer(c);
1569 path->nodes[level] = split;
1570 path->slots[level + 1] += 1;
1572 free_extent_buffer(split);
1578 * how many bytes are required to store the items in a leaf. start
1579 * and nr indicate which items in the leaf to check. This totals up the
1580 * space used both by the item structs and the item data
1582 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1585 int nritems = btrfs_header_nritems(l);
1586 int end = min(nritems, start + nr) - 1;
1590 data_len = btrfs_item_end_nr(l, start);
1591 data_len = data_len - btrfs_item_offset_nr(l, end);
1592 data_len += sizeof(struct btrfs_item) * nr;
1593 WARN_ON(data_len < 0);
1598 * The space between the end of the leaf items and
1599 * the start of the leaf data. IOW, how much room
1600 * the leaf has left for both items and data
1602 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1604 int nritems = btrfs_header_nritems(leaf);
1606 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1608 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1609 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1610 leaf_space_used(leaf, 0, nritems), nritems);
1616 * push some data in the path leaf to the right, trying to free up at
1617 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1619 * returns 1 if the push failed because the other node didn't have enough
1620 * room, 0 if everything worked out and < 0 if there were major errors.
1622 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1623 *root, struct btrfs_path *path, int data_size,
1626 struct extent_buffer *left = path->nodes[0];
1627 struct extent_buffer *right;
1628 struct extent_buffer *upper;
1629 struct btrfs_disk_key disk_key;
1635 struct btrfs_item *item;
1643 slot = path->slots[1];
1644 if (!path->nodes[1]) {
1647 upper = path->nodes[1];
1648 if (slot >= btrfs_header_nritems(upper) - 1)
1651 right = read_node_slot(root, upper, slot + 1);
1652 free_space = btrfs_leaf_free_space(root, right);
1653 if (free_space < data_size) {
1654 free_extent_buffer(right);
1658 /* cow and double check */
1659 ret = btrfs_cow_block(trans, root, right, upper,
1662 free_extent_buffer(right);
1665 free_space = btrfs_leaf_free_space(root, right);
1666 if (free_space < data_size) {
1667 free_extent_buffer(right);
1671 left_nritems = btrfs_header_nritems(left);
1672 if (left_nritems == 0) {
1673 free_extent_buffer(right);
1682 i = left_nritems - 1;
1684 item = btrfs_item_nr(i);
1686 if (path->slots[0] == i)
1687 push_space += data_size + sizeof(*item);
1689 this_item_size = btrfs_item_size(left, item);
1690 if (this_item_size + sizeof(*item) + push_space > free_space)
1693 push_space += this_item_size + sizeof(*item);
1699 if (push_items == 0) {
1700 free_extent_buffer(right);
1704 if (!empty && push_items == left_nritems)
1707 /* push left to right */
1708 right_nritems = btrfs_header_nritems(right);
1710 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1711 push_space -= leaf_data_end(root, left);
1713 /* make room in the right data area */
1714 data_end = leaf_data_end(root, right);
1715 memmove_extent_buffer(right,
1716 btrfs_leaf_data(right) + data_end - push_space,
1717 btrfs_leaf_data(right) + data_end,
1718 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1720 /* copy from the left data area */
1721 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1722 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1723 btrfs_leaf_data(left) + leaf_data_end(root, left),
1726 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1727 btrfs_item_nr_offset(0),
1728 right_nritems * sizeof(struct btrfs_item));
1730 /* copy the items from left to right */
1731 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1732 btrfs_item_nr_offset(left_nritems - push_items),
1733 push_items * sizeof(struct btrfs_item));
1735 /* update the item pointers */
1736 right_nritems += push_items;
1737 btrfs_set_header_nritems(right, right_nritems);
1738 push_space = BTRFS_LEAF_DATA_SIZE(root);
1739 for (i = 0; i < right_nritems; i++) {
1740 item = btrfs_item_nr(i);
1741 push_space -= btrfs_item_size(right, item);
1742 btrfs_set_item_offset(right, item, push_space);
1745 left_nritems -= push_items;
1746 btrfs_set_header_nritems(left, left_nritems);
1749 btrfs_mark_buffer_dirty(left);
1750 btrfs_mark_buffer_dirty(right);
1752 btrfs_item_key(right, &disk_key, 0);
1753 btrfs_set_node_key(upper, &disk_key, slot + 1);
1754 btrfs_mark_buffer_dirty(upper);
1756 /* then fixup the leaf pointer in the path */
1757 if (path->slots[0] >= left_nritems) {
1758 path->slots[0] -= left_nritems;
1759 free_extent_buffer(path->nodes[0]);
1760 path->nodes[0] = right;
1761 path->slots[1] += 1;
1763 free_extent_buffer(right);
1768 * push some data in the path leaf to the left, trying to free up at
1769 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1771 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1772 *root, struct btrfs_path *path, int data_size,
1775 struct btrfs_disk_key disk_key;
1776 struct extent_buffer *right = path->nodes[0];
1777 struct extent_buffer *left;
1783 struct btrfs_item *item;
1784 u32 old_left_nritems;
1789 u32 old_left_item_size;
1791 slot = path->slots[1];
1794 if (!path->nodes[1])
1797 right_nritems = btrfs_header_nritems(right);
1798 if (right_nritems == 0) {
1802 left = read_node_slot(root, path->nodes[1], slot - 1);
1803 free_space = btrfs_leaf_free_space(root, left);
1804 if (free_space < data_size) {
1805 free_extent_buffer(left);
1809 /* cow and double check */
1810 ret = btrfs_cow_block(trans, root, left,
1811 path->nodes[1], slot - 1, &left);
1813 /* we hit -ENOSPC, but it isn't fatal here */
1814 free_extent_buffer(left);
1818 free_space = btrfs_leaf_free_space(root, left);
1819 if (free_space < data_size) {
1820 free_extent_buffer(left);
1827 nr = right_nritems - 1;
1829 for (i = 0; i < nr; i++) {
1830 item = btrfs_item_nr(i);
1832 if (path->slots[0] == i)
1833 push_space += data_size + sizeof(*item);
1835 this_item_size = btrfs_item_size(right, item);
1836 if (this_item_size + sizeof(*item) + push_space > free_space)
1840 push_space += this_item_size + sizeof(*item);
1843 if (push_items == 0) {
1844 free_extent_buffer(left);
1847 if (!empty && push_items == btrfs_header_nritems(right))
1850 /* push data from right to left */
1851 copy_extent_buffer(left, right,
1852 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1853 btrfs_item_nr_offset(0),
1854 push_items * sizeof(struct btrfs_item));
1856 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1857 btrfs_item_offset_nr(right, push_items -1);
1859 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1860 leaf_data_end(root, left) - push_space,
1861 btrfs_leaf_data(right) +
1862 btrfs_item_offset_nr(right, push_items - 1),
1864 old_left_nritems = btrfs_header_nritems(left);
1865 BUG_ON(old_left_nritems == 0);
1867 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1868 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1871 item = btrfs_item_nr(i);
1872 ioff = btrfs_item_offset(left, item);
1873 btrfs_set_item_offset(left, item,
1874 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1876 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1878 /* fixup right node */
1879 if (push_items > right_nritems) {
1880 printk("push items %d nr %u\n", push_items, right_nritems);
1884 if (push_items < right_nritems) {
1885 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1886 leaf_data_end(root, right);
1887 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1888 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1889 btrfs_leaf_data(right) +
1890 leaf_data_end(root, right), push_space);
1892 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1893 btrfs_item_nr_offset(push_items),
1894 (btrfs_header_nritems(right) - push_items) *
1895 sizeof(struct btrfs_item));
1897 right_nritems -= push_items;
1898 btrfs_set_header_nritems(right, right_nritems);
1899 push_space = BTRFS_LEAF_DATA_SIZE(root);
1900 for (i = 0; i < right_nritems; i++) {
1901 item = btrfs_item_nr(i);
1902 push_space = push_space - btrfs_item_size(right, item);
1903 btrfs_set_item_offset(right, item, push_space);
1906 btrfs_mark_buffer_dirty(left);
1908 btrfs_mark_buffer_dirty(right);
1910 btrfs_item_key(right, &disk_key, 0);
1911 btrfs_fixup_low_keys(root, path, &disk_key, 1);
1913 /* then fixup the leaf pointer in the path */
1914 if (path->slots[0] < push_items) {
1915 path->slots[0] += old_left_nritems;
1916 free_extent_buffer(path->nodes[0]);
1917 path->nodes[0] = left;
1918 path->slots[1] -= 1;
1920 free_extent_buffer(left);
1921 path->slots[0] -= push_items;
1923 BUG_ON(path->slots[0] < 0);
1928 * split the path's leaf in two, making sure there is at least data_size
1929 * available for the resulting leaf level of the path.
1931 * returns 0 if all went well and < 0 on failure.
1933 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
1934 struct btrfs_root *root,
1935 struct btrfs_path *path,
1936 struct extent_buffer *l,
1937 struct extent_buffer *right,
1938 int slot, int mid, int nritems)
1945 struct btrfs_disk_key disk_key;
1947 nritems = nritems - mid;
1948 btrfs_set_header_nritems(right, nritems);
1949 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1951 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1952 btrfs_item_nr_offset(mid),
1953 nritems * sizeof(struct btrfs_item));
1955 copy_extent_buffer(right, l,
1956 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1957 data_copy_size, btrfs_leaf_data(l) +
1958 leaf_data_end(root, l), data_copy_size);
1960 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
1961 btrfs_item_end_nr(l, mid);
1963 for (i = 0; i < nritems; i++) {
1964 struct btrfs_item *item = btrfs_item_nr(i);
1965 u32 ioff = btrfs_item_offset(right, item);
1966 btrfs_set_item_offset(right, item, ioff + rt_data_off);
1969 btrfs_set_header_nritems(l, mid);
1971 btrfs_item_key(right, &disk_key, 0);
1972 wret = insert_ptr(trans, root, path, &disk_key, right->start,
1973 path->slots[1] + 1, 1);
1977 btrfs_mark_buffer_dirty(right);
1978 btrfs_mark_buffer_dirty(l);
1979 BUG_ON(path->slots[0] != slot);
1982 free_extent_buffer(path->nodes[0]);
1983 path->nodes[0] = right;
1984 path->slots[0] -= mid;
1985 path->slots[1] += 1;
1987 free_extent_buffer(right);
1990 BUG_ON(path->slots[0] < 0);
1996 * split the path's leaf in two, making sure there is at least data_size
1997 * available for the resulting leaf level of the path.
1999 * returns 0 if all went well and < 0 on failure.
2001 static noinline int split_leaf(struct btrfs_trans_handle *trans,
2002 struct btrfs_root *root,
2003 struct btrfs_key *ins_key,
2004 struct btrfs_path *path, int data_size,
2007 struct btrfs_disk_key disk_key;
2008 struct extent_buffer *l;
2012 struct extent_buffer *right;
2016 int num_doubles = 0;
2019 slot = path->slots[0];
2020 if (extend && data_size + btrfs_item_size_nr(l, slot) +
2021 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root))
2024 /* first try to make some room by pushing left and right */
2025 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
2026 wret = push_leaf_right(trans, root, path, data_size, 0);
2030 wret = push_leaf_left(trans, root, path, data_size, 0);
2036 /* did the pushes work? */
2037 if (btrfs_leaf_free_space(root, l) >= data_size)
2041 if (!path->nodes[1]) {
2042 ret = insert_new_root(trans, root, path, 1);
2049 slot = path->slots[0];
2050 nritems = btrfs_header_nritems(l);
2051 mid = (nritems + 1) / 2;
2055 leaf_space_used(l, mid, nritems - mid) + data_size >
2056 BTRFS_LEAF_DATA_SIZE(root)) {
2057 if (slot >= nritems) {
2061 if (mid != nritems &&
2062 leaf_space_used(l, mid, nritems - mid) +
2063 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2069 if (leaf_space_used(l, 0, mid) + data_size >
2070 BTRFS_LEAF_DATA_SIZE(root)) {
2071 if (!extend && data_size && slot == 0) {
2073 } else if ((extend || !data_size) && slot == 0) {
2077 if (mid != nritems &&
2078 leaf_space_used(l, mid, nritems - mid) +
2079 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2087 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2089 btrfs_item_key(l, &disk_key, mid);
2091 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2092 root->root_key.objectid,
2093 &disk_key, 0, l->start, 0);
2094 if (IS_ERR(right)) {
2096 return PTR_ERR(right);
2099 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2100 btrfs_set_header_bytenr(right, right->start);
2101 btrfs_set_header_generation(right, trans->transid);
2102 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
2103 btrfs_set_header_owner(right, root->root_key.objectid);
2104 btrfs_set_header_level(right, 0);
2105 write_extent_buffer(right, root->fs_info->fsid,
2106 btrfs_header_fsid(), BTRFS_FSID_SIZE);
2108 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2109 btrfs_header_chunk_tree_uuid(right),
2114 btrfs_set_header_nritems(right, 0);
2115 wret = insert_ptr(trans, root, path,
2116 &disk_key, right->start,
2117 path->slots[1] + 1, 1);
2121 free_extent_buffer(path->nodes[0]);
2122 path->nodes[0] = right;
2124 path->slots[1] += 1;
2126 btrfs_set_header_nritems(right, 0);
2127 wret = insert_ptr(trans, root, path,
2133 free_extent_buffer(path->nodes[0]);
2134 path->nodes[0] = right;
2136 if (path->slots[1] == 0) {
2137 btrfs_fixup_low_keys(root, path,
2141 btrfs_mark_buffer_dirty(right);
2145 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
2149 BUG_ON(num_doubles != 0);
2158 * This function splits a single item into two items,
2159 * giving 'new_key' to the new item and splitting the
2160 * old one at split_offset (from the start of the item).
2162 * The path may be released by this operation. After
2163 * the split, the path is pointing to the old item. The
2164 * new item is going to be in the same node as the old one.
2166 * Note, the item being split must be smaller enough to live alone on
2167 * a tree block with room for one extra struct btrfs_item
2169 * This allows us to split the item in place, keeping a lock on the
2170 * leaf the entire time.
2172 int btrfs_split_item(struct btrfs_trans_handle *trans,
2173 struct btrfs_root *root,
2174 struct btrfs_path *path,
2175 struct btrfs_key *new_key,
2176 unsigned long split_offset)
2179 struct extent_buffer *leaf;
2180 struct btrfs_key orig_key;
2181 struct btrfs_item *item;
2182 struct btrfs_item *new_item;
2187 struct btrfs_disk_key disk_key;
2190 leaf = path->nodes[0];
2191 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
2192 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
2195 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2196 btrfs_release_path(path);
2198 path->search_for_split = 1;
2200 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
2201 path->search_for_split = 0;
2203 /* if our item isn't there or got smaller, return now */
2204 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
2209 ret = split_leaf(trans, root, &orig_key, path, 0, 0);
2212 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
2213 leaf = path->nodes[0];
2216 item = btrfs_item_nr(path->slots[0]);
2217 orig_offset = btrfs_item_offset(leaf, item);
2218 item_size = btrfs_item_size(leaf, item);
2221 buf = kmalloc(item_size, GFP_NOFS);
2222 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
2223 path->slots[0]), item_size);
2224 slot = path->slots[0] + 1;
2225 leaf = path->nodes[0];
2227 nritems = btrfs_header_nritems(leaf);
2229 if (slot != nritems) {
2230 /* shift the items */
2231 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2232 btrfs_item_nr_offset(slot),
2233 (nritems - slot) * sizeof(struct btrfs_item));
2237 btrfs_cpu_key_to_disk(&disk_key, new_key);
2238 btrfs_set_item_key(leaf, &disk_key, slot);
2240 new_item = btrfs_item_nr(slot);
2242 btrfs_set_item_offset(leaf, new_item, orig_offset);
2243 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
2245 btrfs_set_item_offset(leaf, item,
2246 orig_offset + item_size - split_offset);
2247 btrfs_set_item_size(leaf, item, split_offset);
2249 btrfs_set_header_nritems(leaf, nritems + 1);
2251 /* write the data for the start of the original item */
2252 write_extent_buffer(leaf, buf,
2253 btrfs_item_ptr_offset(leaf, path->slots[0]),
2256 /* write the data for the new item */
2257 write_extent_buffer(leaf, buf + split_offset,
2258 btrfs_item_ptr_offset(leaf, slot),
2259 item_size - split_offset);
2260 btrfs_mark_buffer_dirty(leaf);
2263 if (btrfs_leaf_free_space(root, leaf) < 0) {
2264 btrfs_print_leaf(root, leaf);
2271 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2272 struct btrfs_root *root,
2273 struct btrfs_path *path,
2274 u32 new_size, int from_end)
2278 struct extent_buffer *leaf;
2279 struct btrfs_item *item;
2281 unsigned int data_end;
2282 unsigned int old_data_start;
2283 unsigned int old_size;
2284 unsigned int size_diff;
2287 leaf = path->nodes[0];
2288 slot = path->slots[0];
2290 old_size = btrfs_item_size_nr(leaf, slot);
2291 if (old_size == new_size)
2294 nritems = btrfs_header_nritems(leaf);
2295 data_end = leaf_data_end(root, leaf);
2297 old_data_start = btrfs_item_offset_nr(leaf, slot);
2299 size_diff = old_size - new_size;
2302 BUG_ON(slot >= nritems);
2305 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2307 /* first correct the data pointers */
2308 for (i = slot; i < nritems; i++) {
2310 item = btrfs_item_nr(i);
2311 ioff = btrfs_item_offset(leaf, item);
2312 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2315 /* shift the data */
2317 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2318 data_end + size_diff, btrfs_leaf_data(leaf) +
2319 data_end, old_data_start + new_size - data_end);
2321 struct btrfs_disk_key disk_key;
2324 btrfs_item_key(leaf, &disk_key, slot);
2326 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2328 struct btrfs_file_extent_item *fi;
2330 fi = btrfs_item_ptr(leaf, slot,
2331 struct btrfs_file_extent_item);
2332 fi = (struct btrfs_file_extent_item *)(
2333 (unsigned long)fi - size_diff);
2335 if (btrfs_file_extent_type(leaf, fi) ==
2336 BTRFS_FILE_EXTENT_INLINE) {
2337 ptr = btrfs_item_ptr_offset(leaf, slot);
2338 memmove_extent_buffer(leaf, ptr,
2340 offsetof(struct btrfs_file_extent_item,
2345 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2346 data_end + size_diff, btrfs_leaf_data(leaf) +
2347 data_end, old_data_start - data_end);
2349 offset = btrfs_disk_key_offset(&disk_key);
2350 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2351 btrfs_set_item_key(leaf, &disk_key, slot);
2353 btrfs_fixup_low_keys(root, path, &disk_key, 1);
2356 item = btrfs_item_nr(slot);
2357 btrfs_set_item_size(leaf, item, new_size);
2358 btrfs_mark_buffer_dirty(leaf);
2361 if (btrfs_leaf_free_space(root, leaf) < 0) {
2362 btrfs_print_leaf(root, leaf);
2368 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2369 struct btrfs_root *root, struct btrfs_path *path,
2374 struct extent_buffer *leaf;
2375 struct btrfs_item *item;
2377 unsigned int data_end;
2378 unsigned int old_data;
2379 unsigned int old_size;
2382 leaf = path->nodes[0];
2384 nritems = btrfs_header_nritems(leaf);
2385 data_end = leaf_data_end(root, leaf);
2387 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2388 btrfs_print_leaf(root, leaf);
2391 slot = path->slots[0];
2392 old_data = btrfs_item_end_nr(leaf, slot);
2395 if (slot >= nritems) {
2396 btrfs_print_leaf(root, leaf);
2397 printk("slot %d too large, nritems %d\n", slot, nritems);
2402 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2404 /* first correct the data pointers */
2405 for (i = slot; i < nritems; i++) {
2407 item = btrfs_item_nr(i);
2408 ioff = btrfs_item_offset(leaf, item);
2409 btrfs_set_item_offset(leaf, item, ioff - data_size);
2412 /* shift the data */
2413 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2414 data_end - data_size, btrfs_leaf_data(leaf) +
2415 data_end, old_data - data_end);
2417 data_end = old_data;
2418 old_size = btrfs_item_size_nr(leaf, slot);
2419 item = btrfs_item_nr(slot);
2420 btrfs_set_item_size(leaf, item, old_size + data_size);
2421 btrfs_mark_buffer_dirty(leaf);
2424 if (btrfs_leaf_free_space(root, leaf) < 0) {
2425 btrfs_print_leaf(root, leaf);
2432 * Given a key and some data, insert an item into the tree.
2433 * This does all the path init required, making room in the tree if needed.
2435 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2436 struct btrfs_root *root,
2437 struct btrfs_path *path,
2438 struct btrfs_key *cpu_key, u32 *data_size,
2441 struct extent_buffer *leaf;
2442 struct btrfs_item *item;
2449 unsigned int data_end;
2450 struct btrfs_disk_key disk_key;
2452 for (i = 0; i < nr; i++) {
2453 total_data += data_size[i];
2456 /* create a root if there isn't one */
2460 total_size = total_data + nr * sizeof(struct btrfs_item);
2461 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2468 leaf = path->nodes[0];
2470 nritems = btrfs_header_nritems(leaf);
2471 data_end = leaf_data_end(root, leaf);
2473 if (btrfs_leaf_free_space(root, leaf) < total_size) {
2474 btrfs_print_leaf(root, leaf);
2475 printk("not enough freespace need %u have %d\n",
2476 total_size, btrfs_leaf_free_space(root, leaf));
2480 slot = path->slots[0];
2483 if (slot != nritems) {
2484 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2486 if (old_data < data_end) {
2487 btrfs_print_leaf(root, leaf);
2488 printk("slot %d old_data %d data_end %d\n",
2489 slot, old_data, data_end);
2493 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2495 /* first correct the data pointers */
2496 for (i = slot; i < nritems; i++) {
2499 item = btrfs_item_nr(i);
2500 ioff = btrfs_item_offset(leaf, item);
2501 btrfs_set_item_offset(leaf, item, ioff - total_data);
2504 /* shift the items */
2505 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2506 btrfs_item_nr_offset(slot),
2507 (nritems - slot) * sizeof(struct btrfs_item));
2509 /* shift the data */
2510 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2511 data_end - total_data, btrfs_leaf_data(leaf) +
2512 data_end, old_data - data_end);
2513 data_end = old_data;
2516 /* setup the item for the new data */
2517 for (i = 0; i < nr; i++) {
2518 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2519 btrfs_set_item_key(leaf, &disk_key, slot + i);
2520 item = btrfs_item_nr(slot + i);
2521 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2522 data_end -= data_size[i];
2523 btrfs_set_item_size(leaf, item, data_size[i]);
2525 btrfs_set_header_nritems(leaf, nritems + nr);
2526 btrfs_mark_buffer_dirty(leaf);
2530 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2531 btrfs_fixup_low_keys(root, path, &disk_key, 1);
2534 if (btrfs_leaf_free_space(root, leaf) < 0) {
2535 btrfs_print_leaf(root, leaf);
2544 * Given a key and some data, insert an item into the tree.
2545 * This does all the path init required, making room in the tree if needed.
2547 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2548 *root, struct btrfs_key *cpu_key, void *data, u32
2552 struct btrfs_path *path;
2553 struct extent_buffer *leaf;
2556 path = btrfs_alloc_path();
2558 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2560 leaf = path->nodes[0];
2561 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2562 write_extent_buffer(leaf, data, ptr, data_size);
2563 btrfs_mark_buffer_dirty(leaf);
2565 btrfs_free_path(path);
2570 * delete the pointer from a given node.
2572 * If the delete empties a node, the node is removed from the tree,
2573 * continuing all the way the root if required. The root is converted into
2574 * a leaf if all the nodes are emptied.
2576 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2577 struct btrfs_path *path, int level, int slot)
2579 struct extent_buffer *parent = path->nodes[level];
2583 nritems = btrfs_header_nritems(parent);
2584 if (slot != nritems -1) {
2585 memmove_extent_buffer(parent,
2586 btrfs_node_key_ptr_offset(slot),
2587 btrfs_node_key_ptr_offset(slot + 1),
2588 sizeof(struct btrfs_key_ptr) *
2589 (nritems - slot - 1));
2592 btrfs_set_header_nritems(parent, nritems);
2593 if (nritems == 0 && parent == root->node) {
2594 BUG_ON(btrfs_header_level(root->node) != 1);
2595 /* just turn the root into a leaf and break */
2596 btrfs_set_header_level(root->node, 0);
2597 } else if (slot == 0) {
2598 struct btrfs_disk_key disk_key;
2600 btrfs_node_key(parent, &disk_key, 0);
2601 btrfs_fixup_low_keys(root, path, &disk_key, level + 1);
2603 btrfs_mark_buffer_dirty(parent);
2608 * a helper function to delete the leaf pointed to by path->slots[1] and
2611 * This deletes the pointer in path->nodes[1] and frees the leaf
2612 * block extent. zero is returned if it all worked out, < 0 otherwise.
2614 * The path must have already been setup for deleting the leaf, including
2615 * all the proper balancing. path->nodes[1] must be locked.
2617 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
2618 struct btrfs_root *root,
2619 struct btrfs_path *path,
2620 struct extent_buffer *leaf)
2624 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
2625 ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
2629 ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
2630 0, root->root_key.objectid, 0, 0);
2635 * delete the item at the leaf level in path. If that empties
2636 * the leaf, remove it from the tree
2638 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2639 struct btrfs_path *path, int slot, int nr)
2641 struct extent_buffer *leaf;
2642 struct btrfs_item *item;
2650 leaf = path->nodes[0];
2651 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2653 for (i = 0; i < nr; i++)
2654 dsize += btrfs_item_size_nr(leaf, slot + i);
2656 nritems = btrfs_header_nritems(leaf);
2658 if (slot + nr != nritems) {
2659 int data_end = leaf_data_end(root, leaf);
2661 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2663 btrfs_leaf_data(leaf) + data_end,
2664 last_off - data_end);
2666 for (i = slot + nr; i < nritems; i++) {
2669 item = btrfs_item_nr(i);
2670 ioff = btrfs_item_offset(leaf, item);
2671 btrfs_set_item_offset(leaf, item, ioff + dsize);
2674 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2675 btrfs_item_nr_offset(slot + nr),
2676 sizeof(struct btrfs_item) *
2677 (nritems - slot - nr));
2679 btrfs_set_header_nritems(leaf, nritems - nr);
2682 /* delete the leaf if we've emptied it */
2684 if (leaf == root->node) {
2685 btrfs_set_header_level(leaf, 0);
2687 clean_tree_block(trans, root, leaf);
2688 wait_on_tree_block_writeback(root, leaf);
2690 wret = btrfs_del_leaf(trans, root, path, leaf);
2696 int used = leaf_space_used(leaf, 0, nritems);
2698 struct btrfs_disk_key disk_key;
2700 btrfs_item_key(leaf, &disk_key, 0);
2701 btrfs_fixup_low_keys(root, path, &disk_key, 1);
2704 /* delete the leaf if it is mostly empty */
2705 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2706 /* push_leaf_left fixes the path.
2707 * make sure the path still points to our leaf
2708 * for possible call to del_ptr below
2710 slot = path->slots[1];
2711 extent_buffer_get(leaf);
2713 wret = push_leaf_left(trans, root, path, 1, 1);
2714 if (wret < 0 && wret != -ENOSPC)
2717 if (path->nodes[0] == leaf &&
2718 btrfs_header_nritems(leaf)) {
2719 wret = push_leaf_right(trans, root, path, 1, 1);
2720 if (wret < 0 && wret != -ENOSPC)
2724 if (btrfs_header_nritems(leaf) == 0) {
2725 clean_tree_block(trans, root, leaf);
2726 wait_on_tree_block_writeback(root, leaf);
2728 path->slots[1] = slot;
2729 ret = btrfs_del_leaf(trans, root, path, leaf);
2731 free_extent_buffer(leaf);
2734 btrfs_mark_buffer_dirty(leaf);
2735 free_extent_buffer(leaf);
2738 btrfs_mark_buffer_dirty(leaf);
2745 * walk up the tree as far as required to find the previous leaf.
2746 * returns 0 if it found something or 1 if there are no lesser leaves.
2747 * returns < 0 on io errors.
2749 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2753 struct extent_buffer *c;
2754 struct extent_buffer *next = NULL;
2756 while(level < BTRFS_MAX_LEVEL) {
2757 if (!path->nodes[level])
2760 slot = path->slots[level];
2761 c = path->nodes[level];
2764 if (level == BTRFS_MAX_LEVEL)
2770 next = read_node_slot(root, c, slot);
2773 path->slots[level] = slot;
2776 c = path->nodes[level];
2777 free_extent_buffer(c);
2778 slot = btrfs_header_nritems(next);
2781 path->nodes[level] = next;
2782 path->slots[level] = slot;
2785 next = read_node_slot(root, next, slot);
2791 * walk up the tree as far as required to find the next leaf.
2792 * returns 0 if it found something or 1 if there are no greater leaves.
2793 * returns < 0 on io errors.
2795 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2799 struct extent_buffer *c;
2800 struct extent_buffer *next = NULL;
2802 while(level < BTRFS_MAX_LEVEL) {
2803 if (!path->nodes[level])
2806 slot = path->slots[level] + 1;
2807 c = path->nodes[level];
2808 if (slot >= btrfs_header_nritems(c)) {
2810 if (level == BTRFS_MAX_LEVEL)
2816 reada_for_search(root, path, level, slot, 0);
2818 next = read_node_slot(root, c, slot);
2823 path->slots[level] = slot;
2826 c = path->nodes[level];
2827 free_extent_buffer(c);
2828 path->nodes[level] = next;
2829 path->slots[level] = 0;
2833 reada_for_search(root, path, level, 0, 0);
2834 next = read_node_slot(root, next, 0);
2841 int btrfs_previous_item(struct btrfs_root *root,
2842 struct btrfs_path *path, u64 min_objectid,
2845 struct btrfs_key found_key;
2846 struct extent_buffer *leaf;
2850 if (path->slots[0] == 0) {
2851 ret = btrfs_prev_leaf(root, path);
2857 leaf = path->nodes[0];
2858 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2859 if (found_key.type == type)
2866 * search in extent tree to find a previous Metadata/Data extent item with
2869 * returns 0 if something is found, 1 if nothing was found and < 0 on error
2871 int btrfs_previous_extent_item(struct btrfs_root *root,
2872 struct btrfs_path *path, u64 min_objectid)
2874 struct btrfs_key found_key;
2875 struct extent_buffer *leaf;
2880 if (path->slots[0] == 0) {
2881 ret = btrfs_prev_leaf(root, path);
2887 leaf = path->nodes[0];
2888 nritems = btrfs_header_nritems(leaf);
2891 if (path->slots[0] == nritems)
2894 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2895 if (found_key.objectid < min_objectid)
2897 if (found_key.type == BTRFS_EXTENT_ITEM_KEY ||
2898 found_key.type == BTRFS_METADATA_ITEM_KEY)
2900 if (found_key.objectid == min_objectid &&
2901 found_key.type < BTRFS_EXTENT_ITEM_KEY)