diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
new file mode 100644
index 0000000..15d0a48
--- /dev/null
+++ b/fs/btrfs/tree-defrag.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2007 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 "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+
+static void reada_defrag(struct btrfs_root *root,
+			 struct btrfs_node *node)
+{
+	int i;
+	u32 nritems;
+	u64 blocknr;
+	int ret;
+
+	nritems = btrfs_header_nritems(&node->header);
+	for (i = 0; i < nritems; i++) {
+		blocknr = btrfs_node_blockptr(node, i);
+		ret = readahead_tree_block(root, blocknr);
+		if (ret)
+			break;
+	}
+}
+
+static int defrag_walk_down(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, int *level,
+			    int cache_only)
+{
+	struct buffer_head *next;
+	struct buffer_head *cur;
+	u64 blocknr;
+	int ret = 0;
+
+	WARN_ON(*level < 0);
+	WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+	while(*level > 0) {
+		WARN_ON(*level < 0);
+		WARN_ON(*level >= BTRFS_MAX_LEVEL);
+		cur = path->nodes[*level];
+
+		if (!cache_only && *level > 1 && path->slots[*level] == 0)
+			reada_defrag(root, btrfs_buffer_node(cur));
+
+		if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
+			WARN_ON(1);
+
+		if (path->slots[*level] >=
+		    btrfs_header_nritems(btrfs_buffer_header(cur)))
+			break;
+
+		if (*level == 1) {
+			ret = btrfs_realloc_node(trans, root,
+						 path->nodes[*level],
+						 cache_only);
+			break;
+		}
+		blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
+					      path->slots[*level]);
+
+		if (cache_only) {
+			next = btrfs_find_tree_block(root, blocknr);
+			if (!next || !buffer_uptodate(next) ||
+			   buffer_locked(next)) {
+				brelse(next);
+				path->slots[*level]++;
+				continue;
+			}
+		} else {
+			next = read_tree_block(root, blocknr);
+		}
+		ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
+				      path->slots[*level], &next);
+		BUG_ON(ret);
+		ret = btrfs_realloc_node(trans, root, next, cache_only);
+		BUG_ON(ret);
+		WARN_ON(*level <= 0);
+		if (path->nodes[*level-1])
+			btrfs_block_release(root, path->nodes[*level-1]);
+		path->nodes[*level-1] = next;
+		*level = btrfs_header_level(btrfs_buffer_header(next));
+		path->slots[*level] = 0;
+	}
+	WARN_ON(*level < 0);
+	WARN_ON(*level >= BTRFS_MAX_LEVEL);
+	btrfs_block_release(root, path->nodes[*level]);
+	path->nodes[*level] = NULL;
+	*level += 1;
+	WARN_ON(ret);
+	return 0;
+}
+
+static int defrag_walk_up(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  struct btrfs_path *path, int *level,
+			  int cache_only)
+{
+	int i;
+	int slot;
+	struct btrfs_node *node;
+
+	for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
+		slot = path->slots[i];
+		if (slot < btrfs_header_nritems(
+		    btrfs_buffer_header(path->nodes[i])) - 1) {
+			path->slots[i]++;
+			*level = i;
+			node = btrfs_buffer_node(path->nodes[i]);
+			WARN_ON(i == 0);
+			btrfs_disk_key_to_cpu(&root->defrag_progress,
+					      &node->ptrs[path->slots[i]].key);
+			root->defrag_level = i;
+			return 0;
+		} else {
+			btrfs_block_release(root, path->nodes[*level]);
+			path->nodes[*level] = NULL;
+			*level = i + 1;
+		}
+	}
+	return 1;
+}
+
+int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, int cache_only)
+{
+	struct btrfs_path *path = NULL;
+	struct buffer_head *tmp;
+	int ret = 0;
+	int wret;
+	int level;
+	int orig_level;
+	int i;
+	int num_runs = 0;
+
+	if (root->ref_cows == 0) {
+		goto out;
+	}
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	level = btrfs_header_level(btrfs_buffer_header(root->node));
+	orig_level = level;
+	if (level == 0) {
+		goto out;
+	}
+	if (root->defrag_progress.objectid == 0) {
+		get_bh(root->node);
+		ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
+		BUG_ON(ret);
+		ret = btrfs_realloc_node(trans, root, root->node, cache_only);
+		BUG_ON(ret);
+		path->nodes[level] = root->node;
+		path->slots[level] = 0;
+	} else {
+		level = root->defrag_level;
+		path->lowest_level = level;
+		wret = btrfs_search_slot(trans, root, &root->defrag_progress,
+					 path, 0, 1);
+
+		if (wret < 0) {
+			ret = wret;
+			goto out;
+		}
+		while(level > 0 && !path->nodes[level])
+			level--;
+		if (!path->nodes[level]) {
+			ret = 0;
+			goto out;
+		}
+	}
+
+	while(1) {
+		wret = defrag_walk_down(trans, root, path, &level, cache_only);
+		if (wret > 0)
+			break;
+		if (wret < 0)
+			ret = wret;
+
+		wret = defrag_walk_up(trans, root, path, &level, cache_only);
+		if (wret > 0)
+			break;
+		if (wret < 0)
+			ret = wret;
+		if (num_runs++ > 8) {
+			ret = -EAGAIN;
+			break;
+		}
+	}
+	for (i = 0; i <= orig_level; i++) {
+		if (path->nodes[i]) {
+			btrfs_block_release(root, path->nodes[i]);
+			path->nodes[i] = 0;
+		}
+	}
+out:
+	if (path)
+		btrfs_free_path(path);
+	if (ret != -EAGAIN) {
+		memset(&root->defrag_progress, 0,
+		       sizeof(root->defrag_progress));
+	}
+	return ret;
+}