rework csum and extent item ordering
[platform/upstream/btrfs-progs.git] / ctree.c
diff --git a/ctree.c b/ctree.c
index 7645ab3..01baa0b 100644 (file)
--- a/ctree.c
+++ b/ctree.c
@@ -6,26 +6,65 @@
 #include "disk-io.h"
 #include "print-tree.h"
 
-int split_node(struct ctree_root *root, struct ctree_path *path, int level);
-int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size);
-int push_node_left(struct ctree_root *root, struct ctree_path *path, int level);
-int push_node_right(struct ctree_root *root,
-                   struct ctree_path *path, int level);
-int del_ptr(struct ctree_root *root, struct ctree_path *path, int level);
-
-inline void init_path(struct ctree_path *p)
+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_path *path, int data_size);
+static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
+                         *root, struct btrfs_buffer *dst, struct btrfs_buffer
+                         *src);
+static int balance_node_right(struct btrfs_trans_handle *trans, struct
+                             btrfs_root *root, struct btrfs_buffer *dst_buf,
+                             struct btrfs_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));
 }
 
-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]);
+               btrfs_block_release(root, p->nodes[i]);
        }
+       memset(p, 0, sizeof(*p));
+}
+
+static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
+                          *root, struct btrfs_buffer *buf, struct btrfs_buffer
+                          *parent, int parent_slot, struct btrfs_buffer
+                          **cow_ret)
+{
+       struct btrfs_buffer *cow;
+
+       if (!list_empty(&buf->dirty)) {
+               *cow_ret = buf;
+               return 0;
+       }
+       cow = btrfs_alloc_free_block(trans, root);
+       memcpy(&cow->node, &buf->node, root->blocksize);
+       btrfs_set_header_blocknr(&cow->node.header, cow->blocknr);
+       *cow_ret = cow;
+       btrfs_inc_ref(trans, root, buf);
+       if (buf == root->node) {
+               root->node = cow;
+               cow->count++;
+               if (buf != root->commit_root)
+                       btrfs_free_extent(trans, root, buf->blocknr, 1, 1);
+               btrfs_block_release(root, buf);
+       } else {
+               btrfs_set_node_blockptr(&parent->node, parent_slot,
+                                       cow->blocknr);
+               BUG_ON(list_empty(&parent->dirty));
+               btrfs_free_extent(trans, root, buf->blocknr, 1, 1);
+       }
+       btrfs_block_release(root, buf);
+       return 0;
 }
 
 /*
@@ -33,12 +72,13 @@ 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 btrfs_leaf *leaf)
 {
-       unsigned int nr = leaf->header.nritems;
+       u32 nr = btrfs_header_nritems(&leaf->header);
        if (nr == 0)
-               return sizeof(leaf->data);
-       return leaf->items[nr-1].offset;
+               return BTRFS_LEAF_DATA_SIZE(root);
+       return btrfs_item_offset(leaf->items + nr - 1);
 }
 
 /*
@@ -46,34 +86,117 @@ static inline unsigned int leaf_data_end(struct leaf *leaf)
  * the start of the leaf data.  IOW, how much room
  * the leaf has left for both items and data
  */
-int leaf_free_space(struct leaf *leaf)
+int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf)
 {
-       int data_end = leaf_data_end(leaf);
-       int nritems = leaf->header.nritems;
+       int data_end = leaf_data_end(root, leaf);
+       int nritems = btrfs_header_nritems(&leaf->header);
        char *items_end = (char *)(leaf->items + nritems + 1);
-       return (char *)(leaf->data + data_end) - (char *)items_end;
+       return (char *)(btrfs_leaf_data(leaf) + data_end) - (char *)items_end;
 }
 
 /*
  * 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.flags > k2->flags)
                return 1;
-       if (k1->flags < k2->flags)
+       if (k1.flags < k2->flags)
                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)
+{
+       int i;
+       struct btrfs_node *parent = NULL;
+       struct btrfs_node *node = &path->nodes[level]->node;
+       int parent_slot;
+       u32 nritems = btrfs_header_nritems(&node->header);
+
+       if (path->nodes[level + 1])
+               parent = &path->nodes[level + 1]->node;
+       parent_slot = path->slots[level + 1];
+       BUG_ON(nritems == 0);
+       if (parent) {
+               struct btrfs_disk_key *parent_key;
+               parent_key = &parent->ptrs[parent_slot].key;
+               BUG_ON(memcmp(parent_key, &node->ptrs[0].key,
+                             sizeof(struct btrfs_disk_key)));
+               BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+                      btrfs_header_blocknr(&node->header));
+       }
+       BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
+       for (i = 0; nritems > 1 && i < nritems - 2; i++) {
+               struct btrfs_key cpukey;
+               btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key);
+               BUG_ON(comp_keys(&node->ptrs[i].key, &cpukey) >= 0);
+       }
+       return 0;
+}
+
+static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
+                     int level)
+{
+       int i;
+       struct btrfs_leaf *leaf = &path->nodes[level]->leaf;
+       struct btrfs_node *parent = NULL;
+       int parent_slot;
+       u32 nritems = btrfs_header_nritems(&leaf->header);
+
+       if (path->nodes[level + 1])
+               parent = &path->nodes[level + 1]->node;
+       parent_slot = path->slots[level + 1];
+       BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
+
+       if (nritems == 0)
+               return 0;
+
+       if (parent) {
+               struct btrfs_disk_key *parent_key;
+               parent_key = &parent->ptrs[parent_slot].key;
+               BUG_ON(memcmp(parent_key, &leaf->items[0].key,
+                      sizeof(struct btrfs_disk_key)));
+               BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+                      btrfs_header_blocknr(&leaf->header));
+       }
+       for (i = 0; nritems > 1 && i < nritems - 2; i++) {
+               struct btrfs_key cpukey;
+               btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key);
+               BUG_ON(comp_keys(&leaf->items[i].key,
+                                &cpukey) >= 0);
+               BUG_ON(btrfs_item_offset(leaf->items + i) !=
+                       btrfs_item_end(leaf->items + i + 1));
+               if (i == 0) {
+                       BUG_ON(btrfs_item_offset(leaf->items + i) +
+                              btrfs_item_size(leaf->items + i) !=
+                              BTRFS_LEAF_DATA_SIZE(root));
+               }
+       }
+       return 0;
+}
+
+static int check_block(struct btrfs_root *root, struct btrfs_path *path,
+                       int level)
+{
+       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
@@ -83,18 +206,18 @@ int comp_keys(struct key *k1, struct key *k2)
  *
  * 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,
+static int generic_bin_search(char *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;
 
        while(low < high) {
                mid = (low + high) / 2;
-               tmp = (struct key *)(p + mid * item_size);
+               tmp = (struct btrfs_disk_key *)(p + mid * item_size);
                ret = comp_keys(tmp, key);
 
                if (ret < 0)
@@ -114,99 +237,284 @@ int generic_bin_search(char *p, int item_size, struct key *key,
  * simple bin_search frontend that does the right thing for
  * leaves vs nodes
  */
-int bin_search(struct node *c, struct key *key, int *slot)
+static int bin_search(struct btrfs_node *c, struct btrfs_key *key, 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 (btrfs_is_leaf(c)) {
+               struct btrfs_leaf *l = (struct btrfs_leaf *)c;
+               return generic_bin_search((void *)l->items,
+                                         sizeof(struct btrfs_item),
+                                         key, btrfs_header_nritems(&c->header),
+                                         slot);
        } else {
-               return generic_bin_search((void *)c->keys, sizeof(struct key),
-                                         key, c->header.nritems, slot);
+               return generic_bin_search((void *)c->ptrs,
+                                         sizeof(struct btrfs_key_ptr),
+                                         key, btrfs_header_nritems(&c->header),
+                                         slot);
        }
        return -1;
 }
 
+static struct btrfs_buffer *read_node_slot(struct btrfs_root *root,
+                                  struct btrfs_buffer *parent_buf,
+                                  int slot)
+{
+       struct btrfs_node *node = &parent_buf->node;
+       if (slot < 0)
+               return NULL;
+       if (slot >= btrfs_header_nritems(&node->header))
+               return NULL;
+       return read_tree_block(root, btrfs_node_blockptr(node, slot));
+}
+
+static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
+                        *root, struct btrfs_path *path, int level)
+{
+       struct btrfs_buffer *right_buf;
+       struct btrfs_buffer *mid_buf;
+       struct btrfs_buffer *left_buf;
+       struct btrfs_buffer *parent_buf = NULL;
+       struct btrfs_node *right = NULL;
+       struct btrfs_node *mid;
+       struct btrfs_node *left = NULL;
+       struct btrfs_node *parent = NULL;
+       int ret = 0;
+       int wret;
+       int pslot;
+       int orig_slot = path->slots[level];
+       u64 orig_ptr;
+
+       if (level == 0)
+               return 0;
+
+       mid_buf = path->nodes[level];
+       mid = &mid_buf->node;
+       orig_ptr = btrfs_node_blockptr(mid, orig_slot);
+
+       if (level < BTRFS_MAX_LEVEL - 1)
+               parent_buf = 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_buf) {
+               struct btrfs_buffer *child;
+               u64 blocknr = mid_buf->blocknr;
+
+               if (btrfs_header_nritems(&mid->header) != 1)
+                       return 0;
+
+               /* promote the child to a root */
+               child = read_node_slot(root, mid_buf, 0);
+               BUG_ON(!child);
+               root->node = child;
+               path->nodes[level] = NULL;
+               /* once for the path */
+               btrfs_block_release(root, mid_buf);
+               /* once for the root ptr */
+               btrfs_block_release(root, mid_buf);
+               clean_tree_block(trans, root, mid_buf);
+               return btrfs_free_extent(trans, root, blocknr, 1, 1);
+       }
+       parent = &parent_buf->node;
+
+       if (btrfs_header_nritems(&mid->header) >
+           BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
+               return 0;
+
+       left_buf = read_node_slot(root, parent_buf, pslot - 1);
+       right_buf = read_node_slot(root, parent_buf, pslot + 1);
+
+       /* first, try to make some room in the middle buffer */
+       if (left_buf) {
+               btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1,
+                               &left_buf);
+               left = &left_buf->node;
+               orig_slot += btrfs_header_nritems(&left->header);
+               wret = push_node_left(trans, root, left_buf, mid_buf);
+               if (wret < 0)
+                       ret = wret;
+       }
+
+       /*
+        * then try to empty the right most buffer into the middle
+        */
+       if (right_buf) {
+               btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1,
+                               &right_buf);
+               right = &right_buf->node;
+               wret = push_node_left(trans, root, mid_buf, right_buf);
+               if (wret < 0)
+                       ret = wret;
+               if (btrfs_header_nritems(&right->header) == 0) {
+                       u64 blocknr = right_buf->blocknr;
+                       btrfs_block_release(root, right_buf);
+                       clean_tree_block(trans, root, right_buf);
+                       right_buf = NULL;
+                       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 {
+                       memcpy(&parent->ptrs[pslot + 1].key,
+                               &right->ptrs[0].key,
+                               sizeof(struct btrfs_disk_key));
+                       BUG_ON(list_empty(&parent_buf->dirty));
+               }
+       }
+       if (btrfs_header_nritems(&mid->header) == 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_buf);
+               wret = balance_node_right(trans, root, mid_buf, left_buf);
+               if (wret < 0)
+                       ret = wret;
+               BUG_ON(wret == 1);
+       }
+       if (btrfs_header_nritems(&mid->header) == 0) {
+               /* we've managed to empty the middle node, drop it */
+               u64 blocknr = mid_buf->blocknr;
+               btrfs_block_release(root, mid_buf);
+               clean_tree_block(trans, root, mid_buf);
+               mid_buf = NULL;
+               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 */
+               memcpy(&parent->ptrs[pslot].key, &mid->ptrs[0].key,
+                      sizeof(struct btrfs_disk_key));
+               BUG_ON(list_empty(&parent_buf->dirty));
+       }
+
+       /* update the path */
+       if (left_buf) {
+               if (btrfs_header_nritems(&left->header) > orig_slot) {
+                       left_buf->count++; // released below
+                       path->nodes[level] = left_buf;
+                       path->slots[level + 1] -= 1;
+                       path->slots[level] = orig_slot;
+                       if (mid_buf)
+                               btrfs_block_release(root, mid_buf);
+               } else {
+                       orig_slot -= btrfs_header_nritems(&left->header);
+                       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]->node,
+                                           path->slots[level]))
+               BUG();
+
+       if (right_buf)
+               btrfs_block_release(root, right_buf);
+       if (left_buf)
+               btrfs_block_release(root, left_buf);
+       return ret;
+}
+
 /*
  * look for key in the tree.  path is filled in with nodes along the way
  * if key is found, we return zero and you can find the item in the leaf
  * level of the path (level 0)
  *
  * If the key isn't found, the path points to the slot where it should
- * be inserted.
+ * 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 ins_len)
+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 btrfs_buffer *b;
+       struct btrfs_buffer *cow_buf;
+       struct btrfs_node *c;
        int slot;
        int ret;
        int level;
 
+again:
+       b = root->node;
        b->count++;
        while (b) {
+               level = btrfs_header_level(&b->node.header);
+               if (cow) {
+                       int wret;
+                       wret = btrfs_cow_block(trans, root, b, p->nodes[level +
+                                              1], p->slots[level + 1],
+                                              &cow_buf);
+                       b = cow_buf;
+               }
+               BUG_ON(!cow && ins_len);
                c = &b->node;
-               level = node_level(c->header.flags);
                p->nodes[level] = b;
+               ret = check_block(root, p, level);
+               if (ret)
+                       return -1;
                ret = bin_search(c, key, &slot);
-               if (!is_leaf(c->header.flags)) {
+               if (!btrfs_is_leaf(c)) {
                        if (ret && slot > 0)
                                slot -= 1;
                        p->slots[level] = slot;
-                       if (ins_len > 0 &&
-                           c->header.nritems == NODEPTRS_PER_BLOCK) {
-                               int sret = split_node(root, p, level);
+                       if (ins_len > 0 && btrfs_header_nritems(&c->header) ==
+                           BTRFS_NODEPTRS_PER_BLOCK(root)) {
+                               int sret = split_node(trans, root, p, level);
                                BUG_ON(sret > 0);
                                if (sret)
                                        return sret;
                                b = p->nodes[level];
                                c = &b->node;
                                slot = p->slots[level];
-                       } else if (ins_len < 0 &&
-                                  c->header.nritems <= NODEPTRS_PER_BLOCK/4) {
-                               u64 blocknr = b->blocknr;
-                               slot = p->slots[level +1];
-                               b->count++;
-                               if (push_node_left(root, p, level))
-                                       push_node_right(root, p, level);
-                               if (c->header.nritems == 0 &&
-                                   level < MAX_LEVEL - 1 &&
-                                   p->nodes[level + 1]) {
-                                       int tslot = p->slots[level + 1];
-
-                                       p->slots[level + 1] = slot;
-                                       del_ptr(root, p, level + 1);
-                                       p->slots[level + 1] = tslot;
-                                       tree_block_release(root, b);
-                                       free_extent(root, blocknr, 1);
-                               } else {
-                                       tree_block_release(root, b);
-                               }
+                       } 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;
                                c = &b->node;
                                slot = p->slots[level];
+                               BUG_ON(btrfs_header_nritems(&c->header) == 1);
                        }
-                       b = read_tree_block(root, c->blockptrs[slot]);
-                       continue;
+                       b = read_tree_block(root, btrfs_node_blockptr(c, slot));
                } else {
-                       struct leaf *l = (struct leaf *)c;
+                       struct btrfs_leaf *l = (struct btrfs_leaf *)c;
                        p->slots[level] = slot;
-                       if (ins_len > 0 && leaf_free_space(l) <
-                           sizeof(struct item) + ins_len) {
-                               int sret = split_leaf(root, p, ins_len);
+                       if (ins_len > 0 && btrfs_leaf_free_space(root, l) <
+                           sizeof(struct btrfs_item) + ins_len) {
+                               int sret = split_leaf(trans, root, p, ins_len);
                                BUG_ON(sret > 0);
                                if (sret)
                                        return sret;
                        }
+                       BUG_ON(root->node->count == 1);
                        return ret;
                }
        }
-       return -1;
+       BUG_ON(root->node->count == 1);
+       return 1;
 }
 
 /*
@@ -215,213 +523,155 @@ int search_slot(struct ctree_root *root, struct key *key,
  * This is used after shifting pointers to the left, so it stops
  * fixing up pointers when a given leaf/node is not in slot 0 of the
  * higher levels
+ *
+ * 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;
+       for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+               struct btrfs_node *t;
                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]);
+               memcpy(&t->ptrs[tslot].key, key, sizeof(*key));
+               BUG_ON(list_empty(&path->nodes[i]->dirty));
                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.
+ * tree.
  *
- * Lower nodes/leaves in the path are not touched, higher nodes may
- * be modified to reflect the push.
- *
- * 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 btrfs_buffer *dst_buf, struct
+                         btrfs_buffer *src_buf)
 {
-       int slot;
-       struct node *left;
-       struct node *right;
+       struct btrfs_node *src = &src_buf->node;
+       struct btrfs_node *dst = &dst_buf->node;
        int push_items = 0;
-       int left_nritems;
-       int right_nritems;
-       struct tree_buffer *t;
-       struct tree_buffer *right_buf;
-
-       if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)
-               return 1;
-       slot = path->slots[level + 1];
-       if (slot == 0)
-               return 1;
+       int src_nritems;
+       int dst_nritems;
+       int ret = 0;
 
-       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);
+       src_nritems = btrfs_header_nritems(&src->header);
+       dst_nritems = btrfs_header_nritems(&dst->header);
+       push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
        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);
-
-       write_tree_block(root, t);
-       write_tree_block(root, right_buf);
+       if (src_nritems < push_items)
+               push_items = src_nritems;
 
-       /* 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);
+       memcpy(dst->ptrs + dst_nritems, src->ptrs,
+               push_items * sizeof(struct btrfs_key_ptr));
+       if (push_items < src_nritems) {
+               memmove(src->ptrs, src->ptrs + push_items,
+                       (src_nritems - push_items) *
+                       sizeof(struct btrfs_key_ptr));
        }
-       return 0;
+       btrfs_set_header_nritems(&src->header, src_nritems - push_items);
+       btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
+       BUG_ON(list_empty(&src_buf->dirty));
+       BUG_ON(list_empty(&dst_buf->dirty));
+       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 btrfs_buffer *dst_buf,
+                             struct btrfs_buffer *src_buf)
 {
-       int slot;
-       struct tree_buffer *t;
-       struct tree_buffer *src_buffer;
-       struct node *dst;
-       struct node *src;
+       struct btrfs_node *src = &src_buf->node;
+       struct btrfs_node *dst = &dst_buf->node;
        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->header);
+       dst_nritems = btrfs_header_nritems(&dst->header);
+       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 (max_push < push_items)
+               push_items = max_push;
 
-       if (slot >= path->nodes[level + 1]->node.header.nritems -1)
-               return 1;
+       memmove(dst->ptrs + push_items, dst->ptrs,
+               dst_nritems * sizeof(struct btrfs_key_ptr));
+       memcpy(dst->ptrs, src->ptrs + src_nritems - push_items,
+               push_items * sizeof(struct btrfs_key_ptr));
 
-       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;
-       }
+       btrfs_set_header_nritems(&src->header, src_nritems - push_items);
+       btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
 
-       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);
-       }
-       return 0;
+       BUG_ON(list_empty(&src_buf->dirty));
+       BUG_ON(list_empty(&dst_buf->dirty));
+       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 ctree_root *root,
-                          struct ctree_path *path, int level)
+static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
+                          *root, struct btrfs_path *path, int level)
 {
-       struct tree_buffer *t;
-       struct node *lower;
-       struct node *c;
-       struct key *lower_key;
+       struct btrfs_buffer *t;
+       struct btrfs_node *lower;
+       struct btrfs_node *c;
+       struct btrfs_disk_key *lower_key;
 
        BUG_ON(path->nodes[level]);
        BUG_ON(path->nodes[level-1] != root->node);
 
-       t = alloc_free_block(root);
+       t = btrfs_alloc_free_block(trans, root);
        c = &t->node;
-       memset(c, 0, sizeof(c));
-       c->header.nritems = 1;
-       c->header.flags = node_level(level);
-       c->header.blocknr = t->blocknr;
-       c->header.parentid = root->node->node.header.parentid;
+       memset(c, 0, root->blocksize);
+       btrfs_set_header_nritems(&c->header, 1);
+       btrfs_set_header_level(&c->header, level);
+       btrfs_set_header_blocknr(&c->header, t->blocknr);
        lower = &path->nodes[level-1]->node;
-       if (is_leaf(lower->header.flags))
-               lower_key = &((struct leaf *)lower)->items[0].key;
+       if (btrfs_is_leaf(lower))
+               lower_key = &((struct btrfs_leaf *)lower)->items[0].key;
        else
-               lower_key = lower->keys;
-       memcpy(c->keys, lower_key, sizeof(struct key));
-       c->blockptrs[0] = path->nodes[level-1]->blocknr;
+               lower_key = &lower->ptrs[0].key;
+       memcpy(&c->ptrs[0].key, lower_key, sizeof(struct btrfs_disk_key));
+       btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->blocknr);
        /* the super has an extra ref to root->node */
-       tree_block_release(root, root->node);
+       btrfs_block_release(root, root->node);
        root->node = t;
        t->count++;
-       write_tree_block(root, t);
        path->nodes[level] = t;
        path->slots[level] = 0;
        return 0;
@@ -433,33 +683,31 @@ static int insert_new_root(struct ctree_root *root,
  *
  * 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 *lower;
+       struct btrfs_node *lower;
        int nritems;
 
        BUG_ON(!path->nodes[level]);
        lower = &path->nodes[level]->node;
-       nritems = lower->header.nritems;
+       nritems = btrfs_header_nritems(&lower->header);
        if (slot > nritems)
                BUG();
-       if (nritems == NODEPTRS_PER_BLOCK)
+       if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
                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));
+               memmove(lower->ptrs + slot + 1, lower->ptrs + slot,
+                       (nritems - slot) * sizeof(struct btrfs_key_ptr));
        }
-       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]);
+       memcpy(&lower->ptrs[slot].key, key, sizeof(struct btrfs_disk_key));
+       btrfs_set_node_blockptr(lower, slot, blocknr);
+       btrfs_set_header_nritems(&lower->header, nritems + 1);
+       BUG_ON(list_empty(&path->nodes[level]->dirty));
        return 0;
 }
 
@@ -469,55 +717,58 @@ int insert_ptr(struct ctree_root *root,
  *
  * 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
  */
-int split_node(struct ctree_root *root, struct ctree_path *path, int level)
+static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
+                     *root, struct btrfs_path *path, int level)
 {
-       struct tree_buffer *t;
-       struct node *c;
-       struct tree_buffer *split_buffer;
-       struct node *split;
+       struct btrfs_buffer *t;
+       struct btrfs_node *c;
+       struct btrfs_buffer *split_buffer;
+       struct btrfs_node *split;
        int mid;
        int ret;
+       int wret;
+       u32 c_nritems;
 
-       ret = push_node_left(root, path, level);
-       if (!ret)
-               return 0;
-       ret = push_node_right(root, path, level);
-       if (!ret)
-               return 0;
        t = path->nodes[level];
        c = &t->node;
        if (t == root->node) {
                /* trying to split the root, lets make a new one */
-               ret = insert_new_root(root, path, level + 1);
+               ret = insert_new_root(trans, root, path, level + 1);
                if (ret)
                        return ret;
        }
-       split_buffer = alloc_free_block(root);
+       c_nritems = btrfs_header_nritems(&c->header);
+       split_buffer = btrfs_alloc_free_block(trans, root);
        split = &split_buffer->node;
-       split->header.flags = c->header.flags;
-       split->header.blocknr = split_buffer->blocknr;
-       split->header.parentid = root->node->node.header.parentid;
-       mid = (c->header.nritems + 1) / 2;
-       memcpy(split->keys, c->keys + mid,
-               (c->header.nritems - mid) * sizeof(struct key));
-       memcpy(split->blockptrs, c->blockptrs + mid,
-               (c->header.nritems - mid) * sizeof(u64));
-       split->header.nritems = c->header.nritems - mid;
-       c->header.nritems = mid;
-       write_tree_block(root, t);
-       write_tree_block(root, split_buffer);
-       insert_ptr(root, path, split->keys, split_buffer->blocknr,
-                    path->slots[level + 1] + 1, level + 1);
+       btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header));
+       btrfs_set_header_level(&split->header, btrfs_header_level(&c->header));
+       btrfs_set_header_blocknr(&split->header, split_buffer->blocknr);
+       mid = (c_nritems + 1) / 2;
+       memcpy(split->ptrs, c->ptrs + mid,
+               (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
+       btrfs_set_header_nritems(&split->header, c_nritems - mid);
+       btrfs_set_header_nritems(&c->header, mid);
+       ret = 0;
+
+       BUG_ON(list_empty(&t->dirty));
+       wret = insert_ptr(trans, root, path, &split->ptrs[0].key,
+                         split_buffer->blocknr, path->slots[level + 1] + 1,
+                         level + 1);
+       if (wret)
+               ret = wret;
+
        if (path->slots[level] >= mid) {
                path->slots[level] -= mid;
-               tree_block_release(root, t);
+               btrfs_block_release(root, t);
                path->nodes[level] = split_buffer;
                path->slots[level + 1] += 1;
        } else {
-               tree_block_release(root, split_buffer);
+               btrfs_block_release(root, split_buffer);
        }
-       return 0;
+       return ret;
 }
 
 /*
@@ -525,107 +776,126 @@ int split_node(struct ctree_root *root, struct ctree_path *path, int level)
  * 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)
+static int leaf_space_used(struct btrfs_leaf *l, int start, int nr)
 {
        int data_len;
        int end = start + nr - 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;
+       data_len = btrfs_item_end(l->items + start);
+       data_len = data_len - btrfs_item_offset(l->items + end);
+       data_len += sizeof(struct btrfs_item) * nr;
        return data_len;
 }
 
 /*
  * 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.
  */
-int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
-                  int data_size)
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+                          *root, struct btrfs_path *path, int data_size)
 {
-       struct tree_buffer *left_buf = path->nodes[0];
-       struct leaf *left = &left_buf->leaf;
-       struct leaf *right;
-       struct tree_buffer *right_buf;
-       struct tree_buffer *upper;
+       struct btrfs_buffer *left_buf = path->nodes[0];
+       struct btrfs_leaf *left = &left_buf->leaf;
+       struct btrfs_leaf *right;
+       struct btrfs_buffer *right_buf;
+       struct btrfs_buffer *upper;
        int slot;
        int i;
        int free_space;
        int push_space = 0;
        int push_items = 0;
-       struct item *item;
+       struct btrfs_item *item;
+       u32 left_nritems;
+       u32 right_nritems;
 
        slot = path->slots[1];
        if (!path->nodes[1]) {
                return 1;
        }
        upper = path->nodes[1];
-       if (slot >= upper->node.header.nritems - 1) {
+       if (slot >= btrfs_header_nritems(&upper->node.header) - 1) {
                return 1;
        }
-       right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]);
+       right_buf = read_tree_block(root, btrfs_node_blockptr(&upper->node,
+                                                             slot + 1));
        right = &right_buf->leaf;
-       free_space = leaf_free_space(right);
-       if (free_space < data_size + sizeof(struct item)) {
-               tree_block_release(root, right_buf);
+       free_space = btrfs_leaf_free_space(root, right);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               btrfs_block_release(root, right_buf);
                return 1;
        }
-       for (i = left->header.nritems - 1; i >= 0; i--) {
+       /* cow and double check */
+       btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf);
+       right = &right_buf->leaf;
+       free_space = btrfs_leaf_free_space(root, right);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               btrfs_block_release(root, right_buf);
+               return 1;
+       }
+
+       left_nritems = btrfs_header_nritems(&left->header);
+       for (i = left_nritems - 1; i >= 0; i--) {
                item = left->items + 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(item) + sizeof(*item) + push_space >
+                   free_space)
                        break;
                push_items++;
-               push_space += item->size + sizeof(*item);
+               push_space += btrfs_item_size(item) + sizeof(*item);
        }
        if (push_items == 0) {
-               tree_block_release(root, right_buf);
+               btrfs_block_release(root, right_buf);
                return 1;
        }
+       right_nritems = btrfs_header_nritems(&right->header);
        /* push left to right */
-       push_space = left->items[left->header.nritems - push_items].offset +
-                    left->items[left->header.nritems - push_items].size;
-       push_space -= leaf_data_end(left);
+       push_space = btrfs_item_end(left->items + left_nritems - push_items);
+       push_space -= leaf_data_end(root, left);
        /* make room in the right data area */
-       memmove(right->data + leaf_data_end(right) - push_space,
-               right->data + leaf_data_end(right),
-               LEAF_DATA_SIZE - leaf_data_end(right));
+       memmove(btrfs_leaf_data(right) + leaf_data_end(root, right) -
+               push_space, btrfs_leaf_data(right) + leaf_data_end(root, right),
+               BTRFS_LEAF_DATA_SIZE(root) - leaf_data_end(root, right));
        /* copy from the left data area */
-       memcpy(right->data + LEAF_DATA_SIZE - push_space,
-               left->data + leaf_data_end(left),
-               push_space);
+       memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - push_space,
+               btrfs_leaf_data(left) + leaf_data_end(root, left), push_space);
        memmove(right->items + push_items, right->items,
-               right->header.nritems * sizeof(struct item));
+               right_nritems * sizeof(struct btrfs_item));
        /* copy the items from left to right */
-       memcpy(right->items, left->items + left->header.nritems - push_items,
-               push_items * sizeof(struct item));
+       memcpy(right->items, left->items + left_nritems - push_items,
+               push_items * sizeof(struct btrfs_item));
 
        /* update the item pointers */
-       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;
+       right_nritems += push_items;
+       btrfs_set_header_nritems(&right->header, right_nritems);
+       push_space = BTRFS_LEAF_DATA_SIZE(root);
+       for (i = 0; i < right_nritems; i++) {
+               btrfs_set_item_offset(right->items + i, push_space -
+                                     btrfs_item_size(right->items + i));
+               push_space = btrfs_item_offset(right->items + i);
        }
-       left->header.nritems -= push_items;
+       left_nritems -= push_items;
+       btrfs_set_header_nritems(&left->header, left_nritems);
+
+       BUG_ON(list_empty(&left_buf->dirty));
+       BUG_ON(list_empty(&right_buf->dirty));
+       memcpy(&upper->node.ptrs[slot + 1].key,
+               &right->items[0].key, sizeof(struct btrfs_disk_key));
+       BUG_ON(list_empty(&upper->dirty));
 
-       write_tree_block(root, left_buf);
-       write_tree_block(root, right_buf);
-       memcpy(upper->node.keys + slot + 1,
-               &right->items[0].key, sizeof(struct key));
-       write_tree_block(root, upper);
        /* then fixup the leaf pointer in the path */
-       // FIXME use nritems in here somehow
-       if (path->slots[0] >= left->header.nritems) {
-               path->slots[0] -= left->header.nritems;
-               tree_block_release(root, path->nodes[0]);
+       if (path->slots[0] >= left_nritems) {
+               path->slots[0] -= left_nritems;
+               btrfs_block_release(root, path->nodes[0]);
                path->nodes[0] = right_buf;
                path->slots[1] += 1;
        } else {
-               tree_block_release(root, right_buf);
+               btrfs_block_release(root, right_buf);
        }
        return 0;
 }
@@ -633,20 +903,22 @@ int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
  * 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_buffer *right_buf = path->nodes[0];
+       struct btrfs_leaf *right = &right_buf->leaf;
+       struct btrfs_buffer *t;
+       struct btrfs_leaf *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;
+       int ret = 0;
+       int wret;
 
        slot = path->slots[1];
        if (slot == 0) {
@@ -655,156 +927,198 @@ int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
        if (!path->nodes[1]) {
                return 1;
        }
-       t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]);
+       t = read_tree_block(root, btrfs_node_blockptr(&path->nodes[1]->node,
+                                                     slot - 1));
+       left = &t->leaf;
+       free_space = btrfs_leaf_free_space(root, left);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               btrfs_block_release(root, t);
+               return 1;
+       }
+
+       /* cow and double check */
+       btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t);
        left = &t->leaf;
-       free_space = leaf_free_space(left);
-       if (free_space < data_size + sizeof(struct item)) {
-               tree_block_release(root, t);
+       free_space = btrfs_leaf_free_space(root, left);
+       if (free_space < data_size + sizeof(struct btrfs_item)) {
+               btrfs_block_release(root, t);
                return 1;
        }
-       for (i = 0; i < right->header.nritems; i++) {
+
+       for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
                item = right->items + 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(item) + sizeof(*item) + push_space >
+                   free_space)
                        break;
                push_items++;
-               push_space += item->size + sizeof(*item);
+               push_space += btrfs_item_size(item) + sizeof(*item);
        }
        if (push_items == 0) {
-               tree_block_release(root, t);
+               btrfs_block_release(root, t);
                return 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,
+       memcpy(left->items + btrfs_header_nritems(&left->header),
+               right->items, push_items * sizeof(struct btrfs_item));
+       push_space = BTRFS_LEAF_DATA_SIZE(root) -
+                    btrfs_item_offset(right->items + push_items -1);
+       memcpy(btrfs_leaf_data(left) + leaf_data_end(root, left) - push_space,
+               btrfs_leaf_data(right) +
+               btrfs_item_offset(right->items + push_items - 1),
                push_space);
-       old_left_nritems = left->header.nritems;
+       old_left_nritems = btrfs_header_nritems(&left->header);
        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 = btrfs_item_offset(left->items + i);
+               btrfs_set_item_offset(left->items + i, ioff -
+                                    (BTRFS_LEAF_DATA_SIZE(root) -
+                                     btrfs_item_offset(left->items +
+                                                       old_left_nritems - 1)));
        }
-       left->header.nritems += push_items;
+       btrfs_set_header_nritems(&left->header, 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);
+       push_space = btrfs_item_offset(right->items + push_items - 1) -
+                    leaf_data_end(root, right);
+       memmove(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+               push_space, btrfs_leaf_data(right) +
+               leaf_data_end(root, 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;
+               (btrfs_header_nritems(&right->header) - push_items) *
+               sizeof(struct btrfs_item));
+       btrfs_set_header_nritems(&right->header,
+                                btrfs_header_nritems(&right->header) -
+                                push_items);
+       push_space = BTRFS_LEAF_DATA_SIZE(root);
+
+       for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
+               btrfs_set_item_offset(right->items + i, push_space -
+                                     btrfs_item_size(right->items + i));
+               push_space = btrfs_item_offset(right->items + i);
        }
 
-       write_tree_block(root, t);
-       write_tree_block(root, right_buf);
+       BUG_ON(list_empty(&t->dirty));
+       BUG_ON(list_empty(&right_buf->dirty));
 
-       fixup_low_keys(root, path, &right->items[0].key, 1);
+       wret = fixup_low_keys(trans, root, path, &right->items[0].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]);
+               btrfs_block_release(root, path->nodes[0]);
                path->nodes[0] = t;
                path->slots[1] -= 1;
        } else {
-               tree_block_release(root, t);
+               btrfs_block_release(root, t);
                path->slots[0] -= push_items;
        }
        BUG_ON(path->slots[0] < 0);
-       return 0;
+       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_path *path, int data_size)
 {
-       struct tree_buffer *l_buf = path->nodes[0];
-       struct leaf *l = &l_buf->leaf;
-       int nritems;
+       struct btrfs_buffer *l_buf;
+       struct btrfs_leaf *l;
+       u32 nritems;
        int mid;
        int slot;
-       struct leaf *right;
-       struct tree_buffer *right_buffer;
-       int space_needed = data_size + sizeof(struct item);
+       struct btrfs_leaf *right;
+       struct btrfs_buffer *right_buffer;
+       int space_needed = data_size + sizeof(struct btrfs_item);
        int data_copy_size;
        int rt_data_off;
        int i;
        int ret;
-
-       if (push_leaf_left(root, path, data_size) == 0 ||
-           push_leaf_right(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;
+       int wret;
+
+       /* 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_buf = path->nodes[0];
+       l = &l_buf->leaf;
+
+       /* 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(root, path, 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->header);
        mid = (nritems + 1)/ 2;
-
-       right_buffer = alloc_free_block(root);
+       right_buffer = btrfs_alloc_free_block(trans, root);
        BUG_ON(!right_buffer);
        BUG_ON(mid == nritems);
        right = &right_buffer->leaf;
-       memset(right, 0, sizeof(*right));
+       memset(&right->header, 0, sizeof(right->header));
        if (mid <= slot) {
                /* FIXME, just alloc a new leaf here */
                if (leaf_space_used(l, mid, nritems - mid) + space_needed >
-                       LEAF_DATA_SIZE)
+                       BTRFS_LEAF_DATA_SIZE(root))
                        BUG();
        } else {
                /* FIXME, just alloc a new leaf here */
                if (leaf_space_used(l, 0, mid + 1) + space_needed >
-                       LEAF_DATA_SIZE)
+                       BTRFS_LEAF_DATA_SIZE(root))
                        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);
+       btrfs_set_header_nritems(&right->header, nritems - mid);
+       btrfs_set_header_blocknr(&right->header, right_buffer->blocknr);
+       btrfs_set_header_level(&right->header, 0);
+       data_copy_size = btrfs_item_end(l->items + mid) -
+                        leaf_data_end(root, 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;
+              (nritems - mid) * sizeof(struct btrfs_item));
+       memcpy(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(l->items + mid);
+
+       for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
+               u32 ioff = btrfs_item_offset(right->items + i);
+               btrfs_set_item_offset(right->items + i, ioff + rt_data_off);
+       }
 
-       l->header.nritems = mid;
-       ret = insert_ptr(root, path, &right->items[0].key,
+       btrfs_set_header_nritems(&l->header, mid);
+       ret = 0;
+       wret = insert_ptr(trans, root, path, &right->items[0].key,
                          right_buffer->blocknr, path->slots[1] + 1, 1);
-       write_tree_block(root, right_buffer);
-       write_tree_block(root, l_buf);
-
+       if (wret)
+               ret = wret;
+       BUG_ON(list_empty(&right_buffer->dirty));
+       BUG_ON(list_empty(&l_buf->dirty));
        BUG_ON(path->slots[0] != slot);
        if (mid <= slot) {
-               tree_block_release(root, path->nodes[0]);
+               btrfs_block_release(root, path->nodes[0]);
                path->nodes[0] = right_buffer;
                path->slots[0] -= mid;
                path->slots[1] += 1;
        } else
-               tree_block_release(root, right_buffer);
+               btrfs_block_release(root, right_buffer);
        BUG_ON(path->slots[0] < 0);
        return ret;
 }
@@ -813,74 +1127,108 @@ 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;
+       int ret = 0;
        int slot;
        int slot_orig;
-       struct leaf *leaf;
-       struct tree_buffer *leaf_buf;
-       unsigned int nritems;
+       struct btrfs_leaf *leaf;
+       struct btrfs_buffer *leaf_buf;
+       u32 nritems;
        unsigned int data_end;
-       struct ctree_path path;
+       struct btrfs_disk_key disk_key;
+
+       btrfs_cpu_key_to_disk(&disk_key, cpu_key);
 
        /* create a root if there isn't one */
        if (!root->node)
                BUG();
-       init_path(&path);
-       ret = search_slot(root, key, &path, data_size);
+       ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
        if (ret == 0) {
-               release_path(root, &path);
+               btrfs_release_path(root, path);
                return -EEXIST;
        }
+       if (ret < 0)
+               goto out;
 
-       slot_orig = path.slots[0];
-       leaf_buf = path.nodes[0];
+       slot_orig = path->slots[0];
+       leaf_buf = path->nodes[0];
        leaf = &leaf_buf->leaf;
 
-       nritems = leaf->header.nritems;
-       data_end = leaf_data_end(leaf);
+       nritems = btrfs_header_nritems(&leaf->header);
+       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(leaf->items + slot);
 
                /*
                 * 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 = btrfs_item_offset(leaf->items + i);
+                       btrfs_set_item_offset(leaf->items + i,
+                                             ioff - data_size);
+               }
 
                /* shift the items */
                memmove(leaf->items + slot + 1, leaf->items + slot,
-                       (nritems - slot) * sizeof(struct item));
+                       (nritems - slot) * sizeof(struct btrfs_item));
 
                /* shift the data */
-               memmove(leaf->data + data_end - data_size, leaf->data +
+               memmove(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 */
+       memcpy(&leaf->items[slot].key, &disk_key,
+               sizeof(struct btrfs_disk_key));
+       btrfs_set_item_offset(leaf->items + slot, data_end - data_size);
+       btrfs_set_item_size(leaf->items + slot, data_size);
+       btrfs_set_header_nritems(&leaf->header, nritems + 1);
+
+       ret = 0;
+       if (slot == 0)
+               ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+
+       BUG_ON(list_empty(&leaf_buf->dirty));
+       if (btrfs_leaf_free_space(root, leaf) < 0)
                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;
+       u8 *ptr;
+
+       btrfs_init_path(&path);
+       ret = btrfs_insert_empty_item(trans, root, &path, cpu_key, data_size);
+       if (!ret) {
+               ptr = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0], u8);
+               memcpy(ptr, data, data_size);
+       }
+       btrfs_release_path(root, &path);
+       return ret;
 }
 
 /*
@@ -890,146 +1238,162 @@ int insert_item(struct ctree_root *root, struct key *key,
  * 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;
-       u64 blocknr;
-
-       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);
-               blocknr = t->blocknr;
-               if (node->header.nritems != 0) {
-                       if (slot == 0)
-                               fixup_low_keys(root, path, node->keys,
-                                              level + 1);
-                       break;
-               }
-               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++;
-               free_extent(root, blocknr, 1);
-               if (!path->nodes[level])
-                       BUG();
+       struct btrfs_node *node;
+       struct btrfs_buffer *parent = path->nodes[level];
+       u32 nritems;
+       int ret = 0;
+       int wret;
+
+       node = &parent->node;
+       nritems = btrfs_header_nritems(&node->header);
+       if (slot != nritems -1) {
+               memmove(node->ptrs + slot, node->ptrs + slot + 1,
+                       sizeof(struct btrfs_key_ptr) * (nritems - slot - 1));
        }
-       return 0;
+       nritems--;
+       btrfs_set_header_nritems(&node->header, nritems);
+       if (nritems == 0 && parent == root->node) {
+               BUG_ON(btrfs_header_level(&root->node->node.header) != 1);
+               /* just turn the root into a leaf and break */
+               btrfs_set_header_level(&root->node->node.header, 0);
+       } else if (slot == 0) {
+               wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key,
+                                     level + 1);
+               if (wret)
+                       ret = wret;
+       }
+       BUG_ON(list_empty(&parent->dirty));
+       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 btrfs_leaf *leaf;
+       struct btrfs_buffer *leaf_buf;
        int doff;
        int dsize;
+       int ret = 0;
+       int wret;
+       u32 nritems;
 
        leaf_buf = path->nodes[0];
        leaf = &leaf_buf->leaf;
        slot = path->slots[0];
-       doff = leaf->items[slot].offset;
-       dsize = leaf->items[slot].size;
+       doff = btrfs_item_offset(leaf->items + slot);
+       dsize = btrfs_item_size(leaf->items + slot);
+       nritems = btrfs_header_nritems(&leaf->header);
 
-       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,
+               int data_end = leaf_data_end(root, leaf);
+               memmove(btrfs_leaf_data(leaf) + data_end + dsize,
+                       btrfs_leaf_data(leaf) + data_end,
                        doff - data_end);
-               for (i = slot + 1; i < leaf->header.nritems; i++)
-                       leaf->items[i].offset += dsize;
+               for (i = slot + 1; i < nritems; i++) {
+                       u32 ioff = btrfs_item_offset(leaf->items + i);
+                       btrfs_set_item_offset(leaf->items + i, ioff + dsize);
+               }
                memmove(leaf->items + slot, leaf->items + slot + 1,
-                       sizeof(struct item) *
-                       (leaf->header.nritems - slot - 1));
+                       sizeof(struct btrfs_item) *
+                       (nritems - slot - 1));
        }
-       leaf->header.nritems -= 1;
+       btrfs_set_header_nritems(&leaf->header, nritems - 1);
+       nritems--;
        /* delete the leaf if we've emptied it */
-       if (leaf->header.nritems == 0) {
+       if (nritems == 0) {
                if (leaf_buf == root->node) {
-                       leaf->header.flags = node_level(0);
-                       write_tree_block(root, leaf_buf);
+                       btrfs_set_header_level(&leaf->header, 0);
+                       BUG_ON(list_empty(&leaf_buf->dirty));
                } else {
-                       del_ptr(root, path, 1);
-                       free_extent(root, leaf_buf->blocknr, 1);
+                       clean_tree_block(trans, root, leaf_buf);
+                       wret = del_ptr(trans, root, path, 1, path->slots[1]);
+                       if (wret)
+                               ret = wret;
+                       wret = btrfs_free_extent(trans, root,
+                                                leaf_buf->blocknr, 1, 1);
+                       if (wret)
+                               ret = wret;
                }
        } else {
-               int used = leaf_space_used(leaf, 0, leaf->header.nritems);
-               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) {
+                       wret = fixup_low_keys(trans, root, path,
+                                             &leaf->items[0].key, 1);
+                       if (wret)
+                               ret = wret;
+               }
+               BUG_ON(list_empty(&leaf_buf->dirty));
+
                /* delete the leaf if it is mostly empty */
-               if (used < LEAF_DATA_SIZE / 3) {
+               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)
-                               push_leaf_right(root, path, 1);
-                       if (leaf->header.nritems == 0) {
+                       wret = push_leaf_left(trans, root, path, 1);
+                       if (wret < 0)
+                               ret = wret;
+                       if (path->nodes[0] == leaf_buf &&
+                           btrfs_header_nritems(&leaf->header)) {
+                               wret = push_leaf_right(trans, root, path, 1);
+                               if (wret < 0)
+                                       ret = wret;
+                       }
+                       if (btrfs_header_nritems(&leaf->header) == 0) {
                                u64 blocknr = leaf_buf->blocknr;
-                               path->slots[1] = slot;
-                               del_ptr(root, path, 1);
-                               tree_block_release(root, leaf_buf);
-                               free_extent(root, blocknr, 1);
+                               clean_tree_block(trans, root, leaf_buf);
+                               wret = del_ptr(trans, root, path, 1, slot);
+                               if (wret)
+                                       ret = wret;
+                               btrfs_block_release(root, leaf_buf);
+                               wret = btrfs_free_extent(trans, root, blocknr,
+                                                        1, 1);
+                               if (wret)
+                                       ret = wret;
                        } else {
-                               tree_block_release(root, leaf_buf);
+                               btrfs_block_release(root, leaf_buf);
                        }
                }
        }
-       return 0;
+       return ret;
 }
 
 /*
  * 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 if it found something or 1 if there are no greater leaves.
+ * returns < 0 on io errors.
  */
-int next_leaf(struct ctree_root *root, struct ctree_path *path)
+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 btrfs_buffer *c;
+       struct btrfs_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->node.header)) {
                        level++;
                        continue;
                }
-               blocknr = c->node.blockptrs[slot];
+               blocknr = btrfs_node_blockptr(&c->node, slot);
                if (next)
-                       tree_block_release(root, next);
+                       btrfs_block_release(root, next);
                next = read_tree_block(root, blocknr);
                break;
        }
@@ -1037,173 +1401,13 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path)
        while(1) {
                level--;
                c = path->nodes[level];
-               tree_block_release(root, c);
+               btrfs_block_release(root, c);
                path->nodes[level] = next;
                path->slots[level] = 0;
                if (!level)
                        break;
-               next = read_tree_block(root, next->node.blockptrs[0]);
-       }
-       return 0;
-}
-
-/* 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 = 20000000;
-       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);
-       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);
-               if (i % 10000 == 0)
-                       fprintf(stderr, "insert %d:%d\n", num, i);
-               ins.objectid = num;
-               ins.offset = 0;
-               ins.flags = 0;
-               ret = insert_item(root, &ins, buf, strlen(buf));
-               if (!ret)
-                       tree_size++;
-               free(buf);
-       }
-       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);
-               if (i % 10000 == 0)
-                       fprintf(stderr, "search %d:%d\n", num, i);
-               ret = search_slot(root, &ins, &path, 0);
-               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, -1);
-               if (!ret) {
-                       if (i % 10000 == 0)
-                               fprintf(stderr, "del %d:%d\n", num, i);
-                       ret = del_item(root, &path);
-                       if (ret != 0)
-                               BUG();
-                       tree_size--;
-               }
-               release_path(root, &path);
-       }
-       write_ctree_super(root, &super);
-       close_ctree(root);
-       root = open_ctree("dbfile", &super);
-       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;
-               if (i % 10000 == 0)
-                       fprintf(stderr, "insert %d:%d\n", num, i);
-               ret = insert_item(root, &ins, buf, strlen(buf));
-               if (!ret)
-                       tree_size++;
-               free(buf);
-       }
-       write_ctree_super(root, &super);
-       close_ctree(root);
-       root = open_ctree("dbfile", &super);
-       srand(128);
-       printf("starting search2\n");
-       for (i = 0; i < run_size; i++) {
-               num = next_key(i, max_key);
-               ins.objectid = num;
-               init_path(&path);
-               if (i % 10000 == 0)
-                       fprintf(stderr, "search %d:%d\n", num, i);
-               ret = search_slot(root, &ins, &path, 0);
-               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, -1);
-               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));
-                       if (tree_size % 10000 == 0)
-                               printf("big del %d:%d\n", tree_size, i);
-                       ret = del_item(root, &path);
-                       if (ret != 0) {
-                               printf("del_item returned %d\n", ret);
-                               BUG();
-                       }
-                       tree_size--;
-               }
-               release_path(root, &path);
+               next = read_tree_block(root,
+                                      btrfs_node_blockptr(&next->node, 0));
        }
-       printf("tree size is now %d\n", tree_size);
-       printf("map tree\n");
-       print_tree(root->extent_root, root->extent_root->node);
-       write_ctree_super(root, &super);
-       close_ctree(root);
        return 0;
 }