Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 4382 deletions

diff --git a/ANDROID_3.4.5/fs/btrfs/ctree.c b/ANDROID_3.4.5/fs/btrfs/ctree.c
deleted file mode 100644
index 4106264f..00000000
--- a/ANDROID_3.4.5/fs/btrfs/ctree.c
+++ /dev/null
@@ -1,4382 +0,0 @@
-/*
- * Copyright (C) 2007,2008 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include "ctree.h"
-#include "disk-io.h"
-#include "transaction.h"
-#include "print-tree.h"
-#include "locking.h"
-
-static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_path *path, int level);
-static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *ins_key,
-		      struct btrfs_path *path, int data_size, int extend);
-static int push_node_left(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root, struct extent_buffer *dst,
-			  struct extent_buffer *src, int empty);
-static int balance_node_right(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root,
-			      struct extent_buffer *dst_buf,
-			      struct extent_buffer *src_buf);
-static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		   struct btrfs_path *path, int level, int slot);
-
-struct btrfs_path *btrfs_alloc_path(void)
-{
-	struct btrfs_path *path;
-	path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
-	return path;
-}
-
-/*
- * set all locked nodes in the path to blocking locks.  This should
- * be done before scheduling
- */
-noinline void btrfs_set_path_blocking(struct btrfs_path *p)
-{
-	int i;
-	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
-		if (!p->nodes[i] || !p->locks[i])
-			continue;
-		btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]);
-		if (p->locks[i] == BTRFS_READ_LOCK)
-			p->locks[i] = BTRFS_READ_LOCK_BLOCKING;
-		else if (p->locks[i] == BTRFS_WRITE_LOCK)
-			p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING;
-	}
-}
-
-/*
- * reset all the locked nodes in the patch to spinning locks.
- *
- * held is used to keep lockdep happy, when lockdep is enabled
- * we set held to a blocking lock before we go around and
- * retake all the spinlocks in the path.  You can safely use NULL
- * for held
- */
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
-					struct extent_buffer *held, int held_rw)
-{
-	int i;
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	/* lockdep really cares that we take all of these spinlocks
-	 * in the right order.  If any of the locks in the path are not
-	 * currently blocking, it is going to complain.  So, make really
-	 * really sure by forcing the path to blocking before we clear
-	 * the path blocking.
-	 */
-	if (held) {
-		btrfs_set_lock_blocking_rw(held, held_rw);
-		if (held_rw == BTRFS_WRITE_LOCK)
-			held_rw = BTRFS_WRITE_LOCK_BLOCKING;
-		else if (held_rw == BTRFS_READ_LOCK)
-			held_rw = BTRFS_READ_LOCK_BLOCKING;
-	}
-	btrfs_set_path_blocking(p);
-#endif
-
-	for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
-		if (p->nodes[i] && p->locks[i]) {
-			btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]);
-			if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING)
-				p->locks[i] = BTRFS_WRITE_LOCK;
-			else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING)
-				p->locks[i] = BTRFS_READ_LOCK;
-		}
-	}
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	if (held)
-		btrfs_clear_lock_blocking_rw(held, held_rw);
-#endif
-}
-
-/* this also releases the path */
-void btrfs_free_path(struct btrfs_path *p)
-{
-	if (!p)
-		return;
-	btrfs_release_path(p);
-	kmem_cache_free(btrfs_path_cachep, p);
-}
-
-/*
- * path release drops references on the extent buffers in the path
- * and it drops any locks held by this path
- *
- * It is safe to call this on paths that no locks or extent buffers held.
- */
-noinline void btrfs_release_path(struct btrfs_path *p)
-{
-	int i;
-
-	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
-		p->slots[i] = 0;
-		if (!p->nodes[i])
-			continue;
-		if (p->locks[i]) {
-			btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]);
-			p->locks[i] = 0;
-		}
-		free_extent_buffer(p->nodes[i]);
-		p->nodes[i] = NULL;
-	}
-}
-
-/*
- * safely gets a reference on the root node of a tree.  A lock
- * is not taken, so a concurrent writer may put a different node
- * at the root of the tree.  See btrfs_lock_root_node for the
- * looping required.
- *
- * The extent buffer returned by this has a reference taken, so
- * it won't disappear.  It may stop being the root of the tree
- * at any time because there are no locks held.
- */
-struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
-{
-	struct extent_buffer *eb;
-
-	while (1) {
-		rcu_read_lock();
-		eb = rcu_dereference(root->node);
-
-		/*
-		 * RCU really hurts here, we could free up the root node because
-		 * it was cow'ed but we may not get the new root node yet so do
-		 * the inc_not_zero dance and if it doesn't work then
-		 * synchronize_rcu and try again.
-		 */
-		if (atomic_inc_not_zero(&eb->refs)) {
-			rcu_read_unlock();
-			break;
-		}
-		rcu_read_unlock();
-		synchronize_rcu();
-	}
-	return eb;
-}
-
-/* loop around taking references on and locking the root node of the
- * tree until you end up with a lock on the root.  A locked buffer
- * is returned, with a reference held.
- */
-struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
-{
-	struct extent_buffer *eb;
-
-	while (1) {
-		eb = btrfs_root_node(root);
-		btrfs_tree_lock(eb);
-		if (eb == root->node)
-			break;
-		btrfs_tree_unlock(eb);
-		free_extent_buffer(eb);
-	}
-	return eb;
-}
-
-/* loop around taking references on and locking the root node of the
- * tree until you end up with a lock on the root.  A locked buffer
- * is returned, with a reference held.
- */
-struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)
-{
-	struct extent_buffer *eb;
-
-	while (1) {
-		eb = btrfs_root_node(root);
-		btrfs_tree_read_lock(eb);
-		if (eb == root->node)
-			break;
-		btrfs_tree_read_unlock(eb);
-		free_extent_buffer(eb);
-	}
-	return eb;
-}
-
-/* cowonly root (everything not a reference counted cow subvolume), just get
- * put onto a simple dirty list.  transaction.c walks this to make sure they
- * get properly updated on disk.
- */
-static void add_root_to_dirty_list(struct btrfs_root *root)
-{
-	spin_lock(&root->fs_info->trans_lock);
-	if (root->track_dirty && list_empty(&root->dirty_list)) {
-		list_add(&root->dirty_list,
-			 &root->fs_info->dirty_cowonly_roots);
-	}
-	spin_unlock(&root->fs_info->trans_lock);
-}
-
-/*
- * used by snapshot creation to make a copy of a root for a tree with
- * a given objectid.  The buffer with the new root node is returned in
- * cow_ret, and this func returns zero on success or a negative error code.
- */
-int btrfs_copy_root(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root,
-		      struct extent_buffer *buf,
-		      struct extent_buffer **cow_ret, u64 new_root_objectid)
-{
-	struct extent_buffer *cow;
-	int ret = 0;
-	int level;
-	struct btrfs_disk_key disk_key;
-
-	WARN_ON(root->ref_cows && trans->transid !=
-		root->fs_info->running_transaction->transid);
-	WARN_ON(root->ref_cows && trans->transid != root->last_trans);
-
-	level = btrfs_header_level(buf);
-	if (level == 0)
-		btrfs_item_key(buf, &disk_key, 0);
-	else
-		btrfs_node_key(buf, &disk_key, 0);
-
-	cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
-				     new_root_objectid, &disk_key, level,
-				     buf->start, 0, 1);
-	if (IS_ERR(cow))
-		return PTR_ERR(cow);
-
-	copy_extent_buffer(cow, buf, 0, 0, cow->len);
-	btrfs_set_header_bytenr(cow, cow->start);
-	btrfs_set_header_generation(cow, trans->transid);
-	btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
-	btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
-				     BTRFS_HEADER_FLAG_RELOC);
-	if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
-		btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
-	else
-		btrfs_set_header_owner(cow, new_root_objectid);
-
-	write_extent_buffer(cow, root->fs_info->fsid,
-			    (unsigned long)btrfs_header_fsid(cow),
-			    BTRFS_FSID_SIZE);
-
-	WARN_ON(btrfs_header_generation(buf) > trans->transid);
-	if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
-		ret = btrfs_inc_ref(trans, root, cow, 1, 1);
-	else
-		ret = btrfs_inc_ref(trans, root, cow, 0, 1);
-
-	if (ret)
-		return ret;
-
-	btrfs_mark_buffer_dirty(cow);
-	*cow_ret = cow;
-	return 0;
-}
-
-/*
- * check if the tree block can be shared by multiple trees
- */
-int btrfs_block_can_be_shared(struct btrfs_root *root,
-			      struct extent_buffer *buf)
-{
-	/*
-	 * Tree blocks not in refernece counted trees and tree roots
-	 * are never shared. If a block was allocated after the last
-	 * snapshot and the block was not allocated by tree relocation,
-	 * we know the block is not shared.
-	 */
-	if (root->ref_cows &&
-	    buf != root->node && buf != root->commit_root &&
-	    (btrfs_header_generation(buf) <=
-	     btrfs_root_last_snapshot(&root->root_item) ||
-	     btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
-		return 1;
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (root->ref_cows &&
-	    btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
-		return 1;
-#endif
-	return 0;
-}
-
-static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
-				       struct btrfs_root *root,
-				       struct extent_buffer *buf,
-				       struct extent_buffer *cow,
-				       int *last_ref)
-{
-	u64 refs;
-	u64 owner;
-	u64 flags;
-	u64 new_flags = 0;
-	int ret;
-
-	/*
-	 * Backrefs update rules:
-	 *
-	 * Always use full backrefs for extent pointers in tree block
-	 * allocated by tree relocation.
-	 *
-	 * If a shared tree block is no longer referenced by its owner
-	 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
-	 * use full backrefs for extent pointers in tree block.
-	 *
-	 * If a tree block is been relocating
-	 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
-	 * use full backrefs for extent pointers in tree block.
-	 * The reason for this is some operations (such as drop tree)
-	 * are only allowed for blocks use full backrefs.
-	 */
-
-	if (btrfs_block_can_be_shared(root, buf)) {
-		ret = btrfs_lookup_extent_info(trans, root, buf->start,
-					       buf->len, &refs, &flags);
-		if (ret)
-			return ret;
-		if (refs == 0) {
-			ret = -EROFS;
-			btrfs_std_error(root->fs_info, ret);
-			return ret;
-		}
-	} else {
-		refs = 1;
-		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
-		    btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
-			flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-		else
-			flags = 0;
-	}
-
-	owner = btrfs_header_owner(buf);
-	BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID &&
-	       !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
-
-	if (refs > 1) {
-		if ((owner == root->root_key.objectid ||
-		     root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
-		    !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
-			ret = btrfs_inc_ref(trans, root, buf, 1, 1);
-			BUG_ON(ret); /* -ENOMEM */
-
-			if (root->root_key.objectid ==
-			    BTRFS_TREE_RELOC_OBJECTID) {
-				ret = btrfs_dec_ref(trans, root, buf, 0, 1);
-				BUG_ON(ret); /* -ENOMEM */
-				ret = btrfs_inc_ref(trans, root, cow, 1, 1);
-				BUG_ON(ret); /* -ENOMEM */
-			}
-			new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
-		} else {
-
-			if (root->root_key.objectid ==
-			    BTRFS_TREE_RELOC_OBJECTID)
-				ret = btrfs_inc_ref(trans, root, cow, 1, 1);
-			else
-				ret = btrfs_inc_ref(trans, root, cow, 0, 1);
-			BUG_ON(ret); /* -ENOMEM */
-		}
-		if (new_flags != 0) {
-			ret = btrfs_set_disk_extent_flags(trans, root,
-							  buf->start,
-							  buf->len,
-							  new_flags, 0);
-			if (ret)
-				return ret;
-		}
-	} else {
-		if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
-			if (root->root_key.objectid ==
-			    BTRFS_TREE_RELOC_OBJECTID)
-				ret = btrfs_inc_ref(trans, root, cow, 1, 1);
-			else
-				ret = btrfs_inc_ref(trans, root, cow, 0, 1);
-			BUG_ON(ret); /* -ENOMEM */
-			ret = btrfs_dec_ref(trans, root, buf, 1, 1);
-			BUG_ON(ret); /* -ENOMEM */
-		}
-		clean_tree_block(trans, root, buf);
-		*last_ref = 1;
-	}
-	return 0;
-}
-
-/*
- * does the dirty work in cow of a single block.  The parent block (if
- * supplied) is updated to point to the new cow copy.  The new buffer is marked
- * dirty and returned locked.  If you modify the block it needs to be marked
- * dirty again.
- *
- * search_start -- an allocation hint for the new block
- *
- * empty_size -- a hint that you plan on doing more cow.  This is the size in
- * bytes the allocator should try to find free next to the block it returns.
- * This is just a hint and may be ignored by the allocator.
- */
-static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root,
-			     struct extent_buffer *buf,
-			     struct extent_buffer *parent, int parent_slot,
-			     struct extent_buffer **cow_ret,
-			     u64 search_start, u64 empty_size)
-{
-	struct btrfs_disk_key disk_key;
-	struct extent_buffer *cow;
-	int level, ret;
-	int last_ref = 0;
-	int unlock_orig = 0;
-	u64 parent_start;
-
-	if (*cow_ret == buf)
-		unlock_orig = 1;
-
-	btrfs_assert_tree_locked(buf);
-
-	WARN_ON(root->ref_cows && trans->transid !=
-		root->fs_info->running_transaction->transid);
-	WARN_ON(root->ref_cows && trans->transid != root->last_trans);
-
-	level = btrfs_header_level(buf);
-
-	if (level == 0)
-		btrfs_item_key(buf, &disk_key, 0);
-	else
-		btrfs_node_key(buf, &disk_key, 0);
-
-	if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
-		if (parent)
-			parent_start = parent->start;
-		else
-			parent_start = 0;
-	} else
-		parent_start = 0;
-
-	cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
-				     root->root_key.objectid, &disk_key,
-				     level, search_start, empty_size, 1);
-	if (IS_ERR(cow))
-		return PTR_ERR(cow);
-
-	/* cow is set to blocking by btrfs_init_new_buffer */
-
-	copy_extent_buffer(cow, buf, 0, 0, cow->len);
-	btrfs_set_header_bytenr(cow, cow->start);
-	btrfs_set_header_generation(cow, trans->transid);
-	btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
-	btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
-				     BTRFS_HEADER_FLAG_RELOC);
-	if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
-		btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
-	else
-		btrfs_set_header_owner(cow, root->root_key.objectid);
-
-	write_extent_buffer(cow, root->fs_info->fsid,
-			    (unsigned long)btrfs_header_fsid(cow),
-			    BTRFS_FSID_SIZE);
-
-	ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);
-	if (ret) {
-		btrfs_abort_transaction(trans, root, ret);
-		return ret;
-	}
-
-	if (root->ref_cows)
-		btrfs_reloc_cow_block(trans, root, buf, cow);
-
-	if (buf == root->node) {
-		WARN_ON(parent && parent != buf);
-		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
-		    btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
-			parent_start = buf->start;
-		else
-			parent_start = 0;
-
-		extent_buffer_get(cow);
-		rcu_assign_pointer(root->node, cow);
-
-		btrfs_free_tree_block(trans, root, buf, parent_start,
-				      last_ref, 1);
-		free_extent_buffer(buf);
-		add_root_to_dirty_list(root);
-	} else {
-		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
-			parent_start = parent->start;
-		else
-			parent_start = 0;
-
-		WARN_ON(trans->transid != btrfs_header_generation(parent));
-		btrfs_set_node_blockptr(parent, parent_slot,
-					cow->start);
-		btrfs_set_node_ptr_generation(parent, parent_slot,
-					      trans->transid);
-		btrfs_mark_buffer_dirty(parent);
-		btrfs_free_tree_block(trans, root, buf, parent_start,
-				      last_ref, 1);
-	}
-	if (unlock_orig)
-		btrfs_tree_unlock(buf);
-	free_extent_buffer_stale(buf);
-	btrfs_mark_buffer_dirty(cow);
-	*cow_ret = cow;
-	return 0;
-}
-
-static inline int should_cow_block(struct btrfs_trans_handle *trans,
-				   struct btrfs_root *root,
-				   struct extent_buffer *buf)
-{
-	/* ensure we can see the force_cow */
-	smp_rmb();
-
-	/*
-	 * We do not need to cow a block if
-	 * 1) this block is not created or changed in this transaction;
-	 * 2) this block does not belong to TREE_RELOC tree;
-	 * 3) the root is not forced COW.
-	 *
-	 * What is forced COW:
-	 *    when we create snapshot during commiting the transaction,
-	 *    after we've finished coping src root, we must COW the shared
-	 *    block to ensure the metadata consistency.
-	 */
-	if (btrfs_header_generation(buf) == trans->transid &&
-	    !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
-	    !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
-	      btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) &&
-	    !root->force_cow)
-		return 0;
-	return 1;
-}
-
-/*
- * cows a single block, see __btrfs_cow_block for the real work.
- * This version of it has extra checks so that a block isn't cow'd more than
- * once per transaction, as long as it hasn't been written yet
- */
-noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
-		    struct btrfs_root *root, struct extent_buffer *buf,
-		    struct extent_buffer *parent, int parent_slot,
-		    struct extent_buffer **cow_ret)
-{
-	u64 search_start;
-	int ret;
-
-	if (trans->transaction != root->fs_info->running_transaction) {
-		printk(KERN_CRIT "trans %llu running %llu\n",
-		       (unsigned long long)trans->transid,
-		       (unsigned long long)
-		       root->fs_info->running_transaction->transid);
-		WARN_ON(1);
-	}
-	if (trans->transid != root->fs_info->generation) {
-		printk(KERN_CRIT "trans %llu running %llu\n",
-		       (unsigned long long)trans->transid,
-		       (unsigned long long)root->fs_info->generation);
-		WARN_ON(1);
-	}
-
-	if (!should_cow_block(trans, root, buf)) {
-		*cow_ret = buf;
-		return 0;
-	}
-
-	search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
-
-	if (parent)
-		btrfs_set_lock_blocking(parent);
-	btrfs_set_lock_blocking(buf);
-
-	ret = __btrfs_cow_block(trans, root, buf, parent,
-				 parent_slot, cow_ret, search_start, 0);
-
-	trace_btrfs_cow_block(root, buf, *cow_ret);
-
-	return ret;
-}
-
-/*
- * helper function for defrag to decide if two blocks pointed to by a
- * node are actually close by
- */
-static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
-{
-	if (blocknr < other && other - (blocknr + blocksize) < 32768)
-		return 1;
-	if (blocknr > other && blocknr - (other + blocksize) < 32768)
-		return 1;
-	return 0;
-}
-
-/*
- * compare two keys in a memcmp fashion
- */
-static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
-{
-	struct btrfs_key k1;
-
-	btrfs_disk_key_to_cpu(&k1, disk);
-
-	return btrfs_comp_cpu_keys(&k1, k2);
-}
-
-/*
- * same as comp_keys only with two btrfs_key's
- */
-int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
-{
-	if (k1->objectid > k2->objectid)
-		return 1;
-	if (k1->objectid < k2->objectid)
-		return -1;
-	if (k1->type > k2->type)
-		return 1;
-	if (k1->type < k2->type)
-		return -1;
-	if (k1->offset > k2->offset)
-		return 1;
-	if (k1->offset < k2->offset)
-		return -1;
-	return 0;
-}
-
-/*
- * this is used by the defrag code to go through all the
- * leaves pointed to by a node and reallocate them so that
- * disk order is close to key order
- */
-int btrfs_realloc_node(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct extent_buffer *parent,
-		       int start_slot, int cache_only, u64 *last_ret,
-		       struct btrfs_key *progress)
-{
-	struct extent_buffer *cur;
-	u64 blocknr;
-	u64 gen;
-	u64 search_start = *last_ret;
-	u64 last_block = 0;
-	u64 other;
-	u32 parent_nritems;
-	int end_slot;
-	int i;
-	int err = 0;
-	int parent_level;
-	int uptodate;
-	u32 blocksize;
-	int progress_passed = 0;
-	struct btrfs_disk_key disk_key;
-
-	parent_level = btrfs_header_level(parent);
-	if (cache_only && parent_level != 1)
-		return 0;
-
-	if (trans->transaction != root->fs_info->running_transaction)
-		WARN_ON(1);
-	if (trans->transid != root->fs_info->generation)
-		WARN_ON(1);
-
-	parent_nritems = btrfs_header_nritems(parent);
-	blocksize = btrfs_level_size(root, parent_level - 1);
-	end_slot = parent_nritems;
-
-	if (parent_nritems == 1)
-		return 0;
-
-	btrfs_set_lock_blocking(parent);
-
-	for (i = start_slot; i < end_slot; i++) {
-		int close = 1;
-
-		btrfs_node_key(parent, &disk_key, i);
-		if (!progress_passed && comp_keys(&disk_key, progress) < 0)
-			continue;
-
-		progress_passed = 1;
-		blocknr = btrfs_node_blockptr(parent, i);
-		gen = btrfs_node_ptr_generation(parent, i);
-		if (last_block == 0)
-			last_block = blocknr;
-
-		if (i > 0) {
-			other = btrfs_node_blockptr(parent, i - 1);
-			close = close_blocks(blocknr, other, blocksize);
-		}
-		if (!close && i < end_slot - 2) {
-			other = btrfs_node_blockptr(parent, i + 1);
-			close = close_blocks(blocknr, other, blocksize);
-		}
-		if (close) {
-			last_block = blocknr;
-			continue;
-		}
-
-		cur = btrfs_find_tree_block(root, blocknr, blocksize);
-		if (cur)
-			uptodate = btrfs_buffer_uptodate(cur, gen, 0);
-		else
-			uptodate = 0;
-		if (!cur || !uptodate) {
-			if (cache_only) {
-				free_extent_buffer(cur);
-				continue;
-			}
-			if (!cur) {
-				cur = read_tree_block(root, blocknr,
-							 blocksize, gen);
-				if (!cur)
-					return -EIO;
-			} else if (!uptodate) {
-				btrfs_read_buffer(cur, gen);
-			}
-		}
-		if (search_start == 0)
-			search_start = last_block;
-
-		btrfs_tree_lock(cur);
-		btrfs_set_lock_blocking(cur);
-		err = __btrfs_cow_block(trans, root, cur, parent, i,
-					&cur, search_start,
-					min(16 * blocksize,
-					    (end_slot - i) * blocksize));
-		if (err) {
-			btrfs_tree_unlock(cur);
-			free_extent_buffer(cur);
-			break;
-		}
-		search_start = cur->start;
-		last_block = cur->start;
-		*last_ret = search_start;
-		btrfs_tree_unlock(cur);
-		free_extent_buffer(cur);
-	}
-	return err;
-}
-
-/*
- * The leaf data grows from end-to-front in the node.
- * this returns the address of the start of the last item,
- * which is the stop of the leaf data stack
- */
-static inline unsigned int leaf_data_end(struct btrfs_root *root,
-					 struct extent_buffer *leaf)
-{
-	u32 nr = btrfs_header_nritems(leaf);
-	if (nr == 0)
-		return BTRFS_LEAF_DATA_SIZE(root);
-	return btrfs_item_offset_nr(leaf, nr - 1);
-}
-
-
-/*
- * search for key in the extent_buffer.  The items start at offset p,
- * and they are item_size apart.  There are 'max' items in p.
- *
- * the slot in the array is returned via slot, and it points to
- * the place where you would insert key if it is not found in
- * the array.
- *
- * slot may point to max if the key is bigger than all of the keys
- */
-static noinline int generic_bin_search(struct extent_buffer *eb,
-				       unsigned long p,
-				       int item_size, struct btrfs_key *key,
-				       int max, int *slot)
-{
-	int low = 0;
-	int high = max;
-	int mid;
-	int ret;
-	struct btrfs_disk_key *tmp = NULL;
-	struct btrfs_disk_key unaligned;
-	unsigned long offset;
-	char *kaddr = NULL;
-	unsigned long map_start = 0;
-	unsigned long map_len = 0;
-	int err;
-
-	while (low < high) {
-		mid = (low + high) / 2;
-		offset = p + mid * item_size;
-
-		if (!kaddr || offset < map_start ||
-		    (offset + sizeof(struct btrfs_disk_key)) >
-		    map_start + map_len) {
-
-			err = map_private_extent_buffer(eb, offset,
-						sizeof(struct btrfs_disk_key),
-						&kaddr, &map_start, &map_len);
-
-			if (!err) {
-				tmp = (struct btrfs_disk_key *)(kaddr + offset -
-							map_start);
-			} else {
-				read_extent_buffer(eb, &unaligned,
-						   offset, sizeof(unaligned));
-				tmp = &unaligned;
-			}
-
-		} else {
-			tmp = (struct btrfs_disk_key *)(kaddr + offset -
-							map_start);
-		}
-		ret = comp_keys(tmp, key);
-
-		if (ret < 0)
-			low = mid + 1;
-		else if (ret > 0)
-			high = mid;
-		else {
-			*slot = mid;
-			return 0;
-		}
-	}
-	*slot = low;
-	return 1;
-}
-
-/*
- * simple bin_search frontend that does the right thing for
- * leaves vs nodes
- */
-static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
-		      int level, int *slot)
-{
-	if (level == 0) {
-		return generic_bin_search(eb,
-					  offsetof(struct btrfs_leaf, items),
-					  sizeof(struct btrfs_item),
-					  key, btrfs_header_nritems(eb),
-					  slot);
-	} else {
-		return generic_bin_search(eb,
-					  offsetof(struct btrfs_node, ptrs),
-					  sizeof(struct btrfs_key_ptr),
-					  key, btrfs_header_nritems(eb),
-					  slot);
-	}
-	return -1;
-}
-
-int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
-		     int level, int *slot)
-{
-	return bin_search(eb, key, level, slot);
-}
-
-static void root_add_used(struct btrfs_root *root, u32 size)
-{
-	spin_lock(&root->accounting_lock);
-	btrfs_set_root_used(&root->root_item,
-			    btrfs_root_used(&root->root_item) + size);
-	spin_unlock(&root->accounting_lock);
-}
-
-static void root_sub_used(struct btrfs_root *root, u32 size)
-{
-	spin_lock(&root->accounting_lock);
-	btrfs_set_root_used(&root->root_item,
-			    btrfs_root_used(&root->root_item) - size);
-	spin_unlock(&root->accounting_lock);
-}
-
-/* given a node and slot number, this reads the blocks it points to.  The
- * extent buffer is returned with a reference taken (but unlocked).
- * NULL is returned on error.
- */
-static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
-				   struct extent_buffer *parent, int slot)
-{
-	int level = btrfs_header_level(parent);
-	if (slot < 0)
-		return NULL;
-	if (slot >= btrfs_header_nritems(parent))
-		return NULL;
-
-	BUG_ON(level == 0);
-
-	return read_tree_block(root, btrfs_node_blockptr(parent, slot),
-		       btrfs_level_size(root, level - 1),
-		       btrfs_node_ptr_generation(parent, slot));
-}
-
-/*
- * node level balancing, used to make sure nodes are in proper order for
- * item deletion.  We balance from the top down, so we have to make sure
- * that a deletion won't leave an node completely empty later on.
- */
-static noinline int balance_level(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 struct btrfs_path *path, int level)
-{
-	struct extent_buffer *right = NULL;
-	struct extent_buffer *mid;
-	struct extent_buffer *left = NULL;
-	struct extent_buffer *parent = NULL;
-	int ret = 0;
-	int wret;
-	int pslot;
-	int orig_slot = path->slots[level];
-	u64 orig_ptr;
-
-	if (level == 0)
-		return 0;
-
-	mid = path->nodes[level];
-
-	WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK &&
-		path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING);
-	WARN_ON(btrfs_header_generation(mid) != trans->transid);
-
-	orig_ptr = btrfs_node_blockptr(mid, orig_slot);
-
-	if (level < BTRFS_MAX_LEVEL - 1) {
-		parent = path->nodes[level + 1];
-		pslot = path->slots[level + 1];
-	}
-
-	/*
-	 * deal with the case where there is only one pointer in the root
-	 * by promoting the node below to a root
-	 */
-	if (!parent) {
-		struct extent_buffer *child;
-
-		if (btrfs_header_nritems(mid) != 1)
-			return 0;
-
-		/* promote the child to a root */
-		child = read_node_slot(root, mid, 0);
-		if (!child) {
-			ret = -EROFS;
-			btrfs_std_error(root->fs_info, ret);
-			goto enospc;
-		}
-
-		btrfs_tree_lock(child);
-		btrfs_set_lock_blocking(child);
-		ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
-		if (ret) {
-			btrfs_tree_unlock(child);
-			free_extent_buffer(child);
-			goto enospc;
-		}
-
-		rcu_assign_pointer(root->node, child);
-
-		add_root_to_dirty_list(root);
-		btrfs_tree_unlock(child);
-
-		path->locks[level] = 0;
-		path->nodes[level] = NULL;
-		clean_tree_block(trans, root, mid);
-		btrfs_tree_unlock(mid);
-		/* once for the path */
-		free_extent_buffer(mid);
-
-		root_sub_used(root, mid->len);
-		btrfs_free_tree_block(trans, root, mid, 0, 1, 0);
-		/* once for the root ptr */
-		free_extent_buffer_stale(mid);
-		return 0;
-	}
-	if (btrfs_header_nritems(mid) >
-	    BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
-		return 0;
-
-	btrfs_header_nritems(mid);
-
-	left = read_node_slot(root, parent, pslot - 1);
-	if (left) {
-		btrfs_tree_lock(left);
-		btrfs_set_lock_blocking(left);
-		wret = btrfs_cow_block(trans, root, left,
-				       parent, pslot - 1, &left);
-		if (wret) {
-			ret = wret;
-			goto enospc;
-		}
-	}
-	right = read_node_slot(root, parent, pslot + 1);
-	if (right) {
-		btrfs_tree_lock(right);
-		btrfs_set_lock_blocking(right);
-		wret = btrfs_cow_block(trans, root, right,
-				       parent, pslot + 1, &right);
-		if (wret) {
-			ret = wret;
-			goto enospc;
-		}
-	}
-
-	/* first, try to make some room in the middle buffer */
-	if (left) {
-		orig_slot += btrfs_header_nritems(left);
-		wret = push_node_left(trans, root, left, mid, 1);
-		if (wret < 0)
-			ret = wret;
-		btrfs_header_nritems(mid);
-	}
-
-	/*
-	 * then try to empty the right most buffer into the middle
-	 */
-	if (right) {
-		wret = push_node_left(trans, root, mid, right, 1);
-		if (wret < 0 && wret != -ENOSPC)
-			ret = wret;
-		if (btrfs_header_nritems(right) == 0) {
-			clean_tree_block(trans, root, right);
-			btrfs_tree_unlock(right);
-			del_ptr(trans, root, path, level + 1, pslot + 1);
-			root_sub_used(root, right->len);
-			btrfs_free_tree_block(trans, root, right, 0, 1, 0);
-			free_extent_buffer_stale(right);
-			right = NULL;
-		} else {
-			struct btrfs_disk_key right_key;
-			btrfs_node_key(right, &right_key, 0);
-			btrfs_set_node_key(parent, &right_key, pslot + 1);
-			btrfs_mark_buffer_dirty(parent);
-		}
-	}
-	if (btrfs_header_nritems(mid) == 1) {
-		/*
-		 * we're not allowed to leave a node with one item in the
-		 * tree during a delete.  A deletion from lower in the tree
-		 * could try to delete the only pointer in this node.
-		 * So, pull some keys from the left.
-		 * There has to be a left pointer at this point because
-		 * otherwise we would have pulled some pointers from the
-		 * right
-		 */
-		if (!left) {
-			ret = -EROFS;
-			btrfs_std_error(root->fs_info, ret);
-			goto enospc;
-		}
-		wret = balance_node_right(trans, root, mid, left);
-		if (wret < 0) {
-			ret = wret;
-			goto enospc;
-		}
-		if (wret == 1) {
-			wret = push_node_left(trans, root, left, mid, 1);
-			if (wret < 0)
-				ret = wret;
-		}
-		BUG_ON(wret == 1);
-	}
-	if (btrfs_header_nritems(mid) == 0) {
-		clean_tree_block(trans, root, mid);
-		btrfs_tree_unlock(mid);
-		del_ptr(trans, root, path, level + 1, pslot);
-		root_sub_used(root, mid->len);
-		btrfs_free_tree_block(trans, root, mid, 0, 1, 0);
-		free_extent_buffer_stale(mid);
-		mid = NULL;
-	} else {
-		/* update the parent key to reflect our changes */
-		struct btrfs_disk_key mid_key;
-		btrfs_node_key(mid, &mid_key, 0);
-		btrfs_set_node_key(parent, &mid_key, pslot);
-		btrfs_mark_buffer_dirty(parent);
-	}
-
-	/* update the path */
-	if (left) {
-		if (btrfs_header_nritems(left) > orig_slot) {
-			extent_buffer_get(left);
-			/* left was locked after cow */
-			path->nodes[level] = left;
-			path->slots[level + 1] -= 1;
-			path->slots[level] = orig_slot;
-			if (mid) {
-				btrfs_tree_unlock(mid);
-				free_extent_buffer(mid);
-			}
-		} else {
-			orig_slot -= btrfs_header_nritems(left);
-			path->slots[level] = orig_slot;
-		}
-	}
-	/* double check we haven't messed things up */
-	if (orig_ptr !=
-	    btrfs_node_blockptr(path->nodes[level], path->slots[level]))
-		BUG();
-enospc:
-	if (right) {
-		btrfs_tree_unlock(right);
-		free_extent_buffer(right);
-	}
-	if (left) {
-		if (path->nodes[level] != left)
-			btrfs_tree_unlock(left);
-		free_extent_buffer(left);
-	}
-	return ret;
-}
-
-/* Node balancing for insertion.  Here we only split or push nodes around
- * when they are completely full.  This is also done top down, so we
- * have to be pessimistic.
- */
-static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
-					  struct btrfs_root *root,
-					  struct btrfs_path *path, int level)
-{
-	struct extent_buffer *right = NULL;
-	struct extent_buffer *mid;
-	struct extent_buffer *left = NULL;
-	struct extent_buffer *parent = NULL;
-	int ret = 0;
-	int wret;
-	int pslot;
-	int orig_slot = path->slots[level];
-
-	if (level == 0)
-		return 1;
-
-	mid = path->nodes[level];
-	WARN_ON(btrfs_header_generation(mid) != trans->transid);
-
-	if (level < BTRFS_MAX_LEVEL - 1) {
-		parent = path->nodes[level + 1];
-		pslot = path->slots[level + 1];
-	}
-
-	if (!parent)
-		return 1;
-
-	left = read_node_slot(root, parent, pslot - 1);
-
-	/* first, try to make some room in the middle buffer */
-	if (left) {
-		u32 left_nr;
-
-		btrfs_tree_lock(left);
-		btrfs_set_lock_blocking(left);
-
-		left_nr = btrfs_header_nritems(left);
-		if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
-			wret = 1;
-		} else {
-			ret = btrfs_cow_block(trans, root, left, parent,
-					      pslot - 1, &left);
-			if (ret)
-				wret = 1;
-			else {
-				wret = push_node_left(trans, root,
-						      left, mid, 0);
-			}
-		}
-		if (wret < 0)
-			ret = wret;
-		if (wret == 0) {
-			struct btrfs_disk_key disk_key;
-			orig_slot += left_nr;
-			btrfs_node_key(mid, &disk_key, 0);
-			btrfs_set_node_key(parent, &disk_key, pslot);
-			btrfs_mark_buffer_dirty(parent);
-			if (btrfs_header_nritems(left) > orig_slot) {
-				path->nodes[level] = left;
-				path->slots[level + 1] -= 1;
-				path->slots[level] = orig_slot;
-				btrfs_tree_unlock(mid);
-				free_extent_buffer(mid);
-			} else {
-				orig_slot -=
-					btrfs_header_nritems(left);
-				path->slots[level] = orig_slot;
-				btrfs_tree_unlock(left);
-				free_extent_buffer(left);
-			}
-			return 0;
-		}
-		btrfs_tree_unlock(left);
-		free_extent_buffer(left);
-	}
-	right = read_node_slot(root, parent, pslot + 1);
-
-	/*
-	 * then try to empty the right most buffer into the middle
-	 */
-	if (right) {
-		u32 right_nr;
-
-		btrfs_tree_lock(right);
-		btrfs_set_lock_blocking(right);
-
-		right_nr = btrfs_header_nritems(right);
-		if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
-			wret = 1;
-		} else {
-			ret = btrfs_cow_block(trans, root, right,
-					      parent, pslot + 1,
-					      &right);
-			if (ret)
-				wret = 1;
-			else {
-				wret = balance_node_right(trans, root,
-							  right, mid);
-			}
-		}
-		if (wret < 0)
-			ret = wret;
-		if (wret == 0) {
-			struct btrfs_disk_key disk_key;
-
-			btrfs_node_key(right, &disk_key, 0);
-			btrfs_set_node_key(parent, &disk_key, pslot + 1);
-			btrfs_mark_buffer_dirty(parent);
-
-			if (btrfs_header_nritems(mid) <= orig_slot) {
-				path->nodes[level] = right;
-				path->slots[level + 1] += 1;
-				path->slots[level] = orig_slot -
-					btrfs_header_nritems(mid);
-				btrfs_tree_unlock(mid);
-				free_extent_buffer(mid);
-			} else {
-				btrfs_tree_unlock(right);
-				free_extent_buffer(right);
-			}
-			return 0;
-		}
-		btrfs_tree_unlock(right);
-		free_extent_buffer(right);
-	}
-	return 1;
-}
-
-/*
- * readahead one full node of leaves, finding things that are close
- * to the block in 'slot', and triggering ra on them.
- */
-static void reada_for_search(struct btrfs_root *root,
-			     struct btrfs_path *path,
-			     int level, int slot, u64 objectid)
-{
-	struct extent_buffer *node;
-	struct btrfs_disk_key disk_key;
-	u32 nritems;
-	u64 search;
-	u64 target;
-	u64 nread = 0;
-	u64 gen;
-	int direction = path->reada;
-	struct extent_buffer *eb;
-	u32 nr;
-	u32 blocksize;
-	u32 nscan = 0;
-
-	if (level != 1)
-		return;
-
-	if (!path->nodes[level])
-		return;
-
-	node = path->nodes[level];
-
-	search = btrfs_node_blockptr(node, slot);
-	blocksize = btrfs_level_size(root, level - 1);
-	eb = btrfs_find_tree_block(root, search, blocksize);
-	if (eb) {
-		free_extent_buffer(eb);
-		return;
-	}
-
-	target = search;
-
-	nritems = btrfs_header_nritems(node);
-	nr = slot;
-
-	while (1) {
-		if (direction < 0) {
-			if (nr == 0)
-				break;
-			nr--;
-		} else if (direction > 0) {
-			nr++;
-			if (nr >= nritems)
-				break;
-		}
-		if (path->reada < 0 && objectid) {
-			btrfs_node_key(node, &disk_key, nr);
-			if (btrfs_disk_key_objectid(&disk_key) != objectid)
-				break;
-		}
-		search = btrfs_node_blockptr(node, nr);
-		if ((search <= target && target - search <= 65536) ||
-		    (search > target && search - target <= 65536)) {
-			gen = btrfs_node_ptr_generation(node, nr);
-			readahead_tree_block(root, search, blocksize, gen);
-			nread += blocksize;
-		}
-		nscan++;
-		if ((nread > 65536 || nscan > 32))
-			break;
-	}
-}
-
-/*
- * returns -EAGAIN if it had to drop the path, or zero if everything was in
- * cache
- */
-static noinline int reada_for_balance(struct btrfs_root *root,
-				      struct btrfs_path *path, int level)
-{
-	int slot;
-	int nritems;
-	struct extent_buffer *parent;
-	struct extent_buffer *eb;
-	u64 gen;
-	u64 block1 = 0;
-	u64 block2 = 0;
-	int ret = 0;
-	int blocksize;
-
-	parent = path->nodes[level + 1];
-	if (!parent)
-		return 0;
-
-	nritems = btrfs_header_nritems(parent);
-	slot = path->slots[level + 1];
-	blocksize = btrfs_level_size(root, level);
-
-	if (slot > 0) {
-		block1 = btrfs_node_blockptr(parent, slot - 1);
-		gen = btrfs_node_ptr_generation(parent, slot - 1);
-		eb = btrfs_find_tree_block(root, block1, blocksize);
-		/*
-		 * if we get -eagain from btrfs_buffer_uptodate, we
-		 * don't want to return eagain here.  That will loop
-		 * forever
-		 */
-		if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0)
-			block1 = 0;
-		free_extent_buffer(eb);
-	}
-	if (slot + 1 < nritems) {
-		block2 = btrfs_node_blockptr(parent, slot + 1);
-		gen = btrfs_node_ptr_generation(parent, slot + 1);
-		eb = btrfs_find_tree_block(root, block2, blocksize);
-		if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0)
-			block2 = 0;
-		free_extent_buffer(eb);
-	}
-	if (block1 || block2) {
-		ret = -EAGAIN;
-
-		/* release the whole path */
-		btrfs_release_path(path);
-
-		/* read the blocks */
-		if (block1)
-			readahead_tree_block(root, block1, blocksize, 0);
-		if (block2)
-			readahead_tree_block(root, block2, blocksize, 0);
-
-		if (block1) {
-			eb = read_tree_block(root, block1, blocksize, 0);
-			free_extent_buffer(eb);
-		}
-		if (block2) {
-			eb = read_tree_block(root, block2, blocksize, 0);
-			free_extent_buffer(eb);
-		}
-	}
-	return ret;
-}
-
-
-/*
- * when we walk down the tree, it is usually safe to unlock the higher layers
- * in the tree.  The exceptions are when our path goes through slot 0, because
- * operations on the tree might require changing key pointers higher up in the
- * tree.
- *
- * callers might also have set path->keep_locks, which tells this code to keep
- * the lock if the path points to the last slot in the block.  This is part of
- * walking through the tree, and selecting the next slot in the higher block.
- *
- * lowest_unlock sets the lowest level in the tree we're allowed to unlock.  so
- * if lowest_unlock is 1, level 0 won't be unlocked
- */
-static noinline void unlock_up(struct btrfs_path *path, int level,
-			       int lowest_unlock, int min_write_lock_level,
-			       int *write_lock_level)
-{
-	int i;
-	int skip_level = level;
-	int no_skips = 0;
-	struct extent_buffer *t;
-
-	for (i = level; i < BTRFS_MAX_LEVEL; i++) {
-		if (!path->nodes[i])
-			break;
-		if (!path->locks[i])
-			break;
-		if (!no_skips && path->slots[i] == 0) {
-			skip_level = i + 1;
-			continue;
-		}
-		if (!no_skips && path->keep_locks) {
-			u32 nritems;
-			t = path->nodes[i];
-			nritems = btrfs_header_nritems(t);
-			if (nritems < 1 || path->slots[i] >= nritems - 1) {
-				skip_level = i + 1;
-				continue;
-			}
-		}
-		if (skip_level < i && i >= lowest_unlock)
-			no_skips = 1;
-
-		t = path->nodes[i];
-		if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
-			btrfs_tree_unlock_rw(t, path->locks[i]);
-			path->locks[i] = 0;
-			if (write_lock_level &&
-			    i > min_write_lock_level &&
-			    i <= *write_lock_level) {
-				*write_lock_level = i - 1;
-			}
-		}
-	}
-}
-
-/*
- * This releases any locks held in the path starting at level and
- * going all the way up to the root.
- *
- * btrfs_search_slot will keep the lock held on higher nodes in a few
- * corner cases, such as COW of the block at slot zero in the node.  This
- * ignores those rules, and it should only be called when there are no
- * more updates to be done higher up in the tree.
- */
-noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
-{
-	int i;
-
-	if (path->keep_locks)
-		return;
-
-	for (i = level; i < BTRFS_MAX_LEVEL; i++) {
-		if (!path->nodes[i])
-			continue;
-		if (!path->locks[i])
-			continue;
-		btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]);
-		path->locks[i] = 0;
-	}
-}
-
-/*
- * helper function for btrfs_search_slot.  The goal is to find a block
- * in cache without setting the path to blocking.  If we find the block
- * we return zero and the path is unchanged.
- *
- * If we can't find the block, we set the path blocking and do some
- * reada.  -EAGAIN is returned and the search must be repeated.
- */
-static int
-read_block_for_search(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct btrfs_path *p,
-		       struct extent_buffer **eb_ret, int level, int slot,
-		       struct btrfs_key *key)
-{
-	u64 blocknr;
-	u64 gen;
-	u32 blocksize;
-	struct extent_buffer *b = *eb_ret;
-	struct extent_buffer *tmp;
-	int ret;
-
-	blocknr = btrfs_node_blockptr(b, slot);
-	gen = btrfs_node_ptr_generation(b, slot);
-	blocksize = btrfs_level_size(root, level - 1);
-
-	tmp = btrfs_find_tree_block(root, blocknr, blocksize);
-	if (tmp) {
-		/* first we do an atomic uptodate check */
-		if (btrfs_buffer_uptodate(tmp, 0, 1) > 0) {
-			if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
-				/*
-				 * we found an up to date block without
-				 * sleeping, return
-				 * right away
-				 */
-				*eb_ret = tmp;
-				return 0;
-			}
-			/* the pages were up to date, but we failed
-			 * the generation number check.  Do a full
-			 * read for the generation number that is correct.
-			 * We must do this without dropping locks so
-			 * we can trust our generation number
-			 */
-			free_extent_buffer(tmp);
-			btrfs_set_path_blocking(p);
-
-			/* now we're allowed to do a blocking uptodate check */
-			tmp = read_tree_block(root, blocknr, blocksize, gen);
-			if (tmp && btrfs_buffer_uptodate(tmp, gen, 0) > 0) {
-				*eb_ret = tmp;
-				return 0;
-			}
-			free_extent_buffer(tmp);
-			btrfs_release_path(p);
-			return -EIO;
-		}
-	}
-
-	/*
-	 * reduce lock contention at high levels
-	 * of the btree by dropping locks before
-	 * we read.  Don't release the lock on the current
-	 * level because we need to walk this node to figure
-	 * out which blocks to read.
-	 */
-	btrfs_unlock_up_safe(p, level + 1);
-	btrfs_set_path_blocking(p);
-
-	free_extent_buffer(tmp);
-	if (p->reada)
-		reada_for_search(root, p, level, slot, key->objectid);
-
-	btrfs_release_path(p);
-
-	ret = -EAGAIN;
-	tmp = read_tree_block(root, blocknr, blocksize, 0);
-	if (tmp) {
-		/*
-		 * If the read above didn't mark this buffer up to date,
-		 * it will never end up being up to date.  Set ret to EIO now
-		 * and give up so that our caller doesn't loop forever
-		 * on our EAGAINs.
-		 */
-		if (!btrfs_buffer_uptodate(tmp, 0, 0))
-			ret = -EIO;
-		free_extent_buffer(tmp);
-	}
-	return ret;
-}
-
-/*
- * helper function for btrfs_search_slot.  This does all of the checks
- * for node-level blocks and does any balancing required based on
- * the ins_len.
- *
- * If no extra work was required, zero is returned.  If we had to
- * drop the path, -EAGAIN is returned and btrfs_search_slot must
- * start over
- */
-static int
-setup_nodes_for_search(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct btrfs_path *p,
-		       struct extent_buffer *b, int level, int ins_len,
-		       int *write_lock_level)
-{
-	int ret;
-	if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
-	    BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
-		int sret;
-
-		if (*write_lock_level < level + 1) {
-			*write_lock_level = level + 1;
-			btrfs_release_path(p);
-			goto again;
-		}
-
-		sret = reada_for_balance(root, p, level);
-		if (sret)
-			goto again;
-
-		btrfs_set_path_blocking(p);
-		sret = split_node(trans, root, p, level);
-		btrfs_clear_path_blocking(p, NULL, 0);
-
-		BUG_ON(sret > 0);
-		if (sret) {
-			ret = sret;
-			goto done;
-		}
-		b = p->nodes[level];
-	} else if (ins_len < 0 && btrfs_header_nritems(b) <
-		   BTRFS_NODEPTRS_PER_BLOCK(root) / 2) {
-		int sret;
-
-		if (*write_lock_level < level + 1) {
-			*write_lock_level = level + 1;
-			btrfs_release_path(p);
-			goto again;
-		}
-
-		sret = reada_for_balance(root, p, level);
-		if (sret)
-			goto again;
-
-		btrfs_set_path_blocking(p);
-		sret = balance_level(trans, root, p, level);
-		btrfs_clear_path_blocking(p, NULL, 0);
-
-		if (sret) {
-			ret = sret;
-			goto done;
-		}
-		b = p->nodes[level];
-		if (!b) {
-			btrfs_release_path(p);
-			goto again;
-		}
-		BUG_ON(btrfs_header_nritems(b) == 1);
-	}
-	return 0;
-
-again:
-	ret = -EAGAIN;
-done:
-	return ret;
-}
-
-/*
- * look for key in the tree.  path is filled in with nodes along the way
- * if key is found, we return zero and you can find the item in the leaf
- * level of the path (level 0)
- *
- * If the key isn't found, the path points to the slot where it should
- * be inserted, and 1 is returned.  If there are other errors during the
- * search a negative error number is returned.
- *
- * if ins_len > 0, nodes and leaves will be split as we walk down the
- * tree.  if ins_len < 0, nodes will be merged as we walk down the tree (if
- * possible)
- */
-int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *key, struct btrfs_path *p, int
-		      ins_len, int cow)
-{
-	struct extent_buffer *b;
-	int slot;
-	int ret;
-	int err;
-	int level;
-	int lowest_unlock = 1;
-	int root_lock;
-	/* everything at write_lock_level or lower must be write locked */
-	int write_lock_level = 0;
-	u8 lowest_level = 0;
-	int min_write_lock_level;
-
-	lowest_level = p->lowest_level;
-	WARN_ON(lowest_level && ins_len > 0);
-	WARN_ON(p->nodes[0] != NULL);
-
-	if (ins_len < 0) {
-		lowest_unlock = 2;
-
-		/* when we are removing items, we might have to go up to level
-		 * two as we update tree pointers  Make sure we keep write
-		 * for those levels as well
-		 */
-		write_lock_level = 2;
-	} else if (ins_len > 0) {
-		/*
-		 * for inserting items, make sure we have a write lock on
-		 * level 1 so we can update keys
-		 */
-		write_lock_level = 1;
-	}
-
-	if (!cow)
-		write_lock_level = -1;
-
-	if (cow && (p->keep_locks || p->lowest_level))
-		write_lock_level = BTRFS_MAX_LEVEL;
-
-	min_write_lock_level = write_lock_level;
-
-again:
-	/*
-	 * we try very hard to do read locks on the root
-	 */
-	root_lock = BTRFS_READ_LOCK;
-	level = 0;
-	if (p->search_commit_root) {
-		/*
-		 * the commit roots are read only
-		 * so we always do read locks
-		 */
-		b = root->commit_root;
-		extent_buffer_get(b);
-		level = btrfs_header_level(b);
-		if (!p->skip_locking)
-			btrfs_tree_read_lock(b);
-	} else {
-		if (p->skip_locking) {
-			b = btrfs_root_node(root);
-			level = btrfs_header_level(b);
-		} else {
-			/* we don't know the level of the root node
-			 * until we actually have it read locked
-			 */
-			b = btrfs_read_lock_root_node(root);
-			level = btrfs_header_level(b);
-			if (level <= write_lock_level) {
-				/* whoops, must trade for write lock */
-				btrfs_tree_read_unlock(b);
-				free_extent_buffer(b);
-				b = btrfs_lock_root_node(root);
-				root_lock = BTRFS_WRITE_LOCK;
-
-				/* the level might have changed, check again */
-				level = btrfs_header_level(b);
-			}
-		}
-	}
-	p->nodes[level] = b;
-	if (!p->skip_locking)
-		p->locks[level] = root_lock;
-
-	while (b) {
-		level = btrfs_header_level(b);
-
-		/*
-		 * setup the path here so we can release it under lock
-		 * contention with the cow code
-		 */
-		if (cow) {
-			/*
-			 * if we don't really need to cow this block
-			 * then we don't want to set the path blocking,
-			 * so we test it here
-			 */
-			if (!should_cow_block(trans, root, b))
-				goto cow_done;
-
-			btrfs_set_path_blocking(p);
-
-			/*
-			 * must have write locks on this node and the
-			 * parent
-			 */
-			if (level + 1 > write_lock_level) {
-				write_lock_level = level + 1;
-				btrfs_release_path(p);
-				goto again;
-			}
-
-			err = btrfs_cow_block(trans, root, b,
-					      p->nodes[level + 1],
-					      p->slots[level + 1], &b);
-			if (err) {
-				ret = err;
-				goto done;
-			}
-		}
-cow_done:
-		BUG_ON(!cow && ins_len);
-
-		p->nodes[level] = b;
-		btrfs_clear_path_blocking(p, NULL, 0);
-
-		/*
-		 * we have a lock on b and as long as we aren't changing
-		 * the tree, there is no way to for the items in b to change.
-		 * It is safe to drop the lock on our parent before we
-		 * go through the expensive btree search on b.
-		 *
-		 * If cow is true, then we might be changing slot zero,
-		 * which may require changing the parent.  So, we can't
-		 * drop the lock until after we know which slot we're
-		 * operating on.
-		 */
-		if (!cow)
-			btrfs_unlock_up_safe(p, level + 1);
-
-		ret = bin_search(b, key, level, &slot);
-
-		if (level != 0) {
-			int dec = 0;
-			if (ret && slot > 0) {
-				dec = 1;
-				slot -= 1;
-			}
-			p->slots[level] = slot;
-			err = setup_nodes_for_search(trans, root, p, b, level,
-					     ins_len, &write_lock_level);
-			if (err == -EAGAIN)
-				goto again;
-			if (err) {
-				ret = err;
-				goto done;
-			}
-			b = p->nodes[level];
-			slot = p->slots[level];
-
-			/*
-			 * slot 0 is special, if we change the key
-			 * we have to update the parent pointer
-			 * which means we must have a write lock
-			 * on the parent
-			 */
-			if (slot == 0 && cow &&
-			    write_lock_level < level + 1) {
-				write_lock_level = level + 1;
-				btrfs_release_path(p);
-				goto again;
-			}
-
-			unlock_up(p, level, lowest_unlock,
-				  min_write_lock_level, &write_lock_level);
-
-			if (level == lowest_level) {
-				if (dec)
-					p->slots[level]++;
-				goto done;
-			}
-
-			err = read_block_for_search(trans, root, p,
-						    &b, level, slot, key);
-			if (err == -EAGAIN)
-				goto again;
-			if (err) {
-				ret = err;
-				goto done;
-			}
-
-			if (!p->skip_locking) {
-				level = btrfs_header_level(b);
-				if (level <= write_lock_level) {
-					err = btrfs_try_tree_write_lock(b);
-					if (!err) {
-						btrfs_set_path_blocking(p);
-						btrfs_tree_lock(b);
-						btrfs_clear_path_blocking(p, b,
-								  BTRFS_WRITE_LOCK);
-					}
-					p->locks[level] = BTRFS_WRITE_LOCK;
-				} else {
-					err = btrfs_try_tree_read_lock(b);
-					if (!err) {
-						btrfs_set_path_blocking(p);
-						btrfs_tree_read_lock(b);
-						btrfs_clear_path_blocking(p, b,
-								  BTRFS_READ_LOCK);
-					}
-					p->locks[level] = BTRFS_READ_LOCK;
-				}
-				p->nodes[level] = b;
-			}
-		} else {
-			p->slots[level] = slot;
-			if (ins_len > 0 &&
-			    btrfs_leaf_free_space(root, b) < ins_len) {
-				if (write_lock_level < 1) {
-					write_lock_level = 1;
-					btrfs_release_path(p);
-					goto again;
-				}
-
-				btrfs_set_path_blocking(p);
-				err = split_leaf(trans, root, key,
-						 p, ins_len, ret == 0);
-				btrfs_clear_path_blocking(p, NULL, 0);
-
-				BUG_ON(err > 0);
-				if (err) {
-					ret = err;
-					goto done;
-				}
-			}
-			if (!p->search_for_split)
-				unlock_up(p, level, lowest_unlock,
-					  min_write_lock_level, &write_lock_level);
-			goto done;
-		}
-	}
-	ret = 1;
-done:
-	/*
-	 * we don't really know what they plan on doing with the path
-	 * from here on, so for now just mark it as blocking
-	 */
-	if (!p->leave_spinning)
-		btrfs_set_path_blocking(p);
-	if (ret < 0)
-		btrfs_release_path(p);
-	return ret;
-}
-
-/*
- * adjust the pointers going up the tree, starting at level
- * making sure the right key of each node is points to 'key'.
- * This is used after shifting pointers to the left, so it stops
- * fixing up pointers when a given leaf/node is not in slot 0 of the
- * higher levels
- *
- */
-static void fixup_low_keys(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root, struct btrfs_path *path,
-			   struct btrfs_disk_key *key, int level)
-{
-	int i;
-	struct extent_buffer *t;
-
-	for (i = level; i < BTRFS_MAX_LEVEL; i++) {
-		int tslot = path->slots[i];
-		if (!path->nodes[i])
-			break;
-		t = path->nodes[i];
-		btrfs_set_node_key(t, key, tslot);
-		btrfs_mark_buffer_dirty(path->nodes[i]);
-		if (tslot != 0)
-			break;
-	}
-}
-
-/*
- * update item key.
- *
- * This function isn't completely safe. It's the caller's responsibility
- * that the new key won't break the order
- */
-void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root, struct btrfs_path *path,
-			     struct btrfs_key *new_key)
-{
-	struct btrfs_disk_key disk_key;
-	struct extent_buffer *eb;
-	int slot;
-
-	eb = path->nodes[0];
-	slot = path->slots[0];
-	if (slot > 0) {
-		btrfs_item_key(eb, &disk_key, slot - 1);
-		BUG_ON(comp_keys(&disk_key, new_key) >= 0);
-	}
-	if (slot < btrfs_header_nritems(eb) - 1) {
-		btrfs_item_key(eb, &disk_key, slot + 1);
-		BUG_ON(comp_keys(&disk_key, new_key) <= 0);
-	}
-
-	btrfs_cpu_key_to_disk(&disk_key, new_key);
-	btrfs_set_item_key(eb, &disk_key, slot);
-	btrfs_mark_buffer_dirty(eb);
-	if (slot == 0)
-		fixup_low_keys(trans, root, path, &disk_key, 1);
-}
-
-/*
- * try to push data from one node into the next node left in the
- * tree.
- *
- * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
- * error, and > 0 if there was no room in the left hand block.
- */
-static int push_node_left(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root, struct extent_buffer *dst,
-			  struct extent_buffer *src, int empty)
-{
-	int push_items = 0;
-	int src_nritems;
-	int dst_nritems;
-	int ret = 0;
-
-	src_nritems = btrfs_header_nritems(src);
-	dst_nritems = btrfs_header_nritems(dst);
-	push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
-	WARN_ON(btrfs_header_generation(src) != trans->transid);
-	WARN_ON(btrfs_header_generation(dst) != trans->transid);
-
-	if (!empty && src_nritems <= 8)
-		return 1;
-
-	if (push_items <= 0)
-		return 1;
-
-	if (empty) {
-		push_items = min(src_nritems, push_items);
-		if (push_items < src_nritems) {
-			/* leave at least 8 pointers in the node if
-			 * we aren't going to empty it
-			 */
-			if (src_nritems - push_items < 8) {
-				if (push_items <= 8)
-					return 1;
-				push_items -= 8;
-			}
-		}
-	} else
-		push_items = min(src_nritems - 8, push_items);
-
-	copy_extent_buffer(dst, src,
-			   btrfs_node_key_ptr_offset(dst_nritems),
-			   btrfs_node_key_ptr_offset(0),
-			   push_items * sizeof(struct btrfs_key_ptr));
-
-	if (push_items < src_nritems) {
-		memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
-				      btrfs_node_key_ptr_offset(push_items),
-				      (src_nritems - push_items) *
-				      sizeof(struct btrfs_key_ptr));
-	}
-	btrfs_set_header_nritems(src, src_nritems - push_items);
-	btrfs_set_header_nritems(dst, dst_nritems + push_items);
-	btrfs_mark_buffer_dirty(src);
-	btrfs_mark_buffer_dirty(dst);
-
-	return ret;
-}
-
-/*
- * try to push data from one node into the next node right in the
- * tree.
- *
- * returns 0 if some ptrs were pushed, < 0 if there was some horrible
- * error, and > 0 if there was no room in the right hand block.
- *
- * this will  only push up to 1/2 the contents of the left node over
- */
-static int balance_node_right(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root,
-			      struct extent_buffer *dst,
-			      struct extent_buffer *src)
-{
-	int push_items = 0;
-	int max_push;
-	int src_nritems;
-	int dst_nritems;
-	int ret = 0;
-
-	WARN_ON(btrfs_header_generation(src) != trans->transid);
-	WARN_ON(btrfs_header_generation(dst) != trans->transid);
-
-	src_nritems = btrfs_header_nritems(src);
-	dst_nritems = btrfs_header_nritems(dst);
-	push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
-	if (push_items <= 0)
-		return 1;
-
-	if (src_nritems < 4)
-		return 1;
-
-	max_push = src_nritems / 2 + 1;
-	/* don't try to empty the node */
-	if (max_push >= src_nritems)
-		return 1;
-
-	if (max_push < push_items)
-		push_items = max_push;
-
-	memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
-				      btrfs_node_key_ptr_offset(0),
-				      (dst_nritems) *
-				      sizeof(struct btrfs_key_ptr));
-
-	copy_extent_buffer(dst, src,
-			   btrfs_node_key_ptr_offset(0),
-			   btrfs_node_key_ptr_offset(src_nritems - push_items),
-			   push_items * sizeof(struct btrfs_key_ptr));
-
-	btrfs_set_header_nritems(src, src_nritems - push_items);
-	btrfs_set_header_nritems(dst, dst_nritems + push_items);
-
-	btrfs_mark_buffer_dirty(src);
-	btrfs_mark_buffer_dirty(dst);
-
-	return ret;
-}
-
-/*
- * helper function to insert a new root level in the tree.
- * A new node is allocated, and a single item is inserted to
- * point to the existing root
- *
- * returns zero on success or < 0 on failure.
- */
-static noinline int insert_new_root(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   struct btrfs_path *path, int level)
-{
-	u64 lower_gen;
-	struct extent_buffer *lower;
-	struct extent_buffer *c;
-	struct extent_buffer *old;
-	struct btrfs_disk_key lower_key;
-
-	BUG_ON(path->nodes[level]);
-	BUG_ON(path->nodes[level-1] != root->node);
-
-	lower = path->nodes[level-1];
-	if (level == 1)
-		btrfs_item_key(lower, &lower_key, 0);
-	else
-		btrfs_node_key(lower, &lower_key, 0);
-
-	c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-				   root->root_key.objectid, &lower_key,
-				   level, root->node->start, 0, 0);
-	if (IS_ERR(c))
-		return PTR_ERR(c);
-
-	root_add_used(root, root->nodesize);
-
-	memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
-	btrfs_set_header_nritems(c, 1);
-	btrfs_set_header_level(c, level);
-	btrfs_set_header_bytenr(c, c->start);
-	btrfs_set_header_generation(c, trans->transid);
-	btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
-	btrfs_set_header_owner(c, root->root_key.objectid);
-
-	write_extent_buffer(c, root->fs_info->fsid,
-			    (unsigned long)btrfs_header_fsid(c),
-			    BTRFS_FSID_SIZE);
-
-	write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
-			    (unsigned long)btrfs_header_chunk_tree_uuid(c),
-			    BTRFS_UUID_SIZE);
-
-	btrfs_set_node_key(c, &lower_key, 0);
-	btrfs_set_node_blockptr(c, 0, lower->start);
-	lower_gen = btrfs_header_generation(lower);
-	WARN_ON(lower_gen != trans->transid);
-
-	btrfs_set_node_ptr_generation(c, 0, lower_gen);
-
-	btrfs_mark_buffer_dirty(c);
-
-	old = root->node;
-	rcu_assign_pointer(root->node, c);
-
-	/* the super has an extra ref to root->node */
-	free_extent_buffer(old);
-
-	add_root_to_dirty_list(root);
-	extent_buffer_get(c);
-	path->nodes[level] = c;
-	path->locks[level] = BTRFS_WRITE_LOCK;
-	path->slots[level] = 0;
-	return 0;
-}
-
-/*
- * worker function to insert a single pointer in a node.
- * the node should have enough room for the pointer already
- *
- * slot and level indicate where you want the key to go, and
- * blocknr is the block the key points to.
- */
-static void insert_ptr(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct btrfs_path *path,
-		       struct btrfs_disk_key *key, u64 bytenr,
-		       int slot, int level)
-{
-	struct extent_buffer *lower;
-	int nritems;
-
-	BUG_ON(!path->nodes[level]);
-	btrfs_assert_tree_locked(path->nodes[level]);
-	lower = path->nodes[level];
-	nritems = btrfs_header_nritems(lower);
-	BUG_ON(slot > nritems);
-	BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root));
-	if (slot != nritems) {
-		memmove_extent_buffer(lower,
-			      btrfs_node_key_ptr_offset(slot + 1),
-			      btrfs_node_key_ptr_offset(slot),
-			      (nritems - slot) * sizeof(struct btrfs_key_ptr));
-	}
-	btrfs_set_node_key(lower, key, slot);
-	btrfs_set_node_blockptr(lower, slot, bytenr);
-	WARN_ON(trans->transid == 0);
-	btrfs_set_node_ptr_generation(lower, slot, trans->transid);
-	btrfs_set_header_nritems(lower, nritems + 1);
-	btrfs_mark_buffer_dirty(lower);
-}
-
-/*
- * split the node at the specified level in path in two.
- * The path is corrected to point to the appropriate node after the split
- *
- * Before splitting this tries to make some room in the node by pushing
- * left and right, if either one works, it returns right away.
- *
- * returns 0 on success and < 0 on failure
- */
-static noinline int split_node(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root,
-			       struct btrfs_path *path, int level)
-{
-	struct extent_buffer *c;
-	struct extent_buffer *split;
-	struct btrfs_disk_key disk_key;
-	int mid;
-	int ret;
-	u32 c_nritems;
-
-	c = path->nodes[level];
-	WARN_ON(btrfs_header_generation(c) != trans->transid);
-	if (c == root->node) {
-		/* trying to split the root, lets make a new one */
-		ret = insert_new_root(trans, root, path, level + 1);
-		if (ret)
-			return ret;
-	} else {
-		ret = push_nodes_for_insert(trans, root, path, level);
-		c = path->nodes[level];
-		if (!ret && btrfs_header_nritems(c) <
-		    BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
-			return 0;
-		if (ret < 0)
-			return ret;
-	}
-
-	c_nritems = btrfs_header_nritems(c);
-	mid = (c_nritems + 1) / 2;
-	btrfs_node_key(c, &disk_key, mid);
-
-	split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-					root->root_key.objectid,
-					&disk_key, level, c->start, 0, 0);
-	if (IS_ERR(split))
-		return PTR_ERR(split);
-
-	root_add_used(root, root->nodesize);
-
-	memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
-	btrfs_set_header_level(split, btrfs_header_level(c));
-	btrfs_set_header_bytenr(split, split->start);
-	btrfs_set_header_generation(split, trans->transid);
-	btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
-	btrfs_set_header_owner(split, root->root_key.objectid);
-	write_extent_buffer(split, root->fs_info->fsid,
-			    (unsigned long)btrfs_header_fsid(split),
-			    BTRFS_FSID_SIZE);
-	write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
-			    (unsigned long)btrfs_header_chunk_tree_uuid(split),
-			    BTRFS_UUID_SIZE);
-
-
-	copy_extent_buffer(split, c,
-			   btrfs_node_key_ptr_offset(0),
-			   btrfs_node_key_ptr_offset(mid),
-			   (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
-	btrfs_set_header_nritems(split, c_nritems - mid);
-	btrfs_set_header_nritems(c, mid);
-	ret = 0;
-
-	btrfs_mark_buffer_dirty(c);
-	btrfs_mark_buffer_dirty(split);
-
-	insert_ptr(trans, root, path, &disk_key, split->start,
-		   path->slots[level + 1] + 1, level + 1);
-
-	if (path->slots[level] >= mid) {
-		path->slots[level] -= mid;
-		btrfs_tree_unlock(c);
-		free_extent_buffer(c);
-		path->nodes[level] = split;
-		path->slots[level + 1] += 1;
-	} else {
-		btrfs_tree_unlock(split);
-		free_extent_buffer(split);
-	}
-	return ret;
-}
-
-/*
- * how many bytes are required to store the items in a leaf.  start
- * and nr indicate which items in the leaf to check.  This totals up the
- * space used both by the item structs and the item data
- */
-static int leaf_space_used(struct extent_buffer *l, int start, int nr)
-{
-	int data_len;
-	int nritems = btrfs_header_nritems(l);
-	int end = min(nritems, start + nr) - 1;
-
-	if (!nr)
-		return 0;
-	data_len = btrfs_item_end_nr(l, start);
-	data_len = data_len - btrfs_item_offset_nr(l, end);
-	data_len += sizeof(struct btrfs_item) * nr;
-	WARN_ON(data_len < 0);
-	return data_len;
-}
-
-/*
- * The space between the end of the leaf items and
- * the start of the leaf data.  IOW, how much room
- * the leaf has left for both items and data
- */
-noinline int btrfs_leaf_free_space(struct btrfs_root *root,
-				   struct extent_buffer *leaf)
-{
-	int nritems = btrfs_header_nritems(leaf);
-	int ret;
-	ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
-	if (ret < 0) {
-		printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, "
-		       "used %d nritems %d\n",
-		       ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
-		       leaf_space_used(leaf, 0, nritems), nritems);
-	}
-	return ret;
-}
-
-/*
- * min slot controls the lowest index we're willing to push to the
- * right.  We'll push up to and including min_slot, but no lower
- */
-static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
-				      struct btrfs_root *root,
-				      struct btrfs_path *path,
-				      int data_size, int empty,
-				      struct extent_buffer *right,
-				      int free_space, u32 left_nritems,
-				      u32 min_slot)
-{
-	struct extent_buffer *left = path->nodes[0];
-	struct extent_buffer *upper = path->nodes[1];
-	struct btrfs_map_token token;
-	struct btrfs_disk_key disk_key;
-	int slot;
-	u32 i;
-	int push_space = 0;
-	int push_items = 0;
-	struct btrfs_item *item;
-	u32 nr;
-	u32 right_nritems;
-	u32 data_end;
-	u32 this_item_size;
-
-	btrfs_init_map_token(&token);
-
-	if (empty)
-		nr = 0;
-	else
-		nr = max_t(u32, 1, min_slot);
-
-	if (path->slots[0] >= left_nritems)
-		push_space += data_size;
-
-	slot = path->slots[1];
-	i = left_nritems - 1;
-	while (i >= nr) {
-		item = btrfs_item_nr(left, i);
-
-		if (!empty && push_items > 0) {
-			if (path->slots[0] > i)
-				break;
-			if (path->slots[0] == i) {
-				int space = btrfs_leaf_free_space(root, left);
-				if (space + push_space * 2 > free_space)
-					break;
-			}
-		}
-
-		if (path->slots[0] == i)
-			push_space += data_size;
-
-		this_item_size = btrfs_item_size(left, item);
-		if (this_item_size + sizeof(*item) + push_space > free_space)
-			break;
-
-		push_items++;
-		push_space += this_item_size + sizeof(*item);
-		if (i == 0)
-			break;
-		i--;
-	}
-
-	if (push_items == 0)
-		goto out_unlock;
-
-	if (!empty && push_items == left_nritems)
-		WARN_ON(1);
-
-	/* push left to right */
-	right_nritems = btrfs_header_nritems(right);
-
-	push_space = btrfs_item_end_nr(left, left_nritems - push_items);
-	push_space -= leaf_data_end(root, left);
-
-	/* make room in the right data area */
-	data_end = leaf_data_end(root, right);
-	memmove_extent_buffer(right,
-			      btrfs_leaf_data(right) + data_end - push_space,
-			      btrfs_leaf_data(right) + data_end,
-			      BTRFS_LEAF_DATA_SIZE(root) - data_end);
-
-	/* copy from the left data area */
-	copy_extent_buffer(right, left, btrfs_leaf_data(right) +
-		     BTRFS_LEAF_DATA_SIZE(root) - push_space,
-		     btrfs_leaf_data(left) + leaf_data_end(root, left),
-		     push_space);
-
-	memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
-			      btrfs_item_nr_offset(0),
-			      right_nritems * sizeof(struct btrfs_item));
-
-	/* copy the items from left to right */
-	copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
-		   btrfs_item_nr_offset(left_nritems - push_items),
-		   push_items * sizeof(struct btrfs_item));
-
-	/* update the item pointers */
-	right_nritems += push_items;
-	btrfs_set_header_nritems(right, right_nritems);
-	push_space = BTRFS_LEAF_DATA_SIZE(root);
-	for (i = 0; i < right_nritems; i++) {
-		item = btrfs_item_nr(right, i);
-		push_space -= btrfs_token_item_size(right, item, &token);
-		btrfs_set_token_item_offset(right, item, push_space, &token);
-	}
-
-	left_nritems -= push_items;
-	btrfs_set_header_nritems(left, left_nritems);
-
-	if (left_nritems)
-		btrfs_mark_buffer_dirty(left);
-	else
-		clean_tree_block(trans, root, left);
-
-	btrfs_mark_buffer_dirty(right);
-
-	btrfs_item_key(right, &disk_key, 0);
-	btrfs_set_node_key(upper, &disk_key, slot + 1);
-	btrfs_mark_buffer_dirty(upper);
-
-	/* then fixup the leaf pointer in the path */
-	if (path->slots[0] >= left_nritems) {
-		path->slots[0] -= left_nritems;
-		if (btrfs_header_nritems(path->nodes[0]) == 0)
-			clean_tree_block(trans, root, path->nodes[0]);
-		btrfs_tree_unlock(path->nodes[0]);
-		free_extent_buffer(path->nodes[0]);
-		path->nodes[0] = right;
-		path->slots[1] += 1;
-	} else {
-		btrfs_tree_unlock(right);
-		free_extent_buffer(right);
-	}
-	return 0;
-
-out_unlock:
-	btrfs_tree_unlock(right);
-	free_extent_buffer(right);
-	return 1;
-}
-
-/*
- * push some data in the path leaf to the right, trying to free up at
- * least data_size bytes.  returns zero if the push worked, nonzero otherwise
- *
- * returns 1 if the push failed because the other node didn't have enough
- * room, 0 if everything worked out and < 0 if there were major errors.
- *
- * this will push starting from min_slot to the end of the leaf.  It won't
- * push any slot lower than min_slot
- */
-static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
-			   *root, struct btrfs_path *path,
-			   int min_data_size, int data_size,
-			   int empty, u32 min_slot)
-{
-	struct extent_buffer *left = path->nodes[0];
-	struct extent_buffer *right;
-	struct extent_buffer *upper;
-	int slot;
-	int free_space;
-	u32 left_nritems;
-	int ret;
-
-	if (!path->nodes[1])
-		return 1;
-
-	slot = path->slots[1];
-	upper = path->nodes[1];
-	if (slot >= btrfs_header_nritems(upper) - 1)
-		return 1;
-
-	btrfs_assert_tree_locked(path->nodes[1]);
-
-	right = read_node_slot(root, upper, slot + 1);
-	if (right == NULL)
-		return 1;
-
-	btrfs_tree_lock(right);
-	btrfs_set_lock_blocking(right);
-
-	free_space = btrfs_leaf_free_space(root, right);
-	if (free_space < data_size)
-		goto out_unlock;
-
-	/* cow and double check */
-	ret = btrfs_cow_block(trans, root, right, upper,
-			      slot + 1, &right);
-	if (ret)
-		goto out_unlock;
-
-	free_space = btrfs_leaf_free_space(root, right);
-	if (free_space < data_size)
-		goto out_unlock;
-
-	left_nritems = btrfs_header_nritems(left);
-	if (left_nritems == 0)
-		goto out_unlock;
-
-	return __push_leaf_right(trans, root, path, min_data_size, empty,
-				right, free_space, left_nritems, min_slot);
-out_unlock:
-	btrfs_tree_unlock(right);
-	free_extent_buffer(right);
-	return 1;
-}
-
-/*
- * push some data in the path leaf to the left, trying to free up at
- * least data_size bytes.  returns zero if the push worked, nonzero otherwise
- *
- * max_slot can put a limit on how far into the leaf we'll push items.  The
- * item at 'max_slot' won't be touched.  Use (u32)-1 to make us do all the
- * items
- */
-static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     struct btrfs_path *path, int data_size,
-				     int empty, struct extent_buffer *left,
-				     int free_space, u32 right_nritems,
-				     u32 max_slot)
-{
-	struct btrfs_disk_key disk_key;
-	struct extent_buffer *right = path->nodes[0];
-	int i;
-	int push_space = 0;
-	int push_items = 0;
-	struct btrfs_item *item;
-	u32 old_left_nritems;
-	u32 nr;
-	int ret = 0;
-	u32 this_item_size;
-	u32 old_left_item_size;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	if (empty)
-		nr = min(right_nritems, max_slot);
-	else
-		nr = min(right_nritems - 1, max_slot);
-
-	for (i = 0; i < nr; i++) {
-		item = btrfs_item_nr(right, i);
-
-		if (!empty && push_items > 0) {
-			if (path->slots[0] < i)
-				break;
-			if (path->slots[0] == i) {
-				int space = btrfs_leaf_free_space(root, right);
-				if (space + push_space * 2 > free_space)
-					break;
-			}
-		}
-
-		if (path->slots[0] == i)
-			push_space += data_size;
-
-		this_item_size = btrfs_item_size(right, item);
-		if (this_item_size + sizeof(*item) + push_space > free_space)
-			break;
-
-		push_items++;
-		push_space += this_item_size + sizeof(*item);
-	}
-
-	if (push_items == 0) {
-		ret = 1;
-		goto out;
-	}
-	if (!empty && push_items == btrfs_header_nritems(right))
-		WARN_ON(1);
-
-	/* push data from right to left */
-	copy_extent_buffer(left, right,
-			   btrfs_item_nr_offset(btrfs_header_nritems(left)),
-			   btrfs_item_nr_offset(0),
-			   push_items * sizeof(struct btrfs_item));
-
-	push_space = BTRFS_LEAF_DATA_SIZE(root) -
-		     btrfs_item_offset_nr(right, push_items - 1);
-
-	copy_extent_buffer(left, right, btrfs_leaf_data(left) +
-		     leaf_data_end(root, left) - push_space,
-		     btrfs_leaf_data(right) +
-		     btrfs_item_offset_nr(right, push_items - 1),
-		     push_space);
-	old_left_nritems = btrfs_header_nritems(left);
-	BUG_ON(old_left_nritems <= 0);
-
-	old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
-	for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
-		u32 ioff;
-
-		item = btrfs_item_nr(left, i);
-
-		ioff = btrfs_token_item_offset(left, item, &token);
-		btrfs_set_token_item_offset(left, item,
-		      ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size),
-		      &token);
-	}
-	btrfs_set_header_nritems(left, old_left_nritems + push_items);
-
-	/* fixup right node */
-	if (push_items > right_nritems) {
-		printk(KERN_CRIT "push items %d nr %u\n", push_items,
-		       right_nritems);
-		WARN_ON(1);
-	}
-
-	if (push_items < right_nritems) {
-		push_space = btrfs_item_offset_nr(right, push_items - 1) -
-						  leaf_data_end(root, right);
-		memmove_extent_buffer(right, btrfs_leaf_data(right) +
-				      BTRFS_LEAF_DATA_SIZE(root) - push_space,
-				      btrfs_leaf_data(right) +
-				      leaf_data_end(root, right), push_space);
-
-		memmove_extent_buffer(right, btrfs_item_nr_offset(0),
-			      btrfs_item_nr_offset(push_items),
-			     (btrfs_header_nritems(right) - push_items) *
-			     sizeof(struct btrfs_item));
-	}
-	right_nritems -= push_items;
-	btrfs_set_header_nritems(right, right_nritems);
-	push_space = BTRFS_LEAF_DATA_SIZE(root);
-	for (i = 0; i < right_nritems; i++) {
-		item = btrfs_item_nr(right, i);
-
-		push_space = push_space - btrfs_token_item_size(right,
-								item, &token);
-		btrfs_set_token_item_offset(right, item, push_space, &token);
-	}
-
-	btrfs_mark_buffer_dirty(left);
-	if (right_nritems)
-		btrfs_mark_buffer_dirty(right);
-	else
-		clean_tree_block(trans, root, right);
-
-	btrfs_item_key(right, &disk_key, 0);
-	fixup_low_keys(trans, root, path, &disk_key, 1);
-
-	/* then fixup the leaf pointer in the path */
-	if (path->slots[0] < push_items) {
-		path->slots[0] += old_left_nritems;
-		btrfs_tree_unlock(path->nodes[0]);
-		free_extent_buffer(path->nodes[0]);
-		path->nodes[0] = left;
-		path->slots[1] -= 1;
-	} else {
-		btrfs_tree_unlock(left);
-		free_extent_buffer(left);
-		path->slots[0] -= push_items;
-	}
-	BUG_ON(path->slots[0] < 0);
-	return ret;
-out:
-	btrfs_tree_unlock(left);
-	free_extent_buffer(left);
-	return ret;
-}
-
-/*
- * push some data in the path leaf to the left, trying to free up at
- * least data_size bytes.  returns zero if the push worked, nonzero otherwise
- *
- * max_slot can put a limit on how far into the leaf we'll push items.  The
- * item at 'max_slot' won't be touched.  Use (u32)-1 to make us push all the
- * items
- */
-static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, struct btrfs_path *path, int min_data_size,
-			  int data_size, int empty, u32 max_slot)
-{
-	struct extent_buffer *right = path->nodes[0];
-	struct extent_buffer *left;
-	int slot;
-	int free_space;
-	u32 right_nritems;
-	int ret = 0;
-
-	slot = path->slots[1];
-	if (slot == 0)
-		return 1;
-	if (!path->nodes[1])
-		return 1;
-
-	right_nritems = btrfs_header_nritems(right);
-	if (right_nritems == 0)
-		return 1;
-
-	btrfs_assert_tree_locked(path->nodes[1]);
-
-	left = read_node_slot(root, path->nodes[1], slot - 1);
-	if (left == NULL)
-		return 1;
-
-	btrfs_tree_lock(left);
-	btrfs_set_lock_blocking(left);
-
-	free_space = btrfs_leaf_free_space(root, left);
-	if (free_space < data_size) {
-		ret = 1;
-		goto out;
-	}
-
-	/* cow and double check */
-	ret = btrfs_cow_block(trans, root, left,
-			      path->nodes[1], slot - 1, &left);
-	if (ret) {
-		/* we hit -ENOSPC, but it isn't fatal here */
-		if (ret == -ENOSPC)
-			ret = 1;
-		goto out;
-	}
-
-	free_space = btrfs_leaf_free_space(root, left);
-	if (free_space < data_size) {
-		ret = 1;
-		goto out;
-	}
-
-	return __push_leaf_left(trans, root, path, min_data_size,
-			       empty, left, free_space, right_nritems,
-			       max_slot);
-out:
-	btrfs_tree_unlock(left);
-	free_extent_buffer(left);
-	return ret;
-}
-
-/*
- * split the path's leaf in two, making sure there is at least data_size
- * available for the resulting leaf level of the path.
- */
-static noinline void copy_for_split(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
-				    struct btrfs_path *path,
-				    struct extent_buffer *l,
-				    struct extent_buffer *right,
-				    int slot, int mid, int nritems)
-{
-	int data_copy_size;
-	int rt_data_off;
-	int i;
-	struct btrfs_disk_key disk_key;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	nritems = nritems - mid;
-	btrfs_set_header_nritems(right, nritems);
-	data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
-
-	copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
-			   btrfs_item_nr_offset(mid),
-			   nritems * sizeof(struct btrfs_item));
-
-	copy_extent_buffer(right, l,
-		     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
-		     data_copy_size, btrfs_leaf_data(l) +
-		     leaf_data_end(root, l), data_copy_size);
-
-	rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
-		      btrfs_item_end_nr(l, mid);
-
-	for (i = 0; i < nritems; i++) {
-		struct btrfs_item *item = btrfs_item_nr(right, i);
-		u32 ioff;
-
-		ioff = btrfs_token_item_offset(right, item, &token);
-		btrfs_set_token_item_offset(right, item,
-					    ioff + rt_data_off, &token);
-	}
-
-	btrfs_set_header_nritems(l, mid);
-	btrfs_item_key(right, &disk_key, 0);
-	insert_ptr(trans, root, path, &disk_key, right->start,
-		   path->slots[1] + 1, 1);
-
-	btrfs_mark_buffer_dirty(right);
-	btrfs_mark_buffer_dirty(l);
-	BUG_ON(path->slots[0] != slot);
-
-	if (mid <= slot) {
-		btrfs_tree_unlock(path->nodes[0]);
-		free_extent_buffer(path->nodes[0]);
-		path->nodes[0] = right;
-		path->slots[0] -= mid;
-		path->slots[1] += 1;
-	} else {
-		btrfs_tree_unlock(right);
-		free_extent_buffer(right);
-	}
-
-	BUG_ON(path->slots[0] < 0);
-}
-
-/*
- * double splits happen when we need to insert a big item in the middle
- * of a leaf.  A double split can leave us with 3 mostly empty leaves:
- * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
- *          A                 B                 C
- *
- * We avoid this by trying to push the items on either side of our target
- * into the adjacent leaves.  If all goes well we can avoid the double split
- * completely.
- */
-static noinline int push_for_double_split(struct btrfs_trans_handle *trans,
-					  struct btrfs_root *root,
-					  struct btrfs_path *path,
-					  int data_size)
-{
-	int ret;
-	int progress = 0;
-	int slot;
-	u32 nritems;
-
-	slot = path->slots[0];
-
-	/*
-	 * try to push all the items after our slot into the
-	 * right leaf
-	 */
-	ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot);
-	if (ret < 0)
-		return ret;
-
-	if (ret == 0)
-		progress++;
-
-	nritems = btrfs_header_nritems(path->nodes[0]);
-	/*
-	 * our goal is to get our slot at the start or end of a leaf.  If
-	 * we've done so we're done
-	 */
-	if (path->slots[0] == 0 || path->slots[0] == nritems)
-		return 0;
-
-	if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
-		return 0;
-
-	/* try to push all the items before our slot into the next leaf */
-	slot = path->slots[0];
-	ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot);
-	if (ret < 0)
-		return ret;
-
-	if (ret == 0)
-		progress++;
-
-	if (progress)
-		return 0;
-	return 1;
-}
-
-/*
- * split the path's leaf in two, making sure there is at least data_size
- * available for the resulting leaf level of the path.
- *
- * returns 0 if all went well and < 0 on failure.
- */
-static noinline int split_leaf(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root,
-			       struct btrfs_key *ins_key,
-			       struct btrfs_path *path, int data_size,
-			       int extend)
-{
-	struct btrfs_disk_key disk_key;
-	struct extent_buffer *l;
-	u32 nritems;
-	int mid;
-	int slot;
-	struct extent_buffer *right;
-	int ret = 0;
-	int wret;
-	int split;
-	int num_doubles = 0;
-	int tried_avoid_double = 0;
-
-	l = path->nodes[0];
-	slot = path->slots[0];
-	if (extend && data_size + btrfs_item_size_nr(l, slot) +
-	    sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root))
-		return -EOVERFLOW;
-
-	/* first try to make some room by pushing left and right */
-	if (data_size) {
-		wret = push_leaf_right(trans, root, path, data_size,
-				       data_size, 0, 0);
-		if (wret < 0)
-			return wret;
-		if (wret) {
-			wret = push_leaf_left(trans, root, path, data_size,
-					      data_size, 0, (u32)-1);
-			if (wret < 0)
-				return wret;
-		}
-		l = path->nodes[0];
-
-		/* did the pushes work? */
-		if (btrfs_leaf_free_space(root, l) >= data_size)
-			return 0;
-	}
-
-	if (!path->nodes[1]) {
-		ret = insert_new_root(trans, root, path, 1);
-		if (ret)
-			return ret;
-	}
-again:
-	split = 1;
-	l = path->nodes[0];
-	slot = path->slots[0];
-	nritems = btrfs_header_nritems(l);
-	mid = (nritems + 1) / 2;
-
-	if (mid <= slot) {
-		if (nritems == 1 ||
-		    leaf_space_used(l, mid, nritems - mid) + data_size >
-			BTRFS_LEAF_DATA_SIZE(root)) {
-			if (slot >= nritems) {
-				split = 0;
-			} else {
-				mid = slot;
-				if (mid != nritems &&
-				    leaf_space_used(l, mid, nritems - mid) +
-				    data_size > BTRFS_LEAF_DATA_SIZE(root)) {
-					if (data_size && !tried_avoid_double)
-						goto push_for_double;
-					split = 2;
-				}
-			}
-		}
-	} else {
-		if (leaf_space_used(l, 0, mid) + data_size >
-			BTRFS_LEAF_DATA_SIZE(root)) {
-			if (!extend && data_size && slot == 0) {
-				split = 0;
-			} else if ((extend || !data_size) && slot == 0) {
-				mid = 1;
-			} else {
-				mid = slot;
-				if (mid != nritems &&
-				    leaf_space_used(l, mid, nritems - mid) +
-				    data_size > BTRFS_LEAF_DATA_SIZE(root)) {
-					if (data_size && !tried_avoid_double)
-						goto push_for_double;
-					split = 2 ;
-				}
-			}
-		}
-	}
-
-	if (split == 0)
-		btrfs_cpu_key_to_disk(&disk_key, ins_key);
-	else
-		btrfs_item_key(l, &disk_key, mid);
-
-	right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
-					root->root_key.objectid,
-					&disk_key, 0, l->start, 0, 0);
-	if (IS_ERR(right))
-		return PTR_ERR(right);
-
-	root_add_used(root, root->leafsize);
-
-	memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
-	btrfs_set_header_bytenr(right, right->start);
-	btrfs_set_header_generation(right, trans->transid);
-	btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
-	btrfs_set_header_owner(right, root->root_key.objectid);
-	btrfs_set_header_level(right, 0);
-	write_extent_buffer(right, root->fs_info->fsid,
-			    (unsigned long)btrfs_header_fsid(right),
-			    BTRFS_FSID_SIZE);
-
-	write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
-			    (unsigned long)btrfs_header_chunk_tree_uuid(right),
-			    BTRFS_UUID_SIZE);
-
-	if (split == 0) {
-		if (mid <= slot) {
-			btrfs_set_header_nritems(right, 0);
-			insert_ptr(trans, root, path, &disk_key, right->start,
-				   path->slots[1] + 1, 1);
-			btrfs_tree_unlock(path->nodes[0]);
-			free_extent_buffer(path->nodes[0]);
-			path->nodes[0] = right;
-			path->slots[0] = 0;
-			path->slots[1] += 1;
-		} else {
-			btrfs_set_header_nritems(right, 0);
-			insert_ptr(trans, root, path, &disk_key, right->start,
-					  path->slots[1], 1);
-			btrfs_tree_unlock(path->nodes[0]);
-			free_extent_buffer(path->nodes[0]);
-			path->nodes[0] = right;
-			path->slots[0] = 0;
-			if (path->slots[1] == 0)
-				fixup_low_keys(trans, root, path,
-					       &disk_key, 1);
-		}
-		btrfs_mark_buffer_dirty(right);
-		return ret;
-	}
-
-	copy_for_split(trans, root, path, l, right, slot, mid, nritems);
-
-	if (split == 2) {
-		BUG_ON(num_doubles != 0);
-		num_doubles++;
-		goto again;
-	}
-
-	return 0;
-
-push_for_double:
-	push_for_double_split(trans, root, path, data_size);
-	tried_avoid_double = 1;
-	if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
-		return 0;
-	goto again;
-}
-
-static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
-					 struct btrfs_root *root,
-					 struct btrfs_path *path, int ins_len)
-{
-	struct btrfs_key key;
-	struct extent_buffer *leaf;
-	struct btrfs_file_extent_item *fi;
-	u64 extent_len = 0;
-	u32 item_size;
-	int ret;
-
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-
-	BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
-	       key.type != BTRFS_EXTENT_CSUM_KEY);
-
-	if (btrfs_leaf_free_space(root, leaf) >= ins_len)
-		return 0;
-
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	if (key.type == BTRFS_EXTENT_DATA_KEY) {
-		fi = btrfs_item_ptr(leaf, path->slots[0],
-				    struct btrfs_file_extent_item);
-		extent_len = btrfs_file_extent_num_bytes(leaf, fi);
-	}
-	btrfs_release_path(path);
-
-	path->keep_locks = 1;
-	path->search_for_split = 1;
-	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
-	path->search_for_split = 0;
-	if (ret < 0)
-		goto err;
-
-	ret = -EAGAIN;
-	leaf = path->nodes[0];
-	/* if our item isn't there or got smaller, return now */
-	if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0]))
-		goto err;
-
-	/* the leaf has  changed, it now has room.  return now */
-	if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len)
-		goto err;
-
-	if (key.type == BTRFS_EXTENT_DATA_KEY) {
-		fi = btrfs_item_ptr(leaf, path->slots[0],
-				    struct btrfs_file_extent_item);
-		if (extent_len != btrfs_file_extent_num_bytes(leaf, fi))
-			goto err;
-	}
-
-	btrfs_set_path_blocking(path);
-	ret = split_leaf(trans, root, &key, path, ins_len, 1);
-	if (ret)
-		goto err;
-
-	path->keep_locks = 0;
-	btrfs_unlock_up_safe(path, 1);
-	return 0;
-err:
-	path->keep_locks = 0;
-	return ret;
-}
-
-static noinline int split_item(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root,
-			       struct btrfs_path *path,
-			       struct btrfs_key *new_key,
-			       unsigned long split_offset)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	struct btrfs_item *new_item;
-	int slot;
-	char *buf;
-	u32 nritems;
-	u32 item_size;
-	u32 orig_offset;
-	struct btrfs_disk_key disk_key;
-
-	leaf = path->nodes[0];
-	BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
-
-	btrfs_set_path_blocking(path);
-
-	item = btrfs_item_nr(leaf, path->slots[0]);
-	orig_offset = btrfs_item_offset(leaf, item);
-	item_size = btrfs_item_size(leaf, item);
-
-	buf = kmalloc(item_size, GFP_NOFS);
-	if (!buf)
-		return -ENOMEM;
-
-	read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
-			    path->slots[0]), item_size);
-
-	slot = path->slots[0] + 1;
-	nritems = btrfs_header_nritems(leaf);
-	if (slot != nritems) {
-		/* shift the items */
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
-				btrfs_item_nr_offset(slot),
-				(nritems - slot) * sizeof(struct btrfs_item));
-	}
-
-	btrfs_cpu_key_to_disk(&disk_key, new_key);
-	btrfs_set_item_key(leaf, &disk_key, slot);
-
-	new_item = btrfs_item_nr(leaf, slot);
-
-	btrfs_set_item_offset(leaf, new_item, orig_offset);
-	btrfs_set_item_size(leaf, new_item, item_size - split_offset);
-
-	btrfs_set_item_offset(leaf, item,
-			      orig_offset + item_size - split_offset);
-	btrfs_set_item_size(leaf, item, split_offset);
-
-	btrfs_set_header_nritems(leaf, nritems + 1);
-
-	/* write the data for the start of the original item */
-	write_extent_buffer(leaf, buf,
-			    btrfs_item_ptr_offset(leaf, path->slots[0]),
-			    split_offset);
-
-	/* write the data for the new item */
-	write_extent_buffer(leaf, buf + split_offset,
-			    btrfs_item_ptr_offset(leaf, slot),
-			    item_size - split_offset);
-	btrfs_mark_buffer_dirty(leaf);
-
-	BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
-	kfree(buf);
-	return 0;
-}
-
-/*
- * This function splits a single item into two items,
- * giving 'new_key' to the new item and splitting the
- * old one at split_offset (from the start of the item).
- *
- * The path may be released by this operation.  After
- * the split, the path is pointing to the old item.  The
- * new item is going to be in the same node as the old one.
- *
- * Note, the item being split must be smaller enough to live alone on
- * a tree block with room for one extra struct btrfs_item
- *
- * This allows us to split the item in place, keeping a lock on the
- * leaf the entire time.
- */
-int btrfs_split_item(struct btrfs_trans_handle *trans,
-		     struct btrfs_root *root,
-		     struct btrfs_path *path,
-		     struct btrfs_key *new_key,
-		     unsigned long split_offset)
-{
-	int ret;
-	ret = setup_leaf_for_split(trans, root, path,
-				   sizeof(struct btrfs_item));
-	if (ret)
-		return ret;
-
-	ret = split_item(trans, root, path, new_key, split_offset);
-	return ret;
-}
-
-/*
- * This function duplicate a item, giving 'new_key' to the new item.
- * It guarantees both items live in the same tree leaf and the new item
- * is contiguous with the original item.
- *
- * This allows us to split file extent in place, keeping a lock on the
- * leaf the entire time.
- */
-int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 struct btrfs_path *path,
-			 struct btrfs_key *new_key)
-{
-	struct extent_buffer *leaf;
-	int ret;
-	u32 item_size;
-
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	ret = setup_leaf_for_split(trans, root, path,
-				   item_size + sizeof(struct btrfs_item));
-	if (ret)
-		return ret;
-
-	path->slots[0]++;
-	setup_items_for_insert(trans, root, path, new_key, &item_size,
-			       item_size, item_size +
-			       sizeof(struct btrfs_item), 1);
-	leaf = path->nodes[0];
-	memcpy_extent_buffer(leaf,
-			     btrfs_item_ptr_offset(leaf, path->slots[0]),
-			     btrfs_item_ptr_offset(leaf, path->slots[0] - 1),
-			     item_size);
-	return 0;
-}
-
-/*
- * make the item pointed to by the path smaller.  new_size indicates
- * how small to make it, and from_end tells us if we just chop bytes
- * off the end of the item or if we shift the item to chop bytes off
- * the front.
- */
-void btrfs_truncate_item(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 struct btrfs_path *path,
-			 u32 new_size, int from_end)
-{
-	int slot;
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	u32 nritems;
-	unsigned int data_end;
-	unsigned int old_data_start;
-	unsigned int old_size;
-	unsigned int size_diff;
-	int i;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	leaf = path->nodes[0];
-	slot = path->slots[0];
-
-	old_size = btrfs_item_size_nr(leaf, slot);
-	if (old_size == new_size)
-		return;
-
-	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(root, leaf);
-
-	old_data_start = btrfs_item_offset_nr(leaf, slot);
-
-	size_diff = old_size - new_size;
-
-	BUG_ON(slot < 0);
-	BUG_ON(slot >= nritems);
-
-	/*
-	 * item0..itemN ... dataN.offset..dataN.size .. data0.size
-	 */
-	/* first correct the data pointers */
-	for (i = slot; i < nritems; i++) {
-		u32 ioff;
-		item = btrfs_item_nr(leaf, i);
-
-		ioff = btrfs_token_item_offset(leaf, item, &token);
-		btrfs_set_token_item_offset(leaf, item,
-					    ioff + size_diff, &token);
-	}
-
-	/* shift the data */
-	if (from_end) {
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end + size_diff, btrfs_leaf_data(leaf) +
-			      data_end, old_data_start + new_size - data_end);
-	} else {
-		struct btrfs_disk_key disk_key;
-		u64 offset;
-
-		btrfs_item_key(leaf, &disk_key, slot);
-
-		if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
-			unsigned long ptr;
-			struct btrfs_file_extent_item *fi;
-
-			fi = btrfs_item_ptr(leaf, slot,
-					    struct btrfs_file_extent_item);
-			fi = (struct btrfs_file_extent_item *)(
-			     (unsigned long)fi - size_diff);
-
-			if (btrfs_file_extent_type(leaf, fi) ==
-			    BTRFS_FILE_EXTENT_INLINE) {
-				ptr = btrfs_item_ptr_offset(leaf, slot);
-				memmove_extent_buffer(leaf, ptr,
-				      (unsigned long)fi,
-				      offsetof(struct btrfs_file_extent_item,
-						 disk_bytenr));
-			}
-		}
-
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end + size_diff, btrfs_leaf_data(leaf) +
-			      data_end, old_data_start - data_end);
-
-		offset = btrfs_disk_key_offset(&disk_key);
-		btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
-		btrfs_set_item_key(leaf, &disk_key, slot);
-		if (slot == 0)
-			fixup_low_keys(trans, root, path, &disk_key, 1);
-	}
-
-	item = btrfs_item_nr(leaf, slot);
-	btrfs_set_item_size(leaf, item, new_size);
-	btrfs_mark_buffer_dirty(leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < 0) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-}
-
-/*
- * make the item pointed to by the path bigger, data_size is the new size.
- */
-void btrfs_extend_item(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct btrfs_path *path,
-		       u32 data_size)
-{
-	int slot;
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	u32 nritems;
-	unsigned int data_end;
-	unsigned int old_data;
-	unsigned int old_size;
-	int i;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	leaf = path->nodes[0];
-
-	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(root, leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < data_size) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-	slot = path->slots[0];
-	old_data = btrfs_item_end_nr(leaf, slot);
-
-	BUG_ON(slot < 0);
-	if (slot >= nritems) {
-		btrfs_print_leaf(root, leaf);
-		printk(KERN_CRIT "slot %d too large, nritems %d\n",
-		       slot, nritems);
-		BUG_ON(1);
-	}
-
-	/*
-	 * item0..itemN ... dataN.offset..dataN.size .. data0.size
-	 */
-	/* first correct the data pointers */
-	for (i = slot; i < nritems; i++) {
-		u32 ioff;
-		item = btrfs_item_nr(leaf, i);
-
-		ioff = btrfs_token_item_offset(leaf, item, &token);
-		btrfs_set_token_item_offset(leaf, item,
-					    ioff - data_size, &token);
-	}
-
-	/* shift the data */
-	memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-		      data_end - data_size, btrfs_leaf_data(leaf) +
-		      data_end, old_data - data_end);
-
-	data_end = old_data;
-	old_size = btrfs_item_size_nr(leaf, slot);
-	item = btrfs_item_nr(leaf, slot);
-	btrfs_set_item_size(leaf, item, old_size + data_size);
-	btrfs_mark_buffer_dirty(leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < 0) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-}
-
-/*
- * Given a key and some data, insert items into the tree.
- * This does all the path init required, making room in the tree if needed.
- * Returns the number of keys that were inserted.
- */
-int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root,
-			    struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
-			    int nr)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	int ret = 0;
-	int slot;
-	int i;
-	u32 nritems;
-	u32 total_data = 0;
-	u32 total_size = 0;
-	unsigned int data_end;
-	struct btrfs_disk_key disk_key;
-	struct btrfs_key found_key;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	for (i = 0; i < nr; i++) {
-		if (total_size + data_size[i] + sizeof(struct btrfs_item) >
-		    BTRFS_LEAF_DATA_SIZE(root)) {
-			break;
-			nr = i;
-		}
-		total_data += data_size[i];
-		total_size += data_size[i] + sizeof(struct btrfs_item);
-	}
-	BUG_ON(nr == 0);
-
-	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
-	if (ret == 0)
-		return -EEXIST;
-	if (ret < 0)
-		goto out;
-
-	leaf = path->nodes[0];
-
-	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(root, leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < total_size) {
-		for (i = nr; i >= 0; i--) {
-			total_data -= data_size[i];
-			total_size -= data_size[i] + sizeof(struct btrfs_item);
-			if (total_size < btrfs_leaf_free_space(root, leaf))
-				break;
-		}
-		nr = i;
-	}
-
-	slot = path->slots[0];
-	BUG_ON(slot < 0);
-
-	if (slot != nritems) {
-		unsigned int old_data = btrfs_item_end_nr(leaf, slot);
-
-		item = btrfs_item_nr(leaf, slot);
-		btrfs_item_key_to_cpu(leaf, &found_key, slot);
-
-		/* figure out how many keys we can insert in here */
-		total_data = data_size[0];
-		for (i = 1; i < nr; i++) {
-			if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0)
-				break;
-			total_data += data_size[i];
-		}
-		nr = i;
-
-		if (old_data < data_end) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
-			       slot, old_data, data_end);
-			BUG_ON(1);
-		}
-		/*
-		 * item0..itemN ... dataN.offset..dataN.size .. data0.size
-		 */
-		/* first correct the data pointers */
-		for (i = slot; i < nritems; i++) {
-			u32 ioff;
-
-			item = btrfs_item_nr(leaf, i);
-			ioff = btrfs_token_item_offset(leaf, item, &token);
-			btrfs_set_token_item_offset(leaf, item,
-						    ioff - total_data, &token);
-		}
-		/* shift the items */
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
-			      btrfs_item_nr_offset(slot),
-			      (nritems - slot) * sizeof(struct btrfs_item));
-
-		/* shift the data */
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end - total_data, btrfs_leaf_data(leaf) +
-			      data_end, old_data - data_end);
-		data_end = old_data;
-	} else {
-		/*
-		 * this sucks but it has to be done, if we are inserting at
-		 * the end of the leaf only insert 1 of the items, since we
-		 * have no way of knowing whats on the next leaf and we'd have
-		 * to drop our current locks to figure it out
-		 */
-		nr = 1;
-	}
-
-	/* setup the item for the new data */
-	for (i = 0; i < nr; i++) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
-		btrfs_set_item_key(leaf, &disk_key, slot + i);
-		item = btrfs_item_nr(leaf, slot + i);
-		btrfs_set_token_item_offset(leaf, item,
-					    data_end - data_size[i], &token);
-		data_end -= data_size[i];
-		btrfs_set_token_item_size(leaf, item, data_size[i], &token);
-	}
-	btrfs_set_header_nritems(leaf, nritems + nr);
-	btrfs_mark_buffer_dirty(leaf);
-
-	ret = 0;
-	if (slot == 0) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-		fixup_low_keys(trans, root, path, &disk_key, 1);
-	}
-
-	if (btrfs_leaf_free_space(root, leaf) < 0) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-out:
-	if (!ret)
-		ret = nr;
-	return ret;
-}
-
-/*
- * this is a helper for btrfs_insert_empty_items, the main goal here is
- * to save stack depth by doing the bulk of the work in a function
- * that doesn't call btrfs_search_slot
- */
-void setup_items_for_insert(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
-			    u32 total_data, u32 total_size, int nr)
-{
-	struct btrfs_item *item;
-	int i;
-	u32 nritems;
-	unsigned int data_end;
-	struct btrfs_disk_key disk_key;
-	struct extent_buffer *leaf;
-	int slot;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	leaf = path->nodes[0];
-	slot = path->slots[0];
-
-	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(root, leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < total_size) {
-		btrfs_print_leaf(root, leaf);
-		printk(KERN_CRIT "not enough freespace need %u have %d\n",
-		       total_size, btrfs_leaf_free_space(root, leaf));
-		BUG();
-	}
-
-	if (slot != nritems) {
-		unsigned int old_data = btrfs_item_end_nr(leaf, slot);
-
-		if (old_data < data_end) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
-			       slot, old_data, data_end);
-			BUG_ON(1);
-		}
-		/*
-		 * item0..itemN ... dataN.offset..dataN.size .. data0.size
-		 */
-		/* first correct the data pointers */
-		for (i = slot; i < nritems; i++) {
-			u32 ioff;
-
-			item = btrfs_item_nr(leaf, i);
-			ioff = btrfs_token_item_offset(leaf, item, &token);
-			btrfs_set_token_item_offset(leaf, item,
-						    ioff - total_data, &token);
-		}
-		/* shift the items */
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
-			      btrfs_item_nr_offset(slot),
-			      (nritems - slot) * sizeof(struct btrfs_item));
-
-		/* shift the data */
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end - total_data, btrfs_leaf_data(leaf) +
-			      data_end, old_data - data_end);
-		data_end = old_data;
-	}
-
-	/* setup the item for the new data */
-	for (i = 0; i < nr; i++) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
-		btrfs_set_item_key(leaf, &disk_key, slot + i);
-		item = btrfs_item_nr(leaf, slot + i);
-		btrfs_set_token_item_offset(leaf, item,
-					    data_end - data_size[i], &token);
-		data_end -= data_size[i];
-		btrfs_set_token_item_size(leaf, item, data_size[i], &token);
-	}
-
-	btrfs_set_header_nritems(leaf, nritems + nr);
-
-	if (slot == 0) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-		fixup_low_keys(trans, root, path, &disk_key, 1);
-	}
-	btrfs_unlock_up_safe(path, 1);
-	btrfs_mark_buffer_dirty(leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < 0) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-}
-
-/*
- * Given a key and some data, insert items into the tree.
- * This does all the path init required, making room in the tree if needed.
- */
-int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root,
-			    struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
-			    int nr)
-{
-	int ret = 0;
-	int slot;
-	int i;
-	u32 total_size = 0;
-	u32 total_data = 0;
-
-	for (i = 0; i < nr; i++)
-		total_data += data_size[i];
-
-	total_size = total_data + (nr * sizeof(struct btrfs_item));
-	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
-	if (ret == 0)
-		return -EEXIST;
-	if (ret < 0)
-		return ret;
-
-	slot = path->slots[0];
-	BUG_ON(slot < 0);
-
-	setup_items_for_insert(trans, root, path, cpu_key, data_size,
-			       total_data, total_size, nr);
-	return 0;
-}
-
-/*
- * Given a key and some data, insert an item into the tree.
- * This does all the path init required, making room in the tree if needed.
- */
-int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *cpu_key, void *data, u32
-		      data_size)
-{
-	int ret = 0;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	unsigned long ptr;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
-	if (!ret) {
-		leaf = path->nodes[0];
-		ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
-		write_extent_buffer(leaf, data, ptr, data_size);
-		btrfs_mark_buffer_dirty(leaf);
-	}
-	btrfs_free_path(path);
-	return ret;
-}
-
-/*
- * delete the pointer from a given node.
- *
- * the tree should have been previously balanced so the deletion does not
- * empty a node.
- */
-static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		    struct btrfs_path *path, int level, int slot)
-{
-	struct extent_buffer *parent = path->nodes[level];
-	u32 nritems;
-
-	nritems = btrfs_header_nritems(parent);
-	if (slot != nritems - 1) {
-		memmove_extent_buffer(parent,
-			      btrfs_node_key_ptr_offset(slot),
-			      btrfs_node_key_ptr_offset(slot + 1),
-			      sizeof(struct btrfs_key_ptr) *
-			      (nritems - slot - 1));
-	}
-	nritems--;
-	btrfs_set_header_nritems(parent, nritems);
-	if (nritems == 0 && parent == root->node) {
-		BUG_ON(btrfs_header_level(root->node) != 1);
-		/* just turn the root into a leaf and break */
-		btrfs_set_header_level(root->node, 0);
-	} else if (slot == 0) {
-		struct btrfs_disk_key disk_key;
-
-		btrfs_node_key(parent, &disk_key, 0);
-		fixup_low_keys(trans, root, path, &disk_key, level + 1);
-	}
-	btrfs_mark_buffer_dirty(parent);
-}
-
-/*
- * a helper function to delete the leaf pointed to by path->slots[1] and
- * path->nodes[1].
- *
- * This deletes the pointer in path->nodes[1] and frees the leaf
- * block extent.  zero is returned if it all worked out, < 0 otherwise.
- *
- * The path must have already been setup for deleting the leaf, including
- * all the proper balancing.  path->nodes[1] must be locked.
- */
-static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
-				    struct btrfs_path *path,
-				    struct extent_buffer *leaf)
-{
-	WARN_ON(btrfs_header_generation(leaf) != trans->transid);
-	del_ptr(trans, root, path, 1, path->slots[1]);
-
-	/*
-	 * btrfs_free_extent is expensive, we want to make sure we
-	 * aren't holding any locks when we call it
-	 */
-	btrfs_unlock_up_safe(path, 0);
-
-	root_sub_used(root, leaf->len);
-
-	extent_buffer_get(leaf);
-	btrfs_free_tree_block(trans, root, leaf, 0, 1, 0);
-	free_extent_buffer_stale(leaf);
-}
-/*
- * delete the item at the leaf level in path.  If that empties
- * the leaf, remove it from the tree
- */
-int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		    struct btrfs_path *path, int slot, int nr)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	int last_off;
-	int dsize = 0;
-	int ret = 0;
-	int wret;
-	int i;
-	u32 nritems;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	leaf = path->nodes[0];
-	last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
-
-	for (i = 0; i < nr; i++)
-		dsize += btrfs_item_size_nr(leaf, slot + i);
-
-	nritems = btrfs_header_nritems(leaf);
-
-	if (slot + nr != nritems) {
-		int data_end = leaf_data_end(root, leaf);
-
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end + dsize,
-			      btrfs_leaf_data(leaf) + data_end,
-			      last_off - data_end);
-
-		for (i = slot + nr; i < nritems; i++) {
-			u32 ioff;
-
-			item = btrfs_item_nr(leaf, i);
-			ioff = btrfs_token_item_offset(leaf, item, &token);
-			btrfs_set_token_item_offset(leaf, item,
-						    ioff + dsize, &token);
-		}
-
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
-			      btrfs_item_nr_offset(slot + nr),
-			      sizeof(struct btrfs_item) *
-			      (nritems - slot - nr));
-	}
-	btrfs_set_header_nritems(leaf, nritems - nr);
-	nritems -= nr;
-
-	/* delete the leaf if we've emptied it */
-	if (nritems == 0) {
-		if (leaf == root->node) {
-			btrfs_set_header_level(leaf, 0);
-		} else {
-			btrfs_set_path_blocking(path);
-			clean_tree_block(trans, root, leaf);
-			btrfs_del_leaf(trans, root, path, leaf);
-		}
-	} else {
-		int used = leaf_space_used(leaf, 0, nritems);
-		if (slot == 0) {
-			struct btrfs_disk_key disk_key;
-
-			btrfs_item_key(leaf, &disk_key, 0);
-			fixup_low_keys(trans, root, path, &disk_key, 1);
-		}
-
-		/* delete the leaf if it is mostly empty */
-		if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
-			/* push_leaf_left fixes the path.
-			 * make sure the path still points to our leaf
-			 * for possible call to del_ptr below
-			 */
-			slot = path->slots[1];
-			extent_buffer_get(leaf);
-
-			btrfs_set_path_blocking(path);
-			wret = push_leaf_left(trans, root, path, 1, 1,
-					      1, (u32)-1);
-			if (wret < 0 && wret != -ENOSPC)
-				ret = wret;
-
-			if (path->nodes[0] == leaf &&
-			    btrfs_header_nritems(leaf)) {
-				wret = push_leaf_right(trans, root, path, 1,
-						       1, 1, 0);
-				if (wret < 0 && wret != -ENOSPC)
-					ret = wret;
-			}
-
-			if (btrfs_header_nritems(leaf) == 0) {
-				path->slots[1] = slot;
-				btrfs_del_leaf(trans, root, path, leaf);
-				free_extent_buffer(leaf);
-				ret = 0;
-			} else {
-				/* if we're still in the path, make sure
-				 * we're dirty.  Otherwise, one of the
-				 * push_leaf functions must have already
-				 * dirtied this buffer
-				 */
-				if (path->nodes[0] == leaf)
-					btrfs_mark_buffer_dirty(leaf);
-				free_extent_buffer(leaf);
-			}
-		} else {
-			btrfs_mark_buffer_dirty(leaf);
-		}
-	}
-	return ret;
-}
-
-/*
- * search the tree again to find a leaf with lesser keys
- * returns 0 if it found something or 1 if there are no lesser leaves.
- * returns < 0 on io errors.
- *
- * This may release the path, and so you may lose any locks held at the
- * time you call it.
- */
-int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
-{
-	struct btrfs_key key;
-	struct btrfs_disk_key found_key;
-	int ret;
-
-	btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
-
-	if (key.offset > 0)
-		key.offset--;
-	else if (key.type > 0)
-		key.type--;
-	else if (key.objectid > 0)
-		key.objectid--;
-	else
-		return 1;
-
-	btrfs_release_path(path);
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	if (ret < 0)
-		return ret;
-	btrfs_item_key(path->nodes[0], &found_key, 0);
-	ret = comp_keys(&found_key, &key);
-	if (ret < 0)
-		return 0;
-	return 1;
-}
-
-/*
- * A helper function to walk down the tree starting at min_key, and looking
- * for nodes or leaves that are either in cache or have a minimum
- * transaction id.  This is used by the btree defrag code, and tree logging
- *
- * This does not cow, but it does stuff the starting key it finds back
- * into min_key, so you can call btrfs_search_slot with cow=1 on the
- * key and get a writable path.
- *
- * This does lock as it descends, and path->keep_locks should be set
- * to 1 by the caller.
- *
- * This honors path->lowest_level to prevent descent past a given level
- * of the tree.
- *
- * min_trans indicates the oldest transaction that you are interested
- * in walking through.  Any nodes or leaves older than min_trans are
- * skipped over (without reading them).
- *
- * returns zero if something useful was found, < 0 on error and 1 if there
- * was nothing in the tree that matched the search criteria.
- */
-int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
-			 struct btrfs_key *max_key,
-			 struct btrfs_path *path, int cache_only,
-			 u64 min_trans)
-{
-	struct extent_buffer *cur;
-	struct btrfs_key found_key;
-	int slot;
-	int sret;
-	u32 nritems;
-	int level;
-	int ret = 1;
-
-	WARN_ON(!path->keep_locks);
-again:
-	cur = btrfs_read_lock_root_node(root);
-	level = btrfs_header_level(cur);
-	WARN_ON(path->nodes[level]);
-	path->nodes[level] = cur;
-	path->locks[level] = BTRFS_READ_LOCK;
-
-	if (btrfs_header_generation(cur) < min_trans) {
-		ret = 1;
-		goto out;
-	}
-	while (1) {
-		nritems = btrfs_header_nritems(cur);
-		level = btrfs_header_level(cur);
-		sret = bin_search(cur, min_key, level, &slot);
-
-		/* at the lowest level, we're done, setup the path and exit */
-		if (level == path->lowest_level) {
-			if (slot >= nritems)
-				goto find_next_key;
-			ret = 0;
-			path->slots[level] = slot;
-			btrfs_item_key_to_cpu(cur, &found_key, slot);
-			goto out;
-		}
-		if (sret && slot > 0)
-			slot--;
-		/*
-		 * check this node pointer against the cache_only and
-		 * min_trans parameters.  If it isn't in cache or is too
-		 * old, skip to the next one.
-		 */
-		while (slot < nritems) {
-			u64 blockptr;
-			u64 gen;
-			struct extent_buffer *tmp;
-			struct btrfs_disk_key disk_key;
-
-			blockptr = btrfs_node_blockptr(cur, slot);
-			gen = btrfs_node_ptr_generation(cur, slot);
-			if (gen < min_trans) {
-				slot++;
-				continue;
-			}
-			if (!cache_only)
-				break;
-
-			if (max_key) {
-				btrfs_node_key(cur, &disk_key, slot);
-				if (comp_keys(&disk_key, max_key) >= 0) {
-					ret = 1;
-					goto out;
-				}
-			}
-
-			tmp = btrfs_find_tree_block(root, blockptr,
-					    btrfs_level_size(root, level - 1));
-
-			if (tmp && btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
-				free_extent_buffer(tmp);
-				break;
-			}
-			if (tmp)
-				free_extent_buffer(tmp);
-			slot++;
-		}
-find_next_key:
-		/*
-		 * we didn't find a candidate key in this node, walk forward
-		 * and find another one
-		 */
-		if (slot >= nritems) {
-			path->slots[level] = slot;
-			btrfs_set_path_blocking(path);
-			sret = btrfs_find_next_key(root, path, min_key, level,
-						  cache_only, min_trans);
-			if (sret == 0) {
-				btrfs_release_path(path);
-				goto again;
-			} else {
-				goto out;
-			}
-		}
-		/* save our key for returning back */
-		btrfs_node_key_to_cpu(cur, &found_key, slot);
-		path->slots[level] = slot;
-		if (level == path->lowest_level) {
-			ret = 0;
-			unlock_up(path, level, 1, 0, NULL);
-			goto out;
-		}
-		btrfs_set_path_blocking(path);
-		cur = read_node_slot(root, cur, slot);
-		BUG_ON(!cur); /* -ENOMEM */
-
-		btrfs_tree_read_lock(cur);
-
-		path->locks[level - 1] = BTRFS_READ_LOCK;
-		path->nodes[level - 1] = cur;
-		unlock_up(path, level, 1, 0, NULL);
-		btrfs_clear_path_blocking(path, NULL, 0);
-	}
-out:
-	if (ret == 0)
-		memcpy(min_key, &found_key, sizeof(found_key));
-	btrfs_set_path_blocking(path);
-	return ret;
-}
-
-/*
- * this is similar to btrfs_next_leaf, but does not try to preserve
- * and fixup the path.  It looks for and returns the next key in the
- * tree based on the current path and the cache_only and min_trans
- * parameters.
- *
- * 0 is returned if another key is found, < 0 if there are any errors
- * and 1 is returned if there are no higher keys in the tree
- *
- * path->keep_locks should be set to 1 on the search made before
- * calling this function.
- */
-int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
-			struct btrfs_key *key, int level,
-			int cache_only, u64 min_trans)
-{
-	int slot;
-	struct extent_buffer *c;
-
-	WARN_ON(!path->keep_locks);
-	while (level < BTRFS_MAX_LEVEL) {
-		if (!path->nodes[level])
-			return 1;
-
-		slot = path->slots[level] + 1;
-		c = path->nodes[level];
-next:
-		if (slot >= btrfs_header_nritems(c)) {
-			int ret;
-			int orig_lowest;
-			struct btrfs_key cur_key;
-			if (level + 1 >= BTRFS_MAX_LEVEL ||
-			    !path->nodes[level + 1])
-				return 1;
-
-			if (path->locks[level + 1]) {
-				level++;
-				continue;
-			}
-
-			slot = btrfs_header_nritems(c) - 1;
-			if (level == 0)
-				btrfs_item_key_to_cpu(c, &cur_key, slot);
-			else
-				btrfs_node_key_to_cpu(c, &cur_key, slot);
-
-			orig_lowest = path->lowest_level;
-			btrfs_release_path(path);
-			path->lowest_level = level;
-			ret = btrfs_search_slot(NULL, root, &cur_key, path,
-						0, 0);
-			path->lowest_level = orig_lowest;
-			if (ret < 0)
-				return ret;
-
-			c = path->nodes[level];
-			slot = path->slots[level];
-			if (ret == 0)
-				slot++;
-			goto next;
-		}
-
-		if (level == 0)
-			btrfs_item_key_to_cpu(c, key, slot);
-		else {
-			u64 blockptr = btrfs_node_blockptr(c, slot);
-			u64 gen = btrfs_node_ptr_generation(c, slot);
-
-			if (cache_only) {
-				struct extent_buffer *cur;
-				cur = btrfs_find_tree_block(root, blockptr,
-					    btrfs_level_size(root, level - 1));
-				if (!cur ||
-				    btrfs_buffer_uptodate(cur, gen, 1) <= 0) {
-					slot++;
-					if (cur)
-						free_extent_buffer(cur);
-					goto next;
-				}
-				free_extent_buffer(cur);
-			}
-			if (gen < min_trans) {
-				slot++;
-				goto next;
-			}
-			btrfs_node_key_to_cpu(c, key, slot);
-		}
-		return 0;
-	}
-	return 1;
-}
-
-/*
- * search the tree again to find a leaf with greater keys
- * returns 0 if it found something or 1 if there are no greater leaves.
- * returns < 0 on io errors.
- */
-int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
-{
-	int slot;
-	int level;
-	struct extent_buffer *c;
-	struct extent_buffer *next;
-	struct btrfs_key key;
-	u32 nritems;
-	int ret;
-	int old_spinning = path->leave_spinning;
-	int next_rw_lock = 0;
-
-	nritems = btrfs_header_nritems(path->nodes[0]);
-	if (nritems == 0)
-		return 1;
-
-	btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
-again:
-	level = 1;
-	next = NULL;
-	next_rw_lock = 0;
-	btrfs_release_path(path);
-
-	path->keep_locks = 1;
-	path->leave_spinning = 1;
-
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	path->keep_locks = 0;
-
-	if (ret < 0)
-		return ret;
-
-	nritems = btrfs_header_nritems(path->nodes[0]);
-	/*
-	 * by releasing the path above we dropped all our locks.  A balance
-	 * could have added more items next to the key that used to be
-	 * at the very end of the block.  So, check again here and
-	 * advance the path if there are now more items available.
-	 */
-	if (nritems > 0 && path->slots[0] < nritems - 1) {
-		if (ret == 0)
-			path->slots[0]++;
-		ret = 0;
-		goto done;
-	}
-
-	while (level < BTRFS_MAX_LEVEL) {
-		if (!path->nodes[level]) {
-			ret = 1;
-			goto done;
-		}
-
-		slot = path->slots[level] + 1;
-		c = path->nodes[level];
-		if (slot >= btrfs_header_nritems(c)) {
-			level++;
-			if (level == BTRFS_MAX_LEVEL) {
-				ret = 1;
-				goto done;
-			}
-			continue;
-		}
-
-		if (next) {
-			btrfs_tree_unlock_rw(next, next_rw_lock);
-			free_extent_buffer(next);
-		}
-
-		next = c;
-		next_rw_lock = path->locks[level];
-		ret = read_block_for_search(NULL, root, path, &next, level,
-					    slot, &key);
-		if (ret == -EAGAIN)
-			goto again;
-
-		if (ret < 0) {
-			btrfs_release_path(path);
-			goto done;
-		}
-
-		if (!path->skip_locking) {
-			ret = btrfs_try_tree_read_lock(next);
-			if (!ret) {
-				btrfs_set_path_blocking(path);
-				btrfs_tree_read_lock(next);
-				btrfs_clear_path_blocking(path, next,
-							  BTRFS_READ_LOCK);
-			}
-			next_rw_lock = BTRFS_READ_LOCK;
-		}
-		break;
-	}
-	path->slots[level] = slot;
-	while (1) {
-		level--;
-		c = path->nodes[level];
-		if (path->locks[level])
-			btrfs_tree_unlock_rw(c, path->locks[level]);
-
-		free_extent_buffer(c);
-		path->nodes[level] = next;
-		path->slots[level] = 0;
-		if (!path->skip_locking)
-			path->locks[level] = next_rw_lock;
-		if (!level)
-			break;
-
-		ret = read_block_for_search(NULL, root, path, &next, level,
-					    0, &key);
-		if (ret == -EAGAIN)
-			goto again;
-
-		if (ret < 0) {
-			btrfs_release_path(path);
-			goto done;
-		}
-
-		if (!path->skip_locking) {
-			ret = btrfs_try_tree_read_lock(next);
-			if (!ret) {
-				btrfs_set_path_blocking(path);
-				btrfs_tree_read_lock(next);
-				btrfs_clear_path_blocking(path, next,
-							  BTRFS_READ_LOCK);
-			}
-			next_rw_lock = BTRFS_READ_LOCK;
-		}
-	}
-	ret = 0;
-done:
-	unlock_up(path, 0, 1, 0, NULL);
-	path->leave_spinning = old_spinning;
-	if (!old_spinning)
-		btrfs_set_path_blocking(path);
-
-	return ret;
-}
-
-/*
- * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
- * searching until it gets past min_objectid or finds an item of 'type'
- *
- * returns 0 if something is found, 1 if nothing was found and < 0 on error
- */
-int btrfs_previous_item(struct btrfs_root *root,
-			struct btrfs_path *path, u64 min_objectid,
-			int type)
-{
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	u32 nritems;
-	int ret;
-
-	while (1) {
-		if (path->slots[0] == 0) {
-			btrfs_set_path_blocking(path);
-			ret = btrfs_prev_leaf(root, path);
-			if (ret != 0)
-				return ret;
-		} else {
-			path->slots[0]--;
-		}
-		leaf = path->nodes[0];
-		nritems = btrfs_header_nritems(leaf);
-		if (nritems == 0)
-			return 1;
-		if (path->slots[0] == nritems)
-			path->slots[0]--;
-
-		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-		if (found_key.objectid < min_objectid)
-			break;
-		if (found_key.type == type)
-			return 0;
-		if (found_key.objectid == min_objectid &&
-		    found_key.type < type)
-			break;
-	}
-	return 1;
-}