2 * Copyright (C) 2007,2008 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/slab.h>
23 #include "transaction.h"
24 #include "print-tree.h"
27 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_path *path, int level);
29 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
30 *root, struct btrfs_key *ins_key,
31 struct btrfs_path *path, int data_size, int extend);
32 static int push_node_left(struct btrfs_trans_handle *trans,
33 struct btrfs_root *root, struct extent_buffer *dst,
34 struct extent_buffer *src, int empty);
35 static int balance_node_right(struct btrfs_trans_handle *trans,
36 struct btrfs_root *root,
37 struct extent_buffer *dst_buf,
38 struct extent_buffer *src_buf);
39 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
40 struct btrfs_path *path, int level, int slot);
41 static int setup_items_for_insert(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root, struct btrfs_path *path,
43 struct btrfs_key *cpu_key, u32 *data_size,
44 u32 total_data, u32 total_size, int nr);
47 struct btrfs_path *btrfs_alloc_path(void)
49 struct btrfs_path *path;
50 path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
57 * set all locked nodes in the path to blocking locks. This should
58 * be done before scheduling
60 noinline void btrfs_set_path_blocking(struct btrfs_path *p)
63 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
64 if (p->nodes[i] && p->locks[i])
65 btrfs_set_lock_blocking(p->nodes[i]);
70 * reset all the locked nodes in the patch to spinning locks.
72 * held is used to keep lockdep happy, when lockdep is enabled
73 * we set held to a blocking lock before we go around and
74 * retake all the spinlocks in the path. You can safely use NULL
77 noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
78 struct extent_buffer *held)
82 #ifdef CONFIG_DEBUG_LOCK_ALLOC
83 /* lockdep really cares that we take all of these spinlocks
84 * in the right order. If any of the locks in the path are not
85 * currently blocking, it is going to complain. So, make really
86 * really sure by forcing the path to blocking before we clear
90 btrfs_set_lock_blocking(held);
91 btrfs_set_path_blocking(p);
94 for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
95 if (p->nodes[i] && p->locks[i])
96 btrfs_clear_lock_blocking(p->nodes[i]);
99 #ifdef CONFIG_DEBUG_LOCK_ALLOC
101 btrfs_clear_lock_blocking(held);
105 /* this also releases the path */
106 void btrfs_free_path(struct btrfs_path *p)
108 btrfs_release_path(NULL, p);
109 kmem_cache_free(btrfs_path_cachep, p);
113 * path release drops references on the extent buffers in the path
114 * and it drops any locks held by this path
116 * It is safe to call this on paths that no locks or extent buffers held.
118 noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
122 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
127 btrfs_tree_unlock(p->nodes[i]);
130 free_extent_buffer(p->nodes[i]);
136 * safely gets a reference on the root node of a tree. A lock
137 * is not taken, so a concurrent writer may put a different node
138 * at the root of the tree. See btrfs_lock_root_node for the
141 * The extent buffer returned by this has a reference taken, so
142 * it won't disappear. It may stop being the root of the tree
143 * at any time because there are no locks held.
145 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
147 struct extent_buffer *eb;
148 spin_lock(&root->node_lock);
150 extent_buffer_get(eb);
151 spin_unlock(&root->node_lock);
155 /* loop around taking references on and locking the root node of the
156 * tree until you end up with a lock on the root. A locked buffer
157 * is returned, with a reference held.
159 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
161 struct extent_buffer *eb;
164 eb = btrfs_root_node(root);
167 spin_lock(&root->node_lock);
168 if (eb == root->node) {
169 spin_unlock(&root->node_lock);
172 spin_unlock(&root->node_lock);
174 btrfs_tree_unlock(eb);
175 free_extent_buffer(eb);
180 /* cowonly root (everything not a reference counted cow subvolume), just get
181 * put onto a simple dirty list. transaction.c walks this to make sure they
182 * get properly updated on disk.
184 static void add_root_to_dirty_list(struct btrfs_root *root)
186 if (root->track_dirty && list_empty(&root->dirty_list)) {
187 list_add(&root->dirty_list,
188 &root->fs_info->dirty_cowonly_roots);
193 * used by snapshot creation to make a copy of a root for a tree with
194 * a given objectid. The buffer with the new root node is returned in
195 * cow_ret, and this func returns zero on success or a negative error code.
197 int btrfs_copy_root(struct btrfs_trans_handle *trans,
198 struct btrfs_root *root,
199 struct extent_buffer *buf,
200 struct extent_buffer **cow_ret, u64 new_root_objectid)
202 struct extent_buffer *cow;
206 struct btrfs_disk_key disk_key;
208 WARN_ON(root->ref_cows && trans->transid !=
209 root->fs_info->running_transaction->transid);
210 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
212 level = btrfs_header_level(buf);
213 nritems = btrfs_header_nritems(buf);
215 btrfs_item_key(buf, &disk_key, 0);
217 btrfs_node_key(buf, &disk_key, 0);
219 cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
220 new_root_objectid, &disk_key, level,
225 copy_extent_buffer(cow, buf, 0, 0, cow->len);
226 btrfs_set_header_bytenr(cow, cow->start);
227 btrfs_set_header_generation(cow, trans->transid);
228 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
229 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
230 BTRFS_HEADER_FLAG_RELOC);
231 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
232 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
234 btrfs_set_header_owner(cow, new_root_objectid);
236 write_extent_buffer(cow, root->fs_info->fsid,
237 (unsigned long)btrfs_header_fsid(cow),
240 WARN_ON(btrfs_header_generation(buf) > trans->transid);
241 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
242 ret = btrfs_inc_ref(trans, root, cow, 1);
244 ret = btrfs_inc_ref(trans, root, cow, 0);
249 btrfs_mark_buffer_dirty(cow);
255 * check if the tree block can be shared by multiple trees
257 int btrfs_block_can_be_shared(struct btrfs_root *root,
258 struct extent_buffer *buf)
261 * Tree blocks not in refernece counted trees and tree roots
262 * are never shared. If a block was allocated after the last
263 * snapshot and the block was not allocated by tree relocation,
264 * we know the block is not shared.
266 if (root->ref_cows &&
267 buf != root->node && buf != root->commit_root &&
268 (btrfs_header_generation(buf) <=
269 btrfs_root_last_snapshot(&root->root_item) ||
270 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
272 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
273 if (root->ref_cows &&
274 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
280 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
281 struct btrfs_root *root,
282 struct extent_buffer *buf,
283 struct extent_buffer *cow,
293 * Backrefs update rules:
295 * Always use full backrefs for extent pointers in tree block
296 * allocated by tree relocation.
298 * If a shared tree block is no longer referenced by its owner
299 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
300 * use full backrefs for extent pointers in tree block.
302 * If a tree block is been relocating
303 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
304 * use full backrefs for extent pointers in tree block.
305 * The reason for this is some operations (such as drop tree)
306 * are only allowed for blocks use full backrefs.
309 if (btrfs_block_can_be_shared(root, buf)) {
310 ret = btrfs_lookup_extent_info(trans, root, buf->start,
311 buf->len, &refs, &flags);
316 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
317 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
318 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
323 owner = btrfs_header_owner(buf);
324 BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID &&
325 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
328 if ((owner == root->root_key.objectid ||
329 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
330 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
331 ret = btrfs_inc_ref(trans, root, buf, 1);
334 if (root->root_key.objectid ==
335 BTRFS_TREE_RELOC_OBJECTID) {
336 ret = btrfs_dec_ref(trans, root, buf, 0);
338 ret = btrfs_inc_ref(trans, root, cow, 1);
341 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
344 if (root->root_key.objectid ==
345 BTRFS_TREE_RELOC_OBJECTID)
346 ret = btrfs_inc_ref(trans, root, cow, 1);
348 ret = btrfs_inc_ref(trans, root, cow, 0);
351 if (new_flags != 0) {
352 ret = btrfs_set_disk_extent_flags(trans, root,
359 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
360 if (root->root_key.objectid ==
361 BTRFS_TREE_RELOC_OBJECTID)
362 ret = btrfs_inc_ref(trans, root, cow, 1);
364 ret = btrfs_inc_ref(trans, root, cow, 0);
366 ret = btrfs_dec_ref(trans, root, buf, 1);
369 clean_tree_block(trans, root, buf);
376 * does the dirty work in cow of a single block. The parent block (if
377 * supplied) is updated to point to the new cow copy. The new buffer is marked
378 * dirty and returned locked. If you modify the block it needs to be marked
381 * search_start -- an allocation hint for the new block
383 * empty_size -- a hint that you plan on doing more cow. This is the size in
384 * bytes the allocator should try to find free next to the block it returns.
385 * This is just a hint and may be ignored by the allocator.
387 static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
388 struct btrfs_root *root,
389 struct extent_buffer *buf,
390 struct extent_buffer *parent, int parent_slot,
391 struct extent_buffer **cow_ret,
392 u64 search_start, u64 empty_size)
394 struct btrfs_disk_key disk_key;
395 struct extent_buffer *cow;
404 btrfs_assert_tree_locked(buf);
406 WARN_ON(root->ref_cows && trans->transid !=
407 root->fs_info->running_transaction->transid);
408 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
410 level = btrfs_header_level(buf);
413 btrfs_item_key(buf, &disk_key, 0);
415 btrfs_node_key(buf, &disk_key, 0);
417 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
419 parent_start = parent->start;
425 cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
426 root->root_key.objectid, &disk_key,
427 level, search_start, empty_size);
431 /* cow is set to blocking by btrfs_init_new_buffer */
433 copy_extent_buffer(cow, buf, 0, 0, cow->len);
434 btrfs_set_header_bytenr(cow, cow->start);
435 btrfs_set_header_generation(cow, trans->transid);
436 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
437 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
438 BTRFS_HEADER_FLAG_RELOC);
439 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
440 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
442 btrfs_set_header_owner(cow, root->root_key.objectid);
444 write_extent_buffer(cow, root->fs_info->fsid,
445 (unsigned long)btrfs_header_fsid(cow),
448 update_ref_for_cow(trans, root, buf, cow, &last_ref);
451 btrfs_reloc_cow_block(trans, root, buf, cow);
453 if (buf == root->node) {
454 WARN_ON(parent && parent != buf);
455 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
456 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
457 parent_start = buf->start;
461 spin_lock(&root->node_lock);
463 extent_buffer_get(cow);
464 spin_unlock(&root->node_lock);
466 btrfs_free_tree_block(trans, root, buf, parent_start,
468 free_extent_buffer(buf);
469 add_root_to_dirty_list(root);
471 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
472 parent_start = parent->start;
476 WARN_ON(trans->transid != btrfs_header_generation(parent));
477 btrfs_set_node_blockptr(parent, parent_slot,
479 btrfs_set_node_ptr_generation(parent, parent_slot,
481 btrfs_mark_buffer_dirty(parent);
482 btrfs_free_tree_block(trans, root, buf, parent_start,
486 btrfs_tree_unlock(buf);
487 free_extent_buffer(buf);
488 btrfs_mark_buffer_dirty(cow);
493 static inline int should_cow_block(struct btrfs_trans_handle *trans,
494 struct btrfs_root *root,
495 struct extent_buffer *buf)
497 if (btrfs_header_generation(buf) == trans->transid &&
498 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
499 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
500 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
506 * cows a single block, see __btrfs_cow_block for the real work.
507 * This version of it has extra checks so that a block isn't cow'd more than
508 * once per transaction, as long as it hasn't been written yet
510 noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
511 struct btrfs_root *root, struct extent_buffer *buf,
512 struct extent_buffer *parent, int parent_slot,
513 struct extent_buffer **cow_ret)
518 if (trans->transaction != root->fs_info->running_transaction) {
519 printk(KERN_CRIT "trans %llu running %llu\n",
520 (unsigned long long)trans->transid,
522 root->fs_info->running_transaction->transid);
525 if (trans->transid != root->fs_info->generation) {
526 printk(KERN_CRIT "trans %llu running %llu\n",
527 (unsigned long long)trans->transid,
528 (unsigned long long)root->fs_info->generation);
532 if (!should_cow_block(trans, root, buf)) {
537 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
540 btrfs_set_lock_blocking(parent);
541 btrfs_set_lock_blocking(buf);
543 ret = __btrfs_cow_block(trans, root, buf, parent,
544 parent_slot, cow_ret, search_start, 0);
549 * helper function for defrag to decide if two blocks pointed to by a
550 * node are actually close by
552 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
554 if (blocknr < other && other - (blocknr + blocksize) < 32768)
556 if (blocknr > other && blocknr - (other + blocksize) < 32768)
562 * compare two keys in a memcmp fashion
564 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
568 btrfs_disk_key_to_cpu(&k1, disk);
570 return btrfs_comp_cpu_keys(&k1, k2);
574 * same as comp_keys only with two btrfs_key's
576 int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
578 if (k1->objectid > k2->objectid)
580 if (k1->objectid < k2->objectid)
582 if (k1->type > k2->type)
584 if (k1->type < k2->type)
586 if (k1->offset > k2->offset)
588 if (k1->offset < k2->offset)
594 * this is used by the defrag code to go through all the
595 * leaves pointed to by a node and reallocate them so that
596 * disk order is close to key order
598 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
599 struct btrfs_root *root, struct extent_buffer *parent,
600 int start_slot, int cache_only, u64 *last_ret,
601 struct btrfs_key *progress)
603 struct extent_buffer *cur;
606 u64 search_start = *last_ret;
616 int progress_passed = 0;
617 struct btrfs_disk_key disk_key;
619 parent_level = btrfs_header_level(parent);
620 if (cache_only && parent_level != 1)
623 if (trans->transaction != root->fs_info->running_transaction)
625 if (trans->transid != root->fs_info->generation)
628 parent_nritems = btrfs_header_nritems(parent);
629 blocksize = btrfs_level_size(root, parent_level - 1);
630 end_slot = parent_nritems;
632 if (parent_nritems == 1)
635 btrfs_set_lock_blocking(parent);
637 for (i = start_slot; i < end_slot; i++) {
640 if (!parent->map_token) {
641 map_extent_buffer(parent,
642 btrfs_node_key_ptr_offset(i),
643 sizeof(struct btrfs_key_ptr),
644 &parent->map_token, &parent->kaddr,
645 &parent->map_start, &parent->map_len,
648 btrfs_node_key(parent, &disk_key, i);
649 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
653 blocknr = btrfs_node_blockptr(parent, i);
654 gen = btrfs_node_ptr_generation(parent, i);
656 last_block = blocknr;
659 other = btrfs_node_blockptr(parent, i - 1);
660 close = close_blocks(blocknr, other, blocksize);
662 if (!close && i < end_slot - 2) {
663 other = btrfs_node_blockptr(parent, i + 1);
664 close = close_blocks(blocknr, other, blocksize);
667 last_block = blocknr;
670 if (parent->map_token) {
671 unmap_extent_buffer(parent, parent->map_token,
673 parent->map_token = NULL;
676 cur = btrfs_find_tree_block(root, blocknr, blocksize);
678 uptodate = btrfs_buffer_uptodate(cur, gen);
681 if (!cur || !uptodate) {
683 free_extent_buffer(cur);
687 cur = read_tree_block(root, blocknr,
689 } else if (!uptodate) {
690 btrfs_read_buffer(cur, gen);
693 if (search_start == 0)
694 search_start = last_block;
696 btrfs_tree_lock(cur);
697 btrfs_set_lock_blocking(cur);
698 err = __btrfs_cow_block(trans, root, cur, parent, i,
701 (end_slot - i) * blocksize));
703 btrfs_tree_unlock(cur);
704 free_extent_buffer(cur);
707 search_start = cur->start;
708 last_block = cur->start;
709 *last_ret = search_start;
710 btrfs_tree_unlock(cur);
711 free_extent_buffer(cur);
713 if (parent->map_token) {
714 unmap_extent_buffer(parent, parent->map_token,
716 parent->map_token = NULL;
722 * The leaf data grows from end-to-front in the node.
723 * this returns the address of the start of the last item,
724 * which is the stop of the leaf data stack
726 static inline unsigned int leaf_data_end(struct btrfs_root *root,
727 struct extent_buffer *leaf)
729 u32 nr = btrfs_header_nritems(leaf);
731 return BTRFS_LEAF_DATA_SIZE(root);
732 return btrfs_item_offset_nr(leaf, nr - 1);
736 * extra debugging checks to make sure all the items in a key are
737 * well formed and in the proper order
739 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
742 struct extent_buffer *parent = NULL;
743 struct extent_buffer *node = path->nodes[level];
744 struct btrfs_disk_key parent_key;
745 struct btrfs_disk_key node_key;
748 struct btrfs_key cpukey;
749 u32 nritems = btrfs_header_nritems(node);
751 if (path->nodes[level + 1])
752 parent = path->nodes[level + 1];
754 slot = path->slots[level];
755 BUG_ON(nritems == 0);
757 parent_slot = path->slots[level + 1];
758 btrfs_node_key(parent, &parent_key, parent_slot);
759 btrfs_node_key(node, &node_key, 0);
760 BUG_ON(memcmp(&parent_key, &node_key,
761 sizeof(struct btrfs_disk_key)));
762 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
763 btrfs_header_bytenr(node));
765 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
767 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
768 btrfs_node_key(node, &node_key, slot);
769 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
771 if (slot < nritems - 1) {
772 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
773 btrfs_node_key(node, &node_key, slot);
774 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
780 * extra checking to make sure all the items in a leaf are
781 * well formed and in the proper order
783 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
786 struct extent_buffer *leaf = path->nodes[level];
787 struct extent_buffer *parent = NULL;
789 struct btrfs_key cpukey;
790 struct btrfs_disk_key parent_key;
791 struct btrfs_disk_key leaf_key;
792 int slot = path->slots[0];
794 u32 nritems = btrfs_header_nritems(leaf);
796 if (path->nodes[level + 1])
797 parent = path->nodes[level + 1];
803 parent_slot = path->slots[level + 1];
804 btrfs_node_key(parent, &parent_key, parent_slot);
805 btrfs_item_key(leaf, &leaf_key, 0);
807 BUG_ON(memcmp(&parent_key, &leaf_key,
808 sizeof(struct btrfs_disk_key)));
809 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
810 btrfs_header_bytenr(leaf));
812 if (slot != 0 && slot < nritems - 1) {
813 btrfs_item_key(leaf, &leaf_key, slot);
814 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
815 if (comp_keys(&leaf_key, &cpukey) <= 0) {
816 btrfs_print_leaf(root, leaf);
817 printk(KERN_CRIT "slot %d offset bad key\n", slot);
820 if (btrfs_item_offset_nr(leaf, slot - 1) !=
821 btrfs_item_end_nr(leaf, slot)) {
822 btrfs_print_leaf(root, leaf);
823 printk(KERN_CRIT "slot %d offset bad\n", slot);
827 if (slot < nritems - 1) {
828 btrfs_item_key(leaf, &leaf_key, slot);
829 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
830 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
831 if (btrfs_item_offset_nr(leaf, slot) !=
832 btrfs_item_end_nr(leaf, slot + 1)) {
833 btrfs_print_leaf(root, leaf);
834 printk(KERN_CRIT "slot %d offset bad\n", slot);
838 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
839 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
843 static noinline int check_block(struct btrfs_root *root,
844 struct btrfs_path *path, int level)
848 return check_leaf(root, path, level);
849 return check_node(root, path, level);
853 * search for key in the extent_buffer. The items start at offset p,
854 * and they are item_size apart. There are 'max' items in p.
856 * the slot in the array is returned via slot, and it points to
857 * the place where you would insert key if it is not found in
860 * slot may point to max if the key is bigger than all of the keys
862 static noinline int generic_bin_search(struct extent_buffer *eb,
864 int item_size, struct btrfs_key *key,
871 struct btrfs_disk_key *tmp = NULL;
872 struct btrfs_disk_key unaligned;
873 unsigned long offset;
874 char *map_token = NULL;
876 unsigned long map_start = 0;
877 unsigned long map_len = 0;
881 mid = (low + high) / 2;
882 offset = p + mid * item_size;
884 if (!map_token || offset < map_start ||
885 (offset + sizeof(struct btrfs_disk_key)) >
886 map_start + map_len) {
888 unmap_extent_buffer(eb, map_token, KM_USER0);
892 err = map_private_extent_buffer(eb, offset,
893 sizeof(struct btrfs_disk_key),
895 &map_start, &map_len, KM_USER0);
898 tmp = (struct btrfs_disk_key *)(kaddr + offset -
901 read_extent_buffer(eb, &unaligned,
902 offset, sizeof(unaligned));
907 tmp = (struct btrfs_disk_key *)(kaddr + offset -
910 ret = comp_keys(tmp, key);
919 unmap_extent_buffer(eb, map_token, KM_USER0);
925 unmap_extent_buffer(eb, map_token, KM_USER0);
930 * simple bin_search frontend that does the right thing for
933 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
934 int level, int *slot)
937 return generic_bin_search(eb,
938 offsetof(struct btrfs_leaf, items),
939 sizeof(struct btrfs_item),
940 key, btrfs_header_nritems(eb),
943 return generic_bin_search(eb,
944 offsetof(struct btrfs_node, ptrs),
945 sizeof(struct btrfs_key_ptr),
946 key, btrfs_header_nritems(eb),
952 int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
953 int level, int *slot)
955 return bin_search(eb, key, level, slot);
958 static void root_add_used(struct btrfs_root *root, u32 size)
960 spin_lock(&root->accounting_lock);
961 btrfs_set_root_used(&root->root_item,
962 btrfs_root_used(&root->root_item) + size);
963 spin_unlock(&root->accounting_lock);
966 static void root_sub_used(struct btrfs_root *root, u32 size)
968 spin_lock(&root->accounting_lock);
969 btrfs_set_root_used(&root->root_item,
970 btrfs_root_used(&root->root_item) - size);
971 spin_unlock(&root->accounting_lock);
974 /* given a node and slot number, this reads the blocks it points to. The
975 * extent buffer is returned with a reference taken (but unlocked).
976 * NULL is returned on error.
978 static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
979 struct extent_buffer *parent, int slot)
981 int level = btrfs_header_level(parent);
984 if (slot >= btrfs_header_nritems(parent))
989 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
990 btrfs_level_size(root, level - 1),
991 btrfs_node_ptr_generation(parent, slot));
995 * node level balancing, used to make sure nodes are in proper order for
996 * item deletion. We balance from the top down, so we have to make sure
997 * that a deletion won't leave an node completely empty later on.
999 static noinline int balance_level(struct btrfs_trans_handle *trans,
1000 struct btrfs_root *root,
1001 struct btrfs_path *path, int level)
1003 struct extent_buffer *right = NULL;
1004 struct extent_buffer *mid;
1005 struct extent_buffer *left = NULL;
1006 struct extent_buffer *parent = NULL;
1010 int orig_slot = path->slots[level];
1011 int err_on_enospc = 0;
1017 mid = path->nodes[level];
1019 WARN_ON(!path->locks[level]);
1020 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1022 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1024 if (level < BTRFS_MAX_LEVEL - 1)
1025 parent = path->nodes[level + 1];
1026 pslot = path->slots[level + 1];
1029 * deal with the case where there is only one pointer in the root
1030 * by promoting the node below to a root
1033 struct extent_buffer *child;
1035 if (btrfs_header_nritems(mid) != 1)
1038 /* promote the child to a root */
1039 child = read_node_slot(root, mid, 0);
1041 btrfs_tree_lock(child);
1042 btrfs_set_lock_blocking(child);
1043 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
1045 btrfs_tree_unlock(child);
1046 free_extent_buffer(child);
1050 spin_lock(&root->node_lock);
1052 spin_unlock(&root->node_lock);
1054 add_root_to_dirty_list(root);
1055 btrfs_tree_unlock(child);
1057 path->locks[level] = 0;
1058 path->nodes[level] = NULL;
1059 clean_tree_block(trans, root, mid);
1060 btrfs_tree_unlock(mid);
1061 /* once for the path */
1062 free_extent_buffer(mid);
1064 root_sub_used(root, mid->len);
1065 btrfs_free_tree_block(trans, root, mid, 0, 1);
1066 /* once for the root ptr */
1067 free_extent_buffer(mid);
1070 if (btrfs_header_nritems(mid) >
1071 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
1074 if (btrfs_header_nritems(mid) < 2)
1077 left = read_node_slot(root, parent, pslot - 1);
1079 btrfs_tree_lock(left);
1080 btrfs_set_lock_blocking(left);
1081 wret = btrfs_cow_block(trans, root, left,
1082 parent, pslot - 1, &left);
1088 right = read_node_slot(root, parent, pslot + 1);
1090 btrfs_tree_lock(right);
1091 btrfs_set_lock_blocking(right);
1092 wret = btrfs_cow_block(trans, root, right,
1093 parent, pslot + 1, &right);
1100 /* first, try to make some room in the middle buffer */
1102 orig_slot += btrfs_header_nritems(left);
1103 wret = push_node_left(trans, root, left, mid, 1);
1106 if (btrfs_header_nritems(mid) < 2)
1111 * then try to empty the right most buffer into the middle
1114 wret = push_node_left(trans, root, mid, right, 1);
1115 if (wret < 0 && wret != -ENOSPC)
1117 if (btrfs_header_nritems(right) == 0) {
1118 clean_tree_block(trans, root, right);
1119 btrfs_tree_unlock(right);
1120 wret = del_ptr(trans, root, path, level + 1, pslot +
1124 root_sub_used(root, right->len);
1125 btrfs_free_tree_block(trans, root, right, 0, 1);
1126 free_extent_buffer(right);
1129 struct btrfs_disk_key right_key;
1130 btrfs_node_key(right, &right_key, 0);
1131 btrfs_set_node_key(parent, &right_key, pslot + 1);
1132 btrfs_mark_buffer_dirty(parent);
1135 if (btrfs_header_nritems(mid) == 1) {
1137 * we're not allowed to leave a node with one item in the
1138 * tree during a delete. A deletion from lower in the tree
1139 * could try to delete the only pointer in this node.
1140 * So, pull some keys from the left.
1141 * There has to be a left pointer at this point because
1142 * otherwise we would have pulled some pointers from the
1146 wret = balance_node_right(trans, root, mid, left);
1152 wret = push_node_left(trans, root, left, mid, 1);
1158 if (btrfs_header_nritems(mid) == 0) {
1159 clean_tree_block(trans, root, mid);
1160 btrfs_tree_unlock(mid);
1161 wret = del_ptr(trans, root, path, level + 1, pslot);
1164 root_sub_used(root, mid->len);
1165 btrfs_free_tree_block(trans, root, mid, 0, 1);
1166 free_extent_buffer(mid);
1169 /* update the parent key to reflect our changes */
1170 struct btrfs_disk_key mid_key;
1171 btrfs_node_key(mid, &mid_key, 0);
1172 btrfs_set_node_key(parent, &mid_key, pslot);
1173 btrfs_mark_buffer_dirty(parent);
1176 /* update the path */
1178 if (btrfs_header_nritems(left) > orig_slot) {
1179 extent_buffer_get(left);
1180 /* left was locked after cow */
1181 path->nodes[level] = left;
1182 path->slots[level + 1] -= 1;
1183 path->slots[level] = orig_slot;
1185 btrfs_tree_unlock(mid);
1186 free_extent_buffer(mid);
1189 orig_slot -= btrfs_header_nritems(left);
1190 path->slots[level] = orig_slot;
1193 /* double check we haven't messed things up */
1194 check_block(root, path, level);
1196 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
1200 btrfs_tree_unlock(right);
1201 free_extent_buffer(right);
1204 if (path->nodes[level] != left)
1205 btrfs_tree_unlock(left);
1206 free_extent_buffer(left);
1211 /* Node balancing for insertion. Here we only split or push nodes around
1212 * when they are completely full. This is also done top down, so we
1213 * have to be pessimistic.
1215 static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
1216 struct btrfs_root *root,
1217 struct btrfs_path *path, int level)
1219 struct extent_buffer *right = NULL;
1220 struct extent_buffer *mid;
1221 struct extent_buffer *left = NULL;
1222 struct extent_buffer *parent = NULL;
1226 int orig_slot = path->slots[level];
1232 mid = path->nodes[level];
1233 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1234 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1236 if (level < BTRFS_MAX_LEVEL - 1)
1237 parent = path->nodes[level + 1];
1238 pslot = path->slots[level + 1];
1243 left = read_node_slot(root, parent, pslot - 1);
1245 /* first, try to make some room in the middle buffer */
1249 btrfs_tree_lock(left);
1250 btrfs_set_lock_blocking(left);
1252 left_nr = btrfs_header_nritems(left);
1253 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1256 ret = btrfs_cow_block(trans, root, left, parent,
1261 wret = push_node_left(trans, root,
1268 struct btrfs_disk_key disk_key;
1269 orig_slot += left_nr;
1270 btrfs_node_key(mid, &disk_key, 0);
1271 btrfs_set_node_key(parent, &disk_key, pslot);
1272 btrfs_mark_buffer_dirty(parent);
1273 if (btrfs_header_nritems(left) > orig_slot) {
1274 path->nodes[level] = left;
1275 path->slots[level + 1] -= 1;
1276 path->slots[level] = orig_slot;
1277 btrfs_tree_unlock(mid);
1278 free_extent_buffer(mid);
1281 btrfs_header_nritems(left);
1282 path->slots[level] = orig_slot;
1283 btrfs_tree_unlock(left);
1284 free_extent_buffer(left);
1288 btrfs_tree_unlock(left);
1289 free_extent_buffer(left);
1291 right = read_node_slot(root, parent, pslot + 1);
1294 * then try to empty the right most buffer into the middle
1299 btrfs_tree_lock(right);
1300 btrfs_set_lock_blocking(right);
1302 right_nr = btrfs_header_nritems(right);
1303 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1306 ret = btrfs_cow_block(trans, root, right,
1312 wret = balance_node_right(trans, root,
1319 struct btrfs_disk_key disk_key;
1321 btrfs_node_key(right, &disk_key, 0);
1322 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1323 btrfs_mark_buffer_dirty(parent);
1325 if (btrfs_header_nritems(mid) <= orig_slot) {
1326 path->nodes[level] = right;
1327 path->slots[level + 1] += 1;
1328 path->slots[level] = orig_slot -
1329 btrfs_header_nritems(mid);
1330 btrfs_tree_unlock(mid);
1331 free_extent_buffer(mid);
1333 btrfs_tree_unlock(right);
1334 free_extent_buffer(right);
1338 btrfs_tree_unlock(right);
1339 free_extent_buffer(right);
1345 * readahead one full node of leaves, finding things that are close
1346 * to the block in 'slot', and triggering ra on them.
1348 static void reada_for_search(struct btrfs_root *root,
1349 struct btrfs_path *path,
1350 int level, int slot, u64 objectid)
1352 struct extent_buffer *node;
1353 struct btrfs_disk_key disk_key;
1358 int direction = path->reada;
1359 struct extent_buffer *eb;
1367 if (!path->nodes[level])
1370 node = path->nodes[level];
1372 search = btrfs_node_blockptr(node, slot);
1373 blocksize = btrfs_level_size(root, level - 1);
1374 eb = btrfs_find_tree_block(root, search, blocksize);
1376 free_extent_buffer(eb);
1382 nritems = btrfs_header_nritems(node);
1385 if (direction < 0) {
1389 } else if (direction > 0) {
1394 if (path->reada < 0 && objectid) {
1395 btrfs_node_key(node, &disk_key, nr);
1396 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1399 search = btrfs_node_blockptr(node, nr);
1400 if ((search <= target && target - search <= 65536) ||
1401 (search > target && search - target <= 65536)) {
1402 readahead_tree_block(root, search, blocksize,
1403 btrfs_node_ptr_generation(node, nr));
1407 if ((nread > 65536 || nscan > 32))
1413 * returns -EAGAIN if it had to drop the path, or zero if everything was in
1416 static noinline int reada_for_balance(struct btrfs_root *root,
1417 struct btrfs_path *path, int level)
1421 struct extent_buffer *parent;
1422 struct extent_buffer *eb;
1429 parent = path->nodes[level + 1];
1433 nritems = btrfs_header_nritems(parent);
1434 slot = path->slots[level + 1];
1435 blocksize = btrfs_level_size(root, level);
1438 block1 = btrfs_node_blockptr(parent, slot - 1);
1439 gen = btrfs_node_ptr_generation(parent, slot - 1);
1440 eb = btrfs_find_tree_block(root, block1, blocksize);
1441 if (eb && btrfs_buffer_uptodate(eb, gen))
1443 free_extent_buffer(eb);
1445 if (slot + 1 < nritems) {
1446 block2 = btrfs_node_blockptr(parent, slot + 1);
1447 gen = btrfs_node_ptr_generation(parent, slot + 1);
1448 eb = btrfs_find_tree_block(root, block2, blocksize);
1449 if (eb && btrfs_buffer_uptodate(eb, gen))
1451 free_extent_buffer(eb);
1453 if (block1 || block2) {
1456 /* release the whole path */
1457 btrfs_release_path(root, path);
1459 /* read the blocks */
1461 readahead_tree_block(root, block1, blocksize, 0);
1463 readahead_tree_block(root, block2, blocksize, 0);
1466 eb = read_tree_block(root, block1, blocksize, 0);
1467 free_extent_buffer(eb);
1470 eb = read_tree_block(root, block2, blocksize, 0);
1471 free_extent_buffer(eb);
1479 * when we walk down the tree, it is usually safe to unlock the higher layers
1480 * in the tree. The exceptions are when our path goes through slot 0, because
1481 * operations on the tree might require changing key pointers higher up in the
1484 * callers might also have set path->keep_locks, which tells this code to keep
1485 * the lock if the path points to the last slot in the block. This is part of
1486 * walking through the tree, and selecting the next slot in the higher block.
1488 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
1489 * if lowest_unlock is 1, level 0 won't be unlocked
1491 static noinline void unlock_up(struct btrfs_path *path, int level,
1495 int skip_level = level;
1497 struct extent_buffer *t;
1499 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1500 if (!path->nodes[i])
1502 if (!path->locks[i])
1504 if (!no_skips && path->slots[i] == 0) {
1508 if (!no_skips && path->keep_locks) {
1511 nritems = btrfs_header_nritems(t);
1512 if (nritems < 1 || path->slots[i] >= nritems - 1) {
1517 if (skip_level < i && i >= lowest_unlock)
1521 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1522 btrfs_tree_unlock(t);
1529 * This releases any locks held in the path starting at level and
1530 * going all the way up to the root.
1532 * btrfs_search_slot will keep the lock held on higher nodes in a few
1533 * corner cases, such as COW of the block at slot zero in the node. This
1534 * ignores those rules, and it should only be called when there are no
1535 * more updates to be done higher up in the tree.
1537 noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
1541 if (path->keep_locks)
1544 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1545 if (!path->nodes[i])
1547 if (!path->locks[i])
1549 btrfs_tree_unlock(path->nodes[i]);
1555 * helper function for btrfs_search_slot. The goal is to find a block
1556 * in cache without setting the path to blocking. If we find the block
1557 * we return zero and the path is unchanged.
1559 * If we can't find the block, we set the path blocking and do some
1560 * reada. -EAGAIN is returned and the search must be repeated.
1563 read_block_for_search(struct btrfs_trans_handle *trans,
1564 struct btrfs_root *root, struct btrfs_path *p,
1565 struct extent_buffer **eb_ret, int level, int slot,
1566 struct btrfs_key *key)
1571 struct extent_buffer *b = *eb_ret;
1572 struct extent_buffer *tmp;
1575 blocknr = btrfs_node_blockptr(b, slot);
1576 gen = btrfs_node_ptr_generation(b, slot);
1577 blocksize = btrfs_level_size(root, level - 1);
1579 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1581 if (btrfs_buffer_uptodate(tmp, 0)) {
1582 if (btrfs_buffer_uptodate(tmp, gen)) {
1584 * we found an up to date block without
1591 /* the pages were up to date, but we failed
1592 * the generation number check. Do a full
1593 * read for the generation number that is correct.
1594 * We must do this without dropping locks so
1595 * we can trust our generation number
1597 free_extent_buffer(tmp);
1598 tmp = read_tree_block(root, blocknr, blocksize, gen);
1599 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
1603 free_extent_buffer(tmp);
1604 btrfs_release_path(NULL, p);
1610 * reduce lock contention at high levels
1611 * of the btree by dropping locks before
1612 * we read. Don't release the lock on the current
1613 * level because we need to walk this node to figure
1614 * out which blocks to read.
1616 btrfs_unlock_up_safe(p, level + 1);
1617 btrfs_set_path_blocking(p);
1619 free_extent_buffer(tmp);
1621 reada_for_search(root, p, level, slot, key->objectid);
1623 btrfs_release_path(NULL, p);
1626 tmp = read_tree_block(root, blocknr, blocksize, 0);
1629 * If the read above didn't mark this buffer up to date,
1630 * it will never end up being up to date. Set ret to EIO now
1631 * and give up so that our caller doesn't loop forever
1634 if (!btrfs_buffer_uptodate(tmp, 0))
1636 free_extent_buffer(tmp);
1642 * helper function for btrfs_search_slot. This does all of the checks
1643 * for node-level blocks and does any balancing required based on
1646 * If no extra work was required, zero is returned. If we had to
1647 * drop the path, -EAGAIN is returned and btrfs_search_slot must
1651 setup_nodes_for_search(struct btrfs_trans_handle *trans,
1652 struct btrfs_root *root, struct btrfs_path *p,
1653 struct extent_buffer *b, int level, int ins_len)
1656 if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
1657 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1660 sret = reada_for_balance(root, p, level);
1664 btrfs_set_path_blocking(p);
1665 sret = split_node(trans, root, p, level);
1666 btrfs_clear_path_blocking(p, NULL);
1673 b = p->nodes[level];
1674 } else if (ins_len < 0 && btrfs_header_nritems(b) <
1675 BTRFS_NODEPTRS_PER_BLOCK(root) / 2) {
1678 sret = reada_for_balance(root, p, level);
1682 btrfs_set_path_blocking(p);
1683 sret = balance_level(trans, root, p, level);
1684 btrfs_clear_path_blocking(p, NULL);
1690 b = p->nodes[level];
1692 btrfs_release_path(NULL, p);
1695 BUG_ON(btrfs_header_nritems(b) == 1);
1706 * look for key in the tree. path is filled in with nodes along the way
1707 * if key is found, we return zero and you can find the item in the leaf
1708 * level of the path (level 0)
1710 * If the key isn't found, the path points to the slot where it should
1711 * be inserted, and 1 is returned. If there are other errors during the
1712 * search a negative error number is returned.
1714 * if ins_len > 0, nodes and leaves will be split as we walk down the
1715 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1718 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1719 *root, struct btrfs_key *key, struct btrfs_path *p, int
1722 struct extent_buffer *b;
1727 int lowest_unlock = 1;
1728 u8 lowest_level = 0;
1730 lowest_level = p->lowest_level;
1731 WARN_ON(lowest_level && ins_len > 0);
1732 WARN_ON(p->nodes[0] != NULL);
1738 if (p->search_commit_root) {
1739 b = root->commit_root;
1740 extent_buffer_get(b);
1741 if (!p->skip_locking)
1744 if (p->skip_locking)
1745 b = btrfs_root_node(root);
1747 b = btrfs_lock_root_node(root);
1751 level = btrfs_header_level(b);
1754 * setup the path here so we can release it under lock
1755 * contention with the cow code
1757 p->nodes[level] = b;
1758 if (!p->skip_locking)
1759 p->locks[level] = 1;
1763 * if we don't really need to cow this block
1764 * then we don't want to set the path blocking,
1765 * so we test it here
1767 if (!should_cow_block(trans, root, b))
1770 btrfs_set_path_blocking(p);
1772 err = btrfs_cow_block(trans, root, b,
1773 p->nodes[level + 1],
1774 p->slots[level + 1], &b);
1781 BUG_ON(!cow && ins_len);
1782 if (level != btrfs_header_level(b))
1784 level = btrfs_header_level(b);
1786 p->nodes[level] = b;
1787 if (!p->skip_locking)
1788 p->locks[level] = 1;
1790 btrfs_clear_path_blocking(p, NULL);
1793 * we have a lock on b and as long as we aren't changing
1794 * the tree, there is no way to for the items in b to change.
1795 * It is safe to drop the lock on our parent before we
1796 * go through the expensive btree search on b.
1798 * If cow is true, then we might be changing slot zero,
1799 * which may require changing the parent. So, we can't
1800 * drop the lock until after we know which slot we're
1804 btrfs_unlock_up_safe(p, level + 1);
1806 ret = check_block(root, p, level);
1812 ret = bin_search(b, key, level, &slot);
1816 if (ret && slot > 0) {
1820 p->slots[level] = slot;
1821 err = setup_nodes_for_search(trans, root, p, b, level,
1829 b = p->nodes[level];
1830 slot = p->slots[level];
1832 unlock_up(p, level, lowest_unlock);
1834 if (level == lowest_level) {
1840 err = read_block_for_search(trans, root, p,
1841 &b, level, slot, key);
1849 if (!p->skip_locking) {
1850 btrfs_clear_path_blocking(p, NULL);
1851 err = btrfs_try_spin_lock(b);
1854 btrfs_set_path_blocking(p);
1856 btrfs_clear_path_blocking(p, b);
1860 p->slots[level] = slot;
1862 btrfs_leaf_free_space(root, b) < ins_len) {
1863 btrfs_set_path_blocking(p);
1864 err = split_leaf(trans, root, key,
1865 p, ins_len, ret == 0);
1866 btrfs_clear_path_blocking(p, NULL);
1874 if (!p->search_for_split)
1875 unlock_up(p, level, lowest_unlock);
1882 * we don't really know what they plan on doing with the path
1883 * from here on, so for now just mark it as blocking
1885 if (!p->leave_spinning)
1886 btrfs_set_path_blocking(p);
1888 btrfs_release_path(root, p);
1893 * adjust the pointers going up the tree, starting at level
1894 * making sure the right key of each node is points to 'key'.
1895 * This is used after shifting pointers to the left, so it stops
1896 * fixing up pointers when a given leaf/node is not in slot 0 of the
1899 * If this fails to write a tree block, it returns -1, but continues
1900 * fixing up the blocks in ram so the tree is consistent.
1902 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1903 struct btrfs_root *root, struct btrfs_path *path,
1904 struct btrfs_disk_key *key, int level)
1908 struct extent_buffer *t;
1910 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1911 int tslot = path->slots[i];
1912 if (!path->nodes[i])
1915 btrfs_set_node_key(t, key, tslot);
1916 btrfs_mark_buffer_dirty(path->nodes[i]);
1926 * This function isn't completely safe. It's the caller's responsibility
1927 * that the new key won't break the order
1929 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1930 struct btrfs_root *root, struct btrfs_path *path,
1931 struct btrfs_key *new_key)
1933 struct btrfs_disk_key disk_key;
1934 struct extent_buffer *eb;
1937 eb = path->nodes[0];
1938 slot = path->slots[0];
1940 btrfs_item_key(eb, &disk_key, slot - 1);
1941 if (comp_keys(&disk_key, new_key) >= 0)
1944 if (slot < btrfs_header_nritems(eb) - 1) {
1945 btrfs_item_key(eb, &disk_key, slot + 1);
1946 if (comp_keys(&disk_key, new_key) <= 0)
1950 btrfs_cpu_key_to_disk(&disk_key, new_key);
1951 btrfs_set_item_key(eb, &disk_key, slot);
1952 btrfs_mark_buffer_dirty(eb);
1954 fixup_low_keys(trans, root, path, &disk_key, 1);
1959 * try to push data from one node into the next node left in the
1962 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1963 * error, and > 0 if there was no room in the left hand block.
1965 static int push_node_left(struct btrfs_trans_handle *trans,
1966 struct btrfs_root *root, struct extent_buffer *dst,
1967 struct extent_buffer *src, int empty)
1974 src_nritems = btrfs_header_nritems(src);
1975 dst_nritems = btrfs_header_nritems(dst);
1976 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1977 WARN_ON(btrfs_header_generation(src) != trans->transid);
1978 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1980 if (!empty && src_nritems <= 8)
1983 if (push_items <= 0)
1987 push_items = min(src_nritems, push_items);
1988 if (push_items < src_nritems) {
1989 /* leave at least 8 pointers in the node if
1990 * we aren't going to empty it
1992 if (src_nritems - push_items < 8) {
1993 if (push_items <= 8)
1999 push_items = min(src_nritems - 8, push_items);
2001 copy_extent_buffer(dst, src,
2002 btrfs_node_key_ptr_offset(dst_nritems),
2003 btrfs_node_key_ptr_offset(0),
2004 push_items * sizeof(struct btrfs_key_ptr));
2006 if (push_items < src_nritems) {
2007 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
2008 btrfs_node_key_ptr_offset(push_items),
2009 (src_nritems - push_items) *
2010 sizeof(struct btrfs_key_ptr));
2012 btrfs_set_header_nritems(src, src_nritems - push_items);
2013 btrfs_set_header_nritems(dst, dst_nritems + push_items);
2014 btrfs_mark_buffer_dirty(src);
2015 btrfs_mark_buffer_dirty(dst);
2021 * try to push data from one node into the next node right in the
2024 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
2025 * error, and > 0 if there was no room in the right hand block.
2027 * this will only push up to 1/2 the contents of the left node over
2029 static int balance_node_right(struct btrfs_trans_handle *trans,
2030 struct btrfs_root *root,
2031 struct extent_buffer *dst,
2032 struct extent_buffer *src)
2040 WARN_ON(btrfs_header_generation(src) != trans->transid);
2041 WARN_ON(btrfs_header_generation(dst) != trans->transid);
2043 src_nritems = btrfs_header_nritems(src);
2044 dst_nritems = btrfs_header_nritems(dst);
2045 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
2046 if (push_items <= 0)
2049 if (src_nritems < 4)
2052 max_push = src_nritems / 2 + 1;
2053 /* don't try to empty the node */
2054 if (max_push >= src_nritems)
2057 if (max_push < push_items)
2058 push_items = max_push;
2060 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
2061 btrfs_node_key_ptr_offset(0),
2063 sizeof(struct btrfs_key_ptr));
2065 copy_extent_buffer(dst, src,
2066 btrfs_node_key_ptr_offset(0),
2067 btrfs_node_key_ptr_offset(src_nritems - push_items),
2068 push_items * sizeof(struct btrfs_key_ptr));
2070 btrfs_set_header_nritems(src, src_nritems - push_items);
2071 btrfs_set_header_nritems(dst, dst_nritems + push_items);
2073 btrfs_mark_buffer_dirty(src);
2074 btrfs_mark_buffer_dirty(dst);
2080 * helper function to insert a new root level in the tree.
2081 * A new node is allocated, and a single item is inserted to
2082 * point to the existing root
2084 * returns zero on success or < 0 on failure.
2086 static noinline int insert_new_root(struct btrfs_trans_handle *trans,
2087 struct btrfs_root *root,
2088 struct btrfs_path *path, int level)
2091 struct extent_buffer *lower;
2092 struct extent_buffer *c;
2093 struct extent_buffer *old;
2094 struct btrfs_disk_key lower_key;
2096 BUG_ON(path->nodes[level]);
2097 BUG_ON(path->nodes[level-1] != root->node);
2099 lower = path->nodes[level-1];
2101 btrfs_item_key(lower, &lower_key, 0);
2103 btrfs_node_key(lower, &lower_key, 0);
2105 c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
2106 root->root_key.objectid, &lower_key,
2107 level, root->node->start, 0);
2111 root_add_used(root, root->nodesize);
2113 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
2114 btrfs_set_header_nritems(c, 1);
2115 btrfs_set_header_level(c, level);
2116 btrfs_set_header_bytenr(c, c->start);
2117 btrfs_set_header_generation(c, trans->transid);
2118 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
2119 btrfs_set_header_owner(c, root->root_key.objectid);
2121 write_extent_buffer(c, root->fs_info->fsid,
2122 (unsigned long)btrfs_header_fsid(c),
2125 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
2126 (unsigned long)btrfs_header_chunk_tree_uuid(c),
2129 btrfs_set_node_key(c, &lower_key, 0);
2130 btrfs_set_node_blockptr(c, 0, lower->start);
2131 lower_gen = btrfs_header_generation(lower);
2132 WARN_ON(lower_gen != trans->transid);
2134 btrfs_set_node_ptr_generation(c, 0, lower_gen);
2136 btrfs_mark_buffer_dirty(c);
2138 spin_lock(&root->node_lock);
2141 spin_unlock(&root->node_lock);
2143 /* the super has an extra ref to root->node */
2144 free_extent_buffer(old);
2146 add_root_to_dirty_list(root);
2147 extent_buffer_get(c);
2148 path->nodes[level] = c;
2149 path->locks[level] = 1;
2150 path->slots[level] = 0;
2155 * worker function to insert a single pointer in a node.
2156 * the node should have enough room for the pointer already
2158 * slot and level indicate where you want the key to go, and
2159 * blocknr is the block the key points to.
2161 * returns zero on success and < 0 on any error
2163 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
2164 *root, struct btrfs_path *path, struct btrfs_disk_key
2165 *key, u64 bytenr, int slot, int level)
2167 struct extent_buffer *lower;
2170 BUG_ON(!path->nodes[level]);
2171 btrfs_assert_tree_locked(path->nodes[level]);
2172 lower = path->nodes[level];
2173 nritems = btrfs_header_nritems(lower);
2174 BUG_ON(slot > nritems);
2175 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
2177 if (slot != nritems) {
2178 memmove_extent_buffer(lower,
2179 btrfs_node_key_ptr_offset(slot + 1),
2180 btrfs_node_key_ptr_offset(slot),
2181 (nritems - slot) * sizeof(struct btrfs_key_ptr));
2183 btrfs_set_node_key(lower, key, slot);
2184 btrfs_set_node_blockptr(lower, slot, bytenr);
2185 WARN_ON(trans->transid == 0);
2186 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
2187 btrfs_set_header_nritems(lower, nritems + 1);
2188 btrfs_mark_buffer_dirty(lower);
2193 * split the node at the specified level in path in two.
2194 * The path is corrected to point to the appropriate node after the split
2196 * Before splitting this tries to make some room in the node by pushing
2197 * left and right, if either one works, it returns right away.
2199 * returns 0 on success and < 0 on failure
2201 static noinline int split_node(struct btrfs_trans_handle *trans,
2202 struct btrfs_root *root,
2203 struct btrfs_path *path, int level)
2205 struct extent_buffer *c;
2206 struct extent_buffer *split;
2207 struct btrfs_disk_key disk_key;
2213 c = path->nodes[level];
2214 WARN_ON(btrfs_header_generation(c) != trans->transid);
2215 if (c == root->node) {
2216 /* trying to split the root, lets make a new one */
2217 ret = insert_new_root(trans, root, path, level + 1);
2221 ret = push_nodes_for_insert(trans, root, path, level);
2222 c = path->nodes[level];
2223 if (!ret && btrfs_header_nritems(c) <
2224 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
2230 c_nritems = btrfs_header_nritems(c);
2231 mid = (c_nritems + 1) / 2;
2232 btrfs_node_key(c, &disk_key, mid);
2234 split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
2235 root->root_key.objectid,
2236 &disk_key, level, c->start, 0);
2238 return PTR_ERR(split);
2240 root_add_used(root, root->nodesize);
2242 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
2243 btrfs_set_header_level(split, btrfs_header_level(c));
2244 btrfs_set_header_bytenr(split, split->start);
2245 btrfs_set_header_generation(split, trans->transid);
2246 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
2247 btrfs_set_header_owner(split, root->root_key.objectid);
2248 write_extent_buffer(split, root->fs_info->fsid,
2249 (unsigned long)btrfs_header_fsid(split),
2251 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
2252 (unsigned long)btrfs_header_chunk_tree_uuid(split),
2256 copy_extent_buffer(split, c,
2257 btrfs_node_key_ptr_offset(0),
2258 btrfs_node_key_ptr_offset(mid),
2259 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
2260 btrfs_set_header_nritems(split, c_nritems - mid);
2261 btrfs_set_header_nritems(c, mid);
2264 btrfs_mark_buffer_dirty(c);
2265 btrfs_mark_buffer_dirty(split);
2267 wret = insert_ptr(trans, root, path, &disk_key, split->start,
2268 path->slots[level + 1] + 1,
2273 if (path->slots[level] >= mid) {
2274 path->slots[level] -= mid;
2275 btrfs_tree_unlock(c);
2276 free_extent_buffer(c);
2277 path->nodes[level] = split;
2278 path->slots[level + 1] += 1;
2280 btrfs_tree_unlock(split);
2281 free_extent_buffer(split);
2287 * how many bytes are required to store the items in a leaf. start
2288 * and nr indicate which items in the leaf to check. This totals up the
2289 * space used both by the item structs and the item data
2291 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
2294 int nritems = btrfs_header_nritems(l);
2295 int end = min(nritems, start + nr) - 1;
2299 data_len = btrfs_item_end_nr(l, start);
2300 data_len = data_len - btrfs_item_offset_nr(l, end);
2301 data_len += sizeof(struct btrfs_item) * nr;
2302 WARN_ON(data_len < 0);
2307 * The space between the end of the leaf items and
2308 * the start of the leaf data. IOW, how much room
2309 * the leaf has left for both items and data
2311 noinline int btrfs_leaf_free_space(struct btrfs_root *root,
2312 struct extent_buffer *leaf)
2314 int nritems = btrfs_header_nritems(leaf);
2316 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
2318 printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, "
2319 "used %d nritems %d\n",
2320 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
2321 leaf_space_used(leaf, 0, nritems), nritems);
2327 * min slot controls the lowest index we're willing to push to the
2328 * right. We'll push up to and including min_slot, but no lower
2330 static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
2331 struct btrfs_root *root,
2332 struct btrfs_path *path,
2333 int data_size, int empty,
2334 struct extent_buffer *right,
2335 int free_space, u32 left_nritems,
2338 struct extent_buffer *left = path->nodes[0];
2339 struct extent_buffer *upper = path->nodes[1];
2340 struct btrfs_disk_key disk_key;
2345 struct btrfs_item *item;
2354 nr = max_t(u32, 1, min_slot);
2356 if (path->slots[0] >= left_nritems)
2357 push_space += data_size;
2359 slot = path->slots[1];
2360 i = left_nritems - 1;
2362 item = btrfs_item_nr(left, i);
2364 if (!empty && push_items > 0) {
2365 if (path->slots[0] > i)
2367 if (path->slots[0] == i) {
2368 int space = btrfs_leaf_free_space(root, left);
2369 if (space + push_space * 2 > free_space)
2374 if (path->slots[0] == i)
2375 push_space += data_size;
2377 if (!left->map_token) {
2378 map_extent_buffer(left, (unsigned long)item,
2379 sizeof(struct btrfs_item),
2380 &left->map_token, &left->kaddr,
2381 &left->map_start, &left->map_len,
2385 this_item_size = btrfs_item_size(left, item);
2386 if (this_item_size + sizeof(*item) + push_space > free_space)
2390 push_space += this_item_size + sizeof(*item);
2395 if (left->map_token) {
2396 unmap_extent_buffer(left, left->map_token, KM_USER1);
2397 left->map_token = NULL;
2400 if (push_items == 0)
2403 if (!empty && push_items == left_nritems)
2406 /* push left to right */
2407 right_nritems = btrfs_header_nritems(right);
2409 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
2410 push_space -= leaf_data_end(root, left);
2412 /* make room in the right data area */
2413 data_end = leaf_data_end(root, right);
2414 memmove_extent_buffer(right,
2415 btrfs_leaf_data(right) + data_end - push_space,
2416 btrfs_leaf_data(right) + data_end,
2417 BTRFS_LEAF_DATA_SIZE(root) - data_end);
2419 /* copy from the left data area */
2420 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
2421 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2422 btrfs_leaf_data(left) + leaf_data_end(root, left),
2425 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
2426 btrfs_item_nr_offset(0),
2427 right_nritems * sizeof(struct btrfs_item));
2429 /* copy the items from left to right */
2430 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
2431 btrfs_item_nr_offset(left_nritems - push_items),
2432 push_items * sizeof(struct btrfs_item));
2434 /* update the item pointers */
2435 right_nritems += push_items;
2436 btrfs_set_header_nritems(right, right_nritems);
2437 push_space = BTRFS_LEAF_DATA_SIZE(root);
2438 for (i = 0; i < right_nritems; i++) {
2439 item = btrfs_item_nr(right, i);
2440 if (!right->map_token) {
2441 map_extent_buffer(right, (unsigned long)item,
2442 sizeof(struct btrfs_item),
2443 &right->map_token, &right->kaddr,
2444 &right->map_start, &right->map_len,
2447 push_space -= btrfs_item_size(right, item);
2448 btrfs_set_item_offset(right, item, push_space);
2451 if (right->map_token) {
2452 unmap_extent_buffer(right, right->map_token, KM_USER1);
2453 right->map_token = NULL;
2455 left_nritems -= push_items;
2456 btrfs_set_header_nritems(left, left_nritems);
2459 btrfs_mark_buffer_dirty(left);
2461 clean_tree_block(trans, root, left);
2463 btrfs_mark_buffer_dirty(right);
2465 btrfs_item_key(right, &disk_key, 0);
2466 btrfs_set_node_key(upper, &disk_key, slot + 1);
2467 btrfs_mark_buffer_dirty(upper);
2469 /* then fixup the leaf pointer in the path */
2470 if (path->slots[0] >= left_nritems) {
2471 path->slots[0] -= left_nritems;
2472 if (btrfs_header_nritems(path->nodes[0]) == 0)
2473 clean_tree_block(trans, root, path->nodes[0]);
2474 btrfs_tree_unlock(path->nodes[0]);
2475 free_extent_buffer(path->nodes[0]);
2476 path->nodes[0] = right;
2477 path->slots[1] += 1;
2479 btrfs_tree_unlock(right);
2480 free_extent_buffer(right);
2485 btrfs_tree_unlock(right);
2486 free_extent_buffer(right);
2491 * push some data in the path leaf to the right, trying to free up at
2492 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2494 * returns 1 if the push failed because the other node didn't have enough
2495 * room, 0 if everything worked out and < 0 if there were major errors.
2497 * this will push starting from min_slot to the end of the leaf. It won't
2498 * push any slot lower than min_slot
2500 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
2501 *root, struct btrfs_path *path,
2502 int min_data_size, int data_size,
2503 int empty, u32 min_slot)
2505 struct extent_buffer *left = path->nodes[0];
2506 struct extent_buffer *right;
2507 struct extent_buffer *upper;
2513 if (!path->nodes[1])
2516 slot = path->slots[1];
2517 upper = path->nodes[1];
2518 if (slot >= btrfs_header_nritems(upper) - 1)
2521 btrfs_assert_tree_locked(path->nodes[1]);
2523 right = read_node_slot(root, upper, slot + 1);
2524 btrfs_tree_lock(right);
2525 btrfs_set_lock_blocking(right);
2527 free_space = btrfs_leaf_free_space(root, right);
2528 if (free_space < data_size)
2531 /* cow and double check */
2532 ret = btrfs_cow_block(trans, root, right, upper,
2537 free_space = btrfs_leaf_free_space(root, right);
2538 if (free_space < data_size)
2541 left_nritems = btrfs_header_nritems(left);
2542 if (left_nritems == 0)
2545 return __push_leaf_right(trans, root, path, min_data_size, empty,
2546 right, free_space, left_nritems, min_slot);
2548 btrfs_tree_unlock(right);
2549 free_extent_buffer(right);
2554 * push some data in the path leaf to the left, trying to free up at
2555 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2557 * max_slot can put a limit on how far into the leaf we'll push items. The
2558 * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
2561 static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
2562 struct btrfs_root *root,
2563 struct btrfs_path *path, int data_size,
2564 int empty, struct extent_buffer *left,
2565 int free_space, u32 right_nritems,
2568 struct btrfs_disk_key disk_key;
2569 struct extent_buffer *right = path->nodes[0];
2574 struct btrfs_item *item;
2575 u32 old_left_nritems;
2580 u32 old_left_item_size;
2582 slot = path->slots[1];
2585 nr = min(right_nritems, max_slot);
2587 nr = min(right_nritems - 1, max_slot);
2589 for (i = 0; i < nr; i++) {
2590 item = btrfs_item_nr(right, i);
2591 if (!right->map_token) {
2592 map_extent_buffer(right, (unsigned long)item,
2593 sizeof(struct btrfs_item),
2594 &right->map_token, &right->kaddr,
2595 &right->map_start, &right->map_len,
2599 if (!empty && push_items > 0) {
2600 if (path->slots[0] < i)
2602 if (path->slots[0] == i) {
2603 int space = btrfs_leaf_free_space(root, right);
2604 if (space + push_space * 2 > free_space)
2609 if (path->slots[0] == i)
2610 push_space += data_size;
2612 this_item_size = btrfs_item_size(right, item);
2613 if (this_item_size + sizeof(*item) + push_space > free_space)
2617 push_space += this_item_size + sizeof(*item);
2620 if (right->map_token) {
2621 unmap_extent_buffer(right, right->map_token, KM_USER1);
2622 right->map_token = NULL;
2625 if (push_items == 0) {
2629 if (!empty && push_items == btrfs_header_nritems(right))
2632 /* push data from right to left */
2633 copy_extent_buffer(left, right,
2634 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2635 btrfs_item_nr_offset(0),
2636 push_items * sizeof(struct btrfs_item));
2638 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2639 btrfs_item_offset_nr(right, push_items - 1);
2641 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2642 leaf_data_end(root, left) - push_space,
2643 btrfs_leaf_data(right) +
2644 btrfs_item_offset_nr(right, push_items - 1),
2646 old_left_nritems = btrfs_header_nritems(left);
2647 BUG_ON(old_left_nritems <= 0);
2649 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2650 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2653 item = btrfs_item_nr(left, i);
2654 if (!left->map_token) {
2655 map_extent_buffer(left, (unsigned long)item,
2656 sizeof(struct btrfs_item),
2657 &left->map_token, &left->kaddr,
2658 &left->map_start, &left->map_len,
2662 ioff = btrfs_item_offset(left, item);
2663 btrfs_set_item_offset(left, item,
2664 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2666 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2667 if (left->map_token) {
2668 unmap_extent_buffer(left, left->map_token, KM_USER1);
2669 left->map_token = NULL;
2672 /* fixup right node */
2673 if (push_items > right_nritems) {
2674 printk(KERN_CRIT "push items %d nr %u\n", push_items,
2679 if (push_items < right_nritems) {
2680 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2681 leaf_data_end(root, right);
2682 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2683 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2684 btrfs_leaf_data(right) +
2685 leaf_data_end(root, right), push_space);
2687 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2688 btrfs_item_nr_offset(push_items),
2689 (btrfs_header_nritems(right) - push_items) *
2690 sizeof(struct btrfs_item));
2692 right_nritems -= push_items;
2693 btrfs_set_header_nritems(right, right_nritems);
2694 push_space = BTRFS_LEAF_DATA_SIZE(root);
2695 for (i = 0; i < right_nritems; i++) {
2696 item = btrfs_item_nr(right, i);
2698 if (!right->map_token) {
2699 map_extent_buffer(right, (unsigned long)item,
2700 sizeof(struct btrfs_item),
2701 &right->map_token, &right->kaddr,
2702 &right->map_start, &right->map_len,
2706 push_space = push_space - btrfs_item_size(right, item);
2707 btrfs_set_item_offset(right, item, push_space);
2709 if (right->map_token) {
2710 unmap_extent_buffer(right, right->map_token, KM_USER1);
2711 right->map_token = NULL;
2714 btrfs_mark_buffer_dirty(left);
2716 btrfs_mark_buffer_dirty(right);
2718 clean_tree_block(trans, root, right);
2720 btrfs_item_key(right, &disk_key, 0);
2721 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2725 /* then fixup the leaf pointer in the path */
2726 if (path->slots[0] < push_items) {
2727 path->slots[0] += old_left_nritems;
2728 btrfs_tree_unlock(path->nodes[0]);
2729 free_extent_buffer(path->nodes[0]);
2730 path->nodes[0] = left;
2731 path->slots[1] -= 1;
2733 btrfs_tree_unlock(left);
2734 free_extent_buffer(left);
2735 path->slots[0] -= push_items;
2737 BUG_ON(path->slots[0] < 0);
2740 btrfs_tree_unlock(left);
2741 free_extent_buffer(left);
2746 * push some data in the path leaf to the left, trying to free up at
2747 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2749 * max_slot can put a limit on how far into the leaf we'll push items. The
2750 * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
2753 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
2754 *root, struct btrfs_path *path, int min_data_size,
2755 int data_size, int empty, u32 max_slot)
2757 struct extent_buffer *right = path->nodes[0];
2758 struct extent_buffer *left;
2764 slot = path->slots[1];
2767 if (!path->nodes[1])
2770 right_nritems = btrfs_header_nritems(right);
2771 if (right_nritems == 0)
2774 btrfs_assert_tree_locked(path->nodes[1]);
2776 left = read_node_slot(root, path->nodes[1], slot - 1);
2777 btrfs_tree_lock(left);
2778 btrfs_set_lock_blocking(left);
2780 free_space = btrfs_leaf_free_space(root, left);
2781 if (free_space < data_size) {
2786 /* cow and double check */
2787 ret = btrfs_cow_block(trans, root, left,
2788 path->nodes[1], slot - 1, &left);
2790 /* we hit -ENOSPC, but it isn't fatal here */
2795 free_space = btrfs_leaf_free_space(root, left);
2796 if (free_space < data_size) {
2801 return __push_leaf_left(trans, root, path, min_data_size,
2802 empty, left, free_space, right_nritems,
2805 btrfs_tree_unlock(left);
2806 free_extent_buffer(left);
2811 * split the path's leaf in two, making sure there is at least data_size
2812 * available for the resulting leaf level of the path.
2814 * returns 0 if all went well and < 0 on failure.
2816 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
2817 struct btrfs_root *root,
2818 struct btrfs_path *path,
2819 struct extent_buffer *l,
2820 struct extent_buffer *right,
2821 int slot, int mid, int nritems)
2828 struct btrfs_disk_key disk_key;
2830 nritems = nritems - mid;
2831 btrfs_set_header_nritems(right, nritems);
2832 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2834 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2835 btrfs_item_nr_offset(mid),
2836 nritems * sizeof(struct btrfs_item));
2838 copy_extent_buffer(right, l,
2839 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2840 data_copy_size, btrfs_leaf_data(l) +
2841 leaf_data_end(root, l), data_copy_size);
2843 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2844 btrfs_item_end_nr(l, mid);
2846 for (i = 0; i < nritems; i++) {
2847 struct btrfs_item *item = btrfs_item_nr(right, i);
2850 if (!right->map_token) {
2851 map_extent_buffer(right, (unsigned long)item,
2852 sizeof(struct btrfs_item),
2853 &right->map_token, &right->kaddr,
2854 &right->map_start, &right->map_len,
2858 ioff = btrfs_item_offset(right, item);
2859 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2862 if (right->map_token) {
2863 unmap_extent_buffer(right, right->map_token, KM_USER1);
2864 right->map_token = NULL;
2867 btrfs_set_header_nritems(l, mid);
2869 btrfs_item_key(right, &disk_key, 0);
2870 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2871 path->slots[1] + 1, 1);
2875 btrfs_mark_buffer_dirty(right);
2876 btrfs_mark_buffer_dirty(l);
2877 BUG_ON(path->slots[0] != slot);
2880 btrfs_tree_unlock(path->nodes[0]);
2881 free_extent_buffer(path->nodes[0]);
2882 path->nodes[0] = right;
2883 path->slots[0] -= mid;
2884 path->slots[1] += 1;
2886 btrfs_tree_unlock(right);
2887 free_extent_buffer(right);
2890 BUG_ON(path->slots[0] < 0);
2896 * double splits happen when we need to insert a big item in the middle
2897 * of a leaf. A double split can leave us with 3 mostly empty leaves:
2898 * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
2901 * We avoid this by trying to push the items on either side of our target
2902 * into the adjacent leaves. If all goes well we can avoid the double split
2905 static noinline int push_for_double_split(struct btrfs_trans_handle *trans,
2906 struct btrfs_root *root,
2907 struct btrfs_path *path,
2915 slot = path->slots[0];
2918 * try to push all the items after our slot into the
2921 ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot);
2928 nritems = btrfs_header_nritems(path->nodes[0]);
2930 * our goal is to get our slot at the start or end of a leaf. If
2931 * we've done so we're done
2933 if (path->slots[0] == 0 || path->slots[0] == nritems)
2936 if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
2939 /* try to push all the items before our slot into the next leaf */
2940 slot = path->slots[0];
2941 ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot);
2954 * split the path's leaf in two, making sure there is at least data_size
2955 * available for the resulting leaf level of the path.
2957 * returns 0 if all went well and < 0 on failure.
2959 static noinline int split_leaf(struct btrfs_trans_handle *trans,
2960 struct btrfs_root *root,
2961 struct btrfs_key *ins_key,
2962 struct btrfs_path *path, int data_size,
2965 struct btrfs_disk_key disk_key;
2966 struct extent_buffer *l;
2970 struct extent_buffer *right;
2974 int num_doubles = 0;
2975 int tried_avoid_double = 0;
2978 slot = path->slots[0];
2979 if (extend && data_size + btrfs_item_size_nr(l, slot) +
2980 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root))
2983 /* first try to make some room by pushing left and right */
2985 wret = push_leaf_right(trans, root, path, data_size,
2990 wret = push_leaf_left(trans, root, path, data_size,
2991 data_size, 0, (u32)-1);
2997 /* did the pushes work? */
2998 if (btrfs_leaf_free_space(root, l) >= data_size)
3002 if (!path->nodes[1]) {
3003 ret = insert_new_root(trans, root, path, 1);
3010 slot = path->slots[0];
3011 nritems = btrfs_header_nritems(l);
3012 mid = (nritems + 1) / 2;
3016 leaf_space_used(l, mid, nritems - mid) + data_size >
3017 BTRFS_LEAF_DATA_SIZE(root)) {
3018 if (slot >= nritems) {
3022 if (mid != nritems &&
3023 leaf_space_used(l, mid, nritems - mid) +
3024 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
3025 if (data_size && !tried_avoid_double)
3026 goto push_for_double;
3032 if (leaf_space_used(l, 0, mid) + data_size >
3033 BTRFS_LEAF_DATA_SIZE(root)) {
3034 if (!extend && data_size && slot == 0) {
3036 } else if ((extend || !data_size) && slot == 0) {
3040 if (mid != nritems &&
3041 leaf_space_used(l, mid, nritems - mid) +
3042 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
3043 if (data_size && !tried_avoid_double)
3044 goto push_for_double;
3052 btrfs_cpu_key_to_disk(&disk_key, ins_key);
3054 btrfs_item_key(l, &disk_key, mid);
3056 right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
3057 root->root_key.objectid,
3058 &disk_key, 0, l->start, 0);
3060 return PTR_ERR(right);
3062 root_add_used(root, root->leafsize);
3064 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
3065 btrfs_set_header_bytenr(right, right->start);
3066 btrfs_set_header_generation(right, trans->transid);
3067 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
3068 btrfs_set_header_owner(right, root->root_key.objectid);
3069 btrfs_set_header_level(right, 0);
3070 write_extent_buffer(right, root->fs_info->fsid,
3071 (unsigned long)btrfs_header_fsid(right),
3074 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
3075 (unsigned long)btrfs_header_chunk_tree_uuid(right),
3080 btrfs_set_header_nritems(right, 0);
3081 wret = insert_ptr(trans, root, path,
3082 &disk_key, right->start,
3083 path->slots[1] + 1, 1);
3087 btrfs_tree_unlock(path->nodes[0]);
3088 free_extent_buffer(path->nodes[0]);
3089 path->nodes[0] = right;
3091 path->slots[1] += 1;
3093 btrfs_set_header_nritems(right, 0);
3094 wret = insert_ptr(trans, root, path,
3100 btrfs_tree_unlock(path->nodes[0]);
3101 free_extent_buffer(path->nodes[0]);
3102 path->nodes[0] = right;
3104 if (path->slots[1] == 0) {
3105 wret = fixup_low_keys(trans, root,
3106 path, &disk_key, 1);
3111 btrfs_mark_buffer_dirty(right);
3115 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
3119 BUG_ON(num_doubles != 0);
3127 push_for_double_split(trans, root, path, data_size);
3128 tried_avoid_double = 1;
3129 if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
3134 static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
3135 struct btrfs_root *root,
3136 struct btrfs_path *path, int ins_len)
3138 struct btrfs_key key;
3139 struct extent_buffer *leaf;
3140 struct btrfs_file_extent_item *fi;
3145 leaf = path->nodes[0];
3146 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3148 BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
3149 key.type != BTRFS_EXTENT_CSUM_KEY);
3151 if (btrfs_leaf_free_space(root, leaf) >= ins_len)
3154 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3155 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3156 fi = btrfs_item_ptr(leaf, path->slots[0],
3157 struct btrfs_file_extent_item);
3158 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
3160 btrfs_release_path(root, path);
3162 path->keep_locks = 1;
3163 path->search_for_split = 1;
3164 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3165 path->search_for_split = 0;
3170 leaf = path->nodes[0];
3171 /* if our item isn't there or got smaller, return now */
3172 if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0]))
3175 /* the leaf has changed, it now has room. return now */
3176 if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len)
3179 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3180 fi = btrfs_item_ptr(leaf, path->slots[0],
3181 struct btrfs_file_extent_item);
3182 if (extent_len != btrfs_file_extent_num_bytes(leaf, fi))
3186 btrfs_set_path_blocking(path);
3187 ret = split_leaf(trans, root, &key, path, ins_len, 1);
3191 path->keep_locks = 0;
3192 btrfs_unlock_up_safe(path, 1);
3195 path->keep_locks = 0;
3199 static noinline int split_item(struct btrfs_trans_handle *trans,
3200 struct btrfs_root *root,
3201 struct btrfs_path *path,
3202 struct btrfs_key *new_key,
3203 unsigned long split_offset)
3205 struct extent_buffer *leaf;
3206 struct btrfs_item *item;
3207 struct btrfs_item *new_item;
3213 struct btrfs_disk_key disk_key;
3215 leaf = path->nodes[0];
3216 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
3218 btrfs_set_path_blocking(path);
3220 item = btrfs_item_nr(leaf, path->slots[0]);
3221 orig_offset = btrfs_item_offset(leaf, item);
3222 item_size = btrfs_item_size(leaf, item);
3224 buf = kmalloc(item_size, GFP_NOFS);
3228 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
3229 path->slots[0]), item_size);
3231 slot = path->slots[0] + 1;
3232 nritems = btrfs_header_nritems(leaf);
3233 if (slot != nritems) {
3234 /* shift the items */
3235 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
3236 btrfs_item_nr_offset(slot),
3237 (nritems - slot) * sizeof(struct btrfs_item));
3240 btrfs_cpu_key_to_disk(&disk_key, new_key);
3241 btrfs_set_item_key(leaf, &disk_key, slot);
3243 new_item = btrfs_item_nr(leaf, slot);
3245 btrfs_set_item_offset(leaf, new_item, orig_offset);
3246 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
3248 btrfs_set_item_offset(leaf, item,
3249 orig_offset + item_size - split_offset);
3250 btrfs_set_item_size(leaf, item, split_offset);
3252 btrfs_set_header_nritems(leaf, nritems + 1);
3254 /* write the data for the start of the original item */
3255 write_extent_buffer(leaf, buf,
3256 btrfs_item_ptr_offset(leaf, path->slots[0]),
3259 /* write the data for the new item */
3260 write_extent_buffer(leaf, buf + split_offset,
3261 btrfs_item_ptr_offset(leaf, slot),
3262 item_size - split_offset);
3263 btrfs_mark_buffer_dirty(leaf);
3265 BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
3271 * This function splits a single item into two items,
3272 * giving 'new_key' to the new item and splitting the
3273 * old one at split_offset (from the start of the item).
3275 * The path may be released by this operation. After
3276 * the split, the path is pointing to the old item. The
3277 * new item is going to be in the same node as the old one.
3279 * Note, the item being split must be smaller enough to live alone on
3280 * a tree block with room for one extra struct btrfs_item
3282 * This allows us to split the item in place, keeping a lock on the
3283 * leaf the entire time.
3285 int btrfs_split_item(struct btrfs_trans_handle *trans,
3286 struct btrfs_root *root,
3287 struct btrfs_path *path,
3288 struct btrfs_key *new_key,
3289 unsigned long split_offset)
3292 ret = setup_leaf_for_split(trans, root, path,
3293 sizeof(struct btrfs_item));
3297 ret = split_item(trans, root, path, new_key, split_offset);
3302 * This function duplicate a item, giving 'new_key' to the new item.
3303 * It guarantees both items live in the same tree leaf and the new item
3304 * is contiguous with the original item.
3306 * This allows us to split file extent in place, keeping a lock on the
3307 * leaf the entire time.
3309 int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
3310 struct btrfs_root *root,
3311 struct btrfs_path *path,
3312 struct btrfs_key *new_key)
3314 struct extent_buffer *leaf;
3318 leaf = path->nodes[0];
3319 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3320 ret = setup_leaf_for_split(trans, root, path,
3321 item_size + sizeof(struct btrfs_item));
3326 ret = setup_items_for_insert(trans, root, path, new_key, &item_size,
3327 item_size, item_size +
3328 sizeof(struct btrfs_item), 1);
3331 leaf = path->nodes[0];
3332 memcpy_extent_buffer(leaf,
3333 btrfs_item_ptr_offset(leaf, path->slots[0]),
3334 btrfs_item_ptr_offset(leaf, path->slots[0] - 1),
3340 * make the item pointed to by the path smaller. new_size indicates
3341 * how small to make it, and from_end tells us if we just chop bytes
3342 * off the end of the item or if we shift the item to chop bytes off
3345 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
3346 struct btrfs_root *root,
3347 struct btrfs_path *path,
3348 u32 new_size, int from_end)
3353 struct extent_buffer *leaf;
3354 struct btrfs_item *item;
3356 unsigned int data_end;
3357 unsigned int old_data_start;
3358 unsigned int old_size;
3359 unsigned int size_diff;
3362 slot_orig = path->slots[0];
3363 leaf = path->nodes[0];
3364 slot = path->slots[0];
3366 old_size = btrfs_item_size_nr(leaf, slot);
3367 if (old_size == new_size)
3370 nritems = btrfs_header_nritems(leaf);
3371 data_end = leaf_data_end(root, leaf);
3373 old_data_start = btrfs_item_offset_nr(leaf, slot);
3375 size_diff = old_size - new_size;
3378 BUG_ON(slot >= nritems);
3381 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3383 /* first correct the data pointers */
3384 for (i = slot; i < nritems; i++) {
3386 item = btrfs_item_nr(leaf, i);
3388 if (!leaf->map_token) {
3389 map_extent_buffer(leaf, (unsigned long)item,
3390 sizeof(struct btrfs_item),
3391 &leaf->map_token, &leaf->kaddr,
3392 &leaf->map_start, &leaf->map_len,
3396 ioff = btrfs_item_offset(leaf, item);
3397 btrfs_set_item_offset(leaf, item, ioff + size_diff);
3400 if (leaf->map_token) {
3401 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3402 leaf->map_token = NULL;
3405 /* shift the data */
3407 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3408 data_end + size_diff, btrfs_leaf_data(leaf) +
3409 data_end, old_data_start + new_size - data_end);
3411 struct btrfs_disk_key disk_key;
3414 btrfs_item_key(leaf, &disk_key, slot);
3416 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
3418 struct btrfs_file_extent_item *fi;
3420 fi = btrfs_item_ptr(leaf, slot,
3421 struct btrfs_file_extent_item);
3422 fi = (struct btrfs_file_extent_item *)(
3423 (unsigned long)fi - size_diff);
3425 if (btrfs_file_extent_type(leaf, fi) ==
3426 BTRFS_FILE_EXTENT_INLINE) {
3427 ptr = btrfs_item_ptr_offset(leaf, slot);
3428 memmove_extent_buffer(leaf, ptr,
3430 offsetof(struct btrfs_file_extent_item,
3435 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3436 data_end + size_diff, btrfs_leaf_data(leaf) +
3437 data_end, old_data_start - data_end);
3439 offset = btrfs_disk_key_offset(&disk_key);
3440 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
3441 btrfs_set_item_key(leaf, &disk_key, slot);
3443 fixup_low_keys(trans, root, path, &disk_key, 1);
3446 item = btrfs_item_nr(leaf, slot);
3447 btrfs_set_item_size(leaf, item, new_size);
3448 btrfs_mark_buffer_dirty(leaf);
3451 if (btrfs_leaf_free_space(root, leaf) < 0) {
3452 btrfs_print_leaf(root, leaf);
3459 * make the item pointed to by the path bigger, data_size is the new size.
3461 int btrfs_extend_item(struct btrfs_trans_handle *trans,
3462 struct btrfs_root *root, struct btrfs_path *path,
3468 struct extent_buffer *leaf;
3469 struct btrfs_item *item;
3471 unsigned int data_end;
3472 unsigned int old_data;
3473 unsigned int old_size;
3476 slot_orig = path->slots[0];
3477 leaf = path->nodes[0];
3479 nritems = btrfs_header_nritems(leaf);
3480 data_end = leaf_data_end(root, leaf);
3482 if (btrfs_leaf_free_space(root, leaf) < data_size) {
3483 btrfs_print_leaf(root, leaf);
3486 slot = path->slots[0];
3487 old_data = btrfs_item_end_nr(leaf, slot);
3490 if (slot >= nritems) {
3491 btrfs_print_leaf(root, leaf);
3492 printk(KERN_CRIT "slot %d too large, nritems %d\n",
3498 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3500 /* first correct the data pointers */
3501 for (i = slot; i < nritems; i++) {
3503 item = btrfs_item_nr(leaf, i);
3505 if (!leaf->map_token) {
3506 map_extent_buffer(leaf, (unsigned long)item,
3507 sizeof(struct btrfs_item),
3508 &leaf->map_token, &leaf->kaddr,
3509 &leaf->map_start, &leaf->map_len,
3512 ioff = btrfs_item_offset(leaf, item);
3513 btrfs_set_item_offset(leaf, item, ioff - data_size);
3516 if (leaf->map_token) {
3517 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3518 leaf->map_token = NULL;
3521 /* shift the data */
3522 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3523 data_end - data_size, btrfs_leaf_data(leaf) +
3524 data_end, old_data - data_end);
3526 data_end = old_data;
3527 old_size = btrfs_item_size_nr(leaf, slot);
3528 item = btrfs_item_nr(leaf, slot);
3529 btrfs_set_item_size(leaf, item, old_size + data_size);
3530 btrfs_mark_buffer_dirty(leaf);
3533 if (btrfs_leaf_free_space(root, leaf) < 0) {
3534 btrfs_print_leaf(root, leaf);
3541 * Given a key and some data, insert items into the tree.
3542 * This does all the path init required, making room in the tree if needed.
3543 * Returns the number of keys that were inserted.
3545 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
3546 struct btrfs_root *root,
3547 struct btrfs_path *path,
3548 struct btrfs_key *cpu_key, u32 *data_size,
3551 struct extent_buffer *leaf;
3552 struct btrfs_item *item;
3559 unsigned int data_end;
3560 struct btrfs_disk_key disk_key;
3561 struct btrfs_key found_key;
3563 for (i = 0; i < nr; i++) {
3564 if (total_size + data_size[i] + sizeof(struct btrfs_item) >
3565 BTRFS_LEAF_DATA_SIZE(root)) {
3569 total_data += data_size[i];
3570 total_size += data_size[i] + sizeof(struct btrfs_item);
3574 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3580 leaf = path->nodes[0];
3582 nritems = btrfs_header_nritems(leaf);
3583 data_end = leaf_data_end(root, leaf);
3585 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3586 for (i = nr; i >= 0; i--) {
3587 total_data -= data_size[i];
3588 total_size -= data_size[i] + sizeof(struct btrfs_item);
3589 if (total_size < btrfs_leaf_free_space(root, leaf))
3595 slot = path->slots[0];
3598 if (slot != nritems) {
3599 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3601 item = btrfs_item_nr(leaf, slot);
3602 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3604 /* figure out how many keys we can insert in here */
3605 total_data = data_size[0];
3606 for (i = 1; i < nr; i++) {
3607 if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0)
3609 total_data += data_size[i];
3613 if (old_data < data_end) {
3614 btrfs_print_leaf(root, leaf);
3615 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
3616 slot, old_data, data_end);
3620 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3622 /* first correct the data pointers */
3623 WARN_ON(leaf->map_token);
3624 for (i = slot; i < nritems; i++) {
3627 item = btrfs_item_nr(leaf, i);
3628 if (!leaf->map_token) {
3629 map_extent_buffer(leaf, (unsigned long)item,
3630 sizeof(struct btrfs_item),
3631 &leaf->map_token, &leaf->kaddr,
3632 &leaf->map_start, &leaf->map_len,
3636 ioff = btrfs_item_offset(leaf, item);
3637 btrfs_set_item_offset(leaf, item, ioff - total_data);
3639 if (leaf->map_token) {
3640 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3641 leaf->map_token = NULL;
3644 /* shift the items */
3645 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3646 btrfs_item_nr_offset(slot),
3647 (nritems - slot) * sizeof(struct btrfs_item));
3649 /* shift the data */
3650 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3651 data_end - total_data, btrfs_leaf_data(leaf) +
3652 data_end, old_data - data_end);
3653 data_end = old_data;
3656 * this sucks but it has to be done, if we are inserting at
3657 * the end of the leaf only insert 1 of the items, since we
3658 * have no way of knowing whats on the next leaf and we'd have
3659 * to drop our current locks to figure it out
3664 /* setup the item for the new data */
3665 for (i = 0; i < nr; i++) {
3666 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3667 btrfs_set_item_key(leaf, &disk_key, slot + i);
3668 item = btrfs_item_nr(leaf, slot + i);
3669 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3670 data_end -= data_size[i];
3671 btrfs_set_item_size(leaf, item, data_size[i]);
3673 btrfs_set_header_nritems(leaf, nritems + nr);
3674 btrfs_mark_buffer_dirty(leaf);
3678 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3679 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3682 if (btrfs_leaf_free_space(root, leaf) < 0) {
3683 btrfs_print_leaf(root, leaf);
3693 * this is a helper for btrfs_insert_empty_items, the main goal here is
3694 * to save stack depth by doing the bulk of the work in a function
3695 * that doesn't call btrfs_search_slot
3697 static noinline_for_stack int
3698 setup_items_for_insert(struct btrfs_trans_handle *trans,
3699 struct btrfs_root *root, struct btrfs_path *path,
3700 struct btrfs_key *cpu_key, u32 *data_size,
3701 u32 total_data, u32 total_size, int nr)
3703 struct btrfs_item *item;
3706 unsigned int data_end;
3707 struct btrfs_disk_key disk_key;
3709 struct extent_buffer *leaf;
3712 leaf = path->nodes[0];
3713 slot = path->slots[0];
3715 nritems = btrfs_header_nritems(leaf);
3716 data_end = leaf_data_end(root, leaf);
3718 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3719 btrfs_print_leaf(root, leaf);
3720 printk(KERN_CRIT "not enough freespace need %u have %d\n",
3721 total_size, btrfs_leaf_free_space(root, leaf));
3725 if (slot != nritems) {
3726 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3728 if (old_data < data_end) {
3729 btrfs_print_leaf(root, leaf);
3730 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
3731 slot, old_data, data_end);
3735 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3737 /* first correct the data pointers */
3738 WARN_ON(leaf->map_token);
3739 for (i = slot; i < nritems; i++) {
3742 item = btrfs_item_nr(leaf, i);
3743 if (!leaf->map_token) {
3744 map_extent_buffer(leaf, (unsigned long)item,
3745 sizeof(struct btrfs_item),
3746 &leaf->map_token, &leaf->kaddr,
3747 &leaf->map_start, &leaf->map_len,
3751 ioff = btrfs_item_offset(leaf, item);
3752 btrfs_set_item_offset(leaf, item, ioff - total_data);
3754 if (leaf->map_token) {
3755 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3756 leaf->map_token = NULL;
3759 /* shift the items */
3760 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3761 btrfs_item_nr_offset(slot),
3762 (nritems - slot) * sizeof(struct btrfs_item));
3764 /* shift the data */
3765 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3766 data_end - total_data, btrfs_leaf_data(leaf) +
3767 data_end, old_data - data_end);
3768 data_end = old_data;
3771 /* setup the item for the new data */
3772 for (i = 0; i < nr; i++) {
3773 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3774 btrfs_set_item_key(leaf, &disk_key, slot + i);
3775 item = btrfs_item_nr(leaf, slot + i);
3776 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3777 data_end -= data_size[i];
3778 btrfs_set_item_size(leaf, item, data_size[i]);
3781 btrfs_set_header_nritems(leaf, nritems + nr);
3785 struct btrfs_disk_key disk_key;
3786 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3787 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3789 btrfs_unlock_up_safe(path, 1);
3790 btrfs_mark_buffer_dirty(leaf);
3792 if (btrfs_leaf_free_space(root, leaf) < 0) {
3793 btrfs_print_leaf(root, leaf);
3800 * Given a key and some data, insert items into the tree.
3801 * This does all the path init required, making room in the tree if needed.
3803 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
3804 struct btrfs_root *root,
3805 struct btrfs_path *path,
3806 struct btrfs_key *cpu_key, u32 *data_size,
3809 struct extent_buffer *leaf;
3816 for (i = 0; i < nr; i++)
3817 total_data += data_size[i];
3819 total_size = total_data + (nr * sizeof(struct btrfs_item));
3820 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3826 leaf = path->nodes[0];
3827 slot = path->slots[0];
3830 ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
3831 total_data, total_size, nr);
3838 * Given a key and some data, insert an item into the tree.
3839 * This does all the path init required, making room in the tree if needed.
3841 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
3842 *root, struct btrfs_key *cpu_key, void *data, u32
3846 struct btrfs_path *path;
3847 struct extent_buffer *leaf;
3850 path = btrfs_alloc_path();
3852 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
3854 leaf = path->nodes[0];
3855 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3856 write_extent_buffer(leaf, data, ptr, data_size);
3857 btrfs_mark_buffer_dirty(leaf);
3859 btrfs_free_path(path);
3864 * delete the pointer from a given node.
3866 * the tree should have been previously balanced so the deletion does not
3869 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3870 struct btrfs_path *path, int level, int slot)
3872 struct extent_buffer *parent = path->nodes[level];
3877 nritems = btrfs_header_nritems(parent);
3878 if (slot != nritems - 1) {
3879 memmove_extent_buffer(parent,
3880 btrfs_node_key_ptr_offset(slot),
3881 btrfs_node_key_ptr_offset(slot + 1),
3882 sizeof(struct btrfs_key_ptr) *
3883 (nritems - slot - 1));
3886 btrfs_set_header_nritems(parent, nritems);
3887 if (nritems == 0 && parent == root->node) {
3888 BUG_ON(btrfs_header_level(root->node) != 1);
3889 /* just turn the root into a leaf and break */
3890 btrfs_set_header_level(root->node, 0);
3891 } else if (slot == 0) {
3892 struct btrfs_disk_key disk_key;
3894 btrfs_node_key(parent, &disk_key, 0);
3895 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
3899 btrfs_mark_buffer_dirty(parent);
3904 * a helper function to delete the leaf pointed to by path->slots[1] and
3907 * This deletes the pointer in path->nodes[1] and frees the leaf
3908 * block extent. zero is returned if it all worked out, < 0 otherwise.
3910 * The path must have already been setup for deleting the leaf, including
3911 * all the proper balancing. path->nodes[1] must be locked.
3913 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
3914 struct btrfs_root *root,
3915 struct btrfs_path *path,
3916 struct extent_buffer *leaf)
3920 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
3921 ret = del_ptr(trans, root, path, 1, path->slots[1]);
3926 * btrfs_free_extent is expensive, we want to make sure we
3927 * aren't holding any locks when we call it
3929 btrfs_unlock_up_safe(path, 0);
3931 root_sub_used(root, leaf->len);
3933 btrfs_free_tree_block(trans, root, leaf, 0, 1);
3937 * delete the item at the leaf level in path. If that empties
3938 * the leaf, remove it from the tree
3940 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3941 struct btrfs_path *path, int slot, int nr)
3943 struct extent_buffer *leaf;
3944 struct btrfs_item *item;
3952 leaf = path->nodes[0];
3953 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
3955 for (i = 0; i < nr; i++)
3956 dsize += btrfs_item_size_nr(leaf, slot + i);
3958 nritems = btrfs_header_nritems(leaf);
3960 if (slot + nr != nritems) {
3961 int data_end = leaf_data_end(root, leaf);
3963 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3965 btrfs_leaf_data(leaf) + data_end,
3966 last_off - data_end);
3968 for (i = slot + nr; i < nritems; i++) {
3971 item = btrfs_item_nr(leaf, i);
3972 if (!leaf->map_token) {
3973 map_extent_buffer(leaf, (unsigned long)item,
3974 sizeof(struct btrfs_item),
3975 &leaf->map_token, &leaf->kaddr,
3976 &leaf->map_start, &leaf->map_len,
3979 ioff = btrfs_item_offset(leaf, item);
3980 btrfs_set_item_offset(leaf, item, ioff + dsize);
3983 if (leaf->map_token) {
3984 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3985 leaf->map_token = NULL;
3988 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
3989 btrfs_item_nr_offset(slot + nr),
3990 sizeof(struct btrfs_item) *
3991 (nritems - slot - nr));
3993 btrfs_set_header_nritems(leaf, nritems - nr);
3996 /* delete the leaf if we've emptied it */
3998 if (leaf == root->node) {
3999 btrfs_set_header_level(leaf, 0);
4001 btrfs_set_path_blocking(path);
4002 clean_tree_block(trans, root, leaf);
4003 ret = btrfs_del_leaf(trans, root, path, leaf);
4007 int used = leaf_space_used(leaf, 0, nritems);
4009 struct btrfs_disk_key disk_key;
4011 btrfs_item_key(leaf, &disk_key, 0);
4012 wret = fixup_low_keys(trans, root, path,
4018 /* delete the leaf if it is mostly empty */
4019 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
4020 /* push_leaf_left fixes the path.
4021 * make sure the path still points to our leaf
4022 * for possible call to del_ptr below
4024 slot = path->slots[1];
4025 extent_buffer_get(leaf);
4027 btrfs_set_path_blocking(path);
4028 wret = push_leaf_left(trans, root, path, 1, 1,
4030 if (wret < 0 && wret != -ENOSPC)
4033 if (path->nodes[0] == leaf &&
4034 btrfs_header_nritems(leaf)) {
4035 wret = push_leaf_right(trans, root, path, 1,
4037 if (wret < 0 && wret != -ENOSPC)
4041 if (btrfs_header_nritems(leaf) == 0) {
4042 path->slots[1] = slot;
4043 ret = btrfs_del_leaf(trans, root, path, leaf);
4045 free_extent_buffer(leaf);
4047 /* if we're still in the path, make sure
4048 * we're dirty. Otherwise, one of the
4049 * push_leaf functions must have already
4050 * dirtied this buffer
4052 if (path->nodes[0] == leaf)
4053 btrfs_mark_buffer_dirty(leaf);
4054 free_extent_buffer(leaf);
4057 btrfs_mark_buffer_dirty(leaf);
4064 * search the tree again to find a leaf with lesser keys
4065 * returns 0 if it found something or 1 if there are no lesser leaves.
4066 * returns < 0 on io errors.
4068 * This may release the path, and so you may lose any locks held at the
4071 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
4073 struct btrfs_key key;
4074 struct btrfs_disk_key found_key;
4077 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
4081 else if (key.type > 0)
4083 else if (key.objectid > 0)
4088 btrfs_release_path(root, path);
4089 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4092 btrfs_item_key(path->nodes[0], &found_key, 0);
4093 ret = comp_keys(&found_key, &key);
4100 * A helper function to walk down the tree starting at min_key, and looking
4101 * for nodes or leaves that are either in cache or have a minimum
4102 * transaction id. This is used by the btree defrag code, and tree logging
4104 * This does not cow, but it does stuff the starting key it finds back
4105 * into min_key, so you can call btrfs_search_slot with cow=1 on the
4106 * key and get a writable path.
4108 * This does lock as it descends, and path->keep_locks should be set
4109 * to 1 by the caller.
4111 * This honors path->lowest_level to prevent descent past a given level
4114 * min_trans indicates the oldest transaction that you are interested
4115 * in walking through. Any nodes or leaves older than min_trans are
4116 * skipped over (without reading them).
4118 * returns zero if something useful was found, < 0 on error and 1 if there
4119 * was nothing in the tree that matched the search criteria.
4121 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
4122 struct btrfs_key *max_key,
4123 struct btrfs_path *path, int cache_only,
4126 struct extent_buffer *cur;
4127 struct btrfs_key found_key;
4134 WARN_ON(!path->keep_locks);
4136 cur = btrfs_lock_root_node(root);
4137 level = btrfs_header_level(cur);
4138 WARN_ON(path->nodes[level]);
4139 path->nodes[level] = cur;
4140 path->locks[level] = 1;
4142 if (btrfs_header_generation(cur) < min_trans) {
4147 nritems = btrfs_header_nritems(cur);
4148 level = btrfs_header_level(cur);
4149 sret = bin_search(cur, min_key, level, &slot);
4151 /* at the lowest level, we're done, setup the path and exit */
4152 if (level == path->lowest_level) {
4153 if (slot >= nritems)
4156 path->slots[level] = slot;
4157 btrfs_item_key_to_cpu(cur, &found_key, slot);
4160 if (sret && slot > 0)
4163 * check this node pointer against the cache_only and
4164 * min_trans parameters. If it isn't in cache or is too
4165 * old, skip to the next one.
4167 while (slot < nritems) {
4170 struct extent_buffer *tmp;
4171 struct btrfs_disk_key disk_key;
4173 blockptr = btrfs_node_blockptr(cur, slot);
4174 gen = btrfs_node_ptr_generation(cur, slot);
4175 if (gen < min_trans) {
4183 btrfs_node_key(cur, &disk_key, slot);
4184 if (comp_keys(&disk_key, max_key) >= 0) {
4190 tmp = btrfs_find_tree_block(root, blockptr,
4191 btrfs_level_size(root, level - 1));
4193 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
4194 free_extent_buffer(tmp);
4198 free_extent_buffer(tmp);
4203 * we didn't find a candidate key in this node, walk forward
4204 * and find another one
4206 if (slot >= nritems) {
4207 path->slots[level] = slot;
4208 btrfs_set_path_blocking(path);
4209 sret = btrfs_find_next_key(root, path, min_key, level,
4210 cache_only, min_trans);
4212 btrfs_release_path(root, path);
4218 /* save our key for returning back */
4219 btrfs_node_key_to_cpu(cur, &found_key, slot);
4220 path->slots[level] = slot;
4221 if (level == path->lowest_level) {
4223 unlock_up(path, level, 1);
4226 btrfs_set_path_blocking(path);
4227 cur = read_node_slot(root, cur, slot);
4229 btrfs_tree_lock(cur);
4231 path->locks[level - 1] = 1;
4232 path->nodes[level - 1] = cur;
4233 unlock_up(path, level, 1);
4234 btrfs_clear_path_blocking(path, NULL);
4238 memcpy(min_key, &found_key, sizeof(found_key));
4239 btrfs_set_path_blocking(path);
4244 * this is similar to btrfs_next_leaf, but does not try to preserve
4245 * and fixup the path. It looks for and returns the next key in the
4246 * tree based on the current path and the cache_only and min_trans
4249 * 0 is returned if another key is found, < 0 if there are any errors
4250 * and 1 is returned if there are no higher keys in the tree
4252 * path->keep_locks should be set to 1 on the search made before
4253 * calling this function.
4255 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
4256 struct btrfs_key *key, int level,
4257 int cache_only, u64 min_trans)
4260 struct extent_buffer *c;
4262 WARN_ON(!path->keep_locks);
4263 while (level < BTRFS_MAX_LEVEL) {
4264 if (!path->nodes[level])
4267 slot = path->slots[level] + 1;
4268 c = path->nodes[level];
4270 if (slot >= btrfs_header_nritems(c)) {
4273 struct btrfs_key cur_key;
4274 if (level + 1 >= BTRFS_MAX_LEVEL ||
4275 !path->nodes[level + 1])
4278 if (path->locks[level + 1]) {
4283 slot = btrfs_header_nritems(c) - 1;
4285 btrfs_item_key_to_cpu(c, &cur_key, slot);
4287 btrfs_node_key_to_cpu(c, &cur_key, slot);
4289 orig_lowest = path->lowest_level;
4290 btrfs_release_path(root, path);
4291 path->lowest_level = level;
4292 ret = btrfs_search_slot(NULL, root, &cur_key, path,
4294 path->lowest_level = orig_lowest;
4298 c = path->nodes[level];
4299 slot = path->slots[level];
4306 btrfs_item_key_to_cpu(c, key, slot);
4308 u64 blockptr = btrfs_node_blockptr(c, slot);
4309 u64 gen = btrfs_node_ptr_generation(c, slot);
4312 struct extent_buffer *cur;
4313 cur = btrfs_find_tree_block(root, blockptr,
4314 btrfs_level_size(root, level - 1));
4315 if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
4318 free_extent_buffer(cur);
4321 free_extent_buffer(cur);
4323 if (gen < min_trans) {
4327 btrfs_node_key_to_cpu(c, key, slot);
4335 * search the tree again to find a leaf with greater keys
4336 * returns 0 if it found something or 1 if there are no greater leaves.
4337 * returns < 0 on io errors.
4339 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
4343 struct extent_buffer *c;
4344 struct extent_buffer *next;
4345 struct btrfs_key key;
4348 int old_spinning = path->leave_spinning;
4349 int force_blocking = 0;
4351 nritems = btrfs_header_nritems(path->nodes[0]);
4356 * we take the blocks in an order that upsets lockdep. Using
4357 * blocking mode is the only way around it.
4359 #ifdef CONFIG_DEBUG_LOCK_ALLOC
4363 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
4367 btrfs_release_path(root, path);
4369 path->keep_locks = 1;
4371 if (!force_blocking)
4372 path->leave_spinning = 1;
4374 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4375 path->keep_locks = 0;
4380 nritems = btrfs_header_nritems(path->nodes[0]);
4382 * by releasing the path above we dropped all our locks. A balance
4383 * could have added more items next to the key that used to be
4384 * at the very end of the block. So, check again here and
4385 * advance the path if there are now more items available.
4387 if (nritems > 0 && path->slots[0] < nritems - 1) {
4394 while (level < BTRFS_MAX_LEVEL) {
4395 if (!path->nodes[level]) {
4400 slot = path->slots[level] + 1;
4401 c = path->nodes[level];
4402 if (slot >= btrfs_header_nritems(c)) {
4404 if (level == BTRFS_MAX_LEVEL) {
4412 btrfs_tree_unlock(next);
4413 free_extent_buffer(next);
4417 ret = read_block_for_search(NULL, root, path, &next, level,
4423 btrfs_release_path(root, path);
4427 if (!path->skip_locking) {
4428 ret = btrfs_try_spin_lock(next);
4430 btrfs_set_path_blocking(path);
4431 btrfs_tree_lock(next);
4432 if (!force_blocking)
4433 btrfs_clear_path_blocking(path, next);
4436 btrfs_set_lock_blocking(next);
4440 path->slots[level] = slot;
4443 c = path->nodes[level];
4444 if (path->locks[level])
4445 btrfs_tree_unlock(c);
4447 free_extent_buffer(c);
4448 path->nodes[level] = next;
4449 path->slots[level] = 0;
4450 if (!path->skip_locking)
4451 path->locks[level] = 1;
4456 ret = read_block_for_search(NULL, root, path, &next, level,
4462 btrfs_release_path(root, path);
4466 if (!path->skip_locking) {
4467 btrfs_assert_tree_locked(path->nodes[level]);
4468 ret = btrfs_try_spin_lock(next);
4470 btrfs_set_path_blocking(path);
4471 btrfs_tree_lock(next);
4472 if (!force_blocking)
4473 btrfs_clear_path_blocking(path, next);
4476 btrfs_set_lock_blocking(next);
4481 unlock_up(path, 0, 1);
4482 path->leave_spinning = old_spinning;
4484 btrfs_set_path_blocking(path);
4490 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
4491 * searching until it gets past min_objectid or finds an item of 'type'
4493 * returns 0 if something is found, 1 if nothing was found and < 0 on error
4495 int btrfs_previous_item(struct btrfs_root *root,
4496 struct btrfs_path *path, u64 min_objectid,
4499 struct btrfs_key found_key;
4500 struct extent_buffer *leaf;
4505 if (path->slots[0] == 0) {
4506 btrfs_set_path_blocking(path);
4507 ret = btrfs_prev_leaf(root, path);
4513 leaf = path->nodes[0];
4514 nritems = btrfs_header_nritems(leaf);
4517 if (path->slots[0] == nritems)
4520 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4521 if (found_key.objectid < min_objectid)
4523 if (found_key.type == type)
4525 if (found_key.objectid == min_objectid &&
4526 found_key.type < type)