--- /dev/null
+/*
+ * Copyright (C) 2011 Fujitsu.  All rights reserved.
+ * Written by Miao Xie <miaox@cn.fujitsu.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/slab.h>
+#include "delayed-inode.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+#define BTRFS_DELAYED_WRITEBACK                400
+#define BTRFS_DELAYED_BACKGROUND       100
+
+static struct kmem_cache *delayed_node_cache;
+
+int __init btrfs_delayed_inode_init(void)
+{
+       delayed_node_cache = kmem_cache_create("delayed_node",
+                                       sizeof(struct btrfs_delayed_node),
+                                       0,
+                                       SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+                                       NULL);
+       if (!delayed_node_cache)
+               return -ENOMEM;
+       return 0;
+}
+
+void btrfs_delayed_inode_exit(void)
+{
+       if (delayed_node_cache)
+               kmem_cache_destroy(delayed_node_cache);
+}
+
+static inline void btrfs_init_delayed_node(
+                               struct btrfs_delayed_node *delayed_node,
+                               struct btrfs_root *root, u64 inode_id)
+{
+       delayed_node->root = root;
+       delayed_node->inode_id = inode_id;
+       atomic_set(&delayed_node->refs, 0);
+       delayed_node->count = 0;
+       delayed_node->in_list = 0;
+       delayed_node->inode_dirty = 0;
+       delayed_node->ins_root = RB_ROOT;
+       delayed_node->del_root = RB_ROOT;
+       mutex_init(&delayed_node->mutex);
+       delayed_node->index_cnt = 0;
+       INIT_LIST_HEAD(&delayed_node->n_list);
+       INIT_LIST_HEAD(&delayed_node->p_list);
+       delayed_node->bytes_reserved = 0;
+}
+
+static inline int btrfs_is_continuous_delayed_item(
+                                       struct btrfs_delayed_item *item1,
+                                       struct btrfs_delayed_item *item2)
+{
+       if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
+           item1->key.objectid == item2->key.objectid &&
+           item1->key.type == item2->key.type &&
+           item1->key.offset + 1 == item2->key.offset)
+               return 1;
+       return 0;
+}
+
+static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
+                                                       struct btrfs_root *root)
+{
+       return root->fs_info->delayed_root;
+}
+
+static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
+                                                       struct inode *inode)
+{
+       struct btrfs_delayed_node *node;
+       struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
+       struct btrfs_root *root = btrfs_inode->root;
+       int ret;
+
+again:
+       node = ACCESS_ONCE(btrfs_inode->delayed_node);
+       if (node) {
+               atomic_inc(&node->refs);        /* can be accessed */
+               return node;
+       }
+
+       spin_lock(&root->inode_lock);
+       node = radix_tree_lookup(&root->delayed_nodes_tree, inode->i_ino);
+       if (node) {
+               if (btrfs_inode->delayed_node) {
+                       spin_unlock(&root->inode_lock);
+                       goto again;
+               }
+               btrfs_inode->delayed_node = node;
+               atomic_inc(&node->refs);        /* can be accessed */
+               atomic_inc(&node->refs);        /* cached in the inode */
+               spin_unlock(&root->inode_lock);
+               return node;
+       }
+       spin_unlock(&root->inode_lock);
+
+       node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
+       if (!node)
+               return ERR_PTR(-ENOMEM);
+       btrfs_init_delayed_node(node, root, inode->i_ino);
+
+       atomic_inc(&node->refs);        /* cached in the btrfs inode */
+       atomic_inc(&node->refs);        /* can be accessed */
+
+       ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
+       if (ret) {
+               kmem_cache_free(delayed_node_cache, node);
+               return ERR_PTR(ret);
+       }
+
+       spin_lock(&root->inode_lock);
+       ret = radix_tree_insert(&root->delayed_nodes_tree, inode->i_ino, node);
+       if (ret == -EEXIST) {
+               kmem_cache_free(delayed_node_cache, node);
+               spin_unlock(&root->inode_lock);
+               radix_tree_preload_end();
+               goto again;
+       }
+       btrfs_inode->delayed_node = node;
+       spin_unlock(&root->inode_lock);
+       radix_tree_preload_end();
+
+       return node;
+}
+
+/*
+ * Call it when holding delayed_node->mutex
+ *
+ * If mod = 1, add this node into the prepared list.
+ */
+static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
+                                    struct btrfs_delayed_node *node,
+                                    int mod)
+{
+       spin_lock(&root->lock);
+       if (node->in_list) {
+               if (!list_empty(&node->p_list))
+                       list_move_tail(&node->p_list, &root->prepare_list);
+               else if (mod)
+                       list_add_tail(&node->p_list, &root->prepare_list);
+       } else {
+               list_add_tail(&node->n_list, &root->node_list);
+               list_add_tail(&node->p_list, &root->prepare_list);
+               atomic_inc(&node->refs);        /* inserted into list */
+               root->nodes++;
+               node->in_list = 1;
+       }
+       spin_unlock(&root->lock);
+}
+
+/* Call it when holding delayed_node->mutex */
+static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
+                                      struct btrfs_delayed_node *node)
+{
+       spin_lock(&root->lock);
+       if (node->in_list) {
+               root->nodes--;
+               atomic_dec(&node->refs);        /* not in the list */
+               list_del_init(&node->n_list);
+               if (!list_empty(&node->p_list))
+                       list_del_init(&node->p_list);
+               node->in_list = 0;
+       }
+       spin_unlock(&root->lock);
+}
+
+struct btrfs_delayed_node *btrfs_first_delayed_node(
+                       struct btrfs_delayed_root *delayed_root)
+{
+       struct list_head *p;
+       struct btrfs_delayed_node *node = NULL;
+
+       spin_lock(&delayed_root->lock);
+       if (list_empty(&delayed_root->node_list))
+               goto out;
+
+       p = delayed_root->node_list.next;
+       node = list_entry(p, struct btrfs_delayed_node, n_list);
+       atomic_inc(&node->refs);
+out:
+       spin_unlock(&delayed_root->lock);
+
+       return node;
+}
+
+struct btrfs_delayed_node *btrfs_next_delayed_node(
+                                               struct btrfs_delayed_node *node)
+{
+       struct btrfs_delayed_root *delayed_root;
+       struct list_head *p;
+       struct btrfs_delayed_node *next = NULL;
+
+       delayed_root = node->root->fs_info->delayed_root;
+       spin_lock(&delayed_root->lock);
+       if (!node->in_list) {   /* not in the list */
+               if (list_empty(&delayed_root->node_list))
+                       goto out;
+               p = delayed_root->node_list.next;
+       } else if (list_is_last(&node->n_list, &delayed_root->node_list))
+               goto out;
+       else
+               p = node->n_list.next;
+
+       next = list_entry(p, struct btrfs_delayed_node, n_list);
+       atomic_inc(&next->refs);
+out:
+       spin_unlock(&delayed_root->lock);
+
+       return next;
+}
+
+static void __btrfs_release_delayed_node(
+                               struct btrfs_delayed_node *delayed_node,
+                               int mod)
+{
+       struct btrfs_delayed_root *delayed_root;
+
+       if (!delayed_node)
+               return;
+
+       delayed_root = delayed_node->root->fs_info->delayed_root;
+
+       mutex_lock(&delayed_node->mutex);
+       if (delayed_node->count)
+               btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
+       else
+               btrfs_dequeue_delayed_node(delayed_root, delayed_node);
+       mutex_unlock(&delayed_node->mutex);
+
+       if (atomic_dec_and_test(&delayed_node->refs)) {
+               struct btrfs_root *root = delayed_node->root;
+               spin_lock(&root->inode_lock);
+               if (atomic_read(&delayed_node->refs) == 0) {
+                       radix_tree_delete(&root->delayed_nodes_tree,
+                                         delayed_node->inode_id);
+                       kmem_cache_free(delayed_node_cache, delayed_node);
+               }
+               spin_unlock(&root->inode_lock);
+       }
+}
+
+static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
+{
+       __btrfs_release_delayed_node(node, 0);
+}
+
+struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
+                                       struct btrfs_delayed_root *delayed_root)
+{
+       struct list_head *p;
+       struct btrfs_delayed_node *node = NULL;
+
+       spin_lock(&delayed_root->lock);
+       if (list_empty(&delayed_root->prepare_list))
+               goto out;
+
+       p = delayed_root->prepare_list.next;
+       list_del_init(p);
+       node = list_entry(p, struct btrfs_delayed_node, p_list);
+       atomic_inc(&node->refs);
+out:
+       spin_unlock(&delayed_root->lock);
+
+       return node;
+}
+
+static inline void btrfs_release_prepared_delayed_node(
+                                       struct btrfs_delayed_node *node)
+{
+       __btrfs_release_delayed_node(node, 1);
+}
+
+struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
+{
+       struct btrfs_delayed_item *item;
+       item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
+       if (item) {
+               item->data_len = data_len;
+               item->ins_or_del = 0;
+               item->bytes_reserved = 0;
+               item->block_rsv = NULL;
+               item->delayed_node = NULL;
+               atomic_set(&item->refs, 1);
+       }
+       return item;
+}
+
+/*
+ * __btrfs_lookup_delayed_item - look up the delayed item by key
+ * @delayed_node: pointer to the delayed node
+ * @key:         the key to look up
+ * @prev:        used to store the prev item if the right item isn't found
+ * @next:        used to store the next item if the right item isn't found
+ *
+ * Note: if we don't find the right item, we will return the prev item and
+ * the next item.
+ */
+static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
+                               struct rb_root *root,
+                               struct btrfs_key *key,
+                               struct btrfs_delayed_item **prev,
+                               struct btrfs_delayed_item **next)
+{
+       struct rb_node *node, *prev_node = NULL;
+       struct btrfs_delayed_item *delayed_item = NULL;
+       int ret = 0;
+
+       node = root->rb_node;
+
+       while (node) {
+               delayed_item = rb_entry(node, struct btrfs_delayed_item,
+                                       rb_node);
+               prev_node = node;
+               ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
+               if (ret < 0)
+                       node = node->rb_right;
+               else if (ret > 0)
+                       node = node->rb_left;
+               else
+                       return delayed_item;
+       }
+
+       if (prev) {
+               if (!prev_node)
+                       *prev = NULL;
+               else if (ret < 0)
+                       *prev = delayed_item;
+               else if ((node = rb_prev(prev_node)) != NULL) {
+                       *prev = rb_entry(node, struct btrfs_delayed_item,
+                                        rb_node);
+               } else
+                       *prev = NULL;
+       }
+
+       if (next) {
+               if (!prev_node)
+                       *next = NULL;
+               else if (ret > 0)
+                       *next = delayed_item;
+               else if ((node = rb_next(prev_node)) != NULL) {
+                       *next = rb_entry(node, struct btrfs_delayed_item,
+                                        rb_node);
+               } else
+                       *next = NULL;
+       }
+       return NULL;
+}
+
+struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
+                                       struct btrfs_delayed_node *delayed_node,
+                                       struct btrfs_key *key)
+{
+       struct btrfs_delayed_item *item;
+
+       item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
+                                          NULL, NULL);
+       return item;
+}
+
+struct btrfs_delayed_item *__btrfs_lookup_delayed_deletion_item(
+                                       struct btrfs_delayed_node *delayed_node,
+                                       struct btrfs_key *key)
+{
+       struct btrfs_delayed_item *item;
+
+       item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
+                                          NULL, NULL);
+       return item;
+}
+
+struct btrfs_delayed_item *__btrfs_search_delayed_insertion_item(
+                                       struct btrfs_delayed_node *delayed_node,
+                                       struct btrfs_key *key)
+{
+       struct btrfs_delayed_item *item, *next;
+
+       item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
+                                          NULL, &next);
+       if (!item)
+               item = next;
+
+       return item;
+}
+
+struct btrfs_delayed_item *__btrfs_search_delayed_deletion_item(
+                                       struct btrfs_delayed_node *delayed_node,
+                                       struct btrfs_key *key)
+{
+       struct btrfs_delayed_item *item, *next;
+
+       item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
+                                          NULL, &next);
+       if (!item)
+               item = next;
+
+       return item;
+}
+
+static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
+                                   struct btrfs_delayed_item *ins,
+                                   int action)
+{
+       struct rb_node **p, *node;
+       struct rb_node *parent_node = NULL;
+       struct rb_root *root;
+       struct btrfs_delayed_item *item;
+       int cmp;
+
+       if (action == BTRFS_DELAYED_INSERTION_ITEM)
+               root = &delayed_node->ins_root;
+       else if (action == BTRFS_DELAYED_DELETION_ITEM)
+               root = &delayed_node->del_root;
+       else
+               BUG();
+       p = &root->rb_node;
+       node = &ins->rb_node;
+
+       while (*p) {
+               parent_node = *p;
+               item = rb_entry(parent_node, struct btrfs_delayed_item,
+                                rb_node);
+
+               cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
+               if (cmp < 0)
+                       p = &(*p)->rb_right;
+               else if (cmp > 0)
+                       p = &(*p)->rb_left;
+               else
+                       return -EEXIST;
+       }
+
+       rb_link_node(node, parent_node, p);
+       rb_insert_color(node, root);
+       ins->delayed_node = delayed_node;
+       ins->ins_or_del = action;
+
+       if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
+           action == BTRFS_DELAYED_INSERTION_ITEM &&
+           ins->key.offset >= delayed_node->index_cnt)
+                       delayed_node->index_cnt = ins->key.offset + 1;
+
+       delayed_node->count++;
+       atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
+       return 0;
+}
+
+static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
+                                             struct btrfs_delayed_item *item)
+{
+       return __btrfs_add_delayed_item(node, item,
+                                       BTRFS_DELAYED_INSERTION_ITEM);
+}
+
+static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
+                                            struct btrfs_delayed_item *item)
+{
+       return __btrfs_add_delayed_item(node, item,
+                                       BTRFS_DELAYED_DELETION_ITEM);
+}
+
+static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
+{
+       struct rb_root *root;
+       struct btrfs_delayed_root *delayed_root;
+
+       delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
+
+       BUG_ON(!delayed_root);
+       BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
+              delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
+
+       if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
+               root = &delayed_item->delayed_node->ins_root;
+       else
+               root = &delayed_item->delayed_node->del_root;
+
+       rb_erase(&delayed_item->rb_node, root);
+       delayed_item->delayed_node->count--;
+       atomic_dec(&delayed_root->items);
+       if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND &&
+           waitqueue_active(&delayed_root->wait))
+               wake_up(&delayed_root->wait);
+}
+
+static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
+{
+       if (item) {
+               __btrfs_remove_delayed_item(item);
+               if (atomic_dec_and_test(&item->refs))
+                       kfree(item);
+       }
+}
+
+struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
+                                       struct btrfs_delayed_node *delayed_node)
+{
+       struct rb_node *p;
+       struct btrfs_delayed_item *item = NULL;
+
+       p = rb_first(&delayed_node->ins_root);
+       if (p)
+               item = rb_entry(p, struct btrfs_delayed_item, rb_node);
+
+       return item;
+}
+
+struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
+                                       struct btrfs_delayed_node *delayed_node)
+{
+       struct rb_node *p;
+       struct btrfs_delayed_item *item = NULL;
+
+       p = rb_first(&delayed_node->del_root);
+       if (p)
+               item = rb_entry(p, struct btrfs_delayed_item, rb_node);
+
+       return item;
+}
+
+struct btrfs_delayed_item *__btrfs_next_delayed_item(
+                                               struct btrfs_delayed_item *item)
+{
+       struct rb_node *p;
+       struct btrfs_delayed_item *next = NULL;
+
+       p = rb_next(&item->rb_node);
+       if (p)
+               next = rb_entry(p, struct btrfs_delayed_item, rb_node);
+
+       return next;
+}
+
+static inline struct btrfs_delayed_node *btrfs_get_delayed_node(
+                                                       struct inode *inode)
+{
+       struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
+       struct btrfs_delayed_node *delayed_node;
+
+       delayed_node = btrfs_inode->delayed_node;
+       if (delayed_node)
+               atomic_inc(&delayed_node->refs);
+
+       return delayed_node;
+}
+
+static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
+                                                  u64 root_id)
+{
+       struct btrfs_key root_key;
+
+       if (root->objectid == root_id)
+               return root;
+
+       root_key.objectid = root_id;
+       root_key.type = BTRFS_ROOT_ITEM_KEY;
+       root_key.offset = (u64)-1;
+       return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
+}
+
+static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
+                                              struct btrfs_root *root,
+                                              struct btrfs_delayed_item *item)
+{
+       struct btrfs_block_rsv *src_rsv;
+       struct btrfs_block_rsv *dst_rsv;
+       u64 num_bytes;
+       int ret;
+
+       if (!trans->bytes_reserved)
+               return 0;
+
+       src_rsv = trans->block_rsv;
+       dst_rsv = &root->fs_info->global_block_rsv;
+
+       num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+       ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+       if (!ret) {
+               item->bytes_reserved = num_bytes;
+               item->block_rsv = dst_rsv;
+       }
+
+       return ret;
+}
+
+static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
+                                               struct btrfs_delayed_item *item)
+{
+       if (!item->bytes_reserved)
+               return;
+
+       btrfs_block_rsv_release(root, item->block_rsv,
+                               item->bytes_reserved);
+}
+
+static int btrfs_delayed_inode_reserve_metadata(
+                                       struct btrfs_trans_handle *trans,
+                                       struct btrfs_root *root,
+                                       struct btrfs_delayed_node *node)
+{
+       struct btrfs_block_rsv *src_rsv;
+       struct btrfs_block_rsv *dst_rsv;
+       u64 num_bytes;
+       int ret;
+
+       if (!trans->bytes_reserved)
+               return 0;
+
+       src_rsv = trans->block_rsv;
+       dst_rsv = &root->fs_info->global_block_rsv;
+
+       num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+       ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+       if (!ret)
+               node->bytes_reserved = num_bytes;
+
+       return ret;
+}
+
+static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
+                                               struct btrfs_delayed_node *node)
+{
+       struct btrfs_block_rsv *rsv;
+
+       if (!node->bytes_reserved)
+               return;
+
+       rsv = &root->fs_info->global_block_rsv;
+       btrfs_block_rsv_release(root, rsv,
+                               node->bytes_reserved);
+       node->bytes_reserved = 0;
+}
+
+/*
+ * This helper will insert some continuous items into the same leaf according
+ * to the free space of the leaf.
+ */
+static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root,
+                               struct btrfs_path *path,
+                               struct btrfs_delayed_item *item)
+{
+       struct btrfs_delayed_item *curr, *next;
+       int free_space;
+       int total_data_size = 0, total_size = 0;
+       struct extent_buffer *leaf;
+       char *data_ptr;
+       struct btrfs_key *keys;
+       u32 *data_size;
+       struct list_head head;
+       int slot;
+       int nitems;
+       int i;
+       int ret = 0;
+
+       BUG_ON(!path->nodes[0]);
+
+       leaf = path->nodes[0];
+       free_space = btrfs_leaf_free_space(root, leaf);
+       INIT_LIST_HEAD(&head);
+
+       next = item;
+
+       /*
+        * count the number of the continuous items that we can insert in batch
+        */
+       while (total_size + next->data_len + sizeof(struct btrfs_item) <=
+              free_space) {
+               total_data_size += next->data_len;
+               total_size += next->data_len + sizeof(struct btrfs_item);
+               list_add_tail(&next->tree_list, &head);
+               nitems++;
+
+               curr = next;
+               next = __btrfs_next_delayed_item(curr);
+               if (!next)
+                       break;
+
+               if (!btrfs_is_continuous_delayed_item(curr, next))
+                       break;
+       }
+
+       if (!nitems) {
+               ret = 0;
+               goto out;
+       }
+
+       /*
+        * we need allocate some memory space, but it might cause the task
+        * to sleep, so we set all locked nodes in the path to blocking locks
+        * first.
+        */
+       btrfs_set_path_blocking(path);
+
+       keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
+       if (!keys) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
+       if (!data_size) {
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       /* get keys of all the delayed items */
+       i = 0;
+       list_for_each_entry(next, &head, tree_list) {
+               keys[i] = next->key;
+               data_size[i] = next->data_len;
+               i++;
+       }
+
+       /* reset all the locked nodes in the patch to spinning locks. */
+       btrfs_clear_path_blocking(path, NULL);
+
+       /* insert the keys of the items */
+       ret = setup_items_for_insert(trans, root, path, keys, data_size,
+                                    total_data_size, total_size, nitems);
+       if (ret)
+               goto error;
+
+       /* insert the dir index items */
+       slot = path->slots[0];
+       list_for_each_entry_safe(curr, next, &head, tree_list) {
+               data_ptr = btrfs_item_ptr(leaf, slot, char);
+               write_extent_buffer(leaf, &curr->data,
+                                   (unsigned long)data_ptr,
+                                   curr->data_len);
+               slot++;
+
+               btrfs_delayed_item_release_metadata(root, curr);
+
+               list_del(&curr->tree_list);
+               btrfs_release_delayed_item(curr);
+       }
+
+error:
+       kfree(data_size);
+       kfree(keys);
+out:
+       return ret;
+}
+
+/*
+ * This helper can just do simple insertion that needn't extend item for new
+ * data, such as directory name index insertion, inode insertion.
+ */
+static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    struct btrfs_path *path,
+                                    struct btrfs_delayed_item *delayed_item)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
+       char *ptr;
+       int ret;
+
+       ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
+                                     delayed_item->data_len);
+       if (ret < 0 && ret != -EEXIST)
+               return ret;
+
+       leaf = path->nodes[0];
+
+       item = btrfs_item_nr(leaf, path->slots[0]);
+       ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+
+       write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
+                           delayed_item->data_len);
+       btrfs_mark_buffer_dirty(leaf);
+
+       btrfs_delayed_item_release_metadata(root, delayed_item);
+       return 0;
+}
+
+/*
+ * we insert an item first, then if there are some continuous items, we try
+ * to insert those items into the same leaf.
+ */
+static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
+                                     struct btrfs_path *path,
+                                     struct btrfs_root *root,
+                                     struct btrfs_delayed_node *node)
+{
+       struct btrfs_delayed_item *curr, *prev;
+       int ret = 0;
+
+do_again:
+       mutex_lock(&node->mutex);
+       curr = __btrfs_first_delayed_insertion_item(node);
+       if (!curr)
+               goto insert_end;
+
+       ret = btrfs_insert_delayed_item(trans, root, path, curr);
+       if (ret < 0) {
+               btrfs_release_path(root, path);
+               goto insert_end;
+       }
+
+       prev = curr;
+       curr = __btrfs_next_delayed_item(prev);
+       if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
+               /* insert the continuous items into the same leaf */
+               path->slots[0]++;
+               btrfs_batch_insert_items(trans, root, path, curr);
+       }
+       btrfs_release_delayed_item(prev);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+
+       btrfs_release_path(root, path);
+       mutex_unlock(&node->mutex);
+       goto do_again;
+
+insert_end:
+       mutex_unlock(&node->mutex);
+       return ret;
+}
+
+static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
+                                   struct btrfs_root *root,
+                                   struct btrfs_path *path,
+                                   struct btrfs_delayed_item *item)
+{
+       struct btrfs_delayed_item *curr, *next;
+       struct extent_buffer *leaf;
+       struct btrfs_key key;
+       struct list_head head;
+       int nitems, i, last_item;
+       int ret = 0;
+
+       BUG_ON(!path->nodes[0]);
+
+       leaf = path->nodes[0];
+
+       i = path->slots[0];
+       last_item = btrfs_header_nritems(leaf) - 1;
+       if (i > last_item)
+               return -ENOENT; /* FIXME: Is errno suitable? */
+
+       next = item;
+       INIT_LIST_HEAD(&head);
+       btrfs_item_key_to_cpu(leaf, &key, i);
+       nitems = 0;
+       /*
+        * count the number of the dir index items that we can delete in batch
+        */
+       while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
+               list_add_tail(&next->tree_list, &head);
+               nitems++;
+
+               curr = next;
+               next = __btrfs_next_delayed_item(curr);
+               if (!next)
+                       break;
+
+               if (!btrfs_is_continuous_delayed_item(curr, next))
+                       break;
+
+               i++;
+               if (i > last_item)
+                       break;
+               btrfs_item_key_to_cpu(leaf, &key, i);
+       }
+
+       if (!nitems)
+               return 0;
+
+       ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
+       if (ret)
+               goto out;
+
+       list_for_each_entry_safe(curr, next, &head, tree_list) {
+               btrfs_delayed_item_release_metadata(root, curr);
+               list_del(&curr->tree_list);
+               btrfs_release_delayed_item(curr);
+       }
+
+out:
+       return ret;
+}
+
+static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
+                                     struct btrfs_path *path,
+                                     struct btrfs_root *root,
+                                     struct btrfs_delayed_node *node)
+{
+       struct btrfs_delayed_item *curr, *prev;
+       int ret = 0;
+
+do_again:
+       mutex_lock(&node->mutex);
+       curr = __btrfs_first_delayed_deletion_item(node);
+       if (!curr)
+               goto delete_fail;
+
+       ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
+       if (ret < 0)
+               goto delete_fail;
+       else if (ret > 0) {
+               /*
+                * can't find the item which the node points to, so this node
+                * is invalid, just drop it.
+                */
+               prev = curr;
+               curr = __btrfs_next_delayed_item(prev);
+               btrfs_release_delayed_item(prev);
+               ret = 0;
+               btrfs_release_path(root, path);
+               if (curr)
+                       goto do_again;
+               else
+                       goto delete_fail;
+       }
+
+       btrfs_batch_delete_items(trans, root, path, curr);
+       btrfs_release_path(root, path);
+       mutex_unlock(&node->mutex);
+       goto do_again;
+
+delete_fail:
+       btrfs_release_path(root, path);
+       mutex_unlock(&node->mutex);
+       return ret;
+}
+
+static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
+{
+       struct btrfs_delayed_root *delayed_root;
+
+       if (delayed_node && delayed_node->inode_dirty) {
+               BUG_ON(!delayed_node->root);
+               delayed_node->inode_dirty = 0;
+               delayed_node->count--;
+
+               delayed_root = delayed_node->root->fs_info->delayed_root;
+               atomic_dec(&delayed_root->items);
+               if (atomic_read(&delayed_root->items) <
+                   BTRFS_DELAYED_BACKGROUND &&
+                   waitqueue_active(&delayed_root->wait))
+                       wake_up(&delayed_root->wait);
+       }
+}
+
+static int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
+                                     struct btrfs_root *root,
+                                     struct btrfs_path *path,
+                                     struct btrfs_delayed_node *node)
+{
+       struct btrfs_key key;
+       struct btrfs_inode_item *inode_item;
+       struct extent_buffer *leaf;
+       int ret;
+
+       mutex_lock(&node->mutex);
+       if (!node->inode_dirty) {
+               mutex_unlock(&node->mutex);
+               return 0;
+       }
+
+       key.objectid = node->inode_id;
+       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+       key.offset = 0;
+       ret = btrfs_lookup_inode(trans, root, path, &key, 1);
+       if (ret > 0) {
+               btrfs_release_path(root, path);
+               mutex_unlock(&node->mutex);
+               return -ENOENT;
+       } else if (ret < 0) {
+               mutex_unlock(&node->mutex);
+               return ret;
+       }
+
+       btrfs_unlock_up_safe(path, 1);
+       leaf = path->nodes[0];
+       inode_item = btrfs_item_ptr(leaf, path->slots[0],
+                                   struct btrfs_inode_item);
+       write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
+                           sizeof(struct btrfs_inode_item));
+       btrfs_mark_buffer_dirty(leaf);
+       btrfs_release_path(root, path);
+
+       btrfs_delayed_inode_release_metadata(root, node);
+       btrfs_release_delayed_inode(node);
+       mutex_unlock(&node->mutex);
+
+       return 0;
+}
+
+/* Called when committing the transaction. */
+int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root)
+{
+       struct btrfs_delayed_root *delayed_root;
+       struct btrfs_delayed_node *curr_node, *prev_node;
+       struct btrfs_path *path;
+       int ret = 0;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+       path->leave_spinning = 1;
+
+       delayed_root = btrfs_get_delayed_root(root);
+
+       curr_node = btrfs_first_delayed_node(delayed_root);
+       while (curr_node) {
+               root = curr_node->root;
+               ret = btrfs_insert_delayed_items(trans, path, root,
+                                                curr_node);
+               if (!ret)
+                       ret = btrfs_delete_delayed_items(trans, path, root,
+                                                        curr_node);
+               if (!ret)
+                       ret = btrfs_update_delayed_inode(trans, root, path,
+                                                        curr_node);
+               if (ret) {
+                       btrfs_release_delayed_node(curr_node);
+                       break;
+               }
+
+               prev_node = curr_node;
+               curr_node = btrfs_next_delayed_node(curr_node);
+               btrfs_release_delayed_node(prev_node);
+       }
+
+       btrfs_free_path(path);
+       return ret;
+}
+
+static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+                                             struct btrfs_delayed_node *node)
+{
+       struct btrfs_path *path;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+       path->leave_spinning = 1;
+
+       ret = btrfs_insert_delayed_items(trans, path, node->root, node);
+       if (!ret)
+               ret = btrfs_delete_delayed_items(trans, path, node->root, node);
+       if (!ret)
+               ret = btrfs_update_delayed_inode(trans, node->root, path, node);
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+                                    struct inode *inode)
+{
+       struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
+       int ret;
+
+       if (!delayed_node)
+               return 0;
+
+       mutex_lock(&delayed_node->mutex);
+       if (!delayed_node->count) {
+               mutex_unlock(&delayed_node->mutex);
+               btrfs_release_delayed_node(delayed_node);
+               return 0;
+       }
+       mutex_unlock(&delayed_node->mutex);
+
+       ret = __btrfs_commit_inode_delayed_items(trans, delayed_node);
+       btrfs_release_delayed_node(delayed_node);
+       return ret;
+}
+
+void btrfs_remove_delayed_node(struct inode *inode)
+{
+       struct btrfs_delayed_node *delayed_node;
+
+       delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
+       if (!delayed_node)
+               return;
+
+       BTRFS_I(inode)->delayed_node = NULL;
+       btrfs_release_delayed_node(delayed_node);
+}
+
+struct btrfs_async_delayed_node {
+       struct btrfs_root *root;
+       struct btrfs_delayed_node *delayed_node;
+       struct btrfs_work work;
+};
+
+static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
+{
+       struct btrfs_async_delayed_node *async_node;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_path *path;
+       struct btrfs_delayed_node *delayed_node = NULL;
+       struct btrfs_root *root;
+       unsigned long nr = 0;
+       int need_requeue = 0;
+       int ret;
+
+       async_node = container_of(work, struct btrfs_async_delayed_node, work);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               goto out;
+       path->leave_spinning = 1;
+
+       delayed_node = async_node->delayed_node;
+       root = delayed_node->root;
+
+       trans = btrfs_join_transaction(root, 0);
+       if (IS_ERR(trans))
+               goto free_path;
+
+       ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
+       if (!ret)
+               ret = btrfs_delete_delayed_items(trans, path, root,
+                                                delayed_node);
+
+       if (!ret)
+               btrfs_update_delayed_inode(trans, root, path, delayed_node);
+
+       /*
+        * Maybe new delayed items have been inserted, so we need requeue
+        * the work. Besides that, we must dequeue the empty delayed nodes
+        * to avoid the race between delayed items balance and the worker.
+        * The race like this:
+        *      Task1                           Worker thread
+        *                                      count == 0, needn't requeue
+        *                                        also needn't insert the
+        *                                        delayed node into prepare
+        *                                        list again.
+        *      add lots of delayed items
+        *      queue the delayed node
+        *        already in the list,
+        *        and not in the prepare
+        *        list, it means the delayed
+        *        node is being dealt with
+        *        by the worker.
+        *      do delayed items balance
+        *        the delayed node is being
+        *        dealt with by the worker
+        *        now, just wait.
+        *                                      the worker goto idle.
+        * Task1 will sleep until the transaction is commited.
+        */
+       mutex_lock(&delayed_node->mutex);
+       if (delayed_node->count)
+               need_requeue = 1;
+       else
+               btrfs_dequeue_delayed_node(root->fs_info->delayed_root,
+                                          delayed_node);
+       mutex_unlock(&delayed_node->mutex);
+
+       nr = trans->blocks_used;
+
+       btrfs_end_transaction_dmeta(trans, root);
+       __btrfs_btree_balance_dirty(root, nr);
+free_path:
+       btrfs_free_path(path);
+out:
+       if (need_requeue)
+               btrfs_requeue_work(&async_node->work);
+       else {
+               btrfs_release_prepared_delayed_node(delayed_node);
+               kfree(async_node);
+       }
+}
+
+static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
+                                    struct btrfs_root *root, int all)
+{
+       struct btrfs_async_delayed_node *async_node;
+       struct btrfs_delayed_node *curr;
+       int count = 0;
+
+again:
+       curr = btrfs_first_prepared_delayed_node(delayed_root);
+       if (!curr)
+               return 0;
+
+       async_node = kmalloc(sizeof(*async_node), GFP_NOFS);
+       if (!async_node) {
+               btrfs_release_prepared_delayed_node(curr);
+               return -ENOMEM;
+       }
+
+       async_node->root = root;
+       async_node->delayed_node = curr;
+
+       async_node->work.func = btrfs_async_run_delayed_node_done;
+       async_node->work.flags = 0;
+
+       btrfs_queue_worker(&root->fs_info->delayed_workers, &async_node->work);
+       count++;
+
+       if (all || count < 4)
+               goto again;
+
+       return 0;
+}
+
+void btrfs_balance_delayed_items(struct btrfs_root *root)
+{
+       struct btrfs_delayed_root *delayed_root;
+
+       delayed_root = btrfs_get_delayed_root(root);
+
+       if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
+               return;
+
+       if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
+               int ret;
+               ret = btrfs_wq_run_delayed_node(delayed_root, root, 1);
+               if (ret)
+                       return;
+
+               wait_event_interruptible_timeout(
+                               delayed_root->wait,
+                               (atomic_read(&delayed_root->items) <
+                                BTRFS_DELAYED_BACKGROUND),
+                               HZ);
+               return;
+       }
+
+       btrfs_wq_run_delayed_node(delayed_root, root, 0);
+}
+
+int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root, const char *name,
+                                  int name_len, struct inode *dir,
+                                  struct btrfs_disk_key *disk_key, u8 type,
+                                  u64 index)
+{
+       struct btrfs_delayed_node *delayed_node;
+       struct btrfs_delayed_item *delayed_item;
+       struct btrfs_dir_item *dir_item;
+       int ret;
+
+       delayed_node = btrfs_get_or_create_delayed_node(dir);
+       if (IS_ERR(delayed_node))
+               return PTR_ERR(delayed_node);
+
+       delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
+       if (!delayed_item) {
+               ret = -ENOMEM;
+               goto release_node;
+       }
+
+       ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
+       /*
+        * we have reserved enough space when we start a new transaction,
+        * so reserving metadata failure is impossible
+        */
+       BUG_ON(ret);
+
+       delayed_item->key.objectid = dir->i_ino;
+       btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
+       delayed_item->key.offset = index;
+
+       dir_item = (struct btrfs_dir_item *)delayed_item->data;
+       dir_item->location = *disk_key;
+       dir_item->transid = cpu_to_le64(trans->transid);
+       dir_item->data_len = 0;
+       dir_item->name_len = cpu_to_le16(name_len);
+       dir_item->type = type;
+       memcpy((char *)(dir_item + 1), name, name_len);
+
+       mutex_lock(&delayed_node->mutex);
+       ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
+       if (unlikely(ret)) {
+               printk(KERN_ERR "err add delayed dir index item(name: %s) into "
+                               "the insertion tree of the delayed node"
+                               "(root id: %llu, inode id: %llu, errno: %d)\n",
+                               name,
+                               (unsigned long long)delayed_node->root->objectid,
+                               (unsigned long long)delayed_node->inode_id,
+                               ret);
+               BUG();
+       }
+       mutex_unlock(&delayed_node->mutex);
+
+release_node:
+       btrfs_release_delayed_node(delayed_node);
+       return ret;
+}
+
+static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
+                                              struct btrfs_delayed_node *node,
+                                              struct btrfs_key *key)
+{
+       struct btrfs_delayed_item *item;
+
+       mutex_lock(&node->mutex);
+       item = __btrfs_lookup_delayed_insertion_item(node, key);
+       if (!item) {
+               mutex_unlock(&node->mutex);
+               return 1;
+       }
+
+       btrfs_delayed_item_release_metadata(root, item);
+       btrfs_release_delayed_item(item);
+       mutex_unlock(&node->mutex);
+       return 0;
+}
+
+int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root, struct inode *dir,
+                                  u64 index)
+{
+       struct btrfs_delayed_node *node;
+       struct btrfs_delayed_item *item;
+       struct btrfs_key item_key;
+       int ret;
+
+       node = btrfs_get_or_create_delayed_node(dir);
+       if (IS_ERR(node))
+               return PTR_ERR(node);
+
+       item_key.objectid = dir->i_ino;
+       btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
+       item_key.offset = index;
+
+       ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
+       if (!ret)
+               goto end;
+
+       item = btrfs_alloc_delayed_item(0);
+       if (!item) {
+               ret = -ENOMEM;
+               goto end;
+       }
+
+       item->key = item_key;
+
+       ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
+       /*
+        * we have reserved enough space when we start a new transaction,
+        * so reserving metadata failure is impossible.
+        */
+       BUG_ON(ret);
+
+       mutex_lock(&node->mutex);
+       ret = __btrfs_add_delayed_deletion_item(node, item);
+       if (unlikely(ret)) {
+               printk(KERN_ERR "err add delayed dir index item(index: %llu) "
+                               "into the deletion tree of the delayed node"
+                               "(root id: %llu, inode id: %llu, errno: %d)\n",
+                               (unsigned long long)index,
+                               (unsigned long long)node->root->objectid,
+                               (unsigned long long)node->inode_id,
+                               ret);
+               BUG();
+       }
+       mutex_unlock(&node->mutex);
+end:
+       btrfs_release_delayed_node(node);
+       return ret;
+}
+
+int btrfs_inode_delayed_dir_index_count(struct inode *inode)
+{
+       struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
+       int ret = 0;
+
+       if (!delayed_node)
+               return -ENOENT;
+
+       /*
+        * Since we have held i_mutex of this directory, it is impossible that
+        * a new directory index is added into the delayed node and index_cnt
+        * is updated now. So we needn't lock the delayed node.
+        */
+       if (!delayed_node->index_cnt)
+               return -EINVAL;
+
+       BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
+       return ret;
+}
+
+void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
+                            struct list_head *del_list)
+{
+       struct btrfs_delayed_node *delayed_node;
+       struct btrfs_delayed_item *item;
+
+       delayed_node = btrfs_get_delayed_node(inode);
+       if (!delayed_node)
+               return;
+
+       mutex_lock(&delayed_node->mutex);
+       item = __btrfs_first_delayed_insertion_item(delayed_node);
+       while (item) {
+               atomic_inc(&item->refs);
+               list_add_tail(&item->readdir_list, ins_list);
+               item = __btrfs_next_delayed_item(item);
+       }
+
+       item = __btrfs_first_delayed_deletion_item(delayed_node);
+       while (item) {
+               atomic_inc(&item->refs);
+               list_add_tail(&item->readdir_list, del_list);
+               item = __btrfs_next_delayed_item(item);
+       }
+       mutex_unlock(&delayed_node->mutex);
+       /*
+        * This delayed node is still cached in the btrfs inode, so refs
+        * must be > 1 now, and we needn't check it is going to be freed
+        * or not.
+        *
+        * Besides that, this function is used to read dir, we do not
+        * insert/delete delayed items in this period. So we also needn't
+        * requeue or dequeue this delayed node.
+        */
+       atomic_dec(&delayed_node->refs);
+}
+
+void btrfs_put_delayed_items(struct list_head *ins_list,
+                            struct list_head *del_list)
+{
+       struct btrfs_delayed_item *curr, *next;
+
+       list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
+               list_del(&curr->readdir_list);
+               if (atomic_dec_and_test(&curr->refs))
+                       kfree(curr);
+       }
+
+       list_for_each_entry_safe(curr, next, del_list, readdir_list) {
+               list_del(&curr->readdir_list);
+               if (atomic_dec_and_test(&curr->refs))
+                       kfree(curr);
+       }
+}
+
+int btrfs_should_delete_dir_index(struct list_head *del_list,
+                                 u64 index)
+{
+       struct btrfs_delayed_item *curr, *next;
+       int ret;
+
+       if (list_empty(del_list))
+               return 0;
+
+       list_for_each_entry_safe(curr, next, del_list, readdir_list) {
+               if (curr->key.offset > index)
+                       break;
+
+               list_del(&curr->readdir_list);
+               ret = (curr->key.offset == index);
+
+               if (atomic_dec_and_test(&curr->refs))
+                       kfree(curr);
+
+               if (ret)
+                       return 1;
+               else
+                       continue;
+       }
+       return 0;
+}
+
+/*
+ * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
+ *
+ */
+int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
+                                   filldir_t filldir,
+                                   struct list_head *ins_list)
+{
+       struct btrfs_dir_item *di;
+       struct btrfs_delayed_item *curr, *next;
+       struct btrfs_key location;
+       char *name;
+       int name_len;
+       int over = 0;
+       unsigned char d_type;
+
+       if (list_empty(ins_list))
+               return 0;
+
+       /*
+        * Changing the data of the delayed item is impossible. So
+        * we needn't lock them. And we have held i_mutex of the
+        * directory, nobody can delete any directory indexes now.
+        */
+       list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
+               list_del(&curr->readdir_list);
+
+               if (curr->key.offset < filp->f_pos) {
+                       if (atomic_dec_and_test(&curr->refs))
+                               kfree(curr);
+                       continue;
+               }
+
+               filp->f_pos = curr->key.offset;
+
+               di = (struct btrfs_dir_item *)curr->data;
+               name = (char *)(di + 1);
+               name_len = le16_to_cpu(di->name_len);
+
+               d_type = btrfs_filetype_table[di->type];
+               btrfs_disk_key_to_cpu(&location, &di->location);
+
+               over = filldir(dirent, name, name_len, curr->key.offset,
+                              location.objectid, d_type);
+
+               if (atomic_dec_and_test(&curr->refs))
+                       kfree(curr);
+
+               if (over)
+                       return 1;
+       }
+       return 0;
+}
+
+BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
+                        generation, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
+                        sequence, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
+                        transid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
+                        nbytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
+                        block_group, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
+
+static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
+                                 struct btrfs_inode_item *inode_item,
+                                 struct inode *inode)
+{
+       btrfs_set_stack_inode_uid(inode_item, inode->i_uid);
+       btrfs_set_stack_inode_gid(inode_item, inode->i_gid);
+       btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
+       btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
+       btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
+       btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
+       btrfs_set_stack_inode_generation(inode_item,
+                                        BTRFS_I(inode)->generation);
+       btrfs_set_stack_inode_sequence(inode_item, BTRFS_I(inode)->sequence);
+       btrfs_set_stack_inode_transid(inode_item, trans->transid);
+       btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
+       btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
+       btrfs_set_stack_inode_block_group(inode_item,
+                                         BTRFS_I(inode)->block_group);
+
+       btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
+                                    inode->i_atime.tv_sec);
+       btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
+                                     inode->i_atime.tv_nsec);
+
+       btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
+                                    inode->i_mtime.tv_sec);
+       btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
+                                     inode->i_mtime.tv_nsec);
+
+       btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
+                                    inode->i_ctime.tv_sec);
+       btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
+                                     inode->i_ctime.tv_nsec);
+}
+
+int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
+                              struct btrfs_root *root, struct inode *inode)
+{
+       struct btrfs_delayed_node *delayed_node;
+       int ret;
+
+       delayed_node = btrfs_get_or_create_delayed_node(inode);
+       if (IS_ERR(delayed_node))
+               return PTR_ERR(delayed_node);
+
+       mutex_lock(&delayed_node->mutex);
+       if (delayed_node->inode_dirty) {
+               fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
+               goto release_node;
+       }
+
+       ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
+       /*
+        * we must reserve enough space when we start a new transaction,
+        * so reserving metadata failure is impossible
+        */
+       BUG_ON(ret);
+
+       fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
+       delayed_node->inode_dirty = 1;
+       delayed_node->count++;
+       atomic_inc(&root->fs_info->delayed_root->items);
+release_node:
+       mutex_unlock(&delayed_node->mutex);
+       btrfs_release_delayed_node(delayed_node);
+       return ret;
+}
+
+static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
+{
+       struct btrfs_root *root = delayed_node->root;
+       struct btrfs_delayed_item *curr_item, *prev_item;
+
+       mutex_lock(&delayed_node->mutex);
+       curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
+       while (curr_item) {
+               btrfs_delayed_item_release_metadata(root, curr_item);
+               prev_item = curr_item;
+               curr_item = __btrfs_next_delayed_item(prev_item);
+               btrfs_release_delayed_item(prev_item);
+       }
+
+       curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
+       while (curr_item) {
+               btrfs_delayed_item_release_metadata(root, curr_item);
+               prev_item = curr_item;
+               curr_item = __btrfs_next_delayed_item(prev_item);
+               btrfs_release_delayed_item(prev_item);
+       }
+
+       if (delayed_node->inode_dirty) {
+               btrfs_delayed_inode_release_metadata(root, delayed_node);
+               btrfs_release_delayed_inode(delayed_node);
+       }
+       mutex_unlock(&delayed_node->mutex);
+}
+
+void btrfs_kill_delayed_inode_items(struct inode *inode)
+{
+       struct btrfs_delayed_node *delayed_node;
+
+       delayed_node = btrfs_get_delayed_node(inode);
+       if (!delayed_node)
+               return;
+
+       __btrfs_kill_delayed_node(delayed_node);
+       btrfs_release_delayed_node(delayed_node);
+}
+
+void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
+{
+       u64 inode_id = 0;
+       struct btrfs_delayed_node *delayed_nodes[8];
+       int i, n;
+
+       while (1) {
+               spin_lock(&root->inode_lock);
+               n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
+                                          (void **)delayed_nodes, inode_id,
+                                          ARRAY_SIZE(delayed_nodes));
+               if (!n) {
+                       spin_unlock(&root->inode_lock);
+                       break;
+               }
+
+               inode_id = delayed_nodes[n - 1]->inode_id + 1;
+
+               for (i = 0; i < n; i++)
+                       atomic_inc(&delayed_nodes[i]->refs);
+               spin_unlock(&root->inode_lock);
+
+               for (i = 0; i < n; i++) {
+                       __btrfs_kill_delayed_node(delayed_nodes[i]);
+                       btrfs_release_delayed_node(delayed_nodes[i]);
+               }
+       }
+}