Btrfs: Replace the big fs_mutex with a collection of other locks
[linux-2.6-block.git] / fs / btrfs / ctree.c
index 74fec6b83a8b2fce59b63a1e5a9a02c9cfded6f4..dff4da082d06bcae80550d9f595033db20f4c1d4 100644 (file)
 #include "disk-io.h"
 #include "transaction.h"
 #include "print-tree.h"
+#include "locking.h"
 
 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_path *path, int level);
 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *ins_key,
-                     struct btrfs_path *path, int data_size);
+                     struct btrfs_path *path, int data_size, int extend);
 static int push_node_left(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, struct extent_buffer *dst,
-                         struct extent_buffer *src);
+                         struct extent_buffer *src, int empty);
 static int balance_node_right(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct extent_buffer *dst_buf,
@@ -62,28 +63,165 @@ void btrfs_free_path(struct btrfs_path *p)
 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
 {
        int i;
+       int skip = p->skip_locking;
+       int keep = p->keep_locks;
+
        for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
                if (!p->nodes[i])
-                       break;
+                       continue;
+               if (p->locks[i]) {
+                       btrfs_tree_unlock(p->nodes[i]);
+                       p->locks[i] = 0;
+               }
                free_extent_buffer(p->nodes[i]);
        }
        memset(p, 0, sizeof(*p));
+       p->skip_locking = skip;
+       p->keep_locks = keep;
+}
+
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
+{
+       struct extent_buffer *eb;
+       spin_lock(&root->node_lock);
+       eb = root->node;
+       extent_buffer_get(eb);
+       spin_unlock(&root->node_lock);
+       return eb;
+}
+
+struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
+{
+       struct extent_buffer *eb;
+
+       while(1) {
+               eb = btrfs_root_node(root);
+               btrfs_tree_lock(eb);
+
+               spin_lock(&root->node_lock);
+               if (eb == root->node) {
+                       spin_unlock(&root->node_lock);
+                       break;
+               }
+               spin_unlock(&root->node_lock);
+
+               btrfs_tree_unlock(eb);
+               free_extent_buffer(eb);
+       }
+       return eb;
+}
+
+static void add_root_to_dirty_list(struct btrfs_root *root)
+{
+       if (root->track_dirty && list_empty(&root->dirty_list)) {
+               list_add(&root->dirty_list,
+                        &root->fs_info->dirty_cowonly_roots);
+       }
+}
+
+int btrfs_copy_root(struct btrfs_trans_handle *trans,
+                     struct btrfs_root *root,
+                     struct extent_buffer *buf,
+                     struct extent_buffer **cow_ret, u64 new_root_objectid)
+{
+       struct extent_buffer *cow;
+       u32 nritems;
+       int ret = 0;
+       int level;
+       struct btrfs_key first_key;
+       struct btrfs_root *new_root;
+
+       new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
+       if (!new_root)
+               return -ENOMEM;
+
+       memcpy(new_root, root, sizeof(*new_root));
+       new_root->root_key.objectid = new_root_objectid;
+
+       WARN_ON(root->ref_cows && trans->transid !=
+               root->fs_info->running_transaction->transid);
+       WARN_ON(root->ref_cows && trans->transid != root->last_trans);
+
+       level = btrfs_header_level(buf);
+       nritems = btrfs_header_nritems(buf);
+       if (nritems) {
+               if (level == 0)
+                       btrfs_item_key_to_cpu(buf, &first_key, 0);
+               else
+                       btrfs_node_key_to_cpu(buf, &first_key, 0);
+       } else {
+               first_key.objectid = 0;
+       }
+       cow = btrfs_alloc_free_block(trans, new_root, buf->len,
+                                      new_root_objectid,
+                                      trans->transid, first_key.objectid,
+                                      level, buf->start, 0);
+       if (IS_ERR(cow)) {
+               kfree(new_root);
+               return PTR_ERR(cow);
+       }
+
+       copy_extent_buffer(cow, buf, 0, 0, cow->len);
+       btrfs_set_header_bytenr(cow, cow->start);
+       btrfs_set_header_generation(cow, trans->transid);
+       btrfs_set_header_owner(cow, new_root_objectid);
+       btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
+
+       WARN_ON(btrfs_header_generation(buf) > trans->transid);
+       ret = btrfs_inc_ref(trans, new_root, buf);
+       kfree(new_root);
+
+       if (ret)
+               return ret;
+
+       btrfs_mark_buffer_dirty(cow);
+       *cow_ret = cow;
+       return 0;
 }
 
-static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
+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)
 {
+       u64 root_gen;
        struct extent_buffer *cow;
+       u32 nritems;
        int ret = 0;
        int different_trans = 0;
+       int level;
+       int unlock_orig = 0;
+       struct btrfs_key first_key;
 
+       if (*cow_ret == buf)
+               unlock_orig = 1;
+
+       WARN_ON(!btrfs_tree_locked(buf));
+
+       if (root->ref_cows) {
+               root_gen = trans->transid;
+       } else {
+               root_gen = 0;
+       }
+       WARN_ON(root->ref_cows && trans->transid !=
+               root->fs_info->running_transaction->transid);
        WARN_ON(root->ref_cows && trans->transid != root->last_trans);
 
+       level = btrfs_header_level(buf);
+       nritems = btrfs_header_nritems(buf);
+       if (nritems) {
+               if (level == 0)
+                       btrfs_item_key_to_cpu(buf, &first_key, 0);
+               else
+                       btrfs_node_key_to_cpu(buf, &first_key, 0);
+       } else {
+               first_key.objectid = 0;
+       }
        cow = btrfs_alloc_free_block(trans, root, buf->len,
+                                    root->root_key.objectid,
+                                    root_gen, first_key.objectid, level,
                                     search_start, empty_size);
        if (IS_ERR(cow))
                return PTR_ERR(cow);
@@ -92,6 +230,7 @@ static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
        btrfs_set_header_bytenr(cow, cow->start);
        btrfs_set_header_generation(cow, trans->transid);
        btrfs_set_header_owner(cow, root->root_key.objectid);
+       btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
 
        WARN_ON(btrfs_header_generation(buf) > trans->transid);
        if (btrfs_header_generation(buf) != trans->transid) {
@@ -104,20 +243,36 @@ static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
        }
 
        if (buf == root->node) {
+               WARN_ON(parent && parent != buf);
+               root_gen = btrfs_header_generation(buf);
+
+               spin_lock(&root->node_lock);
                root->node = cow;
                extent_buffer_get(cow);
+               spin_unlock(&root->node_lock);
+
                if (buf != root->commit_root) {
                        btrfs_free_extent(trans, root, buf->start,
-                                         buf->len, 1);
+                                         buf->len, root->root_key.objectid,
+                                         root_gen, 0, 0, 1);
                }
                free_extent_buffer(buf);
+               add_root_to_dirty_list(root);
        } else {
+               root_gen = btrfs_header_generation(parent);
                btrfs_set_node_blockptr(parent, parent_slot,
                                        cow->start);
+               WARN_ON(trans->transid == 0);
+               btrfs_set_node_ptr_generation(parent, parent_slot,
+                                             trans->transid);
                btrfs_mark_buffer_dirty(parent);
                WARN_ON(btrfs_header_generation(parent) != trans->transid);
-               btrfs_free_extent(trans, root, buf->start, buf->len, 1);
+               btrfs_free_extent(trans, root, buf->start, buf->len,
+                                 btrfs_header_owner(parent), root_gen,
+                                 0, 0, 1);
        }
+       if (unlock_orig)
+               btrfs_tree_unlock(buf);
        free_extent_buffer(buf);
        btrfs_mark_buffer_dirty(cow);
        *cow_ret = cow;
@@ -130,7 +285,9 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans,
                    struct extent_buffer **cow_ret)
 {
        u64 search_start;
+       u64 header_trans;
        int ret;
+
        if (trans->transaction != root->fs_info->running_transaction) {
                printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
                       root->fs_info->running_transaction->transid);
@@ -141,12 +298,17 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans,
                       root->fs_info->generation);
                WARN_ON(1);
        }
-       if (btrfs_header_generation(buf) == trans->transid) {
+
+       header_trans = btrfs_header_generation(buf);
+       spin_lock(&root->fs_info->hash_lock);
+       if (header_trans == trans->transid &&
+           !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
                *cow_ret = buf;
+               spin_unlock(&root->fs_info->hash_lock);
                return 0;
        }
-
-       search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
+       spin_unlock(&root->fs_info->hash_lock);
+       search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
        ret = __btrfs_cow_block(trans, root, buf, parent,
                                 parent_slot, cow_ret, search_start, 0);
        return ret;
@@ -161,34 +323,31 @@ static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
        return 0;
 }
 
-static int should_defrag_leaf(struct extent_buffer *leaf)
+/*
+ * compare two keys in a memcmp fashion
+ */
+static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
 {
-       struct btrfs_key key;
-       u32 nritems;
-
-       if (btrfs_buffer_defrag(leaf))
-               return 1;
+       struct btrfs_key k1;
 
-       nritems = btrfs_header_nritems(leaf);
-       if (nritems == 0)
-               return 0;
+       btrfs_disk_key_to_cpu(&k1, disk);
 
-       btrfs_item_key_to_cpu(leaf, &key, 0);
-       if (key.type == BTRFS_DIR_ITEM_KEY)
+       if (k1.objectid > k2->objectid)
                return 1;
-
-
-       btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
-       if (key.type == BTRFS_DIR_ITEM_KEY)
+       if (k1.objectid < k2->objectid)
+               return -1;
+       if (k1.type > k2->type)
                return 1;
-       if (nritems > 4) {
-               btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
-               if (key.type == BTRFS_DIR_ITEM_KEY)
-                       return 1;
-       }
+       if (k1.type < k2->type)
+               return -1;
+       if (k1.offset > k2->offset)
+               return 1;
+       if (k1.offset < k2->offset)
+               return -1;
        return 0;
 }
 
+
 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct extent_buffer *parent,
                       int start_slot, int cache_only, u64 *last_ret,
@@ -197,6 +356,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
        struct extent_buffer *cur;
        struct extent_buffer *tmp;
        u64 blocknr;
+       u64 gen;
        u64 search_start = *last_ret;
        u64 last_block = 0;
        u64 other;
@@ -207,6 +367,15 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
        int parent_level;
        int uptodate;
        u32 blocksize;
+       int progress_passed = 0;
+       struct btrfs_disk_key disk_key;
+
+       /* FIXME this code needs locking */
+       return 0;
+
+       parent_level = btrfs_header_level(parent);
+       if (cache_only && parent_level != 1)
+               return 0;
 
        if (trans->transaction != root->fs_info->running_transaction) {
                printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
@@ -218,7 +387,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                       root->fs_info->generation);
                WARN_ON(1);
        }
-       parent_level = btrfs_header_level(parent);
 
        parent_nritems = btrfs_header_nritems(parent);
        blocksize = btrfs_level_size(root, parent_level - 1);
@@ -227,27 +395,32 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
        if (parent_nritems == 1)
                return 0;
 
-       if (root != root->fs_info->extent_root) {
-               struct btrfs_key first_key;
-               struct btrfs_key last_key;
-
-               btrfs_node_key_to_cpu(parent, &first_key, 0);
-               btrfs_node_key_to_cpu(parent, &last_key, parent_nritems - 1);
-               if (first_key.objectid != last_key.objectid)
-                       return 0;
-       }
-
        for (i = start_slot; i < end_slot; i++) {
                int close = 1;
 
+               if (!parent->map_token) {
+                       map_extent_buffer(parent,
+                                       btrfs_node_key_ptr_offset(i),
+                                       sizeof(struct btrfs_key_ptr),
+                                       &parent->map_token, &parent->kaddr,
+                                       &parent->map_start, &parent->map_len,
+                                       KM_USER1);
+               }
+               btrfs_node_key(parent, &disk_key, i);
+               if (!progress_passed && comp_keys(&disk_key, progress) < 0)
+                       continue;
+
+               progress_passed = 1;
                blocknr = btrfs_node_blockptr(parent, i);
+               gen = btrfs_node_ptr_generation(parent, i);
                if (last_block == 0)
                        last_block = blocknr;
+
                if (i > 0) {
                        other = btrfs_node_blockptr(parent, i - 1);
                        close = close_blocks(blocknr, other, blocksize);
                }
-               if (close && i < end_slot - 1) {
+               if (!close && i < end_slot - 2) {
                        other = btrfs_node_blockptr(parent, i + 1);
                        close = close_blocks(blocknr, other, blocksize);
                }
@@ -255,24 +428,27 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        last_block = blocknr;
                        continue;
                }
+               if (parent->map_token) {
+                       unmap_extent_buffer(parent, parent->map_token,
+                                           KM_USER1);
+                       parent->map_token = NULL;
+               }
 
                cur = btrfs_find_tree_block(root, blocknr, blocksize);
                if (cur)
-                       uptodate = btrfs_buffer_uptodate(cur);
+                       uptodate = btrfs_buffer_uptodate(cur, gen);
                else
                        uptodate = 0;
-               if (!cur || !uptodate ||
-                   (parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
-                   (parent_level == 1 && !should_defrag_leaf(cur))) {
+               if (!cur || !uptodate) {
                        if (cache_only) {
                                free_extent_buffer(cur);
                                continue;
                        }
                        if (!cur) {
                                cur = read_tree_block(root, blocknr,
-                                                        blocksize);
+                                                        blocksize, gen);
                        } else if (!uptodate) {
-                               btrfs_read_buffer(cur);
+                               btrfs_read_buffer(cur, gen);
                        }
                }
                if (search_start == 0)
@@ -287,11 +463,17 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        break;
                }
                search_start = tmp->start;
+               last_block = tmp->start;
                *last_ret = search_start;
                if (parent_level == 1)
                        btrfs_clear_buffer_defrag(tmp);
                free_extent_buffer(tmp);
        }
+       if (parent->map_token) {
+               unmap_extent_buffer(parent, parent->map_token,
+                                   KM_USER1);
+               parent->map_token = NULL;
+       }
        return err;
 }
 
@@ -309,30 +491,6 @@ static inline unsigned int leaf_data_end(struct btrfs_root *root,
        return btrfs_item_offset_nr(leaf, nr - 1);
 }
 
-/*
- * compare two keys in a memcmp fashion
- */
-static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
-{
-       struct btrfs_key k1;
-
-       btrfs_disk_key_to_cpu(&k1, disk);
-
-       if (k1.objectid > k2->objectid)
-               return 1;
-       if (k1.objectid < k2->objectid)
-               return -1;
-       if (k1.type > k2->type)
-               return 1;
-       if (k1.type < k2->type)
-               return -1;
-       if (k1.offset > k2->offset)
-               return 1;
-       if (k1.offset < k2->offset)
-               return -1;
-       return 0;
-}
-
 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
                      int level)
 {
@@ -466,10 +624,20 @@ static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
        return 0;
 }
 
-static int check_block(struct btrfs_root *root, struct btrfs_path *path,
-                       int level)
+static int noinline check_block(struct btrfs_root *root,
+                               struct btrfs_path *path, int level)
 {
+       u64 found_start;
        return 0;
+       if (btrfs_header_level(path->nodes[level]) != level)
+           printk("warning: bad level %Lu wanted %d found %d\n",
+                  path->nodes[level]->start, level,
+                  btrfs_header_level(path->nodes[level]));
+       found_start = btrfs_header_bytenr(path->nodes[level]);
+       if (found_start != path->nodes[level]->start) {
+           printk("warning: bad bytentr %Lu found %Lu\n",
+                  path->nodes[level]->start, found_start);
+       }
 #if 0
        struct extent_buffer *buf = path->nodes[level];
 
@@ -586,16 +754,22 @@ static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
                                   struct extent_buffer *parent, int slot)
 {
+       int level = btrfs_header_level(parent);
        if (slot < 0)
                return NULL;
        if (slot >= btrfs_header_nritems(parent))
                return NULL;
+
+       BUG_ON(level == 0);
+
        return read_tree_block(root, btrfs_node_blockptr(parent, slot),
-                      btrfs_level_size(root, btrfs_header_level(parent) - 1));
+                      btrfs_level_size(root, level - 1),
+                      btrfs_node_ptr_generation(parent, slot));
 }
 
-static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
-                        *root, struct btrfs_path *path, int level)
+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;
@@ -612,6 +786,9 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
                return 0;
 
        mid = path->nodes[level];
+       WARN_ON(!path->locks[level]);
+       WARN_ON(btrfs_header_generation(mid) != trans->transid);
+
        orig_ptr = btrfs_node_blockptr(mid, orig_slot);
 
        if (level < BTRFS_MAX_LEVEL - 1)
@@ -630,14 +807,26 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 
                /* promote the child to a root */
                child = read_node_slot(root, mid, 0);
+               btrfs_tree_lock(child);
                BUG_ON(!child);
+               ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
+               BUG_ON(ret);
+
+               spin_lock(&root->node_lock);
                root->node = child;
+               spin_unlock(&root->node_lock);
+
+               add_root_to_dirty_list(root);
+               btrfs_tree_unlock(child);
+               path->locks[level] = 0;
                path->nodes[level] = NULL;
                clean_tree_block(trans, root, mid);
-               wait_on_tree_block_writeback(root, mid);
+               btrfs_tree_unlock(mid);
                /* once for the path */
                free_extent_buffer(mid);
-               ret = btrfs_free_extent(trans, root, mid->start, mid->len, 1);
+               ret = btrfs_free_extent(trans, root, mid->start, mid->len,
+                                       root->root_key.objectid,
+                                       btrfs_header_generation(mid), 0, 0, 1);
                /* once for the root ptr */
                free_extent_buffer(mid);
                return ret;
@@ -651,6 +840,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 
        left = read_node_slot(root, parent, pslot - 1);
        if (left) {
+               btrfs_tree_lock(left);
                wret = btrfs_cow_block(trans, root, left,
                                       parent, pslot - 1, &left);
                if (wret) {
@@ -660,6 +850,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
        }
        right = read_node_slot(root, parent, pslot + 1);
        if (right) {
+               btrfs_tree_lock(right);
                wret = btrfs_cow_block(trans, root, right,
                                       parent, pslot + 1, &right);
                if (wret) {
@@ -671,7 +862,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
        /* 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);
+               wret = push_node_left(trans, root, left, mid, 1);
                if (wret < 0)
                        ret = wret;
                if (btrfs_header_nritems(mid) < 2)
@@ -682,15 +873,16 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
         * then try to empty the right most buffer into the middle
         */
        if (right) {
-               wret = push_node_left(trans, root, mid, right);
+               wret = push_node_left(trans, root, mid, right, 1);
                if (wret < 0 && wret != -ENOSPC)
                        ret = wret;
                if (btrfs_header_nritems(right) == 0) {
                        u64 bytenr = right->start;
+                       u64 generation = btrfs_header_generation(parent);
                        u32 blocksize = right->len;
 
                        clean_tree_block(trans, root, right);
-                       wait_on_tree_block_writeback(root, right);
+                       btrfs_tree_unlock(right);
                        free_extent_buffer(right);
                        right = NULL;
                        wret = del_ptr(trans, root, path, level + 1, pslot +
@@ -698,7 +890,9 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
                        if (wret)
                                ret = wret;
                        wret = btrfs_free_extent(trans, root, bytenr,
-                                                blocksize, 1);
+                                                blocksize,
+                                                btrfs_header_owner(parent),
+                                                generation, 0, 0, 1);
                        if (wret)
                                ret = wret;
                } else {
@@ -724,20 +918,29 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
                        ret = wret;
                        goto enospc;
                }
+               if (wret == 1) {
+                       wret = push_node_left(trans, root, left, mid, 1);
+                       if (wret < 0)
+                               ret = wret;
+               }
                BUG_ON(wret == 1);
        }
        if (btrfs_header_nritems(mid) == 0) {
                /* we've managed to empty the middle node, drop it */
+               u64 root_gen = btrfs_header_generation(parent);
                u64 bytenr = mid->start;
                u32 blocksize = mid->len;
+
                clean_tree_block(trans, root, mid);
-               wait_on_tree_block_writeback(root, mid);
+               btrfs_tree_unlock(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, bytenr, blocksize, 1);
+               wret = btrfs_free_extent(trans, root, bytenr, blocksize,
+                                        btrfs_header_owner(parent),
+                                        root_gen, 0, 0, 1);
                if (wret)
                        ret = wret;
        } else {
@@ -752,11 +955,14 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
        if (left) {
                if (btrfs_header_nritems(left) > orig_slot) {
                        extent_buffer_get(left);
+                       /* left was locked after cow */
                        path->nodes[level] = left;
                        path->slots[level + 1] -= 1;
                        path->slots[level] = orig_slot;
-                       if (mid)
+                       if (mid) {
+                               btrfs_tree_unlock(mid);
                                free_extent_buffer(mid);
+                       }
                } else {
                        orig_slot -= btrfs_header_nritems(left);
                        path->slots[level] = orig_slot;
@@ -768,17 +974,22 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
            btrfs_node_blockptr(path->nodes[level], path->slots[level]))
                BUG();
 enospc:
-       if (right)
+       if (right) {
+               btrfs_tree_unlock(right);
                free_extent_buffer(right);
-       if (left)
+       }
+       if (left) {
+               if (path->nodes[level] != left)
+                       btrfs_tree_unlock(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)
+static int noinline 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;
@@ -794,6 +1005,7 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                return 1;
 
        mid = path->nodes[level];
+       WARN_ON(btrfs_header_generation(mid) != trans->transid);
        orig_ptr = btrfs_node_blockptr(mid, orig_slot);
 
        if (level < BTRFS_MAX_LEVEL - 1)
@@ -808,6 +1020,8 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
        /* first, try to make some room in the middle buffer */
        if (left) {
                u32 left_nr;
+
+               btrfs_tree_lock(left);
                left_nr = btrfs_header_nritems(left);
                if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                        wret = 1;
@@ -818,7 +1032,7 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                                wret = 1;
                        else {
                                wret = push_node_left(trans, root,
-                                                     left, mid);
+                                                     left, mid, 0);
                        }
                }
                if (wret < 0)
@@ -833,24 +1047,28 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                                path->nodes[level] = left;
                                path->slots[level + 1] -= 1;
                                path->slots[level] = orig_slot;
+                               btrfs_tree_unlock(mid);
                                free_extent_buffer(mid);
                        } else {
                                orig_slot -=
                                        btrfs_header_nritems(left);
                                path->slots[level] = orig_slot;
+                               btrfs_tree_unlock(left);
                                free_extent_buffer(left);
                        }
                        return 0;
                }
+               btrfs_tree_unlock(left);
                free_extent_buffer(left);
        }
-       right= read_node_slot(root, parent, pslot + 1);
+       right = read_node_slot(root, parent, pslot + 1);
 
        /*
         * then try to empty the right most buffer into the middle
         */
        if (right) {
                u32 right_nr;
+               btrfs_tree_lock(right);
                right_nr = btrfs_header_nritems(right);
                if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                        wret = 1;
@@ -879,12 +1097,15 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                                path->slots[level + 1] += 1;
                                path->slots[level] = orig_slot -
                                        btrfs_header_nritems(mid);
+                               btrfs_tree_unlock(mid);
                                free_extent_buffer(mid);
                        } else {
+                               btrfs_tree_unlock(right);
                                free_extent_buffer(right);
                        }
                        return 0;
                }
+               btrfs_tree_unlock(right);
                free_extent_buffer(right);
        }
        return 1;
@@ -894,9 +1115,10 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
  * readahead one full node of leaves
  */
 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
-                            int level, int slot)
+                            int level, int slot, u64 objectid)
 {
        struct extent_buffer *node;
+       struct btrfs_disk_key disk_key;
        u32 nritems;
        u64 search;
        u64 lowest_read;
@@ -915,6 +1137,8 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
                return;
 
        node = path->nodes[level];
+       WARN_ON(!path->skip_locking && !btrfs_tree_locked(node));
+
        search = btrfs_node_blockptr(node, slot);
        blocksize = btrfs_level_size(root, level - 1);
        eb = btrfs_find_tree_block(root, search, blocksize);
@@ -938,11 +1162,17 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
                        if (nr >= nritems)
                                break;
                }
+               if (path->reada < 0 && objectid) {
+                       btrfs_node_key(node, &disk_key, nr);
+                       if (btrfs_disk_key_objectid(&disk_key) != objectid)
+                               break;
+               }
                search = btrfs_node_blockptr(node, nr);
                if ((search >= lowest_read && search <= highest_read) ||
                    (search < lowest_read && lowest_read - search <= 32768) ||
                    (search > highest_read && search - highest_read <= 32768)) {
-                       readahead_tree_block(root, search, blocksize);
+                       readahead_tree_block(root, search, blocksize,
+                                    btrfs_node_ptr_generation(node, nr));
                        nread += blocksize;
                }
                nscan++;
@@ -957,6 +1187,45 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
                        highest_read = search;
        }
 }
+
+static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock)
+{
+       int i;
+       int skip_level = level;
+       struct extent_buffer *t;
+
+       for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+               if (!path->nodes[i])
+                       break;
+               if (!path->locks[i])
+                       break;
+               if (path->slots[i] == 0) {
+                       skip_level = i + 1;
+                       continue;
+               }
+               if (path->keep_locks) {
+                       u32 nritems;
+                       t = path->nodes[i];
+                       nritems = btrfs_header_nritems(t);
+                       if (nritems < 2 || path->slots[i] >= nritems - 2) {
+if (path->keep_locks) {
+//printk("path %p skip level now %d\n", path, skip_level);
+}
+                               skip_level = i + 1;
+                               continue;
+                       }
+               }
+               t = path->nodes[i];
+               if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
+if (path->keep_locks) {
+//printk("path %p unlocking level %d slot %d nritems %d skip_level %d\n", path, i, path->slots[i], btrfs_header_nritems(t), skip_level);
+}
+                       btrfs_tree_unlock(t);
+                       path->locks[i] = 0;
+               }
+       }
+}
+
 /*
  * 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
@@ -975,20 +1244,30 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
                      ins_len, int cow)
 {
        struct extent_buffer *b;
-       u64 bytenr;
        int slot;
        int ret;
        int level;
        int should_reada = p->reada;
+       int lowest_unlock = 1;
        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));
+       WARN_ON(root == root->fs_info->extent_root &&
+               !mutex_is_locked(&root->fs_info->alloc_mutex));
+       WARN_ON(root == root->fs_info->chunk_root &&
+               !mutex_is_locked(&root->fs_info->chunk_mutex));
+       WARN_ON(root == root->fs_info->dev_root &&
+               !mutex_is_locked(&root->fs_info->chunk_mutex));
+       if (ins_len < 0)
+               lowest_unlock = 2;
 again:
-       b = root->node;
-       extent_buffer_get(b);
+       if (!p->skip_locking)
+               b = btrfs_lock_root_node(root);
+       else
+               b = btrfs_root_node(root);
+
        while (b) {
                level = btrfs_header_level(b);
                if (cow) {
@@ -1007,16 +1286,19 @@ again:
                        WARN_ON(1);
                level = btrfs_header_level(b);
                p->nodes[level] = b;
+               if (!p->skip_locking)
+                       p->locks[level] = 1;
                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;
                        if (ins_len > 0 && btrfs_header_nritems(b) >=
-                           BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
+                           BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
                                int sret = split_node(trans, root, p, level);
                                BUG_ON(sret > 0);
                                if (sret)
@@ -1037,23 +1319,30 @@ again:
                                BUG_ON(btrfs_header_nritems(b) == 1);
                        }
                        /* this is only true while dropping a snapshot */
-                       if (level == lowest_level)
+                       if (level == lowest_level) {
+                               unlock_up(p, level, lowest_unlock);
                                break;
-                       bytenr = btrfs_node_blockptr(b, slot);
+                       }
+
                        if (should_reada)
-                               reada_for_search(root, p, level, slot);
-                       b = read_tree_block(root, bytenr,
-                                           btrfs_level_size(root, level - 1));
+                               reada_for_search(root, p, level, slot,
+                                                key->objectid);
+
+                       b = read_node_slot(root, b, slot);
+                       if (!p->skip_locking)
+                               btrfs_tree_lock(b);
+                       unlock_up(p, level + 1, lowest_unlock);
                } 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);
+                                                     p, ins_len, ret == 0);
                                BUG_ON(sret > 0);
                                if (sret)
                                        return sret;
                        }
+                       unlock_up(p, level, lowest_unlock);
                        return ret;
                }
        }
@@ -1084,6 +1373,13 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans,
                        break;
                t = path->nodes[i];
                btrfs_set_node_key(t, key, tslot);
+               if (!btrfs_tree_locked(path->nodes[i])) {
+                       int ii;
+printk("fixup without lock on level %d\n", btrfs_header_level(path->nodes[i]));
+                       for (ii = 0; ii < BTRFS_MAX_LEVEL; ii++) {
+printk("level %d slot %d\n", ii, path->slots[ii]);
+                       }
+               }
                btrfs_mark_buffer_dirty(path->nodes[i]);
                if (tslot != 0)
                        break;
@@ -1098,9 +1394,9 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans,
  * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
  * error, and > 0 if there was no room in the left hand block.
  */
-static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
-                         *root, struct extent_buffer *dst,
-                         struct extent_buffer *src)
+static int push_node_left(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root, struct extent_buffer *dst,
+                         struct extent_buffer *src, int empty)
 {
        int push_items = 0;
        int src_nritems;
@@ -1110,13 +1406,30 @@ static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
        src_nritems = btrfs_header_nritems(src);
        dst_nritems = btrfs_header_nritems(dst);
        push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
+       WARN_ON(btrfs_header_generation(src) != trans->transid);
+       WARN_ON(btrfs_header_generation(dst) != trans->transid);
+
+       if (!empty && src_nritems <= 8)
+               return 1;
 
        if (push_items <= 0) {
                return 1;
        }
 
-       if (src_nritems < push_items)
-               push_items = src_nritems;
+       if (empty) {
+               push_items = min(src_nritems, push_items);
+               if (push_items < src_nritems) {
+                       /* leave at least 8 pointers in the node if
+                        * we aren't going to empty it
+                        */
+                       if (src_nritems - push_items < 8) {
+                               if (push_items <= 8)
+                                       return 1;
+                               push_items -= 8;
+                       }
+               }
+       } else
+               push_items = min(src_nritems - 8, push_items);
 
        copy_extent_buffer(dst, src,
                           btrfs_node_key_ptr_offset(dst_nritems),
@@ -1156,16 +1469,25 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
        int dst_nritems;
        int ret = 0;
 
+       WARN_ON(btrfs_header_generation(src) != trans->transid);
+       WARN_ON(btrfs_header_generation(dst) != trans->transid);
+
        src_nritems = btrfs_header_nritems(src);
        dst_nritems = btrfs_header_nritems(dst);
        push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
-       if (push_items <= 0)
+       if (push_items <= 0) {
+               return 1;
+       }
+
+       if (src_nritems < 4) {
                return 1;
+       }
 
        max_push = src_nritems / 2 + 1;
        /* don't try to empty the node */
-       if (max_push >= src_nritems)
+       if (max_push >= src_nritems) {
                return 1;
+       }
 
        if (max_push < push_items)
                push_items = max_push;
@@ -1195,47 +1517,89 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
  *
  * returns zero on success or < 0 on failure.
  */
-static int insert_new_root(struct btrfs_trans_handle *trans,
+static int noinline insert_new_root(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           struct btrfs_path *path, int level)
 {
+       u64 root_gen;
+       u64 lower_gen;
        struct extent_buffer *lower;
        struct extent_buffer *c;
+       struct extent_buffer *old;
        struct btrfs_disk_key lower_key;
 
        BUG_ON(path->nodes[level]);
        BUG_ON(path->nodes[level-1] != root->node);
 
+       if (root->ref_cows)
+               root_gen = trans->transid;
+       else
+               root_gen = 0;
+
+       lower = path->nodes[level-1];
+       if (level == 1)
+               btrfs_item_key(lower, &lower_key, 0);
+       else
+               btrfs_node_key(lower, &lower_key, 0);
+
        c = btrfs_alloc_free_block(trans, root, root->nodesize,
+                                  root->root_key.objectid,
+                                  root_gen, lower_key.objectid, level,
                                   root->node->start, 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_bytenr(c, c->start);
        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);
+
+       write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
+                           (unsigned long)btrfs_header_chunk_tree_uuid(c),
+                           BTRFS_UUID_SIZE);
+
        btrfs_set_node_key(c, &lower_key, 0);
        btrfs_set_node_blockptr(c, 0, lower->start);
+       lower_gen = btrfs_header_generation(lower);
+       WARN_ON(lower_gen == 0);
+
+       btrfs_set_node_ptr_generation(c, 0, lower_gen);
 
        btrfs_mark_buffer_dirty(c);
 
-       /* the super has an extra ref to root->node */
-       free_extent_buffer(root->node);
+       spin_lock(&root->node_lock);
+       old = root->node;
        root->node = c;
+       spin_unlock(&root->node_lock);
+
+       /* the super has an extra ref to root->node */
+       free_extent_buffer(old);
+
+       add_root_to_dirty_list(root);
        extent_buffer_get(c);
        path->nodes[level] = c;
+       path->locks[level] = 1;
        path->slots[level] = 0;
+
+       if (root->ref_cows && lower_gen != trans->transid) {
+               struct btrfs_path *back_path = btrfs_alloc_path();
+               int ret;
+               mutex_lock(&root->fs_info->alloc_mutex);
+               ret = btrfs_insert_extent_backref(trans,
+                                                 root->fs_info->extent_root,
+                                                 path, lower->start,
+                                                 root->root_key.objectid,
+                                                 trans->transid, 0, 0);
+               BUG_ON(ret);
+               mutex_unlock(&root->fs_info->alloc_mutex);
+               btrfs_free_path(back_path);
+       }
        return 0;
 }
 
@@ -1270,6 +1634,8 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
        }
        btrfs_set_node_key(lower, key, slot);
        btrfs_set_node_blockptr(lower, slot, bytenr);
+       WARN_ON(trans->transid == 0);
+       btrfs_set_node_ptr_generation(lower, slot, trans->transid);
        btrfs_set_header_nritems(lower, nritems + 1);
        btrfs_mark_buffer_dirty(lower);
        return 0;
@@ -1287,6 +1653,7 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_path *path, int level)
 {
+       u64 root_gen;
        struct extent_buffer *c;
        struct extent_buffer *split;
        struct btrfs_disk_key disk_key;
@@ -1296,6 +1663,7 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
        u32 c_nritems;
 
        c = path->nodes[level];
+       WARN_ON(btrfs_header_generation(c) != trans->transid);
        if (c == root->node) {
                /* trying to split the root, lets make a new one */
                ret = insert_new_root(trans, root, path, level + 1);
@@ -1305,15 +1673,24 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
                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)
+                   BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
                        return 0;
                if (ret < 0)
                        return ret;
        }
 
        c_nritems = btrfs_header_nritems(c);
+       if (root->ref_cows)
+               root_gen = trans->transid;
+       else
+               root_gen = 0;
+
+       btrfs_node_key(c, &disk_key, 0);
        split = btrfs_alloc_free_block(trans, root, root->nodesize,
-                                      c->start, 0);
+                                        root->root_key.objectid,
+                                        root_gen,
+                                        btrfs_disk_key_objectid(&disk_key),
+                                        level, c->start, 0);
        if (IS_ERR(split))
                return PTR_ERR(split);
 
@@ -1322,9 +1699,13 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
        btrfs_set_header_bytenr(split, split->start);
        btrfs_set_header_generation(split, trans->transid);
        btrfs_set_header_owner(split, root->root_key.objectid);
+       btrfs_set_header_flags(split, 0);
        write_extent_buffer(split, root->fs_info->fsid,
                            (unsigned long)btrfs_header_fsid(split),
                            BTRFS_FSID_SIZE);
+       write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
+                           (unsigned long)btrfs_header_chunk_tree_uuid(split),
+                           BTRFS_UUID_SIZE);
 
        mid = (c_nritems + 1) / 2;
 
@@ -1348,10 +1729,12 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
 
        if (path->slots[level] >= mid) {
                path->slots[level] -= mid;
+               btrfs_tree_unlock(c);
                free_extent_buffer(c);
                path->nodes[level] = split;
                path->slots[level + 1] += 1;
        } else {
+               btrfs_tree_unlock(split);
                free_extent_buffer(split);
        }
        return ret;
@@ -1389,7 +1772,7 @@ int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
        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),
+                      ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
                       leaf_space_used(leaf, 0, nritems), nritems);
        }
        return ret;
@@ -1403,19 +1786,21 @@ int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
  * 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)
+                          *root, struct btrfs_path *path, int data_size,
+                          int empty)
 {
        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;
+       u32 i;
        int free_space;
        int push_space = 0;
        int push_items = 0;
        struct btrfs_item *item;
        u32 left_nritems;
+       u32 nr;
        u32 right_nritems;
        u32 data_end;
        u32 this_item_size;
@@ -1429,34 +1814,35 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
        if (slot >= btrfs_header_nritems(upper) - 1)
                return 1;
 
-       right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
-                               root->leafsize);
+       WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+
+       right = read_node_slot(root, upper, slot + 1);
+       btrfs_tree_lock(right);
        free_space = btrfs_leaf_free_space(root, right);
-       if (free_space < data_size + sizeof(struct btrfs_item)) {
-               free_extent_buffer(right);
-               return 1;
-       }
+       if (free_space < data_size + sizeof(struct btrfs_item))
+               goto out_unlock;
 
        /* cow and double check */
        ret = btrfs_cow_block(trans, root, right, upper,
                              slot + 1, &right);
-       if (ret) {
-               free_extent_buffer(right);
-               return 1;
-       }
+       if (ret)
+               goto out_unlock;
+
        free_space = btrfs_leaf_free_space(root, right);
-       if (free_space < data_size + sizeof(struct btrfs_item)) {
-               free_extent_buffer(right);
-               return 1;
-       }
+       if (free_space < data_size + sizeof(struct btrfs_item))
+               goto out_unlock;
 
        left_nritems = btrfs_header_nritems(left);
-       if (left_nritems == 0) {
-               free_extent_buffer(right);
-               return 1;
-       }
+       if (left_nritems == 0)
+               goto out_unlock;
 
-       for (i = left_nritems - 1; i >= 1; i--) {
+       if (empty)
+               nr = 0;
+       else
+               nr = 1;
+
+       i = left_nritems - 1;
+       while (i >= nr) {
                item = btrfs_item_nr(left, i);
 
                if (path->slots[0] == i)
@@ -1475,22 +1861,24 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
                        break;
                push_items++;
                push_space += this_item_size + sizeof(*item);
+               if (i == 0)
+                       break;
+               i--;
        }
        if (left->map_token) {
                unmap_extent_buffer(left, left->map_token, KM_USER1);
                left->map_token = NULL;
        }
 
-       if (push_items == 0) {
-               free_extent_buffer(right);
-               return 1;
-       }
+       if (push_items == 0)
+               goto out_unlock;
 
-       if (push_items == left_nritems)
+       if (!empty && push_items == left_nritems)
                WARN_ON(1);
 
        /* push left to right */
        right_nritems = btrfs_header_nritems(right);
+
        push_space = btrfs_item_end_nr(left, left_nritems - push_items);
        push_space -= leaf_data_end(root, left);
 
@@ -1520,7 +1908,6 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
        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);
                if (!right->map_token) {
@@ -1541,7 +1928,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
        left_nritems -= push_items;
        btrfs_set_header_nritems(left, left_nritems);
 
-       btrfs_mark_buffer_dirty(left);
+       if (left_nritems)
+               btrfs_mark_buffer_dirty(left);
        btrfs_mark_buffer_dirty(right);
 
        btrfs_item_key(right, &disk_key, 0);
@@ -1551,20 +1939,31 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
        /* then fixup the leaf pointer in the path */
        if (path->slots[0] >= left_nritems) {
                path->slots[0] -= left_nritems;
+               if (btrfs_header_nritems(path->nodes[0]) == 0)
+                       clean_tree_block(trans, root, path->nodes[0]);
+               btrfs_tree_unlock(path->nodes[0]);
                free_extent_buffer(path->nodes[0]);
                path->nodes[0] = right;
                path->slots[1] += 1;
        } else {
+               btrfs_tree_unlock(right);
                free_extent_buffer(right);
        }
        return 0;
+
+out_unlock:
+       btrfs_tree_unlock(right);
+       free_extent_buffer(right);
+       return 1;
 }
+
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
  */
 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-                         *root, struct btrfs_path *path, int data_size)
+                         *root, struct btrfs_path *path, int data_size,
+                         int empty)
 {
        struct btrfs_disk_key disk_key;
        struct extent_buffer *right = path->nodes[0];
@@ -1577,6 +1976,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        struct btrfs_item *item;
        u32 old_left_nritems;
        u32 right_nritems;
+       u32 nr;
        int ret = 0;
        int wret;
        u32 this_item_size;
@@ -1588,12 +1988,19 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        if (!path->nodes[1])
                return 1;
 
-       left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
-                              slot - 1), root->leafsize);
+       right_nritems = btrfs_header_nritems(right);
+       if (right_nritems == 0) {
+               return 1;
+       }
+
+       WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+
+       left = read_node_slot(root, path->nodes[1], slot - 1);
+       btrfs_tree_lock(left);
        free_space = btrfs_leaf_free_space(root, left);
        if (free_space < data_size + sizeof(struct btrfs_item)) {
-               free_extent_buffer(left);
-               return 1;
+               ret = 1;
+               goto out;
        }
 
        /* cow and double check */
@@ -1601,22 +2008,22 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
                              path->nodes[1], slot - 1, &left);
        if (ret) {
                /* we hit -ENOSPC, but it isn't fatal here */
-               free_extent_buffer(left);
-               return 1;
+               ret = 1;
+               goto out;
        }
+
        free_space = btrfs_leaf_free_space(root, left);
        if (free_space < data_size + sizeof(struct btrfs_item)) {
-               free_extent_buffer(left);
-               return 1;
+               ret = 1;
+               goto out;
        }
 
-       right_nritems = btrfs_header_nritems(right);
-       if (right_nritems == 0) {
-               free_extent_buffer(left);
-               return 1;
-       }
+       if (empty)
+               nr = right_nritems;
+       else
+               nr = right_nritems - 1;
 
-       for (i = 0; i < right_nritems - 1; i++) {
+       for (i = 0; i < nr; i++) {
                item = btrfs_item_nr(right, i);
                if (!right->map_token) {
                        map_extent_buffer(right, (unsigned long)item,
@@ -1643,10 +2050,10 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        }
 
        if (push_items == 0) {
-               free_extent_buffer(left);
-               return 1;
+               ret = 1;
+               goto out;
        }
-       if (push_items == btrfs_header_nritems(right))
+       if (!empty && push_items == btrfs_header_nritems(right))
                WARN_ON(1);
 
        /* push data from right to left */
@@ -1690,22 +2097,27 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        }
 
        /* fixup right node */
-       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),
+       if (push_items > right_nritems) {
+               printk("push items %d nr %u\n", push_items, right_nritems);
+               WARN_ON(1);
+       }
+
+       if (push_items < right_nritems) {
+               push_space = btrfs_item_offset_nr(right, push_items - 1) -
+                                                 leaf_data_end(root, right);
+               memmove_extent_buffer(right, btrfs_leaf_data(right) +
+                                     BTRFS_LEAF_DATA_SIZE(root) - push_space,
+                                     btrfs_leaf_data(right) +
+                                     leaf_data_end(root, right), push_space);
+
+               memmove_extent_buffer(right, btrfs_item_nr_offset(0),
                              btrfs_item_nr_offset(push_items),
                             (btrfs_header_nritems(right) - push_items) *
                             sizeof(struct btrfs_item));
-
-       right_nritems = btrfs_header_nritems(right) - push_items;
+       }
+       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);
 
@@ -1726,7 +2138,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        }
 
        btrfs_mark_buffer_dirty(left);
-       btrfs_mark_buffer_dirty(right);
+       if (right_nritems)
+               btrfs_mark_buffer_dirty(right);
 
        btrfs_item_key(right, &disk_key, 0);
        wret = fixup_low_keys(trans, root, path, &disk_key, 1);
@@ -1736,15 +2149,23 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
        /* then fixup the leaf pointer in the path */
        if (path->slots[0] < push_items) {
                path->slots[0] += old_left_nritems;
+               if (btrfs_header_nritems(path->nodes[0]) == 0)
+                       clean_tree_block(trans, root, path->nodes[0]);
+               btrfs_tree_unlock(path->nodes[0]);
                free_extent_buffer(path->nodes[0]);
                path->nodes[0] = left;
                path->slots[1] -= 1;
        } else {
+               btrfs_tree_unlock(left);
                free_extent_buffer(left);
                path->slots[0] -= push_items;
        }
        BUG_ON(path->slots[0] < 0);
        return ret;
+out:
+       btrfs_tree_unlock(left);
+       free_extent_buffer(left);
+       return ret;
 }
 
 /*
@@ -1755,8 +2176,9 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
  */
 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 btrfs_path *path, int data_size, int extend)
 {
+       u64 root_gen;
        struct extent_buffer *l;
        u32 nritems;
        int mid;
@@ -1768,25 +2190,34 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        int i;
        int ret = 0;
        int wret;
-       int double_split = 0;
+       int double_split;
+       int num_doubles = 0;
        struct btrfs_disk_key disk_key;
 
+       if (extend)
+               space_needed = data_size;
+
+       if (root->ref_cows)
+               root_gen = trans->transid;
+       else
+               root_gen = 0;
+
        /* 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)
+       if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
+               wret = push_leaf_right(trans, root, path, data_size, 0);
+               if (wret < 0) {
                        return wret;
-       }
-       l = path->nodes[0];
+               }
+               if (wret) {
+                       wret = push_leaf_left(trans, root, path, data_size, 0);
+                       if (wret < 0)
+                               return wret;
+               }
+               l = path->nodes[0];
 
-       /* did the pushes work? */
-       if (btrfs_leaf_free_space(root, l) >=
-           sizeof(struct btrfs_item) + data_size) {
-               return 0;
+               /* did the pushes work? */
+               if (btrfs_leaf_free_space(root, l) >= space_needed)
+                       return 0;
        }
 
        if (!path->nodes[1]) {
@@ -1794,14 +2225,23 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                if (ret)
                        return ret;
        }
+again:
+       double_split = 0;
+       l = path->nodes[0];
        slot = path->slots[0];
        nritems = btrfs_header_nritems(l);
        mid = (nritems + 1)/ 2;
 
+       btrfs_item_key(l, &disk_key, 0);
+
        right = btrfs_alloc_free_block(trans, root, root->leafsize,
-                                      l->start, 0);
-       if (IS_ERR(right))
+                                        root->root_key.objectid,
+                                        root_gen, disk_key.objectid, 0,
+                                        l->start, 0);
+       if (IS_ERR(right)) {
+               BUG_ON(1);
                return PTR_ERR(right);
+       }
 
        memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
        btrfs_set_header_bytenr(right, right->start);
@@ -1812,6 +2252,9 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                            (unsigned long)btrfs_header_fsid(right),
                            BTRFS_FSID_SIZE);
 
+       write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
+                           (unsigned long)btrfs_header_chunk_tree_uuid(right),
+                           BTRFS_UUID_SIZE);
        if (mid <= slot) {
                if (nritems == 1 ||
                    leaf_space_used(l, mid, nritems - mid) + space_needed >
@@ -1824,10 +2267,13 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                                  path->slots[1] + 1, 1);
                                if (wret)
                                        ret = wret;
+
+                               btrfs_tree_unlock(path->nodes[0]);
                                free_extent_buffer(path->nodes[0]);
                                path->nodes[0] = right;
                                path->slots[0] = 0;
                                path->slots[1] += 1;
+                               btrfs_mark_buffer_dirty(right);
                                return ret;
                        }
                        mid = slot;
@@ -1840,7 +2286,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        } else {
                if (leaf_space_used(l, 0, mid + 1) + space_needed >
                        BTRFS_LEAF_DATA_SIZE(root)) {
-                       if (slot == 0) {
+                       if (!extend && slot == 0) {
                                btrfs_cpu_key_to_disk(&disk_key, ins_key);
                                btrfs_set_header_nritems(right, 0);
                                wret = insert_ptr(trans, root, path,
@@ -1849,6 +2295,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                                  path->slots[1], 1);
                                if (wret)
                                        ret = wret;
+                               btrfs_tree_unlock(path->nodes[0]);
                                free_extent_buffer(path->nodes[0]);
                                path->nodes[0] = right;
                                path->slots[0] = 0;
@@ -1858,10 +2305,18 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                        if (wret)
                                                ret = wret;
                                }
+                               btrfs_mark_buffer_dirty(right);
                                return ret;
+                       } else if (extend && slot == 0) {
+                               mid = 1;
+                       } else {
+                               mid = slot;
+                               if (mid != nritems &&
+                                   leaf_space_used(l, mid, nritems - mid) +
+                                   space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
+                                       double_split = 1;
+                               }
                        }
-                       mid = slot;
-                       double_split = 1;
                }
        }
        nritems = nritems - mid;
@@ -1914,55 +2369,30 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        BUG_ON(path->slots[0] != slot);
 
        if (mid <= slot) {
+               btrfs_tree_unlock(path->nodes[0]);
                free_extent_buffer(path->nodes[0]);
                path->nodes[0] = right;
                path->slots[0] -= mid;
                path->slots[1] += 1;
-       } else
+       } else {
+               btrfs_tree_unlock(right);
                free_extent_buffer(right);
-
-       BUG_ON(path->slots[0] < 0);
-
-       if (!double_split) {
-               return ret;
        }
 
-       right = btrfs_alloc_free_block(trans, root, root->leafsize,
-                                      l->start, 0);
-       if (IS_ERR(right))
-               return PTR_ERR(right);
-
-       memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
-       btrfs_set_header_bytenr(right, right->start);
-       btrfs_set_header_generation(right, trans->transid);
-       btrfs_set_header_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);
+       BUG_ON(path->slots[0] < 0);
 
-       btrfs_cpu_key_to_disk(&disk_key, ins_key);
-       btrfs_set_header_nritems(right, 0);
-       wret = insert_ptr(trans, root, path,
-                         &disk_key, right->start,
-                         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;
+       if (double_split) {
+               BUG_ON(num_doubles != 0);
+               num_doubles++;
+               goto again;
        }
-       free_extent_buffer(path->nodes[0]);
-       path->nodes[0] = right;
-       path->slots[0] = 0;
        return ret;
 }
 
 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
                        struct btrfs_path *path,
-                       u32 new_size)
+                       u32 new_size, int from_end)
 {
        int ret = 0;
        int slot;
@@ -1978,14 +2408,17 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 
        slot_orig = path->slots[0];
        leaf = path->nodes[0];
+       slot = path->slots[0];
+
+       old_size = btrfs_item_size_nr(leaf, slot);
+       if (old_size == new_size)
+               return 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);
@@ -2017,9 +2450,45 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
        }
 
        /* 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);
+       if (from_end) {
+               memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+                             data_end + size_diff, btrfs_leaf_data(leaf) +
+                             data_end, old_data_start + new_size - data_end);
+       } else {
+               struct btrfs_disk_key disk_key;
+               u64 offset;
+
+               btrfs_item_key(leaf, &disk_key, slot);
+
+               if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
+                       unsigned long ptr;
+                       struct btrfs_file_extent_item *fi;
+
+                       fi = btrfs_item_ptr(leaf, slot,
+                                           struct btrfs_file_extent_item);
+                       fi = (struct btrfs_file_extent_item *)(
+                            (unsigned long)fi - size_diff);
+
+                       if (btrfs_file_extent_type(leaf, fi) ==
+                           BTRFS_FILE_EXTENT_INLINE) {
+                               ptr = btrfs_item_ptr_offset(leaf, slot);
+                               memmove_extent_buffer(leaf, ptr,
+                                       (unsigned long)fi,
+                                       offsetof(struct btrfs_file_extent_item,
+                                                disk_bytenr));
+                       }
+               }
+
+               memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+                             data_end + size_diff, btrfs_leaf_data(leaf) +
+                             data_end, old_data_start - data_end);
+
+               offset = btrfs_disk_key_offset(&disk_key);
+               btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
+               btrfs_set_item_key(leaf, &disk_key, slot);
+               if (slot == 0)
+                       fixup_low_keys(trans, root, path, &disk_key, 1);
+       }
 
        item = btrfs_item_nr(leaf, slot);
        btrfs_set_item_size(leaf, item, new_size);
@@ -2115,27 +2584,30 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
  * 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_empty_item(struct btrfs_trans_handle *trans,
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct btrfs_path *path,
-                           struct btrfs_key *cpu_key, u32 data_size)
+                           struct btrfs_key *cpu_key, u32 *data_size,
+                           int nr)
 {
        struct extent_buffer *leaf;
        struct btrfs_item *item;
        int ret = 0;
        int slot;
        int slot_orig;
+       int i;
        u32 nritems;
+       u32 total_size = 0;
+       u32 total_data = 0;
        unsigned int data_end;
        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();
+       for (i = 0; i < nr; i++) {
+               total_data += data_size[i];
+       }
 
-       ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
+       total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
+       ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
        if (ret == 0) {
                return -EEXIST;
        }
@@ -2149,10 +2621,10 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
        data_end = leaf_data_end(root, leaf);
 
        if (btrfs_leaf_free_space(root, leaf) <
-           sizeof(struct btrfs_item) + data_size) {
+           sizeof(struct btrfs_item) + total_size) {
                btrfs_print_leaf(root, leaf);
                printk("not enough freespace need %u have %d\n",
-                      data_size, btrfs_leaf_free_space(root, leaf));
+                      total_size, btrfs_leaf_free_space(root, leaf));
                BUG();
        }
 
@@ -2187,7 +2659,7 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
                        }
 
                        ioff = btrfs_item_offset(leaf, item);
-                       btrfs_set_item_offset(leaf, item, ioff - data_size);
+                       btrfs_set_item_offset(leaf, item, ioff - total_data);
                }
                if (leaf->map_token) {
                        unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
@@ -2195,28 +2667,34 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
                }
 
                /* shift the items */
-               memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
+               memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
                              btrfs_item_nr_offset(slot),
                              (nritems - slot) * sizeof(struct btrfs_item));
 
                /* shift the data */
                memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-                             data_end - data_size, btrfs_leaf_data(leaf) +
+                             data_end - total_data, btrfs_leaf_data(leaf) +
                              data_end, old_data - data_end);
                data_end = old_data;
        }
 
        /* setup the item for the new data */
-       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);
+       for (i = 0; i < nr; i++) {
+               btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+               btrfs_set_item_key(leaf, &disk_key, slot + i);
+               item = btrfs_item_nr(leaf, slot + i);
+               btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+               data_end -= data_size[i];
+               btrfs_set_item_size(leaf, item, data_size[i]);
+       }
+       btrfs_set_header_nritems(leaf, nritems + nr);
        btrfs_mark_buffer_dirty(leaf);
 
        ret = 0;
-       if (slot == 0)
+       if (slot == 0) {
+               btrfs_cpu_key_to_disk(&disk_key, cpu_key);
                ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+       }
 
        if (btrfs_leaf_free_space(root, leaf) < 0) {
                btrfs_print_leaf(root, leaf);
@@ -2297,34 +2775,36 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
  * delete the item at the leaf level in path.  If that empties
  * the leaf, remove it from the tree
  */
-int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct btrfs_path *path)
+int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                   struct btrfs_path *path, int slot, int nr)
 {
-       int slot;
        struct extent_buffer *leaf;
        struct btrfs_item *item;
-       int doff;
-       int dsize;
+       int last_off;
+       int dsize = 0;
        int ret = 0;
        int wret;
+       int i;
        u32 nritems;
 
        leaf = path->nodes[0];
-       slot = path->slots[0];
-       doff = btrfs_item_offset_nr(leaf, slot);
-       dsize = btrfs_item_size_nr(leaf, slot);
+       last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
+
+       for (i = 0; i < nr; i++)
+               dsize += btrfs_item_size_nr(leaf, slot + i);
+
        nritems = btrfs_header_nritems(leaf);
 
-       if (slot != nritems - 1) {
+       if (slot + nr != nritems) {
                int i;
                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);
+                             last_off - data_end);
 
-               for (i = slot + 1; i < nritems; i++) {
+               for (i = slot + nr; i < nritems; i++) {
                        u32 ioff;
 
                        item = btrfs_item_nr(leaf, i);
@@ -2345,25 +2825,26 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                }
 
                memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
-                             btrfs_item_nr_offset(slot + 1),
+                             btrfs_item_nr_offset(slot + nr),
                              sizeof(struct btrfs_item) *
-                             (nritems - slot - 1));
+                             (nritems - slot - nr));
        }
-       btrfs_set_header_nritems(leaf, nritems - 1);
-       nritems--;
+       btrfs_set_header_nritems(leaf, nritems - nr);
+       nritems -= nr;
 
        /* delete the leaf if we've emptied it */
        if (nritems == 0) {
                if (leaf == root->node) {
                        btrfs_set_header_level(leaf, 0);
                } else {
-                       clean_tree_block(trans, root, leaf);
-                       wait_on_tree_block_writeback(root, leaf);
+                       u64 root_gen = btrfs_header_generation(path->nodes[1]);
                        wret = del_ptr(trans, root, path, 1, path->slots[1]);
                        if (wret)
                                ret = wret;
                        wret = btrfs_free_extent(trans, root,
-                                                leaf->start, leaf->len, 1);
+                                        leaf->start, leaf->len,
+                                        btrfs_header_owner(path->nodes[1]),
+                                        root_gen, 0, 0, 1);
                        if (wret)
                                ret = wret;
                }
@@ -2380,7 +2861,7 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                }
 
                /* delete the leaf if it is mostly empty */
-               if (0 && used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
+               if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
                        /* push_leaf_left fixes the path.
                         * make sure the path still points to our leaf
                         * for possible call to del_ptr below
@@ -2388,23 +2869,24 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                        slot = path->slots[1];
                        extent_buffer_get(leaf);
 
-                       wret = push_leaf_left(trans, root, path, 1);
+                       wret = push_leaf_left(trans, root, path, 1, 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);
+                               wret = push_leaf_right(trans, root, path, 1, 1);
                                if (wret < 0 && wret != -ENOSPC)
                                        ret = wret;
                        }
 
                        if (btrfs_header_nritems(leaf) == 0) {
+                               u64 root_gen;
                                u64 bytenr = leaf->start;
                                u32 blocksize = leaf->len;
 
-                               clean_tree_block(trans, root, leaf);
-                               wait_on_tree_block_writeback(root, leaf);
+                               root_gen = btrfs_header_generation(
+                                                          path->nodes[1]);
 
                                wret = del_ptr(trans, root, path, 1, slot);
                                if (wret)
@@ -2412,11 +2894,19 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 
                                free_extent_buffer(leaf);
                                wret = btrfs_free_extent(trans, root, bytenr,
-                                                        blocksize, 1);
+                                            blocksize,
+                                            btrfs_header_owner(path->nodes[1]),
+                                            root_gen, 0, 0, 1);
                                if (wret)
                                        ret = wret;
                        } else {
-                               btrfs_mark_buffer_dirty(leaf);
+                               /* if we're still in the path, make sure
+                                * we're dirty.  Otherwise, one of the
+                                * push_leaf functions must have already
+                                * dirtied this buffer
+                                */
+                               if (path->nodes[0] == leaf)
+                                       btrfs_mark_buffer_dirty(leaf);
                                free_extent_buffer(leaf);
                        }
                } else {
@@ -2427,7 +2917,40 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 }
 
 /*
- * walk up the tree as far as required to find the next leaf.
+ * search the tree again to find a leaf with lesser keys
+ * returns 0 if it found something or 1 if there are no lesser leaves.
+ * returns < 0 on io errors.
+ */
+int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+       struct btrfs_key key;
+       struct btrfs_disk_key found_key;
+       int ret;
+
+       btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
+
+       if (key.offset > 0)
+               key.offset--;
+       else if (key.type > 0)
+               key.type--;
+       else if (key.objectid > 0)
+               key.objectid--;
+       else
+               return 1;
+
+       btrfs_release_path(root, path);
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               return ret;
+       btrfs_item_key(path->nodes[0], &found_key, 0);
+       ret = comp_keys(&found_key, &key);
+       if (ret < 0)
+               return 0;
+       return 1;
+}
+
+/*
+ * search the tree again to find a leaf with greater keys
  * returns 0 if it found something or 1 if there are no greater leaves.
  * returns < 0 on io errors.
  */
@@ -2435,9 +2958,31 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
        int slot;
        int level = 1;
-       u64 bytenr;
        struct extent_buffer *c;
        struct extent_buffer *next = NULL;
+       struct btrfs_key key;
+       u32 nritems;
+       int ret;
+
+       nritems = btrfs_header_nritems(path->nodes[0]);
+       if (nritems == 0) {
+               return 1;
+       }
+
+       btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+
+       btrfs_release_path(root, path);
+       path->keep_locks = 1;
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       path->keep_locks = 0;
+
+       if (ret < 0)
+               return ret;
+
+       nritems = btrfs_header_nritems(path->nodes[0]);
+       if (nritems > 0 && path->slots[0] < nritems - 1) {
+               goto done;
+       }
 
        while(level < BTRFS_MAX_LEVEL) {
                if (!path->nodes[level])
@@ -2447,33 +2992,80 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
                c = path->nodes[level];
                if (slot >= btrfs_header_nritems(c)) {
                        level++;
+                       if (level == BTRFS_MAX_LEVEL) {
+                               return 1;
+                       }
                        continue;
                }
 
-               bytenr = btrfs_node_blockptr(c, slot);
-               if (next)
+               if (next) {
+                       btrfs_tree_unlock(next);
                        free_extent_buffer(next);
+               }
 
-               if (path->reada)
-                       reada_for_search(root, path, level, slot);
-
-               next = read_tree_block(root, bytenr,
-                                      btrfs_level_size(root, level -1));
+               if (level == 1 && path->locks[1] && path->reada)
+                       reada_for_search(root, path, level, slot, 0);
+
+               next = read_node_slot(root, c, slot);
+               if (!path->skip_locking) {
+                       if (!btrfs_tree_locked(c)) {
+                               int i;
+                               WARN_ON(1);
+printk("path %p no lock on level %d\n", path, level);
+for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+printk("path %p level %d slot %d nritems %d\n", path, i, path->slots[i], btrfs_header_nritems(path->nodes[i]));
+}
+                       }
+                       btrfs_tree_lock(next);
+               }
                break;
        }
        path->slots[level] = slot;
        while(1) {
                level--;
                c = path->nodes[level];
+               if (path->locks[level])
+                       btrfs_tree_unlock(c);
                free_extent_buffer(c);
                path->nodes[level] = next;
                path->slots[level] = 0;
+               path->locks[level] = 1;
                if (!level)
                        break;
-               if (path->reada)
-                       reada_for_search(root, path, level, 0);
-               next = read_tree_block(root, btrfs_node_blockptr(next, 0),
-                                      btrfs_level_size(root, level - 1));
+               if (level == 1 && path->locks[1] && path->reada)
+                       reada_for_search(root, path, level, slot, 0);
+               next = read_node_slot(root, next, 0);
+               if (!path->skip_locking) {
+                       WARN_ON(!btrfs_tree_locked(path->nodes[level]));
+                       btrfs_tree_lock(next);
+               }
        }
+done:
+       unlock_up(path, 0, 1);
        return 0;
 }
+
+int btrfs_previous_item(struct btrfs_root *root,
+                       struct btrfs_path *path, u64 min_objectid,
+                       int type)
+{
+       struct btrfs_key found_key;
+       struct extent_buffer *leaf;
+       int ret;
+
+       while(1) {
+               if (path->slots[0] == 0) {
+                       ret = btrfs_prev_leaf(root, path);
+                       if (ret != 0)
+                               return ret;
+               } else {
+                       path->slots[0]--;
+               }
+               leaf = path->nodes[0];
+               btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+               if (found_key.type == type)
+                       return 0;
+       }
+       return 1;
+}
+