Btrfs: Create extent_buffer interface for large blocksizes
[linux-2.6-block.git] / fs / btrfs / ctree.c
index 2891b582e26f24cfdffd25c51531d1e5fa7c82d5..f60920e8a0e061f7d4cd4eaebe51a483cceb4645 100644 (file)
-#include <stdio.h>
-#include <stdlib.h>
-#include "kerncompat.h"
-#include "radix-tree.h"
+/*
+ * 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/highmem.h>
 #include "ctree.h"
 #include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.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);
+static int push_node_left(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root, struct extent_buffer *dst,
+                         struct extent_buffer *src);
+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 int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                  struct btrfs_path *path, int level, int slot);
+
+inline void btrfs_init_path(struct btrfs_path *p)
+{
+       memset(p, 0, sizeof(*p));
+}
 
-static int refill_alloc_extent(struct ctree_root *root);
+struct btrfs_path *btrfs_alloc_path(void)
+{
+       struct btrfs_path *path;
+       path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+       if (path) {
+               btrfs_init_path(path);
+               path->reada = 1;
+       }
+       return path;
+}
 
-static inline void init_path(struct ctree_path *p)
+void btrfs_free_path(struct btrfs_path *p)
 {
-       memset(p, 0, sizeof(*p));
+       btrfs_release_path(NULL, p);
+       kmem_cache_free(btrfs_path_cachep, p);
 }
 
-static void release_path(struct ctree_root *root, struct ctree_path *p)
+void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
 {
        int i;
-       for (i = 0; i < MAX_LEVEL; i++) {
+       for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
                if (!p->nodes[i])
                        break;
-               tree_block_release(root, p->nodes[i]);
+               free_extent_buffer(p->nodes[i]);
+       }
+       memset(p, 0, sizeof(*p));
+}
+
+static 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 extent_buffer *cow;
+       int ret = 0;
+       int different_trans = 0;
+
+       WARN_ON(root->ref_cows && trans->transid != root->last_trans);
+
+       cow = btrfs_alloc_free_block(trans, root, search_start, empty_size);
+       if (IS_ERR(cow))
+               return PTR_ERR(cow);
+
+       if (buf->len != root->sectorsize || cow->len != root->sectorsize)
+               WARN_ON(1);
+
+       copy_extent_buffer(cow, buf, 0, 0, cow->len);
+       btrfs_set_header_blocknr(cow, extent_buffer_blocknr(cow));
+       btrfs_set_header_generation(cow, trans->transid);
+       btrfs_set_header_owner(cow, root->root_key.objectid);
+
+       WARN_ON(btrfs_header_generation(buf) > trans->transid);
+       if (btrfs_header_generation(buf) != trans->transid) {
+               different_trans = 1;
+               ret = btrfs_inc_ref(trans, root, buf);
+               if (ret)
+                       return ret;
+       } else {
+               clean_tree_block(trans, root, buf);
+       }
+
+       if (buf == root->node) {
+               root->node = cow;
+               extent_buffer_get(cow);
+               if (buf != root->commit_root) {
+                       btrfs_free_extent(trans, root,
+                                         extent_buffer_blocknr(buf), 1, 1);
+               }
+               free_extent_buffer(buf);
+       } else {
+               btrfs_set_node_blockptr(parent, parent_slot,
+                                       extent_buffer_blocknr(cow));
+               btrfs_mark_buffer_dirty(parent);
+               WARN_ON(btrfs_header_generation(parent) != trans->transid);
+               btrfs_free_extent(trans, root, extent_buffer_blocknr(buf),1,1);
+       }
+       free_extent_buffer(buf);
+       btrfs_mark_buffer_dirty(cow);
+       *cow_ret = cow;
+       return 0;
+}
+
+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;
+       if (trans->transaction != root->fs_info->running_transaction) {
+               printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+                      root->fs_info->running_transaction->transid);
+               WARN_ON(1);
+       }
+       if (trans->transid != root->fs_info->generation) {
+               printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+                      root->fs_info->generation);
+               WARN_ON(1);
+       }
+       if (btrfs_header_generation(buf) == trans->transid) {
+               *cow_ret = buf;
+               return 0;
+       }
+
+       search_start = extent_buffer_blocknr(buf) & ~((u64)65535);
+       return __btrfs_cow_block(trans, root, buf, parent,
+                                parent_slot, cow_ret, search_start, 0);
+}
+
+static int close_blocks(u64 blocknr, u64 other)
+{
+       if (blocknr < other && other - blocknr < 8)
+               return 1;
+       if (blocknr > other && blocknr - other < 8)
+               return 1;
+       return 0;
+}
+
+#if 0
+static int should_defrag_leaf(struct extent_buffer *eb)
+{
+       return 0;
+       struct btrfs_leaf *leaf = btrfs_buffer_leaf(eb);
+       struct btrfs_disk_key *key;
+       u32 nritems;
+
+       if (buffer_defrag(bh))
+               return 1;
+
+       nritems = btrfs_header_nritems(&leaf->header);
+       if (nritems == 0)
+               return 0;
+
+       key = &leaf->items[0].key;
+       if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+               return 1;
+
+       key = &leaf->items[nritems-1].key;
+       if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+               return 1;
+       if (nritems > 4) {
+               key = &leaf->items[nritems/2].key;
+               if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+                       return 1;
+       }
+       return 0;
+}
+#endif
+
+int btrfs_realloc_node(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root, struct extent_buffer *parent,
+                      int cache_only, u64 *last_ret)
+{
+       return 0;
+#if 0
+       struct btrfs_node *parent_node;
+       struct extent_buffer *cur_eb;
+       struct extent_buffer *tmp_eb;
+       u64 blocknr;
+       u64 search_start = *last_ret;
+       u64 last_block = 0;
+       u64 other;
+       u32 parent_nritems;
+       int start_slot;
+       int end_slot;
+       int i;
+       int err = 0;
+       int parent_level;
+
+       if (trans->transaction != root->fs_info->running_transaction) {
+               printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+                      root->fs_info->running_transaction->transid);
+               WARN_ON(1);
+       }
+       if (trans->transid != root->fs_info->generation) {
+               printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+                      root->fs_info->generation);
+               WARN_ON(1);
+       }
+       if (buffer_defrag_done(parent))
+               return 0;
+
+       parent_node = btrfs_buffer_node(parent);
+       parent_nritems = btrfs_header_nritems(&parent_node->header);
+       parent_level = btrfs_header_level(&parent_node->header);
+
+       start_slot = 0;
+       end_slot = parent_nritems;
+
+       if (parent_nritems == 1)
+               return 0;
+
+       for (i = start_slot; i < end_slot; i++) {
+               int close = 1;
+               blocknr = btrfs_node_blockptr(parent_node, i);
+               if (last_block == 0)
+                       last_block = blocknr;
+               if (i > 0) {
+                       other = btrfs_node_blockptr(parent_node, i - 1);
+                       close = close_blocks(blocknr, other);
+               }
+               if (close && i < end_slot - 1) {
+                       other = btrfs_node_blockptr(parent_node, i + 1);
+                       close = close_blocks(blocknr, other);
+               }
+               if (close) {
+                       last_block = blocknr;
+                       continue;
+               }
+
+               cur_bh = btrfs_find_tree_block(root, blocknr);
+               if (!cur_bh || !buffer_uptodate(cur_bh) ||
+                   buffer_locked(cur_bh) ||
+                   (parent_level != 1 && !buffer_defrag(cur_bh)) ||
+                   (parent_level == 1 && !should_defrag_leaf(cur_bh))) {
+                       if (cache_only) {
+                               brelse(cur_bh);
+                               continue;
+                       }
+                       if (!cur_bh || !buffer_uptodate(cur_bh) ||
+                           buffer_locked(cur_bh)) {
+                               brelse(cur_bh);
+                               cur_bh = read_tree_block(root, blocknr);
+                       }
+               }
+               if (search_start == 0)
+                       search_start = last_block & ~((u64)65535);
+
+               err = __btrfs_cow_block(trans, root, cur_bh, parent, i,
+                                       &tmp_bh, search_start,
+                                       min(8, end_slot - i));
+               if (err) {
+                       brelse(cur_bh);
+                       break;
+               }
+               search_start = bh_blocknr(tmp_bh);
+               *last_ret = search_start;
+               if (parent_level == 1)
+                       clear_buffer_defrag(tmp_bh);
+               set_buffer_defrag_done(tmp_bh);
+               brelse(tmp_bh);
        }
+       return err;
+#endif
 }
 
 /*
@@ -27,68 +294,248 @@ static void release_path(struct ctree_root *root, struct ctree_path *p)
  * 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 leaf *leaf)
+static inline unsigned int leaf_data_end(struct btrfs_root *root,
+                                        struct extent_buffer *leaf)
 {
-       unsigned int nr = leaf->header.nritems;
+       u32 nr = btrfs_header_nritems(leaf);
        if (nr == 0)
-               return sizeof(leaf->data);
-       return leaf->items[nr-1].offset;
-}
-
-/*
- * 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
- */
-static inline int leaf_free_space(struct leaf *leaf)
-{
-       int data_end = leaf_data_end(leaf);
-       int nritems = leaf->header.nritems;
-       char *items_end = (char *)(leaf->items + nritems + 1);
-       return (char *)(leaf->data + data_end) - (char *)items_end;
+               return BTRFS_LEAF_DATA_SIZE(root);
+       return btrfs_item_offset_nr(leaf, nr - 1);
 }
 
 /*
  * compare two keys in a memcmp fashion
  */
-int comp_keys(struct key *k1, struct key *k2)
+static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
 {
-       if (k1->objectid > k2->objectid)
+       struct btrfs_key k1;
+
+       btrfs_disk_key_to_cpu(&k1, disk);
+
+       if (k1.objectid > k2->objectid)
                return 1;
-       if (k1->objectid < k2->objectid)
+       if (k1.objectid < k2->objectid)
                return -1;
-       if (k1->flags > k2->flags)
+       if (k1.type > k2->type)
                return 1;
-       if (k1->flags < k2->flags)
+       if (k1.type < k2->type)
                return -1;
-       if (k1->offset > k2->offset)
+       if (k1.offset > k2->offset)
                return 1;
-       if (k1->offset < k2->offset)
+       if (k1.offset < k2->offset)
                return -1;
        return 0;
 }
 
+static int check_node(struct btrfs_root *root, struct btrfs_path *path,
+                     int level)
+{
+       struct extent_buffer *parent = NULL;
+       struct extent_buffer *node = path->nodes[level];
+       struct btrfs_disk_key parent_key;
+       struct btrfs_disk_key node_key;
+       int parent_slot;
+       int slot;
+       struct btrfs_key cpukey;
+       u32 nritems = btrfs_header_nritems(node);
+
+       if (path->nodes[level + 1])
+               parent = path->nodes[level + 1];
+
+       slot = path->slots[level];
+       BUG_ON(nritems == 0);
+       if (parent) {
+               parent_slot = path->slots[level + 1];
+               btrfs_node_key(parent, &parent_key, parent_slot);
+               btrfs_node_key(node, &node_key, 0);
+               BUG_ON(memcmp(&parent_key, &node_key,
+                             sizeof(struct btrfs_disk_key)));
+               BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+                      btrfs_header_blocknr(node));
+       }
+       BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
+       if (slot != 0) {
+               btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
+               btrfs_node_key(node, &node_key, slot);
+               BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
+       }
+       if (slot < nritems - 1) {
+               btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
+               btrfs_node_key(node, &node_key, slot);
+               BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
+       }
+       return 0;
+}
+
+static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
+                     int level)
+{
+       struct extent_buffer *leaf = path->nodes[level];
+       struct extent_buffer *parent = NULL;
+       int parent_slot;
+       struct btrfs_key cpukey;
+       struct btrfs_disk_key parent_key;
+       struct btrfs_disk_key leaf_key;
+       int slot = path->slots[0];
+
+       u32 nritems = btrfs_header_nritems(leaf);
+
+       if (path->nodes[level + 1])
+               parent = path->nodes[level + 1];
+
+       if (nritems == 0)
+               return 0;
+
+       if (parent) {
+               parent_slot = path->slots[level + 1];
+               btrfs_node_key(parent, &parent_key, parent_slot);
+               btrfs_item_key(leaf, &leaf_key, 0);
+
+               BUG_ON(memcmp(&parent_key, &leaf_key,
+                      sizeof(struct btrfs_disk_key)));
+               BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+                      btrfs_header_blocknr(leaf));
+       }
+#if 0
+       for (i = 0; nritems > 1 && i < nritems - 2; i++) {
+               btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
+               btrfs_item_key(leaf, &leaf_key, i);
+               if (comp_keys(&leaf_key, &cpukey) >= 0) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("slot %d offset bad key\n", i);
+                       BUG_ON(1);
+               }
+               if (btrfs_item_offset_nr(leaf, i) !=
+                       btrfs_item_end_nr(leaf, i + 1)) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("slot %d offset bad\n", i);
+                       BUG_ON(1);
+               }
+               if (i == 0) {
+                       if (btrfs_item_offset_nr(leaf, i) +
+                              btrfs_item_size_nr(leaf, i) !=
+                              BTRFS_LEAF_DATA_SIZE(root)) {
+                               btrfs_print_leaf(root, leaf);
+                               printk("slot %d first offset bad\n", i);
+                               BUG_ON(1);
+                       }
+               }
+       }
+       if (nritems > 0) {
+               if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
+                               btrfs_print_leaf(root, leaf);
+                               printk("slot %d bad size \n", nritems - 1);
+                               BUG_ON(1);
+               }
+       }
+#endif
+       if (slot != 0 && slot < nritems - 1) {
+               btrfs_item_key(leaf, &leaf_key, slot);
+               btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
+               if (comp_keys(&leaf_key, &cpukey) <= 0) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("slot %d offset bad key\n", slot);
+                       BUG_ON(1);
+               }
+               if (btrfs_item_offset_nr(leaf, slot - 1) !=
+                      btrfs_item_end_nr(leaf, slot)) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("slot %d offset bad\n", slot);
+                       BUG_ON(1);
+               }
+       }
+       if (slot < nritems - 1) {
+               btrfs_item_key(leaf, &leaf_key, slot);
+               btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
+               BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
+               if (btrfs_item_offset_nr(leaf, slot) !=
+                       btrfs_item_end_nr(leaf, slot + 1)) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("slot %d offset bad\n", slot);
+                       BUG_ON(1);
+               }
+       }
+       BUG_ON(btrfs_item_offset_nr(leaf, 0) +
+              btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
+       return 0;
+}
+
+static int check_block(struct btrfs_root *root, struct btrfs_path *path,
+                       int level)
+{
+       struct extent_buffer *buf = path->nodes[level];
+       char fsid[BTRFS_FSID_SIZE];
+
+       read_extent_buffer(buf, fsid, (unsigned long)btrfs_header_fsid(buf),
+                          BTRFS_FSID_SIZE);
+
+       if (memcmp(fsid, root->fs_info->fsid, BTRFS_FSID_SIZE)) {
+               int i = 0;
+               printk("warning bad block %Lu\n", buf->start);
+               if (!btrfs_buffer_uptodate(buf)) {
+                       WARN_ON(1);
+               }
+               for (i = 0; i < BTRFS_FSID_SIZE; i++) {
+                       printk("%x:%x ", root->fs_info->fsid[i], fsid[i]);
+               }
+               printk("\n");
+               // BUG();
+       }
+       if (level == 0)
+               return check_leaf(root, path, level);
+       return check_node(root, path, level);
+}
+
 /*
- * search for key in the array p.  items p are item_size apart
- * and there are 'max' items in p
+ * 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
  */
-int generic_bin_search(char *p, int item_size, struct key *key,
-                      int max, int *slot)
+static 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 key *tmp;
+       struct btrfs_disk_key *tmp;
+       struct btrfs_disk_key unaligned;
+       unsigned long offset;
+       char *map_token = NULL;
+       char *kaddr = NULL;
+       unsigned long map_start = 0;
+       unsigned long map_len = 0;
 
        while(low < high) {
                mid = (low + high) / 2;
-               tmp = (struct key *)(p + mid * item_size);
+               offset = p + mid * item_size;
+
+               if (!map_token || offset < map_start ||
+                   (offset + sizeof(struct btrfs_disk_key)) >
+                   map_start + map_len) {
+                       if (map_token)
+                               unmap_extent_buffer(eb, map_token, KM_USER0);
+                       map_extent_buffer(eb, offset, &map_token, &kaddr,
+                                         &map_start, &map_len, KM_USER0);
+
+               }
+               if (offset + sizeof(struct btrfs_disk_key) >
+                   map_start + map_len) {
+                       unmap_extent_buffer(eb, map_token, KM_USER0);
+                       read_extent_buffer(eb, &unaligned,
+                                          offset, sizeof(unaligned));
+                       map_token = NULL;
+                       tmp = &unaligned;
+               } else {
+                       tmp = (struct btrfs_disk_key *)(kaddr + offset -
+                                                       map_start);
+               }
                ret = comp_keys(tmp, key);
 
                if (ret < 0)
@@ -97,60 +544,504 @@ int generic_bin_search(char *p, int item_size, struct key *key,
                        high = mid;
                else {
                        *slot = mid;
+                       unmap_extent_buffer(eb, map_token, KM_USER0);
                        return 0;
                }
        }
        *slot = low;
+       if (map_token)
+               unmap_extent_buffer(eb, map_token, KM_USER0);
        return 1;
 }
 
-int bin_search(struct node *c, struct key *key, int *slot)
+/*
+ * 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 (is_leaf(c->header.flags)) {
-               struct leaf *l = (struct leaf *)c;
-               return generic_bin_search((void *)l->items, sizeof(struct item),
-                                         key, c->header.nritems, 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((void *)c->keys, sizeof(struct key),
-                                         key, c->header.nritems, slot);
+               return generic_bin_search(eb,
+                                         offsetof(struct btrfs_node, ptrs),
+                                         sizeof(struct btrfs_key_ptr),
+                                         key, btrfs_header_nritems(eb),
+                                         slot);
        }
        return -1;
 }
 
+static struct extent_buffer *read_node_slot(struct btrfs_root *root,
+                                  struct extent_buffer *parent, int slot)
+{
+       if (slot < 0)
+               return NULL;
+       if (slot >= btrfs_header_nritems(parent))
+               return NULL;
+       return read_tree_block(root, btrfs_node_blockptr(parent, slot));
+}
+
+static 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];
+       int err_on_enospc = 0;
+       u64 orig_ptr;
+
+       if (level == 0)
+               return 0;
+
+       mid = path->nodes[level];
+       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;
+               u64 blocknr = extent_buffer_blocknr(mid);
+
+               if (btrfs_header_nritems(mid) != 1)
+                       return 0;
+
+               /* promote the child to a root */
+               child = read_node_slot(root, mid, 0);
+               BUG_ON(!child);
+               root->node = child;
+               path->nodes[level] = NULL;
+               clean_tree_block(trans, root, mid);
+               wait_on_tree_block_writeback(root, mid);
+               /* once for the path */
+               free_extent_buffer(mid);
+               /* once for the root ptr */
+               free_extent_buffer(mid);
+               return btrfs_free_extent(trans, root, blocknr, 1, 1);
+       }
+       if (btrfs_header_nritems(mid) >
+           BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
+               return 0;
+
+       if (btrfs_header_nritems(mid) < 2)
+               err_on_enospc = 1;
+
+       left = read_node_slot(root, parent, pslot - 1);
+       if (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) {
+               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);
+               if (wret < 0)
+                       ret = wret;
+               if (btrfs_header_nritems(mid) < 2)
+                       err_on_enospc = 1;
+       }
+
+       /*
+        * then try to empty the right most buffer into the middle
+        */
+       if (right) {
+               wret = push_node_left(trans, root, mid, right);
+               if (wret < 0 && wret != -ENOSPC)
+                       ret = wret;
+               if (btrfs_header_nritems(right) == 0) {
+                       u64 blocknr = extent_buffer_blocknr(right);
+                       clean_tree_block(trans, root, right);
+                       wait_on_tree_block_writeback(root, right);
+                       free_extent_buffer(right);
+                       right = NULL;
+                       wret = del_ptr(trans, root, path, level + 1, pslot +
+                                      1);
+                       if (wret)
+                               ret = wret;
+                       wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
+                       if (wret)
+                               ret = wret;
+               } 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
+                */
+               BUG_ON(!left);
+               wret = balance_node_right(trans, root, mid, left);
+               if (wret < 0) {
+                       ret = wret;
+                       goto enospc;
+               }
+               BUG_ON(wret == 1);
+       }
+       if (btrfs_header_nritems(mid) == 0) {
+               /* we've managed to empty the middle node, drop it */
+               u64 blocknr = extent_buffer_blocknr(mid);
+               clean_tree_block(trans, root, mid);
+               wait_on_tree_block_writeback(root, mid);
+               free_extent_buffer(mid);
+               mid = NULL;
+               wret = del_ptr(trans, root, path, level + 1, pslot);
+               if (wret)
+                       ret = wret;
+               wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
+               if (wret)
+                       ret = wret;
+       } 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);
+                       path->nodes[level] = left;
+                       path->slots[level + 1] -= 1;
+                       path->slots[level] = orig_slot;
+                       if (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 */
+       check_block(root, path, level);
+       if (orig_ptr !=
+           btrfs_node_blockptr(path->nodes[level], path->slots[level]))
+               BUG();
+enospc:
+       if (right)
+               free_extent_buffer(right);
+       if (left)
+               free_extent_buffer(left);
+       return ret;
+}
+
+/* returns zero if the push worked, non-zero otherwise */
+static 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];
+       u64 orig_ptr;
+
+       if (level == 0)
+               return 1;
+
+       mid = path->nodes[level];
+       orig_ptr = btrfs_node_blockptr(mid, orig_slot);
+
+       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;
+               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);
+                       }
+               }
+               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;
+                               free_extent_buffer(mid);
+                       } else {
+                               orig_slot -=
+                                       btrfs_header_nritems(left);
+                               path->slots[level] = orig_slot;
+                               free_extent_buffer(left);
+                       }
+                       check_node(root, path, level);
+                       return 0;
+               }
+               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;
+               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);
+                               free_extent_buffer(mid);
+                       } else {
+                               free_extent_buffer(right);
+                       }
+                       check_node(root, path, level);
+                       return 0;
+               }
+               free_extent_buffer(right);
+       }
+       check_node(root, path, level);
+       return 1;
+}
+
+/*
+ * readahead one full node of leaves
+ */
+static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
+                            int level, int slot)
+{
+       struct extent_buffer *node;
+       int i;
+       u32 nritems;
+       u64 blocknr;
+       u64 search;
+       u64 cluster_start;
+       int ret;
+       int nread = 0;
+       int direction = path->reada;
+       struct radix_tree_root found;
+       unsigned long gang[8];
+       struct extent_buffer *eb;
+
+       if (level == 0)
+               return;
+
+       if (!path->nodes[level])
+               return;
+
+       node = path->nodes[level];
+       search = btrfs_node_blockptr(node, slot);
+       eb = btrfs_find_tree_block(root, search);
+       if (eb) {
+               free_extent_buffer(eb);
+               return;
+       }
+
+       init_bit_radix(&found);
+       nritems = btrfs_header_nritems(node);
+       for (i = slot; i < nritems; i++) {
+               blocknr = btrfs_node_blockptr(node, i);
+               set_radix_bit(&found, blocknr);
+       }
+       if (direction > 0) {
+               cluster_start = search - 4;
+               if (cluster_start > search)
+                       cluster_start = 0;
+       } else
+               cluster_start = search + 4;
+       while(1) {
+               ret = find_first_radix_bit(&found, gang, 0, ARRAY_SIZE(gang));
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       blocknr = gang[i];
+                       clear_radix_bit(&found, blocknr);
+                       if (path->reada == 1 && nread > 16)
+                               continue;
+                       if (close_blocks(cluster_start, blocknr)) {
+                               readahead_tree_block(root, blocknr);
+                               nread++;
+                               cluster_start = blocknr;
+                       }
+               }
+       }
+}
 /*
  * 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.
+ * 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 search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p)
+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 tree_buffer *b = root->node;
-       struct node *c;
-
+       struct extent_buffer *b;
+       u64 blocknr;
        int slot;
        int ret;
        int level;
-       b->count++;
+       int should_reada = p->reada;
+       u8 lowest_level = 0;
+
+       lowest_level = p->lowest_level;
+       WARN_ON(lowest_level && ins_len);
+       WARN_ON(p->nodes[0] != NULL);
+       WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
+again:
+       b = root->node;
+       extent_buffer_get(b);
        while (b) {
-               c = &b->node;
-               level = node_level(c->header.flags);
+               level = btrfs_header_level(b);
+               if (cow) {
+                       int wret;
+                       wret = btrfs_cow_block(trans, root, b,
+                                              p->nodes[level + 1],
+                                              p->slots[level + 1],
+                                              &b);
+                       if (wret) {
+                               free_extent_buffer(b);
+                               return wret;
+                       }
+               }
+               BUG_ON(!cow && ins_len);
+               if (level != btrfs_header_level(b))
+                       WARN_ON(1);
+               level = btrfs_header_level(b);
                p->nodes[level] = b;
-               ret = bin_search(c, key, &slot);
-               if (!is_leaf(c->header.flags)) {
+               ret = check_block(root, p, level);
+               if (ret)
+                       return -1;
+               ret = bin_search(b, key, level, &slot);
+               if (level != 0) {
                        if (ret && slot > 0)
                                slot -= 1;
                        p->slots[level] = slot;
-                       b = read_tree_block(root, c->blockptrs[slot]);
-                       continue;
+                       if (ins_len > 0 && btrfs_header_nritems(b) >=
+                           BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
+                               int sret = split_node(trans, root, p, level);
+                               BUG_ON(sret > 0);
+                               if (sret)
+                                       return sret;
+                               b = p->nodes[level];
+                               slot = p->slots[level];
+                       } else if (ins_len < 0) {
+                               int sret = balance_level(trans, root, p,
+                                                        level);
+                               if (sret)
+                                       return sret;
+                               b = p->nodes[level];
+                               if (!b)
+                                       goto again;
+                               slot = p->slots[level];
+                               BUG_ON(btrfs_header_nritems(b) == 1);
+                       }
+                       /* this is only true while dropping a snapshot */
+                       if (level == lowest_level)
+                               break;
+                       blocknr = btrfs_node_blockptr(b, slot);
+                       if (should_reada)
+                               reada_for_search(root, p, level, slot);
+                       b = read_tree_block(root, btrfs_node_blockptr(b, slot));
                } else {
                        p->slots[level] = slot;
+                       if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
+                           sizeof(struct btrfs_item) + ins_len) {
+                               int sret = split_leaf(trans, root, key,
+                                                     p, ins_len);
+                               BUG_ON(sret > 0);
+                               if (sret)
+                                       return sret;
+                       }
                        return ret;
                }
        }
-       return -1;
+       return 1;
 }
 
 /*
@@ -159,520 +1050,937 @@ int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p)
  * 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
+ *
+ * If this fails to write a tree block, it returns -1, but continues
+ * fixing up the blocks in ram so the tree is consistent.
  */
-static void fixup_low_keys(struct ctree_root *root,
-                          struct ctree_path *path, struct key *key,
-                          int level)
+static int 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;
-       for (i = level; i < MAX_LEVEL; i++) {
-               struct node *t;
+       int ret = 0;
+       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]->node;
-               memcpy(t->keys + tslot, key, sizeof(*key));
-               write_tree_block(root, path->nodes[i]);
+               t = path->nodes[i];
+               btrfs_set_node_key(t, key, tslot);
+               btrfs_mark_buffer_dirty(path->nodes[i]);
                if (tslot != 0)
                        break;
        }
+       return ret;
 }
 
 /*
  * try to push data from one node into the next node left in the
- * tree.  The src node is found at specified level in the path.
- * If some bytes were pushed, return 0, otherwise return 1.
- *
- * Lower nodes/leaves in the path are not touched, higher nodes may
- * be modified to reflect the push.
+ * tree.
  *
- * The path is altered to reflect the push.
+ * 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.
  */
-int push_node_left(struct ctree_root *root, struct ctree_path *path, int level)
+static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
+                         *root, struct extent_buffer *dst,
+                         struct extent_buffer *src)
 {
-       int slot;
-       struct node *left;
-       struct node *right;
        int push_items = 0;
-       int left_nritems;
-       int right_nritems;
-       struct tree_buffer *t;
-       struct tree_buffer *right_buf;
+       int src_nritems;
+       int dst_nritems;
+       int ret = 0;
 
-       if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)
-               return 1;
-       slot = path->slots[level + 1];
-       if (slot == 0)
-               return 1;
+       src_nritems = btrfs_header_nritems(src);
+       dst_nritems = btrfs_header_nritems(dst);
+       push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
 
-       t = read_tree_block(root,
-                           path->nodes[level + 1]->node.blockptrs[slot - 1]);
-       left = &t->node;
-       right_buf = path->nodes[level];
-       right = &right_buf->node;
-       left_nritems = left->header.nritems;
-       right_nritems = right->header.nritems;
-       push_items = NODEPTRS_PER_BLOCK - (left_nritems + 1);
        if (push_items <= 0) {
-               tree_block_release(root, t);
                return 1;
        }
 
-       if (right_nritems < push_items)
-               push_items = right_nritems;
-       memcpy(left->keys + left_nritems, right->keys,
-               push_items * sizeof(struct key));
-       memcpy(left->blockptrs + left_nritems, right->blockptrs,
-               push_items * sizeof(u64));
-       memmove(right->keys, right->keys + push_items,
-               (right_nritems - push_items) * sizeof(struct key));
-       memmove(right->blockptrs, right->blockptrs + push_items,
-               (right_nritems - push_items) * sizeof(u64));
-       right->header.nritems -= push_items;
-       left->header.nritems += push_items;
-
-       /* adjust the pointers going up the tree */
-       fixup_low_keys(root, path, right->keys, level + 1);
+       if (src_nritems < push_items)
+               push_items = src_nritems;
 
-       write_tree_block(root, t);
-       write_tree_block(root, right_buf);
+       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));
 
-       /* then fixup the leaf pointer in the path */
-       if (path->slots[level] < push_items) {
-               path->slots[level] += left_nritems;
-               tree_block_release(root, path->nodes[level]);
-               path->nodes[level] = t;
-               path->slots[level + 1] -= 1;
-       } else {
-               path->slots[level] -= push_items;
-               tree_block_release(root, t);
+       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));
        }
-       return 0;
+       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.  The src node is found at specified level in the path.
- * If some bytes were pushed, return 0, otherwise return 1.
+ * tree.
  *
- * Lower nodes/leaves in the path are not touched, higher nodes may
- * be modified to reflect the push.
+ * 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.
  *
- * The path is altered to reflect the push.
+ * this will  only push up to 1/2 the contents of the left node over
  */
-int push_node_right(struct ctree_root *root, struct ctree_path *path, int level)
+static int balance_node_right(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct extent_buffer *dst,
+                             struct extent_buffer *src)
 {
-       int slot;
-       struct tree_buffer *t;
-       struct tree_buffer *src_buffer;
-       struct node *dst;
-       struct node *src;
        int push_items = 0;
-       int dst_nritems;
+       int max_push;
        int src_nritems;
+       int dst_nritems;
+       int ret = 0;
 
-       /* can't push from the root */
-       if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)
+       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;
 
-       /* only try to push inside the node higher up */
-       slot = path->slots[level + 1];
-       if (slot == NODEPTRS_PER_BLOCK - 1)
+       max_push = src_nritems / 2 + 1;
+       /* don't try to empty the node */
+       if (max_push >= src_nritems)
                return 1;
 
-       if (slot >= path->nodes[level + 1]->node.header.nritems -1)
-               return 1;
+       if (max_push < push_items)
+               push_items = max_push;
 
-       t = read_tree_block(root,
-                           path->nodes[level + 1]->node.blockptrs[slot + 1]);
-       dst = &t->node;
-       src_buffer = path->nodes[level];
-       src = &src_buffer->node;
-       dst_nritems = dst->header.nritems;
-       src_nritems = src->header.nritems;
-       push_items = NODEPTRS_PER_BLOCK - (dst_nritems + 1);
-       if (push_items <= 0) {
-               tree_block_release(root, t);
-               return 1;
-       }
+       memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
+                                     btrfs_node_key_ptr_offset(0),
+                                     (dst_nritems) *
+                                     sizeof(struct btrfs_key_ptr));
 
-       if (src_nritems < push_items)
-               push_items = src_nritems;
-       memmove(dst->keys + push_items, dst->keys,
-               dst_nritems * sizeof(struct key));
-       memcpy(dst->keys, src->keys + src_nritems - push_items,
-               push_items * sizeof(struct key));
-
-       memmove(dst->blockptrs + push_items, dst->blockptrs,
-               dst_nritems * sizeof(u64));
-       memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items,
-               push_items * sizeof(u64));
-
-       src->header.nritems -= push_items;
-       dst->header.nritems += push_items;
-
-       /* adjust the pointers going up the tree */
-       memcpy(path->nodes[level + 1]->node.keys + path->slots[level + 1] + 1,
-               dst->keys, sizeof(struct key));
-
-       write_tree_block(root, path->nodes[level + 1]);
-       write_tree_block(root, t);
-       write_tree_block(root, src_buffer);
-
-       /* then fixup the pointers in the path */
-       if (path->slots[level] >= src->header.nritems) {
-               path->slots[level] -= src->header.nritems;
-               tree_block_release(root, path->nodes[level]);
-               path->nodes[level] = t;
-               path->slots[level + 1] += 1;
-       } else {
-               tree_block_release(root, t);
-       }
+       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 int insert_new_root(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root,
+                          struct btrfs_path *path, int level)
+{
+       struct extent_buffer *lower;
+       struct extent_buffer *c;
+       struct btrfs_disk_key lower_key;
+
+       BUG_ON(path->nodes[level]);
+       BUG_ON(path->nodes[level-1] != root->node);
+
+       c = btrfs_alloc_free_block(trans, root,
+                                  extent_buffer_blocknr(root->node), 0);
+       if (IS_ERR(c))
+               return PTR_ERR(c);
+       memset_extent_buffer(c, 0, 0, root->nodesize);
+       btrfs_set_header_nritems(c, 1);
+       btrfs_set_header_level(c, level);
+       btrfs_set_header_blocknr(c, extent_buffer_blocknr(c));
+       btrfs_set_header_generation(c, trans->transid);
+       btrfs_set_header_owner(c, root->root_key.objectid);
+       lower = path->nodes[level-1];
+
+       write_extent_buffer(c, root->fs_info->fsid,
+                           (unsigned long)btrfs_header_fsid(c),
+                           BTRFS_FSID_SIZE);
+       if (level == 1)
+               btrfs_item_key(lower, &lower_key, 0);
+       else
+               btrfs_node_key(lower, &lower_key, 0);
+       btrfs_set_node_key(c, &lower_key, 0);
+       btrfs_set_node_blockptr(c, 0, extent_buffer_blocknr(lower));
+
+       btrfs_mark_buffer_dirty(c);
+
+       /* the super has an extra ref to root->node */
+       free_extent_buffer(root->node);
+       root->node = c;
+       extent_buffer_get(c);
+       path->nodes[level] = c;
+       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.
+ *
+ * returns zero on success and < 0 on any error
  */
-int __insert_ptr(struct ctree_root *root,
-               struct ctree_path *path, struct key *key,
-               u64 blocknr, int slot, int level)
+static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
+                     *root, struct btrfs_path *path, struct btrfs_disk_key
+                     *key, u64 blocknr, int slot, int level)
 {
-       struct node *c;
-       struct node *lower;
-       struct key *lower_key;
+       struct extent_buffer *lower;
        int nritems;
-       /* need a new root */
-       if (!path->nodes[level]) {
-               struct tree_buffer *t;
-               t = alloc_free_block(root);
-               c = &t->node;
-               memset(c, 0, sizeof(c));
-               c->header.nritems = 2;
-               c->header.flags = node_level(level);
-               c->header.blocknr = t->blocknr;
-               c->header.parentid = root->node->node.header.parentid;
-               lower = &path->nodes[level-1]->node;
-               if (is_leaf(lower->header.flags))
-                       lower_key = &((struct leaf *)lower)->items[0].key;
-               else
-                       lower_key = lower->keys;
-               memcpy(c->keys, lower_key, sizeof(struct key));
-               memcpy(c->keys + 1, key, sizeof(struct key));
-               c->blockptrs[0] = path->nodes[level-1]->blocknr;
-               c->blockptrs[1] = blocknr;
-               /* the super has an extra ref to root->node */
-               tree_block_release(root, root->node);
-               root->node = t;
-               t->count++;
-               write_tree_block(root, t);
-               path->nodes[level] = t;
-               path->slots[level] = 0;
-               if (c->keys[1].objectid == 0)
-                       BUG();
+
+       BUG_ON(!path->nodes[level]);
+       lower = path->nodes[level];
+       nritems = btrfs_header_nritems(lower);
+       if (slot > nritems)
+               BUG();
+       if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
+               BUG();
+       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, blocknr);
+       btrfs_set_header_nritems(lower, nritems + 1);
+       btrfs_mark_buffer_dirty(lower);
+       check_node(root, path, level);
+       return 0;
+}
+
+/*
+ * 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 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;
+       int wret;
+       u32 c_nritems;
+
+       c = path->nodes[level];
+       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) - 1)
+                       return 0;
+               if (ret < 0)
+                       return ret;
+       }
+
+       c_nritems = btrfs_header_nritems(c);
+       split = btrfs_alloc_free_block(trans, root,
+                                      extent_buffer_blocknr(c), 0);
+       if (IS_ERR(split))
+               return PTR_ERR(split);
+
+       btrfs_set_header_flags(split, btrfs_header_flags(c));
+       btrfs_set_header_level(split, btrfs_header_level(c));
+       btrfs_set_header_blocknr(split, extent_buffer_blocknr(split));
+       btrfs_set_header_generation(split, trans->transid);
+       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);
+
+       mid = (c_nritems + 1) / 2;
+
+       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);
+
+       btrfs_node_key(split, &disk_key, 0);
+       wret = insert_ptr(trans, root, path, &disk_key,
+                         extent_buffer_blocknr(split),
+                         path->slots[level + 1] + 1,
+                         level + 1);
+       if (wret)
+               ret = wret;
+
+       if (path->slots[level] >= mid) {
+               path->slots[level] -= mid;
+               free_extent_buffer(c);
+               path->nodes[level] = split;
+               path->slots[level + 1] += 1;
+       } else {
+               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
+ */
+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("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
+                      ret, BTRFS_LEAF_DATA_SIZE(root),
+                      leaf_space_used(leaf, 0, nritems), nritems);
+       }
+       return ret;
+}
+
+/*
+ * 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.
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+                          *root, struct btrfs_path *path, int data_size)
+{
+       struct extent_buffer *left = path->nodes[0];
+       struct extent_buffer *right;
+       struct extent_buffer *upper;
+       struct btrfs_disk_key disk_key;
+       int slot;
+       int i;
+       int free_space;
+       int push_space = 0;
+       int push_items = 0;
+       struct btrfs_item *item;
+       u32 left_nritems;
+       u32 right_nritems;
+       u32 data_end;
+       int ret;
+
+       slot = path->slots[1];
+       if (!path->nodes[1]) {
+               return 1;
        }
-       lower = &path->nodes[level]->node;
-       nritems = lower->header.nritems;
-       if (slot > nritems)
-               BUG();
-       if (nritems == NODEPTRS_PER_BLOCK)
-               BUG();
-       if (slot != nritems) {
-               memmove(lower->keys + slot + 1, lower->keys + slot,
-                       (nritems - slot) * sizeof(struct key));
-               memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot,
-                       (nritems - slot) * sizeof(u64));
-       }
-       memcpy(lower->keys + slot, key, sizeof(struct key));
-       lower->blockptrs[slot] = blocknr;
-       lower->header.nritems++;
-       if (lower->keys[1].objectid == 0)
-                       BUG();
-       write_tree_block(root, path->nodes[level]);
-       return 0;
-}
+       upper = path->nodes[1];
+       if (slot >= btrfs_header_nritems(upper) - 1)
+               return 1;
 
+       right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1));
+       free_space = btrfs_leaf_free_space(root, right);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               free_extent_buffer(right);
+               return 1;
+       }
 
-/*
- * insert a key,blocknr pair into the tree at a given level
- * If the node at that level in the path doesn't have room,
- * it is split or shifted as appropriate.
- */
-int insert_ptr(struct ctree_root *root,
-               struct ctree_path *path, struct key *key,
-               u64 blocknr, int level)
-{
-       struct tree_buffer *t = path->nodes[level];
-       struct node *c = &path->nodes[level]->node;
-       struct node *b;
-       struct tree_buffer *b_buffer;
-       struct tree_buffer *bal[MAX_LEVEL];
-       int bal_level = level;
-       int mid;
-       int bal_start = -1;
+       /* cow and double check */
+       ret = btrfs_cow_block(trans, root, right, upper,
+                             slot + 1, &right);
+       if (ret) {
+               free_extent_buffer(right);
+               return 1;
+       }
+       free_space = btrfs_leaf_free_space(root, right);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               free_extent_buffer(right);
+               return 1;
+       }
 
-       /*
-        * check to see if we need to make room in the node for this
-        * pointer.  If we do, keep walking the tree, making sure there
-        * is enough room in each level for the required insertions.
-        *
-        * The bal array is filled in with any nodes to be inserted
-        * due to splitting.  Once we've done all the splitting required
-        * do the inserts based on the data in the bal array.
-        */
-       memset(bal, 0, sizeof(bal));
-       while(t && t->node.header.nritems == NODEPTRS_PER_BLOCK) {
-               c = &t->node;
-               if (push_node_left(root, path,
-                  node_level(c->header.flags)) == 0)
-                       break;
-               if (push_node_right(root, path,
-                  node_level(c->header.flags)) == 0)
-                       break;
-               bal_start = bal_level;
-               if (bal_level == MAX_LEVEL - 1)
-                       BUG();
-               b_buffer = alloc_free_block(root);
-               b = &b_buffer->node;
-               b->header.flags = c->header.flags;
-               b->header.blocknr = b_buffer->blocknr;
-               b->header.parentid = root->node->node.header.parentid;
-               mid = (c->header.nritems + 1) / 2;
-               memcpy(b->keys, c->keys + mid,
-                       (c->header.nritems - mid) * sizeof(struct key));
-               memcpy(b->blockptrs, c->blockptrs + mid,
-                       (c->header.nritems - mid) * sizeof(u64));
-               b->header.nritems = c->header.nritems - mid;
-               c->header.nritems = mid;
-
-               write_tree_block(root, t);
-               write_tree_block(root, b_buffer);
-
-               bal[bal_level] = b_buffer;
-               if (bal_level == MAX_LEVEL - 1)
-                       break;
-               bal_level += 1;
-               t = path->nodes[bal_level];
+       left_nritems = btrfs_header_nritems(left);
+       if (left_nritems == 0) {
+               free_extent_buffer(right);
+               return 1;
        }
-       /*
-        * bal_start tells us the first level in the tree that needed to
-        * be split.  Go through the bal array inserting the new nodes
-        * as needed.  The path is fixed as we go.
-        */
-       while(bal_start > 0) {
-               b_buffer = bal[bal_start];
-               c = &path->nodes[bal_start]->node;
-               __insert_ptr(root, path, b_buffer->node.keys, b_buffer->blocknr,
-                               path->slots[bal_start + 1] + 1, bal_start + 1);
-               if (path->slots[bal_start] >= c->header.nritems) {
-                       path->slots[bal_start] -= c->header.nritems;
-                       tree_block_release(root, path->nodes[bal_start]);
-                       path->nodes[bal_start] = b_buffer;
-                       path->slots[bal_start + 1] += 1;
-               } else {
-                       tree_block_release(root, b_buffer);
-               }
-               bal_start--;
-               if (!bal[bal_start])
+
+       for (i = left_nritems - 1; i >= 1; i--) {
+               item = btrfs_item_nr(left, i);
+               if (path->slots[0] == i)
+                       push_space += data_size + sizeof(*item);
+               if (btrfs_item_size(left, item) + sizeof(*item) + push_space >
+                   free_space)
                        break;
+               push_items++;
+               push_space += btrfs_item_size(left, item) + sizeof(*item);
        }
-       /* Now that the tree has room, insert the requested pointer */
-       return __insert_ptr(root, path, key, blocknr, path->slots[level] + 1,
-                           level);
-}
 
-/*
- * 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
- */
-int leaf_space_used(struct leaf *l, int start, int nr)
-{
-       int data_len;
-       int end = start + nr - 1;
+       if (push_items == 0) {
+               free_extent_buffer(right);
+               return 1;
+       }
 
-       if (!nr)
-               return 0;
-       data_len = l->items[start].offset + l->items[start].size;
-       data_len = data_len - l->items[end].offset;
-       data_len += sizeof(struct item) * nr;
-       return data_len;
-}
+       if (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);
+               btrfs_set_item_offset(right, item, push_space -
+                                     btrfs_item_size(right, item));
+               push_space = btrfs_item_offset(right, item);
+       }
+       left_nritems -= push_items;
+       btrfs_set_header_nritems(left, left_nritems);
+
+       btrfs_mark_buffer_dirty(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;
+               free_extent_buffer(path->nodes[0]);
+               path->nodes[0] = right;
+               path->slots[1] += 1;
+       } else {
+               free_extent_buffer(right);
+       }
+       if (path->nodes[1])
+               check_node(root, path, 1);
+       return 0;
+}
 /*
  * 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
  */
-int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
-                  int data_size)
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+                         *root, struct btrfs_path *path, int data_size)
 {
-       struct tree_buffer *right_buf = path->nodes[0];
-       struct leaf *right = &right_buf->leaf;
-       struct tree_buffer *t;
-       struct leaf *left;
+       struct btrfs_disk_key disk_key;
+       struct extent_buffer *right = path->nodes[0];
+       struct extent_buffer *left;
        int slot;
        int i;
        int free_space;
        int push_space = 0;
        int push_items = 0;
-       struct item *item;
-       int old_left_nritems;
+       struct btrfs_item *item;
+       u32 old_left_nritems;
+       u32 right_nritems;
+       int ret = 0;
+       int wret;
 
        slot = path->slots[1];
-       if (slot == 0) {
+       if (slot == 0)
+               return 1;
+       if (!path->nodes[1])
+               return 1;
+
+       left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
+                                                        slot - 1));
+       free_space = btrfs_leaf_free_space(root, left);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               free_extent_buffer(left);
                return 1;
        }
-       if (!path->nodes[1]) {
+
+       /* 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 */
+               free_extent_buffer(left);
+               return 1;
+       }
+       free_space = btrfs_leaf_free_space(root, left);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               free_extent_buffer(left);
                return 1;
        }
-       t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]);
-       left = &t->leaf;
-       free_space = leaf_free_space(left);
-       if (free_space < data_size + sizeof(struct item)) {
-               tree_block_release(root, t);
+
+       right_nritems = btrfs_header_nritems(right);
+       if (right_nritems == 0) {
+               free_extent_buffer(left);
                return 1;
        }
-       for (i = 0; i < right->header.nritems; i++) {
-               item = right->items + i;
+
+       for (i = 0; i < right_nritems - 1; i++) {
+               item = btrfs_item_nr(right, i);
                if (path->slots[0] == i)
                        push_space += data_size + sizeof(*item);
-               if (item->size + sizeof(*item) + push_space > free_space)
+               if (btrfs_item_size(right, item) + sizeof(*item) + push_space >
+                   free_space)
                        break;
                push_items++;
-               push_space += item->size + sizeof(*item);
+               push_space += btrfs_item_size(right, item) + sizeof(*item);
        }
        if (push_items == 0) {
-               tree_block_release(root, t);
+               free_extent_buffer(left);
                return 1;
        }
+       if (push_items == btrfs_header_nritems(right))
+               WARN_ON(1);
+
        /* push data from right to left */
-       memcpy(left->items + left->header.nritems,
-               right->items, push_items * sizeof(struct item));
-       push_space = LEAF_DATA_SIZE - right->items[push_items -1].offset;
-       memcpy(left->data + leaf_data_end(left) - push_space,
-               right->data + right->items[push_items - 1].offset,
-               push_space);
-       old_left_nritems = left->header.nritems;
+       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);
 
-       for(i = old_left_nritems; i < old_left_nritems + push_items; i++) {
-               left->items[i].offset -= LEAF_DATA_SIZE -
-                       left->items[old_left_nritems -1].offset;
+       for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
+               u32 ioff;
+               item = btrfs_item_nr(left, i);
+               ioff = btrfs_item_offset(left, item);
+               btrfs_set_item_offset(left, item,
+                     ioff - (BTRFS_LEAF_DATA_SIZE(root) -
+                     btrfs_item_offset_nr(left, old_left_nritems - 1)));
        }
-       left->header.nritems += push_items;
+       btrfs_set_header_nritems(left, old_left_nritems + push_items);
 
        /* fixup right node */
-       push_space = right->items[push_items-1].offset - leaf_data_end(right);
-       memmove(right->data + LEAF_DATA_SIZE - push_space, right->data +
-               leaf_data_end(right), push_space);
-       memmove(right->items, right->items + push_items,
-               (right->header.nritems - push_items) * sizeof(struct item));
-       right->header.nritems -= push_items;
-       push_space = LEAF_DATA_SIZE;
-
-       for (i = 0; i < right->header.nritems; i++) {
-               right->items[i].offset = push_space - right->items[i].size;
-               push_space = right->items[i].offset;
+       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 = btrfs_header_nritems(right) - 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);
+               btrfs_set_item_offset(right, item, push_space -
+                                     btrfs_item_size(right, item));
+               push_space = btrfs_item_offset(right, item);
        }
 
-       write_tree_block(root, t);
-       write_tree_block(root, right_buf);
+       btrfs_mark_buffer_dirty(left);
+       btrfs_mark_buffer_dirty(right);
 
-       fixup_low_keys(root, path, &right->items[0].key, 1);
+       btrfs_item_key(right, &disk_key, 0);
+       wret = fixup_low_keys(trans, root, path, &disk_key, 1);
+       if (wret)
+               ret = wret;
 
        /* then fixup the leaf pointer in the path */
        if (path->slots[0] < push_items) {
                path->slots[0] += old_left_nritems;
-               tree_block_release(root, path->nodes[0]);
-               path->nodes[0] = t;
+               free_extent_buffer(path->nodes[0]);
+               path->nodes[0] = left;
                path->slots[1] -= 1;
        } else {
-               tree_block_release(root, t);
+               free_extent_buffer(left);
                path->slots[0] -= push_items;
        }
        BUG_ON(path->slots[0] < 0);
-       return 0;
+       if (path->nodes[1])
+               check_node(root, path, 1);
+       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.
+ *
+ * returns 0 if all went well and < 0 on failure.
  */
-int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size)
+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)
 {
-       struct tree_buffer *l_buf = path->nodes[0];
-       struct leaf *l = &l_buf->leaf;
-       int nritems;
+       struct extent_buffer *l;
+       u32 nritems;
        int mid;
        int slot;
-       struct leaf *right;
-       struct tree_buffer *right_buffer;
-       int space_needed = data_size + sizeof(struct item);
+       struct extent_buffer *right;
+       int space_needed = data_size + sizeof(struct btrfs_item);
        int data_copy_size;
        int rt_data_off;
        int i;
-       int ret;
+       int ret = 0;
+       int wret;
+       int double_split = 0;
+       struct btrfs_disk_key disk_key;
+
+       /* first try to make some room by pushing left and right */
+       wret = push_leaf_left(trans, root, path, data_size);
+       if (wret < 0)
+               return wret;
+       if (wret) {
+               wret = push_leaf_right(trans, root, path, data_size);
+               if (wret < 0)
+                       return wret;
+       }
+       l = path->nodes[0];
 
-       if (push_leaf_left(root, path, data_size) == 0) {
-               l_buf = path->nodes[0];
-               l = &l_buf->leaf;
-               if (leaf_free_space(l) >= sizeof(struct item) + data_size)
-                       return 0;
+       /* did the pushes work? */
+       if (btrfs_leaf_free_space(root, l) >=
+           sizeof(struct btrfs_item) + data_size)
+               return 0;
+
+       if (!path->nodes[1]) {
+               ret = insert_new_root(trans, root, path, 1);
+               if (ret)
+                       return ret;
        }
        slot = path->slots[0];
-       nritems = l->header.nritems;
+       nritems = btrfs_header_nritems(l);
        mid = (nritems + 1)/ 2;
 
-       right_buffer = alloc_free_block(root);
-       BUG_ON(!right_buffer);
-       BUG_ON(mid == nritems);
-       right = &right_buffer->leaf;
-       memset(right, 0, sizeof(*right));
+       right = btrfs_alloc_free_block(trans, root,
+                                             extent_buffer_blocknr(l), 0);
+       if (IS_ERR(right))
+               return PTR_ERR(right);
+
+       memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
+       btrfs_set_header_blocknr(right, extent_buffer_blocknr(right));
+       btrfs_set_header_generation(right, trans->transid);
+       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);
+
        if (mid <= slot) {
-               if (leaf_space_used(l, mid, nritems - mid) + space_needed >
-                       LEAF_DATA_SIZE)
-                       BUG();
+               if (nritems == 1 ||
+                   leaf_space_used(l, mid, nritems - mid) + space_needed >
+                       BTRFS_LEAF_DATA_SIZE(root)) {
+                       if (slot >= nritems) {
+                               btrfs_cpu_key_to_disk(&disk_key, ins_key);
+                               btrfs_set_header_nritems(right, 0);
+                               wret = insert_ptr(trans, root, path,
+                                                 &disk_key,
+                                                 extent_buffer_blocknr(right),
+                                                 path->slots[1] + 1, 1);
+                               if (wret)
+                                       ret = wret;
+                               free_extent_buffer(path->nodes[0]);
+                               path->nodes[0] = right;
+                               path->slots[0] = 0;
+                               path->slots[1] += 1;
+                               return ret;
+                       }
+                       mid = slot;
+                       double_split = 1;
+               }
        } else {
                if (leaf_space_used(l, 0, mid + 1) + space_needed >
-                       LEAF_DATA_SIZE)
-                       BUG();
-       }
-       right->header.nritems = nritems - mid;
-       right->header.blocknr = right_buffer->blocknr;
-       right->header.flags = node_level(0);
-       right->header.parentid = root->node->node.header.parentid;
-       data_copy_size = l->items[mid].offset + l->items[mid].size -
-                        leaf_data_end(l);
-       memcpy(right->items, l->items + mid,
-              (nritems - mid) * sizeof(struct item));
-       memcpy(right->data + LEAF_DATA_SIZE - data_copy_size,
-              l->data + leaf_data_end(l), data_copy_size);
-       rt_data_off = LEAF_DATA_SIZE -
-                    (l->items[mid].offset + l->items[mid].size);
-
-       for (i = 0; i < right->header.nritems; i++)
-               right->items[i].offset += rt_data_off;
-
-       l->header.nritems = mid;
-       ret = insert_ptr(root, path, &right->items[0].key,
-                         right_buffer->blocknr, 1);
-
-       write_tree_block(root, right_buffer);
-       write_tree_block(root, l_buf);
+                       BTRFS_LEAF_DATA_SIZE(root)) {
+                       if (slot == 0) {
+                               btrfs_cpu_key_to_disk(&disk_key, ins_key);
+                               btrfs_set_header_nritems(right, 0);
+                               wret = insert_ptr(trans, root, path,
+                                                 &disk_key,
+                                                 extent_buffer_blocknr(right),
+                                                 path->slots[1], 1);
+                               if (wret)
+                                       ret = wret;
+                               free_extent_buffer(path->nodes[0]);
+                               path->nodes[0] = right;
+                               path->slots[0] = 0;
+                               if (path->slots[1] == 0) {
+                                       wret = fixup_low_keys(trans, root,
+                                                  path, &disk_key, 1);
+                                       if (wret)
+                                               ret = wret;
+                               }
+                               return ret;
+                       }
+                       mid = slot;
+                       double_split = 1;
+               }
+       }
+       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 = btrfs_item_offset(right, item);
+               btrfs_set_item_offset(right, item, ioff + rt_data_off);
+       }
+
+       btrfs_set_header_nritems(l, mid);
+       ret = 0;
+       btrfs_item_key(right, &disk_key, 0);
+       wret = insert_ptr(trans, root, path, &disk_key,
+                         extent_buffer_blocknr(right), path->slots[1] + 1, 1);
+       if (wret)
+               ret = wret;
 
+       btrfs_mark_buffer_dirty(right);
+       btrfs_mark_buffer_dirty(l);
        BUG_ON(path->slots[0] != slot);
+
        if (mid <= slot) {
-               tree_block_release(root, path->nodes[0]);
-               path->nodes[0] = right_buffer;
+               free_extent_buffer(path->nodes[0]);
+               path->nodes[0] = right;
                path->slots[0] -= mid;
                path->slots[1] += 1;
        } else
-               tree_block_release(root, right_buffer);
+               free_extent_buffer(right);
+
        BUG_ON(path->slots[0] < 0);
+       check_node(root, path, 1);
+       check_leaf(root, path, 0);
+
+       if (!double_split)
+               return ret;
+
+       right = btrfs_alloc_free_block(trans, root,
+                                      extent_buffer_blocknr(l), 0);
+       if (IS_ERR(right))
+               return PTR_ERR(right);
+
+       memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
+       btrfs_set_header_blocknr(right, extent_buffer_blocknr(right));
+       btrfs_set_header_generation(right, trans->transid);
+       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);
+
+       btrfs_cpu_key_to_disk(&disk_key, ins_key);
+       btrfs_set_header_nritems(right, 0);
+       wret = insert_ptr(trans, root, path,
+                         &disk_key,
+                         extent_buffer_blocknr(right),
+                         path->slots[1], 1);
+       if (wret)
+               ret = wret;
+       if (path->slots[1] == 0) {
+               wret = fixup_low_keys(trans, root, path, &disk_key, 1);
+               if (wret)
+                       ret = wret;
+       }
+       free_extent_buffer(path->nodes[0]);
+       path->nodes[0] = right;
+       path->slots[0] = 0;
+       check_node(root, path, 1);
+       check_leaf(root, path, 0);
+       return ret;
+}
+
+int btrfs_truncate_item(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root,
+                       struct btrfs_path *path,
+                       u32 new_size)
+{
+       int ret = 0;
+       int slot;
+       int slot_orig;
+       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;
+
+       slot_orig = path->slots[0];
+       leaf = path->nodes[0];
+
+       nritems = btrfs_header_nritems(leaf);
+       data_end = leaf_data_end(root, leaf);
+
+       slot = path->slots[0];
+       old_data_start = btrfs_item_offset_nr(leaf, slot);
+       old_size = btrfs_item_size_nr(leaf, slot);
+       BUG_ON(old_size <= new_size);
+       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_item_offset(leaf, item);
+               btrfs_set_item_offset(leaf, item, ioff + size_diff);
+       }
+       /* shift the data */
+       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);
+
+       item = btrfs_item_nr(leaf, slot);
+       btrfs_set_item_size(leaf, item, new_size);
+       btrfs_mark_buffer_dirty(leaf);
+
+       ret = 0;
+       if (btrfs_leaf_free_space(root, leaf) < 0) {
+               btrfs_print_leaf(root, leaf);
+               BUG();
+       }
+       check_leaf(root, path, 0);
+       return ret;
+}
+
+int btrfs_extend_item(struct btrfs_trans_handle *trans,
+                     struct btrfs_root *root, struct btrfs_path *path,
+                     u32 data_size)
+{
+       int ret = 0;
+       int slot;
+       int slot_orig;
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
+       u32 nritems;
+       unsigned int data_end;
+       unsigned int old_data;
+       unsigned int old_size;
+       int i;
+
+       slot_orig = path->slots[0];
+       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);
+       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_item_offset(leaf, item);
+               btrfs_set_item_offset(leaf, item, ioff - data_size);
+       }
+
+       /* 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);
+
+       ret = 0;
+       if (btrfs_leaf_free_space(root, leaf) < 0) {
+               btrfs_print_leaf(root, leaf);
+               BUG();
+       }
+       check_leaf(root, path, 0);
        return ret;
 }
 
@@ -680,240 +1988,318 @@ int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size)
  * 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 insert_item(struct ctree_root *root, struct key *key,
-                         void *data, int data_size)
+int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root,
+                           struct btrfs_path *path,
+                           struct btrfs_key *cpu_key, u32 data_size)
 {
-       int ret;
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
+       int ret = 0;
        int slot;
        int slot_orig;
-       struct leaf *leaf;
-       struct tree_buffer *leaf_buf;
-       unsigned int nritems;
+       u32 nritems;
        unsigned int data_end;
-       struct ctree_path path;
+       struct btrfs_disk_key disk_key;
 
-       refill_alloc_extent(root);
+       btrfs_cpu_key_to_disk(&disk_key, cpu_key);
 
        /* create a root if there isn't one */
-       if (!root->node) {
+       if (!root->node)
                BUG();
-#if 0
-               struct tree_buffer *t;
-               t = alloc_free_block(root);
-               BUG_ON(!t);
-               t->node.header.nritems = 0;
-               t->node.header.flags = node_level(0);
-               t->node.header.blocknr = t->blocknr;
-               root->node = t;
-               write_tree_block(root, t);
-#endif
-       }
-       init_path(&path);
-       ret = search_slot(root, key, &path);
+
+       ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
        if (ret == 0) {
-               release_path(root, &path);
                return -EEXIST;
        }
+       if (ret < 0)
+               goto out;
 
-       slot_orig = path.slots[0];
-       leaf_buf = path.nodes[0];
-       leaf = &leaf_buf->leaf;
+       slot_orig = path->slots[0];
+       leaf = path->nodes[0];
 
-       /* make room if needed */
-       if (leaf_free_space(leaf) <  sizeof(struct item) + data_size) {
-               split_leaf(root, &path, data_size);
-               leaf_buf = path.nodes[0];
-               leaf = &path.nodes[0]->leaf;
-       }
-       nritems = leaf->header.nritems;
-       data_end = leaf_data_end(leaf);
+       nritems = btrfs_header_nritems(leaf);
+       data_end = leaf_data_end(root, leaf);
 
-       if (leaf_free_space(leaf) <  sizeof(struct item) + data_size)
+       if (btrfs_leaf_free_space(root, leaf) <
+           sizeof(struct btrfs_item) + data_size) {
                BUG();
+       }
 
-       slot = path.slots[0];
+       slot = path->slots[0];
        BUG_ON(slot < 0);
-       if (slot == 0)
-               fixup_low_keys(root, &path, key, 1);
+
        if (slot != nritems) {
                int i;
-               unsigned int old_data = leaf->items[slot].offset +
-                                       leaf->items[slot].size;
+               unsigned int old_data = btrfs_item_end_nr(leaf, slot);
 
+               if (old_data < data_end) {
+                       btrfs_print_leaf(root, leaf);
+                       printk("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++)
-                       leaf->items[i].offset -= data_size;
+               for (i = slot; i < nritems; i++) {
+                       u32 ioff;
+                       item = btrfs_item_nr(leaf, i);
+                       ioff = btrfs_item_offset(leaf, item);
+                       btrfs_set_item_offset(leaf, item, ioff - data_size);
+               }
 
                /* shift the items */
-               memmove(leaf->items + slot + 1, leaf->items + slot,
-                       (nritems - slot) * sizeof(struct item));
+               memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
+                             btrfs_item_nr_offset(slot),
+                             (nritems - slot) * sizeof(struct btrfs_item));
 
                /* shift the data */
-               memmove(leaf->data + data_end - data_size, leaf->data +
-                       data_end, old_data - data_end);
+               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;
        }
-       /* copy the new data in */
-       memcpy(&leaf->items[slot].key, key, sizeof(struct key));
-       leaf->items[slot].offset = data_end - data_size;
-       leaf->items[slot].size = data_size;
-       memcpy(leaf->data + data_end - data_size, data, data_size);
-       leaf->header.nritems += 1;
-       write_tree_block(root, leaf_buf);
-       if (leaf_free_space(leaf) < 0)
+
+       /* setup the item for the new data */
+       btrfs_set_item_key(leaf, &disk_key, slot);
+       item = btrfs_item_nr(leaf, slot);
+       btrfs_set_item_offset(leaf, item, data_end - data_size);
+       btrfs_set_item_size(leaf, item, data_size);
+       btrfs_set_header_nritems(leaf, nritems + 1);
+       btrfs_mark_buffer_dirty(leaf);
+
+       ret = 0;
+       if (slot == 0)
+               ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+
+       if (btrfs_leaf_free_space(root, leaf) < 0) {
+               btrfs_print_leaf(root, leaf);
                BUG();
-       release_path(root, &path);
-       return 0;
+       }
+       check_leaf(root, path, 0);
+out:
+       return ret;
+}
+
+/*
+ * 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();
+       BUG_ON(!path);
+       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 level in the path.  The path is not
- * fixed up, so after calling this it is not valid at that level.
+ * delete the pointer from a given node.
  *
  * If the delete empties a node, the node is removed from the tree,
  * continuing all the way the root if required.  The root is converted into
  * a leaf if all the nodes are emptied.
  */
-int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
+static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                  struct btrfs_path *path, int level, int slot)
 {
-       int slot;
-       struct tree_buffer *t;
-       struct node *node;
-       int nritems;
-
-       while(1) {
-               t = path->nodes[level];
-               if (!t)
-                       break;
-               node = &t->node;
-               slot = path->slots[level];
-               nritems = node->header.nritems;
-
-               if (slot != nritems -1) {
-                       memmove(node->keys + slot, node->keys + slot + 1,
-                               sizeof(struct key) * (nritems - slot - 1));
-                       memmove(node->blockptrs + slot,
-                               node->blockptrs + slot + 1,
-                               sizeof(u64) * (nritems - slot - 1));
-               }
-               node->header.nritems--;
-               write_tree_block(root, t);
-               if (node->header.nritems != 0) {
-                       int tslot;
-                       if (slot == 0)
-                               fixup_low_keys(root, path, node->keys,
-                                              level + 1);
-                       tslot = path->slots[level+1];
-                       t->count++;
-                       push_node_left(root, path, level);
-                       if (node->header.nritems) {
-                               push_node_right(root, path, level);
-                       }
-                       if (node->header.nritems) {
-                               tree_block_release(root, t);
-                               break;
-                       }
-                       tree_block_release(root, t);
-                       path->slots[level+1] = tslot;
-               }
-               if (t == root->node) {
-                       /* just turn the root into a leaf and break */
-                       root->node->node.header.flags = node_level(0);
-                       write_tree_block(root, t);
-                       break;
-               }
-               level++;
-               if (!path->nodes[level])
-                       BUG();
+       struct extent_buffer *parent = path->nodes[level];
+       u32 nritems;
+       int ret = 0;
+       int wret;
+
+       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));
        }
-       return 0;
+       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);
+               wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
+               if (wret)
+                       ret = wret;
+       }
+       btrfs_mark_buffer_dirty(parent);
+       return ret;
 }
 
 /*
  * delete the item at the leaf level in path.  If that empties
  * the leaf, remove it from the tree
  */
-int del_item(struct ctree_root *root, struct ctree_path *path)
+int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                  struct btrfs_path *path)
 {
        int slot;
-       struct leaf *leaf;
-       struct tree_buffer *leaf_buf;
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
        int doff;
        int dsize;
+       int ret = 0;
+       int wret;
+       u32 nritems;
 
-       leaf_buf = path->nodes[0];
-       leaf = &leaf_buf->leaf;
+       leaf = path->nodes[0];
        slot = path->slots[0];
-       doff = leaf->items[slot].offset;
-       dsize = leaf->items[slot].size;
+       doff = btrfs_item_offset_nr(leaf, slot);
+       dsize = btrfs_item_size_nr(leaf, slot);
+       nritems = btrfs_header_nritems(leaf);
 
-       if (slot != leaf->header.nritems - 1) {
+       if (slot != nritems - 1) {
                int i;
-               int data_end = leaf_data_end(leaf);
-               memmove(leaf->data + data_end + dsize,
-                       leaf->data + data_end,
-                       doff - data_end);
-               for (i = slot + 1; i < leaf->header.nritems; i++)
-                       leaf->items[i].offset += dsize;
-               memmove(leaf->items + slot, leaf->items + slot + 1,
-                       sizeof(struct item) *
-                       (leaf->header.nritems - slot - 1));
-       }
-       leaf->header.nritems -= 1;
+               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,
+                             doff - data_end);
+
+               for (i = slot + 1; i < nritems; i++) {
+                       u32 ioff;
+                       item = btrfs_item_nr(leaf, i);
+                       ioff = btrfs_item_offset(leaf, item);
+                       btrfs_set_item_offset(leaf, item, ioff + dsize);
+               }
+               memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
+                             btrfs_item_nr_offset(slot + 1),
+                             sizeof(struct btrfs_item) *
+                             (nritems - slot - 1));
+       }
+       btrfs_set_header_nritems(leaf, nritems - 1);
+       nritems--;
+
        /* delete the leaf if we've emptied it */
-       if (leaf->header.nritems == 0) {
-               if (leaf_buf == root->node) {
-                       leaf->header.flags = node_level(0);
-                       write_tree_block(root, leaf_buf);
-               } else
-                       del_ptr(root, path, 1);
+       if (nritems == 0) {
+               if (leaf == root->node) {
+                       btrfs_set_header_level(leaf, 0);
+               } else {
+                       clean_tree_block(trans, root, leaf);
+                       wait_on_tree_block_writeback(root, leaf);
+                       wret = del_ptr(trans, root, path, 1, path->slots[1]);
+                       if (wret)
+                               ret = wret;
+                       wret = btrfs_free_extent(trans, root,
+                                                extent_buffer_blocknr(leaf),
+                                                1, 1);
+                       if (wret)
+                               ret = wret;
+               }
        } else {
-               if (slot == 0)
-                       fixup_low_keys(root, path, &leaf->items[0].key, 1);
-               write_tree_block(root, leaf_buf);
+               int used = leaf_space_used(leaf, 0, nritems);
+               if (slot == 0) {
+                       struct btrfs_disk_key disk_key;
+
+                       btrfs_item_key(leaf, &disk_key, 0);
+                       wret = fixup_low_keys(trans, root, path,
+                                             &disk_key, 1);
+                       if (wret)
+                               ret = wret;
+               }
+
                /* delete the leaf if it is mostly empty */
-               if (leaf_space_used(leaf, 0, leaf->header.nritems) <
-                   LEAF_DATA_SIZE / 4) {
+               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];
-                       leaf_buf->count++;
-                       push_leaf_left(root, path, 1);
-                       if (leaf->header.nritems == 0) {
-                               path->slots[1] = slot;
-                               del_ptr(root, path, 1);
+                       extent_buffer_get(leaf);
+
+                       wret = push_leaf_left(trans, root, path, 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);
+                               if (wret < 0 && wret != -ENOSPC)
+                                       ret = wret;
+                       }
+
+                       if (btrfs_header_nritems(leaf) == 0) {
+                               u64 blocknr = extent_buffer_blocknr(leaf);
+
+                               clean_tree_block(trans, root, leaf);
+                               wait_on_tree_block_writeback(root, leaf);
+
+                               wret = del_ptr(trans, root, path, 1, slot);
+                               if (wret)
+                                       ret = wret;
+
+                               free_extent_buffer(leaf);
+                               wret = btrfs_free_extent(trans, root, blocknr,
+                                                        1, 1);
+                               if (wret)
+                                       ret = wret;
+                       } else {
+                               btrfs_mark_buffer_dirty(leaf);
+                               free_extent_buffer(leaf);
                        }
-                       tree_block_release(root, leaf_buf);
+               } else {
+                       btrfs_mark_buffer_dirty(leaf);
                }
        }
-       return 0;
+       return ret;
 }
 
-int next_leaf(struct ctree_root *root, struct ctree_path *path)
+/*
+ * walk up the tree as far as required to find the next leaf.
+ * 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 = 1;
        u64 blocknr;
-       struct tree_buffer *c;
-       struct tree_buffer *next = NULL;
+       struct extent_buffer *c;
+       struct extent_buffer *next = NULL;
 
-       while(level < MAX_LEVEL) {
+       while(level < BTRFS_MAX_LEVEL) {
                if (!path->nodes[level])
-                       return -1;
+                       return 1;
+
                slot = path->slots[level] + 1;
                c = path->nodes[level];
-               if (slot >= c->node.header.nritems) {
+               if (slot >= btrfs_header_nritems(c)) {
                        level++;
                        continue;
                }
-               blocknr = c->node.blockptrs[slot];
+
+               blocknr = btrfs_node_blockptr(c, slot);
                if (next)
-                       tree_block_release(root, next);
+                       free_extent_buffer(next);
+
+               if (path->reada)
+                       reada_for_search(root, path, level, slot);
+
                next = read_tree_block(root, blocknr);
                break;
        }
@@ -921,330 +2307,14 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path)
        while(1) {
                level--;
                c = path->nodes[level];
-               tree_block_release(root, c);
+               free_extent_buffer(c);
                path->nodes[level] = next;
                path->slots[level] = 0;
                if (!level)
                        break;
-               next = read_tree_block(root, next->node.blockptrs[0]);
-       }
-       return 0;
-}
-
-int alloc_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
-                u64 search_end, u64 owner, struct key *ins)
-{
-       struct ctree_path path;
-       struct key *key;
-       int ret;
-       u64 hole_size = 0;
-       int slot = 0;
-       u64 last_block;
-       int start_found = 0;
-       struct leaf *l;
-       struct extent_item extent_item;
-       struct ctree_root * root = orig_root->extent_root;
-
-       init_path(&path);
-       ins->objectid = search_start;
-       ins->offset = 0;
-       ins->flags = 0;
-
-       ret = search_slot(root, ins, &path);
-       while (1) {
-               l = &path.nodes[0]->leaf;
-               slot = path.slots[0];
-               if (!l) {
-                       // FIXME allocate root
-               }
-               if (slot >= l->header.nritems) {
-                       ret = next_leaf(root, &path);
-                       if (ret == 0)
-                               continue;
-                       if (!start_found) {
-                               ins->objectid = search_start;
-                               ins->offset = num_blocks;
-                               hole_size = search_end - search_start;
-                               goto insert;
-                       }
-                       ins->objectid = last_block;
-                       ins->offset = num_blocks;
-                       hole_size = search_end - last_block;
-                       goto insert;
-               }
-               key = &l->items[slot].key;
-               if (start_found) {
-                       hole_size = key->objectid - last_block;
-                       if (hole_size > num_blocks) {
-                               ins->objectid = last_block;
-                               ins->offset = num_blocks;
-                               goto insert;
-                       }
-               } else
-                       start_found = 1;
-               last_block = key->objectid + key->offset;
-               path.slots[0]++;
-       }
-       // FIXME -ENOSPC
-insert:
-       release_path(root, &path);
-       extent_item.refs = 1;
-       extent_item.owner = owner;
-       if (root == orig_root && root->reserve_extent->num_blocks == 0) {
-               root->reserve_extent->blocknr = ins->objectid;
-               root->reserve_extent->num_blocks = ins->offset;
-               root->reserve_extent->num_used = 0;
-       }
-       ret = insert_item(root->extent_root, ins, &extent_item, sizeof(extent_item));
-       return ret;
-}
-
-static int refill_alloc_extent(struct ctree_root *root)
-{
-       struct alloc_extent *ae = root->alloc_extent;
-       struct key key;
-       int ret;
-       int min_blocks = MAX_LEVEL * 2;
-
-       if (ae->num_blocks > ae->num_used && ae->num_blocks - ae->num_used >
-           min_blocks)
-               return 0;
-       ae = root->reserve_extent;
-       if (ae->num_blocks > ae->num_used) {
-               if (root->alloc_extent->num_blocks == 0) {
-                       /* we should swap reserve/alloc_extent when alloc
-                        * fills up
-                        */
-                       BUG();
-               }
-               if (ae->num_blocks - ae->num_used < min_blocks)
-                       BUG();
-               return 0;
-       }
-       ret = alloc_extent(root,
-                          min_blocks * 2, 0, (unsigned long)-1,
-                          root->node->node.header.parentid, &key);
-       ae->blocknr = key.objectid;
-       ae->num_blocks = key.offset;
-       ae->num_used = 0;
-       return ret;
-}
-
-void print_leaf(struct leaf *l)
-{
-       int i;
-       int nr = l->header.nritems;
-       struct item *item;
-       struct extent_item *ei;
-       printf("leaf %lu total ptrs %d free space %d\n", l->header.blocknr, nr,
-              leaf_free_space(l));
-       fflush(stdout);
-       for (i = 0 ; i < nr ; i++) {
-               item = l->items + i;
-               printf("\titem %d key (%lu %u %lu) itemoff %d itemsize %d\n",
-                       i,
-                       item->key.objectid, item->key.flags, item->key.offset,
-                       item->offset, item->size);
-               fflush(stdout);
-               printf("\t\titem data %.*s\n", item->size, l->data+item->offset);
-               ei = (struct extent_item *)(l->data + item->offset);
-               printf("\t\textent data %u %lu\n", ei->refs, ei->owner);
-               fflush(stdout);
-       }
-}
-void print_tree(struct ctree_root *root, struct tree_buffer *t)
-{
-       int i;
-       int nr;
-       struct node *c;
-
-       if (!t)
-               return;
-       c = &t->node;
-       nr = c->header.nritems;
-       if (c->header.blocknr != t->blocknr)
-               BUG();
-       if (is_leaf(c->header.flags)) {
-               print_leaf((struct leaf *)c);
-               return;
-       }
-       printf("node %lu level %d total ptrs %d free spc %lu\n", t->blocknr,
-               node_level(c->header.flags), c->header.nritems,
-               NODEPTRS_PER_BLOCK - c->header.nritems);
-       fflush(stdout);
-       for (i = 0; i < nr; i++) {
-               printf("\tkey %d (%lu %u %lu) block %lu\n",
-                      i,
-                      c->keys[i].objectid, c->keys[i].flags, c->keys[i].offset,
-                      c->blockptrs[i]);
-               fflush(stdout);
-       }
-       for (i = 0; i < nr; i++) {
-               struct tree_buffer *next_buf = read_tree_block(root,
-                                                           c->blockptrs[i]);
-               struct node *next = &next_buf->node;
-               if (is_leaf(next->header.flags) &&
-                   node_level(c->header.flags) != 1)
-                       BUG();
-               if (node_level(next->header.flags) !=
-                       node_level(c->header.flags) - 1)
-                       BUG();
-               print_tree(root, next_buf);
-               tree_block_release(root, next_buf);
-       }
-
-}
-
-/* for testing only */
-int next_key(int i, int max_key) {
-       return rand() % max_key;
-       // return i;
-}
-
-int main() {
-       struct ctree_root *root;
-       struct key ins;
-       struct key last = { (u64)-1, 0, 0};
-       char *buf;
-       int i;
-       int num;
-       int ret;
-       int run_size = 10000;
-       int max_key = 100000000;
-       int tree_size = 0;
-       struct ctree_path path;
-       struct ctree_super_block super;
-
-       radix_tree_init();
-
-
-       root = open_ctree("dbfile", &super);
-       printf("root tree\n");
-       print_tree(root, root->node);
-       printf("map tree\n");
-       print_tree(root->extent_root, root->extent_root->node);
-
-       srand(55);
-       for (i = 0; i < run_size; i++) {
-               buf = malloc(64);
-               num = next_key(i, max_key);
-               // num = i;
-               sprintf(buf, "string-%d", num);
-               // printf("insert %d\n", num);
-               ins.objectid = num;
-               ins.offset = 0;
-               ins.flags = 0;
-               ret = insert_item(root, &ins, buf, strlen(buf));
-               if (!ret)
-                       tree_size++;
-       }
-       printf("root used: %lu\n", root->alloc_extent->num_used);
-       printf("root tree\n");
-       // print_tree(root, root->node);
-       printf("map tree\n");
-       printf("map used: %lu\n", root->extent_root->alloc_extent->num_used);
-       // print_tree(root->extent_root, root->extent_root->node);
-       write_ctree_super(root, &super);
-       close_ctree(root);
-
-       root = open_ctree("dbfile", &super);
-       printf("starting search\n");
-       srand(55);
-       for (i = 0; i < run_size; i++) {
-               num = next_key(i, max_key);
-               ins.objectid = num;
-               init_path(&path);
-               ret = search_slot(root, &ins, &path);
-               if (ret) {
-                       print_tree(root, root->node);
-                       printf("unable to find %d\n", num);
-                       exit(1);
-               }
-               release_path(root, &path);
-       }
-       write_ctree_super(root, &super);
-       close_ctree(root);
-       root = open_ctree("dbfile", &super);
-       printf("node %p level %d total ptrs %d free spc %lu\n", root->node,
-               node_level(root->node->node.header.flags),
-               root->node->node.header.nritems,
-               NODEPTRS_PER_BLOCK - root->node->node.header.nritems);
-       printf("all searches good, deleting some items\n");
-       i = 0;
-       srand(55);
-       for (i = 0 ; i < run_size/4; i++) {
-               num = next_key(i, max_key);
-               ins.objectid = num;
-               init_path(&path);
-               ret = search_slot(root, &ins, &path);
-               if (ret)
-                       continue;
-               ret = del_item(root, &path);
-               if (ret != 0)
-                       BUG();
-               release_path(root, &path);
-               tree_size--;
-       }
-       srand(128);
-       for (i = 0; i < run_size; i++) {
-               buf = malloc(64);
-               num = next_key(i, max_key);
-               sprintf(buf, "string-%d", num);
-               ins.objectid = num;
-               ret = insert_item(root, &ins, buf, strlen(buf));
-               if (!ret)
-                       tree_size++;
-       }
-       write_ctree_super(root, &super);
-       close_ctree(root);
-       root = open_ctree("dbfile", &super);
-       printf("starting search2\n");
-       srand(128);
-       for (i = 0; i < run_size; i++) {
-               num = next_key(i, max_key);
-               ins.objectid = num;
-               init_path(&path);
-               ret = search_slot(root, &ins, &path);
-               if (ret) {
-                       print_tree(root, root->node);
-                       printf("unable to find %d\n", num);
-                       exit(1);
-               }
-               release_path(root, &path);
-       }
-       printf("starting big long delete run\n");
-       while(root->node && root->node->node.header.nritems > 0) {
-               struct leaf *leaf;
-               int slot;
-               ins.objectid = (u64)-1;
-               init_path(&path);
-               ret = search_slot(root, &ins, &path);
-               if (ret == 0)
-                       BUG();
-
-               leaf = &path.nodes[0]->leaf;
-               slot = path.slots[0];
-               if (slot != leaf->header.nritems)
-                       BUG();
-               while(path.slots[0] > 0) {
-                       path.slots[0] -= 1;
-                       slot = path.slots[0];
-                       leaf = &path.nodes[0]->leaf;
-
-                       if (comp_keys(&last, &leaf->items[slot].key) <= 0)
-                               BUG();
-                       memcpy(&last, &leaf->items[slot].key, sizeof(last));
-                       ret = del_item(root, &path);
-                       if (ret != 0) {
-                               printf("del_item returned %d\n", ret);
-                               BUG();
-                       }
-                       tree_size--;
-               }
-               release_path(root, &path);
+               if (path->reada)
+                       reada_for_search(root, path, level, 0);
+               next = read_tree_block(root, btrfs_node_blockptr(next, 0));
        }
-       write_ctree_super(root, &super);
-       close_ctree(root);
-       printf("tree size is now %d\n", tree_size);
        return 0;
 }