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* [PATCH V3] btrfs: implement delayed inode items operation
@ 2011-03-03  6:06 Miao Xie
  2011-03-05  7:01 ` Itaru Kitayama
  2011-03-08 16:56 ` David Sterba
  0 siblings, 2 replies; 17+ messages in thread
From: Miao Xie @ 2011-03-03  6:06 UTC (permalink / raw)
  To: Chris Mason; +Cc: Linux Btrfs, David Sterba, Ito, Itaru Kitayama

Changelog V2 -> V3:
- Fix the race between the delayed worker and the task which does delayed items
  balance, which is reported by Tsutomu Itoh.
- Modify the patch address David Sterba's comment.
- Fix the bug of the cpu recursion spinlock, reported by Chris Mason
- introduce a list to manage the delayed nodes which is waiting to be dealt
  with by the work thread.

Changelog V1 -> V2:
- break up the global rb-tree, use a list to manage the delayed nodes,
  which is created for every directory and file, and used to manage the
  delayed directory name index items and the delayed inode item.
- introduce a worker to deal with the delayed nodes.

Compare with Ext3/4, the performance of file creation and deletion on btrfs
is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
such as inode item, directory name item, directory name index and so on.

If we can do some delayed b+ tree insertion or deletion, we can improve the
performance, so we made this patch which implemented delayed directory name
index insertion/deletion and delayed inode update.

Implementation:
- introduce a delayed root object into the filesystem, that use two lists to
  manage the delayed nodes which are created for every file/directory.
  One is used to manage all the delayed nodes that have delayed items. And the
  other is used to manage the delayed nodes which is waiting to be dealt with
  by the work thread.
- Every delayed node has two rb-tree, one is used to manage the directory name
  index which is going to be inserted into b+ tree, and the other is used to
  manage the directory name index which is going to be deleted from b+ tree.
- introduce a worker to deal with the delayed operation. This worker is used
  to deal with the works of the delayed directory name index items insertion
  and deletion and the delayed inode update.
  When the delayed items is beyond the lower limit, we create works for some
  delayed nodes and insert them into the work queue of the worker, and then
  go back.
  When the delayed items is beyond the upper bound, we create works for all
  the delayed nodes that haven't been dealt with, and insert them into the work
  queue of the worker, and then wait for that the untreated items is below some
  threshold value.
- When we want to insert a directory name index into b+ tree, we just add the
  information into the delayed inserting rb-tree.
  And then we check the number of the delayed items and do delayed items
  balance. (The balance policy is above.)
- When we want to delete a directory name index from the b+ tree, we search it
  in the inserting rb-tree at first. If we look it up, just drop it. If not,
  add the key of it into the delayed deleting rb-tree.
  Similar to the delayed inserting rb-tree, we also check the number of the
  delayed items and do delayed items balance.
  (The same to inserting manipulation)
- When we want to update the metadata of some inode, we cached the data of the
  inode into the delayed node. the worker will flush it into the b+ tree after
  dealing with the delayed insertion and deletion.
- We will move the delayed node to the tail of the list after we access the
  delayed node, By this way, we can cache more delayed items and merge more
  inode updates.
- If we want to commit transaction, we will deal with all the delayed node.
- the delayed node will be freed when we free the btrfs inode.
- Before we log the inode items, we commit all the directory name index items
  and the delayed inode update.

I did a quick test by the benchmark tool[1] and found we can improve the
performance of file creation by ~15%, and file deletion by ~20%.

Before applying this patch:
Create files:
	Total files: 50000
	Total time: 1.096108
	Average time: 0.000022
Delete files:
	Total files: 50000
	Total time: 1.510403
	Average time: 0.000030

After applying this patch:
Create files:
	Total files: 50000
	Total time: 0.932899
	Average time: 0.000019
Delete files:
	Total files: 50000
	Total time: 1.215732
	Average time: 0.000024

[1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dave@jikos.cz>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
---
 fs/btrfs/Makefile        |    2 +-
 fs/btrfs/btrfs_inode.h   |    5 +
 fs/btrfs/ctree.c         |   14 +-
 fs/btrfs/ctree.h         |   24 +-
 fs/btrfs/delayed-inode.c | 1614 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/delayed-inode.h |  139 ++++
 fs/btrfs/dir-item.c      |   32 +-
 fs/btrfs/disk-io.c       |   26 +-
 fs/btrfs/extent-tree.c   |   18 +-
 fs/btrfs/inode.c         |  109 ++--
 fs/btrfs/ioctl.c         |    2 +-
 fs/btrfs/super.c         |   10 +-
 fs/btrfs/transaction.c   |   49 ++-
 fs/btrfs/transaction.h   |    2 +
 fs/btrfs/tree-log.c      |    7 +
 15 files changed, 1945 insertions(+), 108 deletions(-)
 create mode 100644 fs/btrfs/delayed-inode.c
 create mode 100644 fs/btrfs/delayed-inode.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 31610ea..a8411c2 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -7,4 +7,4 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
 	   extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
 	   export.o tree-log.o acl.o free-space-cache.o zlib.o lzo.o \
-	   compression.o delayed-ref.o relocation.o
+	   compression.o delayed-ref.o relocation.o delayed-inode.o
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index ccc991c..ef3baa8 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -22,6 +22,7 @@
 #include "extent_map.h"
 #include "extent_io.h"
 #include "ordered-data.h"
+#include "delayed-inode.h"
 
 /* in memory btrfs inode */
 struct btrfs_inode {
@@ -159,9 +160,13 @@ struct btrfs_inode {
 	 */
 	unsigned force_compress:4;
 
+	struct btrfs_delayed_node *delayed_node;
+
 	struct inode vfs_inode;
 };
 
+extern unsigned char btrfs_filetype_table[];
+
 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 {
 	return container_of(inode, struct btrfs_inode, vfs_inode);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b5baff0..6e3e4c3 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,11 +38,6 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct extent_buffer *src_buf);
 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		   struct btrfs_path *path, int level, int slot);
-static int setup_items_for_insert(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root, struct btrfs_path *path,
-			struct btrfs_key *cpu_key, u32 *data_size,
-			u32 total_data, u32 total_size, int nr);
-
 
 struct btrfs_path *btrfs_alloc_path(void)
 {
@@ -3688,11 +3683,10 @@ out:
  * to save stack depth by doing the bulk of the work in a function
  * that doesn't call btrfs_search_slot
  */
-static noinline_for_stack int
-setup_items_for_insert(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root, struct btrfs_path *path,
-		      struct btrfs_key *cpu_key, u32 *data_size,
-		      u32 total_data, u32 total_size, int nr)
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr)
 {
 	struct btrfs_item *item;
 	int i;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 28188a7..bafca2e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -859,6 +859,7 @@ struct btrfs_block_group_cache {
 struct reloc_control;
 struct btrfs_device;
 struct btrfs_fs_devices;
+struct btrfs_delayed_root;
 struct btrfs_fs_info {
 	u8 fsid[BTRFS_FSID_SIZE];
 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
@@ -885,7 +886,10 @@ struct btrfs_fs_info {
 	/* logical->physical extent mapping */
 	struct btrfs_mapping_tree mapping_tree;
 
-	/* block reservation for extent, checksum and root tree */
+	/*
+	 * block reservation for extent, checksum, root tree and
+	 * delayed dir index item
+	 */
 	struct btrfs_block_rsv global_block_rsv;
 	/* block reservation for delay allocation */
 	struct btrfs_block_rsv delalloc_block_rsv;
@@ -1012,6 +1016,7 @@ struct btrfs_fs_info {
 	 * for the sys_munmap function call path
 	 */
 	struct btrfs_workers fixup_workers;
+	struct btrfs_workers delayed_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;
 	int thread_pool_size;
@@ -1069,6 +1074,8 @@ struct btrfs_fs_info {
 
 	/* filesystem state */
 	u64 fs_state;
+
+	struct btrfs_delayed_root *delayed_root;
 };
 
 /*
@@ -2086,6 +2093,13 @@ static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
 }
 
 /* extent-tree.c */
+static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
+						 int num_items)
+{
+	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
+		3 * num_items;
+}
+
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root, unsigned long count);
@@ -2277,6 +2291,8 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_set_path_blocking(struct btrfs_path *p);
+void btrfs_clear_path_blocking(struct btrfs_path *p,
+			       struct extent_buffer *held);
 void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -2288,6 +2304,10 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 	return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr);
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
@@ -2349,7 +2369,7 @@ int btrfs_set_root_node(struct btrfs_root_item *item,
 /* dir-item.c */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, const char *name,
-			  int name_len, u64 dir,
+			  int name_len, struct inode *dir,
 			  struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
new file mode 100644
index 0000000..495a6af
--- /dev/null
+++ b/fs/btrfs/delayed-inode.c
@@ -0,0 +1,1614 @@
+/*
+ * 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,
+				u64 root_id, u64 inode_id)
+{
+	delayed_node->root_id = root_id;
+	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;
+	delayed_node->block_rsv = NULL;
+}
+
+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;
+
+	if (btrfs_inode->delayed_node) {
+		node = btrfs_inode->delayed_node;
+		atomic_inc(&node->refs);	/* can be accessed */
+		return node;
+	}
+
+	node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	btrfs_init_delayed_node(node, root->objectid, inode->i_ino);
+
+	btrfs_inode->delayed_node = node;
+	node->delayed_root = btrfs_get_delayed_root(root);
+	atomic_inc(&node->refs);	/* cached in the btrfs inode */
+	atomic_inc(&node->refs);	/* can be accessed */
+
+	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 = node->delayed_root;
+	struct list_head *p;
+	struct btrfs_delayed_node *next = NULL;
+
+	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->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))
+		kmem_cache_free(delayed_node_cache, delayed_node);
+}
+
+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;
+	}
+	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->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->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);
+		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;
+		node->block_rsv = dst_rsv;
+	}
+
+	return ret;
+}
+
+static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
+						struct btrfs_delayed_node *node)
+{
+	if (!node->bytes_reserved)
+		return;
+
+	btrfs_block_rsv_release(root, node->block_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)
+{
+	if (delayed_node && delayed_node->inode_dirty) {
+		BUG_ON(!delayed_node->delayed_root);
+		delayed_node->inode_dirty = 0;
+		delayed_node->count--;
+		atomic_dec(&delayed_node->delayed_root->items);
+		if (atomic_read(&delayed_node->delayed_root->items) <
+		    BTRFS_DELAYED_BACKGROUND &&
+		    waitqueue_active(&delayed_node->delayed_root->wait))
+			wake_up(&delayed_node->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) {
+		/*
+		 * check root, if root is not the one which the delayed item
+		 * wants to be inserted to, we get the right root.
+		 */
+		if (root->objectid != curr_node->root_id) {
+			root = btrfs_get_fs_root(root, curr_node->root_id);
+			BUG_ON(IS_ERR_OR_NULL(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;
+}
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode)
+{
+	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
+	struct btrfs_path *path;
+	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);
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		btrfs_release_delayed_node(delayed_node);
+		return -ENOMEM;
+	}
+	path->leave_spinning = 1;
+
+	ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
+	if (!ret)
+		ret = btrfs_delete_delayed_items(trans, path, root,
+						 delayed_node);
+	if (!ret)
+		ret = btrfs_update_delayed_inode(trans, root, path,
+						 delayed_node);
+	btrfs_free_path(path);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_remove_delayed_node(struct inode *inode)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
+	int ret;
+
+	if (!delayed_node)
+		return 0;
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = btrfs_commit_inode_delayed_items(trans, root, inode);
+	if (ret)
+		goto out;
+
+	BUG_ON(delayed_node->in_list);
+	BUG_ON(delayed_node->count);
+
+	BTRFS_I(inode)->delayed_node = NULL;
+	btrfs_release_delayed_node(delayed_node);
+out:
+	btrfs_end_transaction_dmeta(trans, root);
+
+	return ret;
+}
+
+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;
+
+	root = async_node->root;
+	BUG_ON(!root);
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		goto free_path;
+
+	delayed_node = async_node->delayed_node;
+
+	root = btrfs_get_fs_root(async_node->root, delayed_node->root_id);
+	BUG_ON(IS_ERR_OR_NULL(root));
+
+	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(delayed_node->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_id,
+				(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_id,
+				(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;
+}
+
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode)
+{
+	struct btrfs_delayed_node *delayed_node;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (delayed_node)
+		mutex_lock(&delayed_node->mutex);
+
+	return delayed_node;
+}
+
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node)
+{
+	if (!node)
+		return;
+
+	mutex_unlock(&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(&node->refs);
+}
+
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index)
+{
+	if (!delayed_node)
+		return 0;
+
+	if (IS_ERR(*item))
+		return 0;
+
+	if (!(*item))
+		*item = __btrfs_first_delayed_deletion_item(delayed_node);
+
+	while (*item) {
+		if ((*item)->key.offset < index) {
+			*item = __btrfs_next_delayed_item(*item);
+			continue;
+		} else if ((*item)->key.offset > index)
+			break;
+
+		*item = __btrfs_next_delayed_item(*item);
+		if (!(*item))
+			*item = ERR_PTR(-ERANGE);
+		return 1;
+	}
+
+	if (!(*item))
+		*item = ERR_PTR(-ERANGE);
+	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 btrfs_delayed_node *delayed_node)
+{
+	struct btrfs_dir_item *di;
+	struct btrfs_delayed_item *item;
+	struct btrfs_key location;
+	char *name;
+	int name_len;
+	int over = 0;
+	unsigned char d_type;
+
+	if (!delayed_node)
+		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.
+	 */
+	item = __btrfs_first_delayed_insertion_item(delayed_node);
+	while (item) {
+		if (item->key.offset < filp->f_pos) {
+			item = __btrfs_next_delayed_item(item);
+			continue;
+		}
+
+		filp->f_pos = item->key.offset;
+
+		di = (struct btrfs_dir_item *)item->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, item->key.offset,
+			       location.objectid, d_type);
+
+		if (over)
+			return 1;
+		item = __btrfs_next_delayed_item(item);
+	}
+	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(&delayed_node->delayed_root->items);
+release_node:
+	mutex_unlock(&delayed_node->mutex);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode)
+{
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node;
+	struct btrfs_delayed_item *curr_item, *prev_item;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (!delayed_node)
+		return 0;
+
+	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);
+
+	btrfs_release_delayed_node(delayed_node);
+
+	return 0;
+}
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
new file mode 100644
index 0000000..d4134bc
--- /dev/null
+++ b/fs/btrfs/delayed-inode.h
@@ -0,0 +1,139 @@
+/*
+ * 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.
+ */
+
+#ifndef __DELAYED_TREE_OPERATION_H
+#define __DELAYED_TREE_OPERATION_H
+
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include "ctree.h"
+
+/* types of the delayed item */
+#define BTRFS_DELAYED_INSERTION_ITEM	1
+#define BTRFS_DELAYED_DELETION_ITEM	2
+
+struct btrfs_delayed_root {
+	spinlock_t lock;
+	struct list_head node_list;
+	/*
+	 * Used for delayed nodes which is waiting to be dealt with by the
+	 * worker. If the delayed node is inserted into the work queue, we
+	 * drop it from this list.
+	 */
+	struct list_head prepare_list;
+	atomic_t items;		/* for delayed items */
+	int nodes;		/* for delayed nodes */
+	wait_queue_head_t wait;
+};
+
+struct btrfs_delayed_node {
+	u64 root_id;
+	u64 inode_id;
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_root *delayed_root;
+	/* Used to add the node into the delayed root's node list. */
+	struct list_head n_list;
+	/*
+	 * Used to add the node into the prepare list, the nodes in this list
+	 * is waiting to be dealt with by the async worker.
+	 */
+	struct list_head p_list;
+	struct rb_root ins_root;
+	struct rb_root del_root;
+	struct mutex mutex;
+	struct btrfs_inode_item inode_item;
+	atomic_t refs;
+	u64 index_cnt;
+	bool in_list;
+	bool inode_dirty;
+	int count;
+};
+
+struct btrfs_delayed_item {
+	struct rb_node rb_node;
+	struct btrfs_key key;
+	struct list_head tree_list;	/* used for batch insert/delete items */
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_node *delayed_node;
+	int ins_or_del;
+	u32 data_len;
+	char data[0];
+};
+
+static inline void btrfs_init_delayed_root(
+				struct btrfs_delayed_root *delayed_root)
+{
+	atomic_set(&delayed_root->items, 0);
+	delayed_root->nodes = 0;
+	spin_lock_init(&delayed_root->lock);
+	init_waitqueue_head(&delayed_root->wait);
+	INIT_LIST_HEAD(&delayed_root->node_list);
+	INIT_LIST_HEAD(&delayed_root->prepare_list);
+}
+
+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);
+
+int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
+				   struct btrfs_root *root, struct inode *dir,
+				   u64 index);
+
+int btrfs_inode_delayed_dir_index_count(struct inode *inode);
+
+int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+
+void btrfs_balance_delayed_items(struct btrfs_root *root);
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode);
+/* Used for evicting the inode. */
+int btrfs_remove_delayed_node(struct inode *inode);
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode);
+
+
+int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root, struct inode *inode);
+
+/* Used for readdir() */
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode);
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node);
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index);
+int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
+				    filldir_t filldir,
+				    struct btrfs_delayed_node *delayed_node);
+
+/* for init */
+int __init btrfs_delayed_inode_init(void);
+void btrfs_delayed_inode_exit(void);
+#endif
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f0cad5a..696c793 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -124,8 +124,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  * to use for the second index (if one is created).
  */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, const char *name, int name_len, u64 dir,
-			  struct btrfs_key *location, u8 type, u64 index)
+			  *root, const char *name, int name_len,
+			  struct inode *dir, struct btrfs_key *location,
+			  u8 type, u64 index)
 {
 	int ret = 0;
 	int ret2 = 0;
@@ -137,13 +138,17 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	struct btrfs_disk_key disk_key;
 	u32 data_size;
 
-	key.objectid = dir;
+	key.objectid = dir->i_ino;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
 
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->leave_spinning = 1;
 
+	btrfs_cpu_key_to_disk(&disk_key, location);
+
 	data_size = sizeof(*dir_item) + name_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 					name, name_len);
@@ -155,7 +160,6 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	}
 
 	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
 	btrfs_set_dir_data_len(leaf, dir_item, 0);
@@ -174,24 +178,8 @@ second_insert:
 	}
 	btrfs_release_path(root, path);
 
-	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-	key.offset = index;
-	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
-					name, name_len);
-	if (IS_ERR(dir_item)) {
-		ret2 = PTR_ERR(dir_item);
-		goto out;
-	}
-	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
-	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
-	btrfs_set_dir_type(leaf, dir_item, type);
-	btrfs_set_dir_data_len(leaf, dir_item, 0);
-	btrfs_set_dir_name_len(leaf, dir_item, name_len);
-	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
-	name_ptr = (unsigned long)(dir_item + 1);
-	write_extent_buffer(leaf, name, name_ptr, name_len);
-	btrfs_mark_buffer_dirty(leaf);
+	ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir,
+					      &disk_key, type, index);
 out:
 	btrfs_free_path(path);
 	if (ret)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3e1ea3e..ea3c145 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1676,6 +1676,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	INIT_LIST_HEAD(&fs_info->ordered_extents);
 	spin_lock_init(&fs_info->ordered_extent_lock);
+	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+					GFP_NOFS);
+	if (!fs_info->delayed_root) {
+		err = -ENOMEM;
+		goto fail_iput;
+	}
+	btrfs_init_delayed_root(fs_info->delayed_root);
 
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
@@ -1743,7 +1750,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	bh = btrfs_read_dev_super(fs_devices->latest_bdev);
 	if (!bh) {
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
@@ -1755,7 +1762,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	disk_super = &fs_info->super_copy;
 	if (!btrfs_super_root(disk_super))
-		goto fail_iput;
+		goto fail_alloc;
 
 	/* check FS state, whether FS is broken. */
 	fs_info->fs_state |= btrfs_super_flags(disk_super);
@@ -1765,7 +1772,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	ret = btrfs_parse_options(tree_root, options);
 	if (ret) {
 		err = ret;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super) &
@@ -1775,7 +1782,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported optional features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super);
@@ -1791,7 +1798,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported option features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	btrfs_init_workers(&fs_info->generic_worker,
@@ -1838,6 +1845,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 			   &fs_info->generic_worker);
 	btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
 			   1, &fs_info->generic_worker);
+	btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
+			   fs_info->thread_pool_size,
+			   &fs_info->generic_worker);
 
 	/*
 	 * endios are largely parallel and should have a very
@@ -1859,6 +1869,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
+	btrfs_start_workers(&fs_info->delayed_workers, 1);
 
 	fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
 	fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -2104,6 +2115,9 @@ fail_sb_buffer:
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
+fail_alloc:
+	kfree(fs_info->delayed_root);
 fail_iput:
 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 	iput(fs_info->btree_inode);
@@ -2551,6 +2565,7 @@ int close_ctree(struct btrfs_root *root)
 	del_fs_roots(fs_info);
 
 	iput(fs_info->btree_inode);
+	kfree(fs_info->delayed_root);
 
 	btrfs_stop_workers(&fs_info->generic_worker);
 	btrfs_stop_workers(&fs_info->fixup_workers);
@@ -2562,6 +2577,7 @@ int close_ctree(struct btrfs_root *root)
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
 
 	btrfs_close_devices(fs_info->fs_devices);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 100e409..aed763f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3897,12 +3897,6 @@ static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
 }
 
-static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
-{
-	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
-		3 * num_items;
-}
-
 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 int num_items)
@@ -3913,7 +3907,7 @@ int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 	if (num_items == 0 || root->fs_info->chunk_root == root)
 		return 0;
 
-	num_bytes = calc_trans_metadata_size(root, num_items);
+	num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
 	ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
 				  num_bytes);
 	if (!ret) {
@@ -3952,14 +3946,14 @@ int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * If all of the metadata space is used, we can commit
 	 * transaction and use space it freed.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
 void btrfs_orphan_release_metadata(struct inode *inode)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
 }
 
@@ -3973,7 +3967,7 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * two for root back/forward refs, two for directory entries
 	 * and one for root of the snapshot.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 5);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
 	dst_rsv->space_info = src_rsv->space_info;
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
@@ -4000,7 +3994,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
 	if (nr_extents > BTRFS_I(inode)->reserved_extents) {
 		nr_extents -= BTRFS_I(inode)->reserved_extents;
-		to_reserve = calc_trans_metadata_size(root, nr_extents);
+		to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
 	} else {
 		nr_extents = 0;
 		to_reserve = 0;
@@ -4047,7 +4041,7 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 
 	to_free = calc_csum_metadata_size(inode, num_bytes);
 	if (nr_extents > 0)
-		to_free += calc_trans_metadata_size(root, nr_extents);
+		to_free += btrfs_calc_trans_metadata_size(root, nr_extents);
 
 	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
 				to_free);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7027953..8456d97 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2598,33 +2598,12 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root, struct inode *inode)
 {
-	struct btrfs_inode_item *inode_item;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
 	int ret;
 
-	path = btrfs_alloc_path();
-	BUG_ON(!path);
-	path->leave_spinning = 1;
-	ret = btrfs_lookup_inode(trans, root, path,
-				 &BTRFS_I(inode)->location, 1);
-	if (ret) {
-		if (ret > 0)
-			ret = -ENOENT;
-		goto failed;
-	}
-
-	btrfs_unlock_up_safe(path, 1);
-	leaf = path->nodes[0];
-	inode_item = btrfs_item_ptr(leaf, path->slots[0],
-				  struct btrfs_inode_item);
+	ret = btrfs_delayed_update_inode(trans, root, inode);
+	if (!ret)
+		btrfs_set_inode_last_trans(trans, inode);
 
-	fill_inode_item(trans, leaf, inode_item, inode);
-	btrfs_mark_buffer_dirty(leaf);
-	btrfs_set_inode_last_trans(trans, inode);
-	ret = 0;
-failed:
-	btrfs_free_path(path);
 	return ret;
 }
 
@@ -2680,18 +2659,9 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto err;
 	}
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
-		goto err;
-	}
-	if (!di) {
-		ret = -ENOENT;
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
+	if (ret)
 		goto err;
-	}
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
-	btrfs_release_path(root, path);
 
 	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
 					 inode, dir->i_ino);
@@ -2867,6 +2837,14 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 	index = btrfs_inode_ref_index(path->nodes[0], ref);
 	btrfs_release_path(root, path);
 
+	/*
+	 * This is a commit root search, if we can lookup inode item and other
+	 * relative items in the commit root, it means the transaction of
+	 * dir/file creation has been committed, and the dir index item that we
+	 * delay to insert has also been inserted into the commit root. So
+	 * we needn't worry about the delayed insertion of the dir index item
+	 * here.
+	 */
 	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
 				dentry->d_name.name, dentry->d_name.len, 0);
 	if (IS_ERR(di)) {
@@ -2972,24 +2950,16 @@ int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 		btrfs_release_path(root, path);
 		index = key.offset;
 	}
+	btrfs_release_path(root, path);
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	BUG_ON(!di || IS_ERR(di));
-
-	leaf = path->nodes[0];
-	btrfs_dir_item_key_to_cpu(leaf, di, &key);
-	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
 	BUG_ON(ret);
-	btrfs_release_path(root, path);
 
 	btrfs_i_size_write(dir, dir->i_size - name_len * 2);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 	ret = btrfs_update_inode(trans, root, dir);
 	BUG_ON(ret);
 
-	btrfs_free_path(path);
 	return 0;
 }
 
@@ -3249,6 +3219,15 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	if (root->ref_cows || root == root->fs_info->tree_root)
 		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
 
+	/*
+	 * This function is also used to drop the items in the log tree before
+	 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
+	 * it is used to drop the loged items. So we shouldn't kill the delayed
+	 * items.
+	 */
+	if (min_type == 0 && root == BTRFS_I(inode)->root)
+		btrfs_kill_delayed_inode_items(trans, inode);
+
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
 	path->reada = -1;
@@ -4182,7 +4161,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
 	return d_splice_alias(inode, dentry);
 }
 
-static unsigned char btrfs_filetype_table[] = {
+unsigned char btrfs_filetype_table[] = {
 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
 };
 
@@ -4196,6 +4175,8 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	struct btrfs_path *path;
+	struct btrfs_delayed_node *delayed_node = NULL;
+	struct btrfs_delayed_item *delayed_item = NULL;
 	int ret;
 	u32 nritems;
 	struct extent_buffer *leaf;
@@ -4210,6 +4191,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	char tmp_name[32];
 	char *name_ptr;
 	int name_len;
+	int is_curr = 0;	/* filp->f_pos points to the current index? */
 
 	/* FIXME, use a real flag for deciding about the key type */
 	if (root->fs_info->tree_root == root)
@@ -4234,8 +4216,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 		filp->f_pos = 2;
 	}
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->reada = 2;
 
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		delayed_node = btrfs_get_locked_delayed_node(inode);
+
 	btrfs_set_key_type(&key, key_type);
 	key.offset = filp->f_pos;
 	key.objectid = inode->i_ino;
@@ -4273,8 +4260,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 			break;
 		if (found_key.offset < filp->f_pos)
 			continue;
+		if (key_type == BTRFS_DIR_INDEX_KEY &&
+		    btrfs_should_delete_dir_index(delayed_node, &delayed_item,
+						  found_key.offset))
+			continue;
 
 		filp->f_pos = found_key.offset;
+		is_curr = 1;
 
 		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 		di_cur = 0;
@@ -4324,6 +4316,15 @@ skip:
 		}
 	}
 
+	if (key_type == BTRFS_DIR_INDEX_KEY) {
+		if (is_curr)
+			filp->f_pos++;
+		ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
+						      delayed_node);
+		if (ret)
+			goto nopos;
+	}
+
 	/* Reached end of directory/root. Bump pos past the last item. */
 	if (key_type == BTRFS_DIR_INDEX_KEY)
 		/*
@@ -4336,6 +4337,8 @@ skip:
 nopos:
 	ret = 0;
 err:
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		btrfs_put_locked_delayed_node(delayed_node);
 	btrfs_free_path(path);
 	return ret;
 }
@@ -4481,9 +4484,12 @@ int btrfs_set_inode_index(struct inode *dir, u64 *index)
 	int ret = 0;
 
 	if (BTRFS_I(dir)->index_cnt == (u64)-1) {
-		ret = btrfs_set_inode_index_count(dir);
-		if (ret)
-			return ret;
+		ret = btrfs_inode_delayed_dir_index_count(dir);
+		if (ret) {
+			ret = btrfs_set_inode_index_count(dir);
+			if (ret)
+				return ret;
+		}
 	}
 
 	*index = BTRFS_I(dir)->index_cnt;
@@ -4641,7 +4647,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
 
 	if (ret == 0) {
 		ret = btrfs_insert_dir_item(trans, root, name, name_len,
-					    parent_inode->i_ino, &key,
+					    parent_inode, &key,
 					    btrfs_inode_type(inode), index);
 		BUG_ON(ret);
 
@@ -6642,6 +6648,8 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->dummy_inode = 0;
 	ei->force_compress = BTRFS_COMPRESS_NONE;
 
+	ei->delayed_node = NULL;
+
 	inode = &ei->vfs_inode;
 	extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
 	extent_io_tree_init(&ei->io_tree, &inode->i_data, GFP_NOFS);
@@ -6725,6 +6733,7 @@ void btrfs_destroy_inode(struct inode *inode)
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 free:
+	btrfs_remove_delayed_node(inode);
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..b200e07 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -333,7 +333,7 @@ static noinline int create_subvol(struct btrfs_root *root,
 	BUG_ON(ret);
 
 	ret = btrfs_insert_dir_item(trans, root,
-				    name, namelen, dir->i_ino, &key,
+				    name, namelen, dir, &key,
 				    BTRFS_FT_DIR, index);
 	if (ret)
 		goto fail;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db0a827..593ce8a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -40,6 +40,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include "compat.h"
+#include "delayed-inode.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1163,10 +1164,14 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_extent_io;
 
-	err = btrfs_interface_init();
+	err = btrfs_delayed_inode_init();
 	if (err)
 		goto free_extent_map;
 
+	err = btrfs_interface_init();
+	if (err)
+		goto free_delayed_inode;
+
 	err = register_filesystem(&btrfs_fs_type);
 	if (err)
 		goto unregister_ioctl;
@@ -1176,6 +1181,8 @@ static int __init init_btrfs_fs(void)
 
 unregister_ioctl:
 	btrfs_interface_exit();
+free_delayed_inode:
+	btrfs_delayed_inode_exit();
 free_extent_map:
 	extent_map_exit();
 free_extent_io:
@@ -1192,6 +1199,7 @@ free_sysfs:
 static void __exit exit_btrfs_fs(void)
 {
 	btrfs_destroy_cachep();
+	btrfs_delayed_inode_exit();
 	extent_map_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3d73c8d..31b328b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -478,19 +478,46 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 1, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 1, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 0);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 0);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
+}
+
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root)
+{
+	return __btrfs_end_transaction(trans, root, 1, 1);
 }
 
 /*
@@ -958,7 +985,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	BUG_ON(ret);
 	ret = btrfs_insert_dir_item(trans, parent_root,
 				dentry->d_name.name, dentry->d_name.len,
-				parent_inode->i_ino, &key,
+				parent_inode, &key,
 				BTRFS_FT_DIR, index);
 	BUG_ON(ret);
 
@@ -1027,6 +1054,14 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 	int ret;
 
 	list_for_each_entry(pending, head, list) {
+		/*
+		 * We must deal with the delayed items before creating
+		 * snapshots, or we will create a snapthot with inconsistent
+		 * information.
+		*/
+		ret = btrfs_run_delayed_items(trans, fs_info->fs_root);
+		BUG_ON(ret);
+
 		ret = create_pending_snapshot(trans, fs_info, pending);
 		BUG_ON(ret);
 	}
@@ -1279,6 +1314,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 			BUG_ON(ret);
 		}
 
+		ret = btrfs_run_delayed_items(trans, root);
+		BUG_ON(ret);
+
 		/*
 		 * rename don't use btrfs_join_transaction, so, once we
 		 * set the transaction to blocked above, we aren't going
@@ -1305,6 +1343,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	ret = create_pending_snapshots(trans, root->fs_info);
 	BUG_ON(ret);
 
+	ret = btrfs_run_delayed_items(trans, root);
+	BUG_ON(ret);
+
 	ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
 	BUG_ON(ret);
 
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 229a594..a4a441f 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -115,6 +115,8 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 				   int wait_for_unblock);
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root);
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root);
 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root);
 void btrfs_throttle(struct btrfs_root *root);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a4bbb85..e8a2e95 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2775,6 +2775,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		max_key.type = (u8)-1;
 	max_key.offset = (u64)-1;
 
+	ret = btrfs_commit_inode_delayed_items(trans, root, inode);
+	if (ret) {
+		btrfs_free_path(path);
+		btrfs_free_path(dst_path);
+		return ret;
+	}
+
 	mutex_lock(&BTRFS_I(inode)->log_mutex);
 
 	/*
-- 
1.7.3.1

^ permalink raw reply related	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-03  6:06 [PATCH V3] btrfs: implement delayed inode items operation Miao Xie
@ 2011-03-05  7:01 ` Itaru Kitayama
  2011-03-06 23:25   ` Tsutomu Itoh
  2011-03-08 16:56 ` David Sterba
  1 sibling, 1 reply; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-05  7:01 UTC (permalink / raw)
  To: miaox; +Cc: Chris Mason, Linux Btrfs, David Sterba, Ito

Hi Miao,

The V3 patch on top of the next-rc fails to pass an xfstests test 13.
In the btrfs link path, we need to reserve one more metadata in the
trans_block_rsv for the delayed inode update (if needed) to complete.

Here's the log from the test:

------------[ cut here ]------------
kernel BUG at fs/btrfs/delayed-inode.c:1565!
invalid opcode: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/module/floppy/initstate
CPU 1 
Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc ipv6 uinput snd_ens1371 gameport snd_rawmidi ]

Pid: 6948, comm: fsstress Tainted: G      D W   2.6.36-preempt+ #72 440BX Desktop Reference Platform/VMware Virtual Platform
RIP: 0010:[<ffffffff8120de65>]  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
RSP: 0018:ffff88003b073d68  EFLAGS: 00010286
RAX: 00000000ffffffe4 RBX: ffff88002a876e48 RCX: ffff88004f3702a0
RDX: 00000000000003b9 RSI: 0000000000000001 RDI: ffff88003b072000
RBP: ffff88003b073da8 R08: 0000000000018000 R09: 0000000000000000
R10: ffff88004f3703f0 R11: 09f911029d74e35b R12: ffff88006861cb90
R13: ffff88002ec91c18 R14: 0000000000018000 R15: ffff88002a876ea0
FS:  00007fcad4905720(0000) GS:ffff880005000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46eb380000 CR3: 00000000708b4000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process fsstress (pid: 6948, threadinfo ffff88003b072000, task ffff88004f324710)
Stack:
 ffff88003b073d88 ffff88004f3702a0 0000000000000000 ffff88002ec91c18
<0> ffff88006861cb90 ffff880036783c18 0000000000000000 ffff88006fcaf000
<0> ffff88003b073dc8 ffffffff811d8489 ffff88002ec91c18 ffff88006861cb90
Call Trace:
 [<ffffffff811d8489>] btrfs_update_inode+0x17/0x44
 [<ffffffff811da3e0>] btrfs_link+0xff/0x17a
 [<ffffffff8112300d>] vfs_link+0xda/0x144
 [<ffffffff811257ac>] sys_linkat+0xc4/0x121
 [<ffffffff81118925>] ? fsnotify_modify+0x66/0x6e
 [<ffffffff811190f8>] ? vfs_write+0xd2/0x10a
 [<ffffffff81125827>] sys_link+0x1e/0x20
 [<ffffffff81002ddb>] system_call_fastpath+0x16/0x1b
Code: f0 ff 40 60 eb 02 eb fe 4c 89 ff e8 7d 29 2b 00 31 f6 48 89 df e8 31 fb ff ff 31 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e  
RIP  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
 RSP <ffff88003b073d68>
---[ end trace 38596ade53c80d11 ]---

 

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-05  7:01 ` Itaru Kitayama
@ 2011-03-06 23:25   ` Tsutomu Itoh
  2011-03-07  1:57     ` Miao Xie
  0 siblings, 1 reply; 17+ messages in thread
From: Tsutomu Itoh @ 2011-03-06 23:25 UTC (permalink / raw)
  To: Itaru Kitayama; +Cc: miaox, Chris Mason, David Sterba, Linux Btrfs

(2011/03/05 16:01), Itaru Kitayama wrote:
> Hi Miao,
> 
> The V3 patch on top of the next-rc fails to pass an xfstests test 13.
> In the btrfs link path, we need to reserve one more metadata in the
> trans_block_rsv for the delayed inode update (if needed) to complete.

Miao's patch (http://marc.info/?l=linux-btrfs&m=129802068318176&w=2)
fixed this problem, maybe.

Thanks,
Itoh

> 
> Here's the log from the test:
> 
> ------------[ cut here ]------------
> kernel BUG at fs/btrfs/delayed-inode.c:1565!
> invalid opcode: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC
> last sysfs file: /sys/module/floppy/initstate
> CPU 1 
> Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc ipv6 uinput snd_ens1371 gameport snd_rawmidi ]
> 
> Pid: 6948, comm: fsstress Tainted: G      D W   2.6.36-preempt+ #72 440BX Desktop Reference Platform/VMware Virtual Platform
> RIP: 0010:[<ffffffff8120de65>]  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
> RSP: 0018:ffff88003b073d68  EFLAGS: 00010286
> RAX: 00000000ffffffe4 RBX: ffff88002a876e48 RCX: ffff88004f3702a0
> RDX: 00000000000003b9 RSI: 0000000000000001 RDI: ffff88003b072000
> RBP: ffff88003b073da8 R08: 0000000000018000 R09: 0000000000000000
> R10: ffff88004f3703f0 R11: 09f911029d74e35b R12: ffff88006861cb90
> R13: ffff88002ec91c18 R14: 0000000000018000 R15: ffff88002a876ea0
> FS:  00007fcad4905720(0000) GS:ffff880005000000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f46eb380000 CR3: 00000000708b4000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process fsstress (pid: 6948, threadinfo ffff88003b072000, task ffff88004f324710)
> Stack:
>  ffff88003b073d88 ffff88004f3702a0 0000000000000000 ffff88002ec91c18
> <0> ffff88006861cb90 ffff880036783c18 0000000000000000 ffff88006fcaf000
> <0> ffff88003b073dc8 ffffffff811d8489 ffff88002ec91c18 ffff88006861cb90
> Call Trace:
>  [<ffffffff811d8489>] btrfs_update_inode+0x17/0x44
>  [<ffffffff811da3e0>] btrfs_link+0xff/0x17a
>  [<ffffffff8112300d>] vfs_link+0xda/0x144
>  [<ffffffff811257ac>] sys_linkat+0xc4/0x121
>  [<ffffffff81118925>] ? fsnotify_modify+0x66/0x6e
>  [<ffffffff811190f8>] ? vfs_write+0xd2/0x10a
>  [<ffffffff81125827>] sys_link+0x1e/0x20
>  [<ffffffff81002ddb>] system_call_fastpath+0x16/0x1b
> Code: f0 ff 40 60 eb 02 eb fe 4c 89 ff e8 7d 29 2b 00 31 f6 48 89 df e8 31 fb ff ff 31 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e  
> RIP  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
>  RSP <ffff88003b073d68>
> ---[ end trace 38596ade53c80d11 ]---
> 


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-06 23:25   ` Tsutomu Itoh
@ 2011-03-07  1:57     ` Miao Xie
  2011-03-10  3:07       ` Itaru Kitayama
  0 siblings, 1 reply; 17+ messages in thread
From: Miao Xie @ 2011-03-07  1:57 UTC (permalink / raw)
  To: Tsutomu Itoh; +Cc: Itaru Kitayama, Chris Mason, David Sterba, Linux Btrfs

On mon, 07 Mar 2011 08:25:47 +0900, Tsutomu Itoh wrote:
> (2011/03/05 16:01), Itaru Kitayama wrote:
>> Hi Miao,
>>
>> The V3 patch on top of the next-rc fails to pass an xfstests test 13.
>> In the btrfs link path, we need to reserve one more metadata in the
>> trans_block_rsv for the delayed inode update (if needed) to complete.
> 
> Miao's patch (http://marc.info/?l=linux-btrfs&m=129802068318176&w=2)
> fixed this problem, maybe.

Yes, the above patch fixed this problem.
I think this problem is a bug of btrfs_link(), and hope the fix patch can
be received as early as possible. So I sent the above patch separately,
not with the delayed inode items operation patch.

Thanks
Miao

> 
> Thanks,
> Itoh
> 
>>
>> Here's the log from the test:
>>
>> ------------[ cut here ]------------
>> kernel BUG at fs/btrfs/delayed-inode.c:1565!
>> invalid opcode: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC
>> last sysfs file: /sys/module/floppy/initstate
>> CPU 1 
>> Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc ipv6 uinput snd_ens1371 gameport snd_rawmidi ]
>>
>> Pid: 6948, comm: fsstress Tainted: G      D W   2.6.36-preempt+ #72 440BX Desktop Reference Platform/VMware Virtual Platform
>> RIP: 0010:[<ffffffff8120de65>]  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
>> RSP: 0018:ffff88003b073d68  EFLAGS: 00010286
>> RAX: 00000000ffffffe4 RBX: ffff88002a876e48 RCX: ffff88004f3702a0
>> RDX: 00000000000003b9 RSI: 0000000000000001 RDI: ffff88003b072000
>> RBP: ffff88003b073da8 R08: 0000000000018000 R09: 0000000000000000
>> R10: ffff88004f3703f0 R11: 09f911029d74e35b R12: ffff88006861cb90
>> R13: ffff88002ec91c18 R14: 0000000000018000 R15: ffff88002a876ea0
>> FS:  00007fcad4905720(0000) GS:ffff880005000000(0000) knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007f46eb380000 CR3: 00000000708b4000 CR4: 00000000000006e0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>> Process fsstress (pid: 6948, threadinfo ffff88003b072000, task ffff88004f324710)
>> Stack:
>>  ffff88003b073d88 ffff88004f3702a0 0000000000000000 ffff88002ec91c18
>> <0> ffff88006861cb90 ffff880036783c18 0000000000000000 ffff88006fcaf000
>> <0> ffff88003b073dc8 ffffffff811d8489 ffff88002ec91c18 ffff88006861cb90
>> Call Trace:
>>  [<ffffffff811d8489>] btrfs_update_inode+0x17/0x44
>>  [<ffffffff811da3e0>] btrfs_link+0xff/0x17a
>>  [<ffffffff8112300d>] vfs_link+0xda/0x144
>>  [<ffffffff811257ac>] sys_linkat+0xc4/0x121
>>  [<ffffffff81118925>] ? fsnotify_modify+0x66/0x6e
>>  [<ffffffff811190f8>] ? vfs_write+0xd2/0x10a
>>  [<ffffffff81125827>] sys_link+0x1e/0x20
>>  [<ffffffff81002ddb>] system_call_fastpath+0x16/0x1b
>> Code: f0 ff 40 60 eb 02 eb fe 4c 89 ff e8 7d 29 2b 00 31 f6 48 89 df e8 31 fb ff ff 31 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e  
>> RIP  [<ffffffff8120de65>] btrfs_delayed_update_inode+0xfd/0x101
>>  RSP <ffff88003b073d68>
>> ---[ end trace 38596ade53c80d11 ]---
>>
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-03  6:06 [PATCH V3] btrfs: implement delayed inode items operation Miao Xie
  2011-03-05  7:01 ` Itaru Kitayama
@ 2011-03-08 16:56 ` David Sterba
  2011-03-09  5:40   ` Miao Xie
  1 sibling, 1 reply; 17+ messages in thread
From: David Sterba @ 2011-03-08 16:56 UTC (permalink / raw)
  To: Linux Btrfs

Hi,

I did some testing, the speedup results match yours. I was watching kmem cache
stats of the delayed_node, seem to behave well. Increase and decrease of
number of active objects, from 3 to about ~400 (creat_unlink 50000) and went
back to initial values after a few seconds. On my setup, there are 13
delayed_node objects per page, which gives a good chance of quick allocation of
the spare objects.

Size of the delayed_node is 304 bytes, which would slack 208 bytes (hitting the
nearest kmalloc bucket of 512 bytes) per node.

So to justify the recommendation of kmem_cache use.

I was thinking about reducing size of the structure by a few bytes, to 292
bytes.  In this case it would make 14 objects per slab page. There are padding
holes after
* atomic_t count (4 bytes)
* bool inode_dirty (2 bytes)

you may want to reorder the fileds like this:
* [no change up to inode_item]
* index_cnt
* refs
* count
* the bool fields

Still needed to reduce by 7 from 304-6=298. Does not seem to be possible, the
bool flags provide only 1 byte. Under these conditions, I suggest to make the
bool fields int again to reduce instruction count which manage these flags.
Compiler did not make them int automatically (altough it is free to do it).


dave

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-08 16:56 ` David Sterba
@ 2011-03-09  5:40   ` Miao Xie
  2011-03-11 15:24     ` David Sterba
  0 siblings, 1 reply; 17+ messages in thread
From: Miao Xie @ 2011-03-09  5:40 UTC (permalink / raw)
  To: Linux Btrfs

On tue, 8 Mar 2011 17:56:40 +0100, David Sterba wrote:
> Hi,
> 
> I did some testing, the speedup results match yours. I was watching kmem cache
> stats of the delayed_node, seem to behave well. Increase and decrease of
> number of active objects, from 3 to about ~400 (creat_unlink 50000) and went
> back to initial values after a few seconds. On my setup, there are 13
> delayed_node objects per page, which gives a good chance of quick allocation of
> the spare objects.
> 
> Size of the delayed_node is 304 bytes, which would slack 208 bytes (hitting the
> nearest kmalloc bucket of 512 bytes) per node.
> 
> So to justify the recommendation of kmem_cache use.
> 
> I was thinking about reducing size of the structure by a few bytes, to 292
> bytes.  In this case it would make 14 objects per slab page. There are padding
> holes after
> * atomic_t count (4 bytes)
> * bool inode_dirty (2 bytes)
> 
> you may want to reorder the fileds like this:
> * [no change up to inode_item]
> * index_cnt
> * refs
> * count
> * the bool fields

Thanks for your advice. But AFAIK, reordering the fields like what you said can not
reduce the space of delayed_nodes, because a hole is placed on the end to make the
structure big enough to pack tightly into arrays and maintain proper alignment. So
although we reorder the fields, the size of delayed_node is still 304 bytes.

> Still needed to reduce by 7 from 304-6=298. Does not seem to be possible, the
> bool flags provide only 1 byte. Under these conditions, I suggest to make the
> bool fields int again to reduce instruction count which manage these flags.
> Compiler did not make them int automatically (altough it is free to do it).

Sorry, I don't understand what you said above clearly, Did you mean
we can not access bool variables by one instruction?

Thanks
Miao

> 
> dave
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-07  1:57     ` Miao Xie
@ 2011-03-10  3:07       ` Itaru Kitayama
  0 siblings, 0 replies; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-10  3:07 UTC (permalink / raw)
  To: miaox; +Cc: Tsutomu Itoh, Chris Mason, David Sterba, Linux Btrfs


Thank you both for your help. I agree that we need to reserve 5 items for that operation. 

> > Miao's patch (http://marc.info/?l=linux-btrfs&m=129802068318176&w=2)
> > fixed this problem, maybe.
> 
> Yes, the above patch fixed this problem.
> I think this problem is a bug of btrfs_link(), and hope the fix patch can
> be received as early as possible. So I sent the above patch separately,
> not with the delayed inode items operation patch.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-09  5:40   ` Miao Xie
@ 2011-03-11 15:24     ` David Sterba
  0 siblings, 0 replies; 17+ messages in thread
From: David Sterba @ 2011-03-11 15:24 UTC (permalink / raw)
  To: Linux Btrfs

On Wed, Mar 09, 2011 at 01:40:28PM +0800, Miao Xie wrote:
> Thanks for your advice. But AFAIK, reordering the fields like what you
> said can not reduce the space of delayed_nodes, because a hole is
> placed on the end to make the structure big enough to pack tightly
> into arrays and maintain proper alignment. So although we reorder the
> fields, the size of delayed_node is still 304 bytes.

Let me redo it explicitly:

Your patch does not specify alignment of the cache object

+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;
+}

and default BYTES_PER_WORD == sizeof(void*) will be used. Let's assume
it's 8 (eg. on x86_64). The delayed_node is 304, which is multiple of 8
and the objects will have no padding at the end. A quick test, comparing
adresses of 2 adjacent allocated objects, confirmed that.

If I did the math correctly, we are able to reduce size by 7 bytes:
reorder fileds (6b) and merge bools into one-byte bitfield (1b). This is
not enough, padding to next object alignment will consume this (as you
wrote above).

Hm, nice exercise, no improvement.

> > Still needed to reduce by 7 from 304-6=298. Does not seem to be possible, the
> > bool flags provide only 1 byte. Under these conditions, I suggest to make the
> > bool fields int again to reduce instruction count which manage these flags.
> > Compiler did not make them int automatically (altough it is free to do it).
> 
> Sorry, I don't understand what you said above clearly, Did you mean
> we can not access bool variables by one instruction?

Ah, no I confused myself, I was thinking of bitfields. Checked that gcc
emits one instruction on x86_64, I did not check other arches.

dave

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-18  8:59       ` Itaru Kitayama
@ 2011-03-18  9:18         ` Miao Xie
  0 siblings, 0 replies; 17+ messages in thread
From: Miao Xie @ 2011-03-18  9:18 UTC (permalink / raw)
  To: Itaru Kitayama; +Cc: linux-btrfs

On fri, 18 Mar 2011 17:59:04 +0900, Itaru Kitayama wrote:
> Hi Miao,
> 
> Your updated V4 patch no longer gives me a hang. Thank you.
> 
> In the latest V4, btrfs_remove_delayed_node() does just release
> a delayed node and returns for most of the time, but for space

Right.

> cache inodes, it takes trans_mutex and writes the delayed nodes 
> out to the tree. Is my understanding correct?

for space cache inodes, we just update them in time, don't delayed to
update them.

Thanks
Miao

> 
> On Fri, 18 Mar 2011 11:37:03 +0800
> Miao Xie <miaox@cn.fujitsu.com> wrote:
> 
>> I find the inodes of free space information are updated when committing transaction,
>> and it will lead btrfs to hang.
>>
>> I have fixed this bug in the attached patch, could you test for me? I have tested it
>> on my machine with space_cache mount option, it worked well.
>>
>> Thanks
>> Miao
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-18  3:37     ` Miao Xie
@ 2011-03-18  8:59       ` Itaru Kitayama
  2011-03-18  9:18         ` Miao Xie
  0 siblings, 1 reply; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-18  8:59 UTC (permalink / raw)
  To: miaox; +Cc: linux-btrfs

Hi Miao,

Your updated V4 patch no longer gives me a hang. Thank you.

In the latest V4, btrfs_remove_delayed_node() does just release
a delayed node and returns for most of the time, but for space
cache inodes, it takes trans_mutex and writes the delayed nodes 
out to the tree. Is my understanding correct?

On Fri, 18 Mar 2011 11:37:03 +0800
Miao Xie <miaox@cn.fujitsu.com> wrote:

> I find the inodes of free space information are updated when committing transaction,
> and it will lead btrfs to hang.
> 
> I have fixed this bug in the attached patch, could you test for me? I have tested it
> on my machine with space_cache mount option, it worked well.
> 
> Thanks
> Miao

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-16  9:48   ` Itaru Kitayama
  2011-03-16 14:24     ` Miao Xie
@ 2011-03-18  3:37     ` Miao Xie
  2011-03-18  8:59       ` Itaru Kitayama
  1 sibling, 1 reply; 17+ messages in thread
From: Miao Xie @ 2011-03-18  3:37 UTC (permalink / raw)
  To: Itaru Kitayama; +Cc: linux-btrfs

[-- Attachment #1: Type: text/plain, Size: 3984 bytes --]

Hi, Kitayama-san

On Wed, 16 Mar 2011 18:48:50 +0900, Itaru Kitayama wrote:
> The V4 still hangs. Does the new function, btrfs_update_inode_nodelayed() you introduced to the V4
> need take care of a delayed node (commit delayed items of the inode and set the delayed note to NULL)?
> 
> Below is my experimental patch on top of V4 trying to avoid taking trans_mutex in btrfs_remove_delayed_node(), 
> but still hangs. Could you take a look at it? Thanks.

I find the inodes of free space information are updated when committing transaction,
and it will lead btrfs to hang.

I have fixed this bug in the attached patch, could you test for me? I have tested it
on my machine with space_cache mount option, it worked well.

Thanks
Miao

> 
> Itaru
> 
> diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
> index 495a6af..b6ea082 100644
> --- a/fs/btrfs/delayed-inode.c
> +++ b/fs/btrfs/delayed-inode.c
> @@ -1006,9 +1006,9 @@ int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
>  	return ret;
>  }
>  
> -int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> -				     struct btrfs_root *root,
> -				     struct inode *inode)
> +int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> +				       struct btrfs_root *root,
> +				       struct inode *inode, int delayed_update)
>  {
>  	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
>  	struct btrfs_path *path;
> @@ -1036,7 +1036,7 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  	if (!ret)
>  		ret = btrfs_delete_delayed_items(trans, path, root,
>  						 delayed_node);
> -	if (!ret)
> +	if (!ret && delayed_update)
>  		ret = btrfs_update_delayed_inode(trans, root, path,
>  						 delayed_node);
>  	btrfs_free_path(path);
> @@ -1044,13 +1044,27 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  	return ret;
>  }
>  
> +int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> +				     struct btrfs_root *root,
> +				     struct inode *inode)
> +{
> +	return __btrfs_commit_inode_delayed_items(trans, root, inode, 1);
> +}
> +
> +int btrfs_commit_inode_delayed_items_no_delayed_update(struct btrfs_trans_handle *trans,
> +						       struct btrfs_root *root,
> +						       struct inode *inode)
> +{
> +	return __btrfs_commit_inode_delayed_items(trans, root, inode, 0);
> +}
> +
>  int btrfs_remove_delayed_node(struct inode *inode)
>  {
>  	struct btrfs_trans_handle *trans;
>  	struct btrfs_root *root = BTRFS_I(inode)->root;
>  	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
>  	int ret;
> -
> +	
>  	if (!delayed_node)
>  		return 0;
>  
> diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
> index d4134bc..b6986df 100644
> --- a/fs/btrfs/delayed-inode.h
> +++ b/fs/btrfs/delayed-inode.h
> @@ -114,6 +114,11 @@ void btrfs_balance_delayed_items(struct btrfs_root *root);
>  int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  				     struct btrfs_root *root,
>  				     struct inode *inode);
> +int btrfs_commit_inode_delayed_items_no_delayed_update(
> +				struct btrfs_trans_handle *trans,
> +				struct btrfs_root *root,
> +				struct inode *inode);
> +
>  /* Used for evicting the inode. */
>  int btrfs_remove_delayed_node(struct inode *inode);
>  int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 5299d9c..e198051 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2611,8 +2611,12 @@ noinline int btrfs_update_inode_nodelayed(struct btrfs_trans_handle *trans,
>  	struct btrfs_inode_item *inode_item;
>  	struct btrfs_path *path;
>  	struct extent_buffer *leaf;
> +	struct btrfs_delayed_node *delayed_node;
>  	int ret;
>  
> +	btrfs_commit_inode_delayed_items_no_delayed_update(trans, root, inode);
> +	delayed_node = NULL;
> +
>  	path = btrfs_alloc_path();
>  	if (!path)
>  		return -ENOMEM;
> 


[-- Attachment #2: 0001-btrfs-implement-delayed-inode-items-operation-v4.patch --]
[-- Type: text/plain, Size: 81870 bytes --]

>From 1f0b9c9e403fb22e74f6c3cbb2b9ef70969616fb Mon Sep 17 00:00:00 2001
From: Miao Xie <miaox@cn.fujitsu.com>
Date: Tue, 15 Feb 2011 16:20:15 +0800
Subject: [PATCH] btrfs: implement delayed inode items operation - v4

Changelog V3 -> V4:
- Fix nested lock, which is reported by Itaru Kitayama

Changelog V2 -> V3:
- Fix the race between the delayed worker and the task which does delayed items
  balance, which is reported by Tsutomu Itoh.
- Modify the patch address David Sterba's comment.
- Fix the bug of the cpu recursion spinlock, reported by Chris Mason

Changelog V1 -> V2:
- break up the global rb-tree, use a list to manage the delayed nodes,
  which is created for every directory and file, and used to manage the
  delayed directory name index items and the delayed inode item.
- introduce a worker to deal with the delayed nodes.

Compare with Ext3/4, the performance of file creation and deletion on btrfs
is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
such as inode item, directory name item, directory name index and so on.

If we can do some delayed b+ tree insertion or deletion, we can improve the
performance, so we made this patch which implemented delayed directory name
index insertion/deletion and delayed inode update.

Implementation:
- introduce a delayed root object into the filesystem, that use two lists to
  manage the delayed nodes which are created for every file/directory.
  One is used to manage all the delayed nodes that have delayed items. And the
  other is used to manage the delayed nodes which is waiting to be dealt with
  by the work thread.
- Every delayed node has two rb-tree, one is used to manage the directory name
  index which is going to be inserted into b+ tree, and the other is used to
  manage the directory name index which is going to be deleted from b+ tree.
- introduce a worker to deal with the delayed operation. This worker is used
  to deal with the works of the delayed directory name index items insertion
  and deletion and the delayed inode update.
  When the delayed items is beyond the lower limit, we create works for some
  delayed nodes and insert them into the work queue of the worker, and then
  go back.
  When the delayed items is beyond the upper bound, we create works for all
  the delayed nodes that haven't been dealt with, and insert them into the work
  queue of the worker, and then wait for that the untreated items is below some
  threshold value.
- When we want to insert a directory name index into b+ tree, we just add the
  information into the delayed inserting rb-tree.
  And then we check the number of the delayed items and do delayed items
  balance. (The balance policy is above.)
- When we want to delete a directory name index from the b+ tree, we search it
  in the inserting rb-tree at first. If we look it up, just drop it. If not,
  add the key of it into the delayed deleting rb-tree.
  Similar to the delayed inserting rb-tree, we also check the number of the
  delayed items and do delayed items balance.
  (The same to inserting manipulation)
- When we want to update the metadata of some inode, we cached the data of the
  inode into the delayed node. the worker will flush it into the b+ tree after
  dealing with the delayed insertion and deletion.
- We will move the delayed node to the tail of the list after we access the
  delayed node, By this way, we can cache more delayed items and merge more
  inode updates.
- If we want to commit transaction, we will deal with all the delayed node.
- the delayed node will be freed when we free the btrfs inode.
- Before we log the inode items, we commit all the directory name index items
  and the delayed inode update.

I did a quick test by the benchmark tool[1] and found we can improve the
performance of file creation by ~15%, and file deletion by ~20%.

Before applying this patch:
Create files:
	Total files: 50000
	Total time: 1.096108
	Average time: 0.000022
Delete files:
	Total files: 50000
	Total time: 1.510403
	Average time: 0.000030

After applying this patch:
Create files:
	Total files: 50000
	Total time: 0.932899
	Average time: 0.000019
Delete files:
	Total files: 50000
	Total time: 1.215732
	Average time: 0.000024

[1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 fs/btrfs/Makefile        |    2 +-
 fs/btrfs/btrfs_inode.h   |    5 +
 fs/btrfs/ctree.c         |   14 +-
 fs/btrfs/ctree.h         |   24 +-
 fs/btrfs/delayed-inode.c | 1629 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/delayed-inode.h |  139 ++++
 fs/btrfs/dir-item.c      |   32 +-
 fs/btrfs/disk-io.c       |   26 +-
 fs/btrfs/extent-tree.c   |   18 +-
 fs/btrfs/inode.c         |  108 +++-
 fs/btrfs/ioctl.c         |    2 +-
 fs/btrfs/super.c         |   10 +-
 fs/btrfs/transaction.c   |   49 ++-
 fs/btrfs/transaction.h   |    2 +
 fs/btrfs/tree-log.c      |    7 +
 15 files changed, 1978 insertions(+), 89 deletions(-)
 create mode 100644 fs/btrfs/delayed-inode.c
 create mode 100644 fs/btrfs/delayed-inode.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 31610ea..a8411c2 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -7,4 +7,4 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
 	   extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
 	   export.o tree-log.o acl.o free-space-cache.o zlib.o lzo.o \
-	   compression.o delayed-ref.o relocation.o
+	   compression.o delayed-ref.o relocation.o delayed-inode.o
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index ccc991c..ef3baa8 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -22,6 +22,7 @@
 #include "extent_map.h"
 #include "extent_io.h"
 #include "ordered-data.h"
+#include "delayed-inode.h"
 
 /* in memory btrfs inode */
 struct btrfs_inode {
@@ -159,9 +160,13 @@ struct btrfs_inode {
 	 */
 	unsigned force_compress:4;
 
+	struct btrfs_delayed_node *delayed_node;
+
 	struct inode vfs_inode;
 };
 
+extern unsigned char btrfs_filetype_table[];
+
 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 {
 	return container_of(inode, struct btrfs_inode, vfs_inode);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b5baff0..6e3e4c3 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,11 +38,6 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct extent_buffer *src_buf);
 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		   struct btrfs_path *path, int level, int slot);
-static int setup_items_for_insert(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root, struct btrfs_path *path,
-			struct btrfs_key *cpu_key, u32 *data_size,
-			u32 total_data, u32 total_size, int nr);
-
 
 struct btrfs_path *btrfs_alloc_path(void)
 {
@@ -3688,11 +3683,10 @@ out:
  * to save stack depth by doing the bulk of the work in a function
  * that doesn't call btrfs_search_slot
  */
-static noinline_for_stack int
-setup_items_for_insert(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root, struct btrfs_path *path,
-		      struct btrfs_key *cpu_key, u32 *data_size,
-		      u32 total_data, u32 total_size, int nr)
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr)
 {
 	struct btrfs_item *item;
 	int i;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 28188a7..bafca2e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -859,6 +859,7 @@ struct btrfs_block_group_cache {
 struct reloc_control;
 struct btrfs_device;
 struct btrfs_fs_devices;
+struct btrfs_delayed_root;
 struct btrfs_fs_info {
 	u8 fsid[BTRFS_FSID_SIZE];
 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
@@ -885,7 +886,10 @@ struct btrfs_fs_info {
 	/* logical->physical extent mapping */
 	struct btrfs_mapping_tree mapping_tree;
 
-	/* block reservation for extent, checksum and root tree */
+	/*
+	 * block reservation for extent, checksum, root tree and
+	 * delayed dir index item
+	 */
 	struct btrfs_block_rsv global_block_rsv;
 	/* block reservation for delay allocation */
 	struct btrfs_block_rsv delalloc_block_rsv;
@@ -1012,6 +1016,7 @@ struct btrfs_fs_info {
 	 * for the sys_munmap function call path
 	 */
 	struct btrfs_workers fixup_workers;
+	struct btrfs_workers delayed_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;
 	int thread_pool_size;
@@ -1069,6 +1074,8 @@ struct btrfs_fs_info {
 
 	/* filesystem state */
 	u64 fs_state;
+
+	struct btrfs_delayed_root *delayed_root;
 };
 
 /*
@@ -2086,6 +2093,13 @@ static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
 }
 
 /* extent-tree.c */
+static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
+						 int num_items)
+{
+	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
+		3 * num_items;
+}
+
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root, unsigned long count);
@@ -2277,6 +2291,8 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_set_path_blocking(struct btrfs_path *p);
+void btrfs_clear_path_blocking(struct btrfs_path *p,
+			       struct extent_buffer *held);
 void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -2288,6 +2304,10 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 	return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr);
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
@@ -2349,7 +2369,7 @@ int btrfs_set_root_node(struct btrfs_root_item *item,
 /* dir-item.c */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, const char *name,
-			  int name_len, u64 dir,
+			  int name_len, struct inode *dir,
 			  struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
new file mode 100644
index 0000000..727d9a8
--- /dev/null
+++ b/fs/btrfs/delayed-inode.c
@@ -0,0 +1,1629 @@
+/*
+ * 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,
+				u64 root_id, u64 inode_id)
+{
+	delayed_node->root_id = root_id;
+	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;
+	delayed_node->block_rsv = NULL;
+}
+
+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;
+
+	if (btrfs_inode->delayed_node) {
+		node = btrfs_inode->delayed_node;
+		atomic_inc(&node->refs);	/* can be accessed */
+		return node;
+	}
+
+	node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	btrfs_init_delayed_node(node, root->objectid, inode->i_ino);
+
+	btrfs_inode->delayed_node = node;
+	node->delayed_root = btrfs_get_delayed_root(root);
+	atomic_inc(&node->refs);	/* cached in the btrfs inode */
+	atomic_inc(&node->refs);	/* can be accessed */
+
+	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 = node->delayed_root;
+	struct list_head *p;
+	struct btrfs_delayed_node *next = NULL;
+
+	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->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))
+		kmem_cache_free(delayed_node_cache, delayed_node);
+}
+
+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;
+	}
+	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->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->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);
+		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;
+		node->block_rsv = dst_rsv;
+	}
+
+	return ret;
+}
+
+static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
+						struct btrfs_delayed_node *node)
+{
+	if (!node->bytes_reserved)
+		return;
+
+	btrfs_block_rsv_release(root, node->block_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)
+{
+	if (delayed_node && delayed_node->inode_dirty) {
+		BUG_ON(!delayed_node->delayed_root);
+		delayed_node->inode_dirty = 0;
+		delayed_node->count--;
+		atomic_dec(&delayed_node->delayed_root->items);
+		if (atomic_read(&delayed_node->delayed_root->items) <
+		    BTRFS_DELAYED_BACKGROUND &&
+		    waitqueue_active(&delayed_node->delayed_root->wait))
+			wake_up(&delayed_node->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) {
+		/*
+		 * check root, if root is not the one which the delayed item
+		 * wants to be inserted to, we get the right root.
+		 */
+		if (root->objectid != curr_node->root_id) {
+			root = btrfs_get_fs_root(root, curr_node->root_id);
+			BUG_ON(IS_ERR_OR_NULL(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_root *root,
+					      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, root, node);
+	if (!ret)
+		ret = btrfs_delete_delayed_items(trans, path, root, node);
+	if (!ret)
+		ret = btrfs_update_delayed_inode(trans, root, path, node);
+	btrfs_free_path(path);
+
+	return ret;
+}
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     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, root, delayed_node);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_remove_delayed_node(struct inode *inode)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
+	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);
+		BTRFS_I(inode)->delayed_node = NULL;
+		return 0;
+	}
+	mutex_unlock(&delayed_node->mutex);
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = __btrfs_commit_inode_delayed_items(trans, root, delayed_node);
+	if (ret)
+		goto out;
+
+	BUG_ON(delayed_node->count);
+
+	BTRFS_I(inode)->delayed_node = NULL;
+	btrfs_release_delayed_node(delayed_node);
+out:
+	btrfs_end_transaction_dmeta(trans, root);
+
+	return ret;
+}
+
+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;
+
+	root = async_node->root;
+	BUG_ON(!root);
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		goto free_path;
+
+	delayed_node = async_node->delayed_node;
+
+	root = btrfs_get_fs_root(async_node->root, delayed_node->root_id);
+	BUG_ON(IS_ERR_OR_NULL(root));
+
+	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(delayed_node->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_id,
+				(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_id,
+				(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;
+}
+
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode)
+{
+	struct btrfs_delayed_node *delayed_node;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (delayed_node)
+		mutex_lock(&delayed_node->mutex);
+
+	return delayed_node;
+}
+
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node)
+{
+	if (!node)
+		return;
+
+	mutex_unlock(&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(&node->refs);
+}
+
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index)
+{
+	if (!delayed_node)
+		return 0;
+
+	if (IS_ERR(*item))
+		return 0;
+
+	if (!(*item))
+		*item = __btrfs_first_delayed_deletion_item(delayed_node);
+
+	while (*item) {
+		if ((*item)->key.offset < index) {
+			*item = __btrfs_next_delayed_item(*item);
+			continue;
+		} else if ((*item)->key.offset > index)
+			break;
+
+		*item = __btrfs_next_delayed_item(*item);
+		if (!(*item))
+			*item = ERR_PTR(-ERANGE);
+		return 1;
+	}
+
+	if (!(*item))
+		*item = ERR_PTR(-ERANGE);
+	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 btrfs_delayed_node *delayed_node)
+{
+	struct btrfs_dir_item *di;
+	struct btrfs_delayed_item *item;
+	struct btrfs_key location;
+	char *name;
+	int name_len;
+	int over = 0;
+	unsigned char d_type;
+
+	if (!delayed_node)
+		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.
+	 */
+	item = __btrfs_first_delayed_insertion_item(delayed_node);
+	while (item) {
+		if (item->key.offset < filp->f_pos) {
+			item = __btrfs_next_delayed_item(item);
+			continue;
+		}
+
+		filp->f_pos = item->key.offset;
+
+		di = (struct btrfs_dir_item *)item->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, item->key.offset,
+			       location.objectid, d_type);
+
+		if (over)
+			return 1;
+		item = __btrfs_next_delayed_item(item);
+	}
+	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(&delayed_node->delayed_root->items);
+release_node:
+	mutex_unlock(&delayed_node->mutex);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode)
+{
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node;
+	struct btrfs_delayed_item *curr_item, *prev_item;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (!delayed_node)
+		return 0;
+
+	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);
+
+	btrfs_release_delayed_node(delayed_node);
+
+	return 0;
+}
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
new file mode 100644
index 0000000..d4134bc
--- /dev/null
+++ b/fs/btrfs/delayed-inode.h
@@ -0,0 +1,139 @@
+/*
+ * 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.
+ */
+
+#ifndef __DELAYED_TREE_OPERATION_H
+#define __DELAYED_TREE_OPERATION_H
+
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include "ctree.h"
+
+/* types of the delayed item */
+#define BTRFS_DELAYED_INSERTION_ITEM	1
+#define BTRFS_DELAYED_DELETION_ITEM	2
+
+struct btrfs_delayed_root {
+	spinlock_t lock;
+	struct list_head node_list;
+	/*
+	 * Used for delayed nodes which is waiting to be dealt with by the
+	 * worker. If the delayed node is inserted into the work queue, we
+	 * drop it from this list.
+	 */
+	struct list_head prepare_list;
+	atomic_t items;		/* for delayed items */
+	int nodes;		/* for delayed nodes */
+	wait_queue_head_t wait;
+};
+
+struct btrfs_delayed_node {
+	u64 root_id;
+	u64 inode_id;
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_root *delayed_root;
+	/* Used to add the node into the delayed root's node list. */
+	struct list_head n_list;
+	/*
+	 * Used to add the node into the prepare list, the nodes in this list
+	 * is waiting to be dealt with by the async worker.
+	 */
+	struct list_head p_list;
+	struct rb_root ins_root;
+	struct rb_root del_root;
+	struct mutex mutex;
+	struct btrfs_inode_item inode_item;
+	atomic_t refs;
+	u64 index_cnt;
+	bool in_list;
+	bool inode_dirty;
+	int count;
+};
+
+struct btrfs_delayed_item {
+	struct rb_node rb_node;
+	struct btrfs_key key;
+	struct list_head tree_list;	/* used for batch insert/delete items */
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_node *delayed_node;
+	int ins_or_del;
+	u32 data_len;
+	char data[0];
+};
+
+static inline void btrfs_init_delayed_root(
+				struct btrfs_delayed_root *delayed_root)
+{
+	atomic_set(&delayed_root->items, 0);
+	delayed_root->nodes = 0;
+	spin_lock_init(&delayed_root->lock);
+	init_waitqueue_head(&delayed_root->wait);
+	INIT_LIST_HEAD(&delayed_root->node_list);
+	INIT_LIST_HEAD(&delayed_root->prepare_list);
+}
+
+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);
+
+int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
+				   struct btrfs_root *root, struct inode *dir,
+				   u64 index);
+
+int btrfs_inode_delayed_dir_index_count(struct inode *inode);
+
+int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+
+void btrfs_balance_delayed_items(struct btrfs_root *root);
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode);
+/* Used for evicting the inode. */
+int btrfs_remove_delayed_node(struct inode *inode);
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode);
+
+
+int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root, struct inode *inode);
+
+/* Used for readdir() */
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode);
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node);
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index);
+int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
+				    filldir_t filldir,
+				    struct btrfs_delayed_node *delayed_node);
+
+/* for init */
+int __init btrfs_delayed_inode_init(void);
+void btrfs_delayed_inode_exit(void);
+#endif
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f0cad5a..696c793 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -124,8 +124,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  * to use for the second index (if one is created).
  */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, const char *name, int name_len, u64 dir,
-			  struct btrfs_key *location, u8 type, u64 index)
+			  *root, const char *name, int name_len,
+			  struct inode *dir, struct btrfs_key *location,
+			  u8 type, u64 index)
 {
 	int ret = 0;
 	int ret2 = 0;
@@ -137,13 +138,17 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	struct btrfs_disk_key disk_key;
 	u32 data_size;
 
-	key.objectid = dir;
+	key.objectid = dir->i_ino;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
 
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->leave_spinning = 1;
 
+	btrfs_cpu_key_to_disk(&disk_key, location);
+
 	data_size = sizeof(*dir_item) + name_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 					name, name_len);
@@ -155,7 +160,6 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	}
 
 	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
 	btrfs_set_dir_data_len(leaf, dir_item, 0);
@@ -174,24 +178,8 @@ second_insert:
 	}
 	btrfs_release_path(root, path);
 
-	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-	key.offset = index;
-	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
-					name, name_len);
-	if (IS_ERR(dir_item)) {
-		ret2 = PTR_ERR(dir_item);
-		goto out;
-	}
-	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
-	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
-	btrfs_set_dir_type(leaf, dir_item, type);
-	btrfs_set_dir_data_len(leaf, dir_item, 0);
-	btrfs_set_dir_name_len(leaf, dir_item, name_len);
-	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
-	name_ptr = (unsigned long)(dir_item + 1);
-	write_extent_buffer(leaf, name, name_ptr, name_len);
-	btrfs_mark_buffer_dirty(leaf);
+	ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir,
+					      &disk_key, type, index);
 out:
 	btrfs_free_path(path);
 	if (ret)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3e1ea3e..ea3c145 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1676,6 +1676,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	INIT_LIST_HEAD(&fs_info->ordered_extents);
 	spin_lock_init(&fs_info->ordered_extent_lock);
+	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+					GFP_NOFS);
+	if (!fs_info->delayed_root) {
+		err = -ENOMEM;
+		goto fail_iput;
+	}
+	btrfs_init_delayed_root(fs_info->delayed_root);
 
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
@@ -1743,7 +1750,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	bh = btrfs_read_dev_super(fs_devices->latest_bdev);
 	if (!bh) {
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
@@ -1755,7 +1762,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	disk_super = &fs_info->super_copy;
 	if (!btrfs_super_root(disk_super))
-		goto fail_iput;
+		goto fail_alloc;
 
 	/* check FS state, whether FS is broken. */
 	fs_info->fs_state |= btrfs_super_flags(disk_super);
@@ -1765,7 +1772,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	ret = btrfs_parse_options(tree_root, options);
 	if (ret) {
 		err = ret;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super) &
@@ -1775,7 +1782,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported optional features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super);
@@ -1791,7 +1798,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported option features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	btrfs_init_workers(&fs_info->generic_worker,
@@ -1838,6 +1845,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 			   &fs_info->generic_worker);
 	btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
 			   1, &fs_info->generic_worker);
+	btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
+			   fs_info->thread_pool_size,
+			   &fs_info->generic_worker);
 
 	/*
 	 * endios are largely parallel and should have a very
@@ -1859,6 +1869,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
+	btrfs_start_workers(&fs_info->delayed_workers, 1);
 
 	fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
 	fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -2104,6 +2115,9 @@ fail_sb_buffer:
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
+fail_alloc:
+	kfree(fs_info->delayed_root);
 fail_iput:
 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 	iput(fs_info->btree_inode);
@@ -2551,6 +2565,7 @@ int close_ctree(struct btrfs_root *root)
 	del_fs_roots(fs_info);
 
 	iput(fs_info->btree_inode);
+	kfree(fs_info->delayed_root);
 
 	btrfs_stop_workers(&fs_info->generic_worker);
 	btrfs_stop_workers(&fs_info->fixup_workers);
@@ -2562,6 +2577,7 @@ int close_ctree(struct btrfs_root *root)
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
 
 	btrfs_close_devices(fs_info->fs_devices);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 100e409..aed763f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3897,12 +3897,6 @@ static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
 }
 
-static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
-{
-	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
-		3 * num_items;
-}
-
 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 int num_items)
@@ -3913,7 +3907,7 @@ int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 	if (num_items == 0 || root->fs_info->chunk_root == root)
 		return 0;
 
-	num_bytes = calc_trans_metadata_size(root, num_items);
+	num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
 	ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
 				  num_bytes);
 	if (!ret) {
@@ -3952,14 +3946,14 @@ int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * If all of the metadata space is used, we can commit
 	 * transaction and use space it freed.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
 void btrfs_orphan_release_metadata(struct inode *inode)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
 }
 
@@ -3973,7 +3967,7 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * two for root back/forward refs, two for directory entries
 	 * and one for root of the snapshot.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 5);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
 	dst_rsv->space_info = src_rsv->space_info;
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
@@ -4000,7 +3994,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
 	if (nr_extents > BTRFS_I(inode)->reserved_extents) {
 		nr_extents -= BTRFS_I(inode)->reserved_extents;
-		to_reserve = calc_trans_metadata_size(root, nr_extents);
+		to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
 	} else {
 		nr_extents = 0;
 		to_reserve = 0;
@@ -4047,7 +4041,7 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 
 	to_free = calc_csum_metadata_size(inode, num_bytes);
 	if (nr_extents > 0)
-		to_free += calc_trans_metadata_size(root, nr_extents);
+		to_free += btrfs_calc_trans_metadata_size(root, nr_extents);
 
 	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
 				to_free);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7027953..6ee549f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2603,11 +2603,26 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	int ret;
 
+	/*
+	 * If root is tree root, it means this inode is used to
+	 * store free space information. And these inodes are updated
+	 * when committing the transaction, so they needn't delaye to
+	 * be updated, or deadlock will occured.
+	 */
+	if (likely(root != root->fs_info->tree_root)) {
+		ret = btrfs_delayed_update_inode(trans, root, inode);
+		if (!ret)
+			btrfs_set_inode_last_trans(trans, inode);
+		return ret;
+	}
+
 	path = btrfs_alloc_path();
-	BUG_ON(!path);
+	if (!path)
+		return -ENOMEM;
+
 	path->leave_spinning = 1;
-	ret = btrfs_lookup_inode(trans, root, path,
-				 &BTRFS_I(inode)->location, 1);
+	ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
+				 1);
 	if (ret) {
 		if (ret > 0)
 			ret = -ENOENT;
@@ -2617,7 +2632,7 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
 	btrfs_unlock_up_safe(path, 1);
 	leaf = path->nodes[0];
 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
-				  struct btrfs_inode_item);
+				    struct btrfs_inode_item);
 
 	fill_inode_item(trans, leaf, inode_item, inode);
 	btrfs_mark_buffer_dirty(leaf);
@@ -2628,7 +2643,6 @@ failed:
 	return ret;
 }
 
-
 /*
  * unlink helper that gets used here in inode.c and in the tree logging
  * recovery code.  It remove a link in a directory with a given name, and
@@ -2680,18 +2694,9 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto err;
 	}
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
-		goto err;
-	}
-	if (!di) {
-		ret = -ENOENT;
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
+	if (ret)
 		goto err;
-	}
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
-	btrfs_release_path(root, path);
 
 	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
 					 inode, dir->i_ino);
@@ -2867,6 +2872,14 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 	index = btrfs_inode_ref_index(path->nodes[0], ref);
 	btrfs_release_path(root, path);
 
+	/*
+	 * This is a commit root search, if we can lookup inode item and other
+	 * relative items in the commit root, it means the transaction of
+	 * dir/file creation has been committed, and the dir index item that we
+	 * delay to insert has also been inserted into the commit root. So
+	 * we needn't worry about the delayed insertion of the dir index item
+	 * here.
+	 */
 	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
 				dentry->d_name.name, dentry->d_name.len, 0);
 	if (IS_ERR(di)) {
@@ -2972,24 +2985,16 @@ int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 		btrfs_release_path(root, path);
 		index = key.offset;
 	}
+	btrfs_release_path(root, path);
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	BUG_ON(!di || IS_ERR(di));
-
-	leaf = path->nodes[0];
-	btrfs_dir_item_key_to_cpu(leaf, di, &key);
-	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
 	BUG_ON(ret);
-	btrfs_release_path(root, path);
 
 	btrfs_i_size_write(dir, dir->i_size - name_len * 2);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 	ret = btrfs_update_inode(trans, root, dir);
 	BUG_ON(ret);
 
-	btrfs_free_path(path);
 	return 0;
 }
 
@@ -3249,6 +3254,15 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	if (root->ref_cows || root == root->fs_info->tree_root)
 		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
 
+	/*
+	 * This function is also used to drop the items in the log tree before
+	 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
+	 * it is used to drop the loged items. So we shouldn't kill the delayed
+	 * items.
+	 */
+	if (min_type == 0 && root == BTRFS_I(inode)->root)
+		btrfs_kill_delayed_inode_items(trans, inode);
+
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
 	path->reada = -1;
@@ -4182,7 +4196,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
 	return d_splice_alias(inode, dentry);
 }
 
-static unsigned char btrfs_filetype_table[] = {
+unsigned char btrfs_filetype_table[] = {
 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
 };
 
@@ -4196,6 +4210,8 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	struct btrfs_path *path;
+	struct btrfs_delayed_node *delayed_node = NULL;
+	struct btrfs_delayed_item *delayed_item = NULL;
 	int ret;
 	u32 nritems;
 	struct extent_buffer *leaf;
@@ -4210,6 +4226,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	char tmp_name[32];
 	char *name_ptr;
 	int name_len;
+	int is_curr = 0;	/* filp->f_pos points to the current index? */
 
 	/* FIXME, use a real flag for deciding about the key type */
 	if (root->fs_info->tree_root == root)
@@ -4234,8 +4251,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 		filp->f_pos = 2;
 	}
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->reada = 2;
 
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		delayed_node = btrfs_get_locked_delayed_node(inode);
+
 	btrfs_set_key_type(&key, key_type);
 	key.offset = filp->f_pos;
 	key.objectid = inode->i_ino;
@@ -4273,8 +4295,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 			break;
 		if (found_key.offset < filp->f_pos)
 			continue;
+		if (key_type == BTRFS_DIR_INDEX_KEY &&
+		    btrfs_should_delete_dir_index(delayed_node, &delayed_item,
+						  found_key.offset))
+			continue;
 
 		filp->f_pos = found_key.offset;
+		is_curr = 1;
 
 		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 		di_cur = 0;
@@ -4324,6 +4351,15 @@ skip:
 		}
 	}
 
+	if (key_type == BTRFS_DIR_INDEX_KEY) {
+		if (is_curr)
+			filp->f_pos++;
+		ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
+						      delayed_node);
+		if (ret)
+			goto nopos;
+	}
+
 	/* Reached end of directory/root. Bump pos past the last item. */
 	if (key_type == BTRFS_DIR_INDEX_KEY)
 		/*
@@ -4336,6 +4372,8 @@ skip:
 nopos:
 	ret = 0;
 err:
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		btrfs_put_locked_delayed_node(delayed_node);
 	btrfs_free_path(path);
 	return ret;
 }
@@ -4481,9 +4519,12 @@ int btrfs_set_inode_index(struct inode *dir, u64 *index)
 	int ret = 0;
 
 	if (BTRFS_I(dir)->index_cnt == (u64)-1) {
-		ret = btrfs_set_inode_index_count(dir);
-		if (ret)
-			return ret;
+		ret = btrfs_inode_delayed_dir_index_count(dir);
+		if (ret) {
+			ret = btrfs_set_inode_index_count(dir);
+			if (ret)
+				return ret;
+		}
 	}
 
 	*index = BTRFS_I(dir)->index_cnt;
@@ -4641,7 +4682,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
 
 	if (ret == 0) {
 		ret = btrfs_insert_dir_item(trans, root, name, name_len,
-					    parent_inode->i_ino, &key,
+					    parent_inode, &key,
 					    btrfs_inode_type(inode), index);
 		BUG_ON(ret);
 
@@ -6642,6 +6683,8 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->dummy_inode = 0;
 	ei->force_compress = BTRFS_COMPRESS_NONE;
 
+	ei->delayed_node = NULL;
+
 	inode = &ei->vfs_inode;
 	extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
 	extent_io_tree_init(&ei->io_tree, &inode->i_data, GFP_NOFS);
@@ -6660,6 +6703,7 @@ void btrfs_destroy_inode(struct inode *inode)
 {
 	struct btrfs_ordered_extent *ordered;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	int ret;
 
 	WARN_ON(!list_empty(&inode->i_dentry));
 	WARN_ON(inode->i_data.nrpages);
@@ -6725,6 +6769,8 @@ void btrfs_destroy_inode(struct inode *inode)
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 free:
+	ret = btrfs_remove_delayed_node(inode);
+	BUG_ON(ret);
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..b200e07 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -333,7 +333,7 @@ static noinline int create_subvol(struct btrfs_root *root,
 	BUG_ON(ret);
 
 	ret = btrfs_insert_dir_item(trans, root,
-				    name, namelen, dir->i_ino, &key,
+				    name, namelen, dir, &key,
 				    BTRFS_FT_DIR, index);
 	if (ret)
 		goto fail;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db0a827..593ce8a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -40,6 +40,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include "compat.h"
+#include "delayed-inode.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1163,10 +1164,14 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_extent_io;
 
-	err = btrfs_interface_init();
+	err = btrfs_delayed_inode_init();
 	if (err)
 		goto free_extent_map;
 
+	err = btrfs_interface_init();
+	if (err)
+		goto free_delayed_inode;
+
 	err = register_filesystem(&btrfs_fs_type);
 	if (err)
 		goto unregister_ioctl;
@@ -1176,6 +1181,8 @@ static int __init init_btrfs_fs(void)
 
 unregister_ioctl:
 	btrfs_interface_exit();
+free_delayed_inode:
+	btrfs_delayed_inode_exit();
 free_extent_map:
 	extent_map_exit();
 free_extent_io:
@@ -1192,6 +1199,7 @@ free_sysfs:
 static void __exit exit_btrfs_fs(void)
 {
 	btrfs_destroy_cachep();
+	btrfs_delayed_inode_exit();
 	extent_map_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3d73c8d..31b328b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -478,19 +478,46 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 1, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 1, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 0);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 0);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
+}
+
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root)
+{
+	return __btrfs_end_transaction(trans, root, 1, 1);
 }
 
 /*
@@ -958,7 +985,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	BUG_ON(ret);
 	ret = btrfs_insert_dir_item(trans, parent_root,
 				dentry->d_name.name, dentry->d_name.len,
-				parent_inode->i_ino, &key,
+				parent_inode, &key,
 				BTRFS_FT_DIR, index);
 	BUG_ON(ret);
 
@@ -1027,6 +1054,14 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 	int ret;
 
 	list_for_each_entry(pending, head, list) {
+		/*
+		 * We must deal with the delayed items before creating
+		 * snapshots, or we will create a snapthot with inconsistent
+		 * information.
+		*/
+		ret = btrfs_run_delayed_items(trans, fs_info->fs_root);
+		BUG_ON(ret);
+
 		ret = create_pending_snapshot(trans, fs_info, pending);
 		BUG_ON(ret);
 	}
@@ -1279,6 +1314,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 			BUG_ON(ret);
 		}
 
+		ret = btrfs_run_delayed_items(trans, root);
+		BUG_ON(ret);
+
 		/*
 		 * rename don't use btrfs_join_transaction, so, once we
 		 * set the transaction to blocked above, we aren't going
@@ -1305,6 +1343,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	ret = create_pending_snapshots(trans, root->fs_info);
 	BUG_ON(ret);
 
+	ret = btrfs_run_delayed_items(trans, root);
+	BUG_ON(ret);
+
 	ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
 	BUG_ON(ret);
 
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 229a594..a4a441f 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -115,6 +115,8 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 				   int wait_for_unblock);
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root);
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root);
 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root);
 void btrfs_throttle(struct btrfs_root *root);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a4bbb85..e8a2e95 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2775,6 +2775,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		max_key.type = (u8)-1;
 	max_key.offset = (u64)-1;
 
+	ret = btrfs_commit_inode_delayed_items(trans, root, inode);
+	if (ret) {
+		btrfs_free_path(path);
+		btrfs_free_path(dst_path);
+		return ret;
+	}
+
 	mutex_lock(&BTRFS_I(inode)->log_mutex);
 
 	/*
-- 
1.7.3.1


^ permalink raw reply related	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-16 17:49       ` Chris Mason
@ 2011-03-17  1:37         ` Itaru Kitayama
  0 siblings, 0 replies; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-17  1:37 UTC (permalink / raw)
  To: Chris Mason; +Cc: Miao Xie, linux-btrfs

Hi Chris,
I have been using that option.

Itaru

On Wed, 16 Mar 2011 13:49:36 -0400
Chris Mason <chris.mason@oracle.com> wrote:

> Maybe this is related to the free space cache?  Is one of you using
> mount -o space_cache?
> 
> -chris

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-16 14:24     ` Miao Xie
@ 2011-03-16 17:49       ` Chris Mason
  2011-03-17  1:37         ` Itaru Kitayama
  0 siblings, 1 reply; 17+ messages in thread
From: Chris Mason @ 2011-03-16 17:49 UTC (permalink / raw)
  To: Miao Xie; +Cc: Itaru Kitayama, linux-btrfs

Excerpts from Miao Xie's message of 2011-03-16 10:24:31 -0400:
> On Wed, 16 Mar 2011 18:48:50 +0900, Itaru Kitayama wrote:
> > Hi Miao,
> > 
> > The V4 still hangs. Does the new function, btrfs_update_inode_nodelayed() you introduced to the V4
> > need take care of a delayed node (commit delayed items of the inode and set the delayed note to NULL)?
> 
> I think there no delayed item because we commit all the delayed items when we start committing
> transaction.
> 
> > 
> > Below is my experimental patch on top of V4 trying to avoid taking trans_mutex in btrfs_remove_delayed_node(), 
> > but still hangs. Could you take a look at it? Thanks.
> 
> It is so strange I can not reproduce it on my machine. But by reviewing the code, I think some inodes
> may be updated when committing the transaction, it makes the filesystem hang.

Maybe this is related to the free space cache?  Is one of you using
mount -o space_cache?

-chris

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-16  9:48   ` Itaru Kitayama
@ 2011-03-16 14:24     ` Miao Xie
  2011-03-16 17:49       ` Chris Mason
  2011-03-18  3:37     ` Miao Xie
  1 sibling, 1 reply; 17+ messages in thread
From: Miao Xie @ 2011-03-16 14:24 UTC (permalink / raw)
  To: Itaru Kitayama; +Cc: linux-btrfs

On Wed, 16 Mar 2011 18:48:50 +0900, Itaru Kitayama wrote:
> Hi Miao,
> 
> The V4 still hangs. Does the new function, btrfs_update_inode_nodelayed() you introduced to the V4
> need take care of a delayed node (commit delayed items of the inode and set the delayed note to NULL)?

I think there no delayed item because we commit all the delayed items when we start committing
transaction.

> 
> Below is my experimental patch on top of V4 trying to avoid taking trans_mutex in btrfs_remove_delayed_node(), 
> but still hangs. Could you take a look at it? Thanks.

It is so strange I can not reproduce it on my machine. But by reviewing the code, I think some inodes
may be updated when committing the transaction, it makes the filesystem hang.

> 
> Itaru
> 
> diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
> index 495a6af..b6ea082 100644
> --- a/fs/btrfs/delayed-inode.c
> +++ b/fs/btrfs/delayed-inode.c
> @@ -1006,9 +1006,9 @@ int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
>  	return ret;
>  }
>  
> -int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> -				     struct btrfs_root *root,
> -				     struct inode *inode)
> +int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> +				       struct btrfs_root *root,
> +				       struct inode *inode, int delayed_update)
>  {
>  	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
>  	struct btrfs_path *path;
> @@ -1036,7 +1036,7 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  	if (!ret)
>  		ret = btrfs_delete_delayed_items(trans, path, root,
>  						 delayed_node);
> -	if (!ret)
> +	if (!ret && delayed_update)
>  		ret = btrfs_update_delayed_inode(trans, root, path,
>  						 delayed_node);
>  	btrfs_free_path(path);
> @@ -1044,13 +1044,27 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  	return ret;
>  }
>  
> +int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> +				     struct btrfs_root *root,
> +				     struct inode *inode)
> +{
> +	return __btrfs_commit_inode_delayed_items(trans, root, inode, 1);
> +}
> +
> +int btrfs_commit_inode_delayed_items_no_delayed_update(struct btrfs_trans_handle *trans,
> +						       struct btrfs_root *root,
> +						       struct inode *inode)
> +{
> +	return __btrfs_commit_inode_delayed_items(trans, root, inode, 0);
> +}
> +
>  int btrfs_remove_delayed_node(struct inode *inode)
>  {
>  	struct btrfs_trans_handle *trans;
>  	struct btrfs_root *root = BTRFS_I(inode)->root;
>  	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
>  	int ret;
> -
> +	
>  	if (!delayed_node)
>  		return 0;
>  
> diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
> index d4134bc..b6986df 100644
> --- a/fs/btrfs/delayed-inode.h
> +++ b/fs/btrfs/delayed-inode.h
> @@ -114,6 +114,11 @@ void btrfs_balance_delayed_items(struct btrfs_root *root);
>  int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
>  				     struct btrfs_root *root,
>  				     struct inode *inode);
> +int btrfs_commit_inode_delayed_items_no_delayed_update(
> +				struct btrfs_trans_handle *trans,
> +				struct btrfs_root *root,
> +				struct inode *inode);
> +
>  /* Used for evicting the inode. */
>  int btrfs_remove_delayed_node(struct inode *inode);
>  int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 5299d9c..e198051 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2611,8 +2611,12 @@ noinline int btrfs_update_inode_nodelayed(struct btrfs_trans_handle *trans,
>  	struct btrfs_inode_item *inode_item;
>  	struct btrfs_path *path;
>  	struct extent_buffer *leaf;
> +	struct btrfs_delayed_node *delayed_node;
>  	int ret;
>  
> +	btrfs_commit_inode_delayed_items_no_delayed_update(trans, root, inode);
> +	delayed_node = NULL;
> +
>  	path = btrfs_alloc_path();
>  	if (!path)
>  		return -ENOMEM;
> 


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-10  6:21 ` Miao Xie
@ 2011-03-16  9:48   ` Itaru Kitayama
  2011-03-16 14:24     ` Miao Xie
  2011-03-18  3:37     ` Miao Xie
  0 siblings, 2 replies; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-16  9:48 UTC (permalink / raw)
  To: miaox; +Cc: linux-btrfs

Hi Miao,

The V4 still hangs. Does the new function, btrfs_update_inode_nodelayed() you introduced to the V4
need take care of a delayed node (commit delayed items of the inode and set the delayed note to NULL)?

Below is my experimental patch on top of V4 trying to avoid taking trans_mutex in btrfs_remove_delayed_node(), 
but still hangs. Could you take a look at it? Thanks.

Itaru

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 495a6af..b6ea082 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1006,9 +1006,9 @@ int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     struct inode *inode)
+int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				       struct btrfs_root *root,
+				       struct inode *inode, int delayed_update)
 {
 	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
 	struct btrfs_path *path;
@@ -1036,7 +1036,7 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
 	if (!ret)
 		ret = btrfs_delete_delayed_items(trans, path, root,
 						 delayed_node);
-	if (!ret)
+	if (!ret && delayed_update)
 		ret = btrfs_update_delayed_inode(trans, root, path,
 						 delayed_node);
 	btrfs_free_path(path);
@@ -1044,13 +1044,27 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode)
+{
+	return __btrfs_commit_inode_delayed_items(trans, root, inode, 1);
+}
+
+int btrfs_commit_inode_delayed_items_no_delayed_update(struct btrfs_trans_handle *trans,
+						       struct btrfs_root *root,
+						       struct inode *inode)
+{
+	return __btrfs_commit_inode_delayed_items(trans, root, inode, 0);
+}
+
 int btrfs_remove_delayed_node(struct inode *inode)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
 	int ret;
-
+	
 	if (!delayed_node)
 		return 0;
 
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
index d4134bc..b6986df 100644
--- a/fs/btrfs/delayed-inode.h
+++ b/fs/btrfs/delayed-inode.h
@@ -114,6 +114,11 @@ void btrfs_balance_delayed_items(struct btrfs_root *root);
 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
 				     struct inode *inode);
+int btrfs_commit_inode_delayed_items_no_delayed_update(
+				struct btrfs_trans_handle *trans,
+				struct btrfs_root *root,
+				struct inode *inode);
+
 /* Used for evicting the inode. */
 int btrfs_remove_delayed_node(struct inode *inode);
 int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5299d9c..e198051 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2611,8 +2611,12 @@ noinline int btrfs_update_inode_nodelayed(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_item *inode_item;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
+	struct btrfs_delayed_node *delayed_node;
 	int ret;
 
+	btrfs_commit_inode_delayed_items_no_delayed_update(trans, root, inode);
+	delayed_node = NULL;
+
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;

^ permalink raw reply related	[flat|nested] 17+ messages in thread

* Re: [PATCH V3] btrfs: implement delayed inode items operation
  2011-03-09 15:03 Itaru Kitayama
@ 2011-03-10  6:21 ` Miao Xie
  2011-03-16  9:48   ` Itaru Kitayama
  0 siblings, 1 reply; 17+ messages in thread
From: Miao Xie @ 2011-03-10  6:21 UTC (permalink / raw)
  To: Itaru Kitayama; +Cc: linux-btrfs

[-- Attachment #1: Type: text/plain, Size: 2174 bytes --]

Hi, Kitayama-san

On Thu, 10 Mar 2011 00:03:55 +0900, Itaru Kitayama wrote:
> INFO: task umount:1952 blocked for more than 120 seconds.
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> umount        D 00000000fffd44dc  3024  1952   1714 0x00000000
>  ffff880051ea99e8 0000000000000046 ffff880000000000 ffff880051ea9fd8
>  00000000001d4240 ffff88005cd958d0 ffff88005cd95e60 ffff88005cd95e58
>  ffff880051ea8000 ffff880051ea9fd8 00000000001d4240 00000000001d4240
> Call Trace:
>  [<ffffffff811d2697>] ? start_transaction+0x7b/0x1f8
>  [<ffffffff814b5593>] __mutex_lock_common+0x28c/0x444
>  [<ffffffff811d2697>] ? start_transaction+0x7b/0x1f8
>  [<ffffffff814b5800>] mutex_lock_nested+0x39/0x3e
>  [<ffffffff811d2697>] start_transaction+0x7b/0x1f8
>  [<ffffffff811d2857>] btrfs_join_transaction+0x15/0x17
>  [<ffffffff8120e873>] btrfs_remove_delayed_node+0x36/0xa1
>  [<ffffffff811d32ae>] btrfs_destroy_inode+0x2ae/0x2cc
>  [<ffffffff8112d1c9>] destroy_inode+0x2f/0x45
>  [<ffffffff8112da86>] iput+0x239/0x23e
>  [<ffffffff811c7992>] btrfs_write_dirty_block_groups+0x22a/0x47c
>  [<ffffffff811d0f46>] commit_cowonly_roots+0xd9/0x198
>  [<ffffffff811d20fc>] btrfs_commit_transaction+0x3a0/0x658
>  [<ffffffff814b5176>] ? __mutex_unlock_slowpath+0x129/0x13a
>  [<ffffffff810603de>] ? autoremove_wake_function+0x0/0x39
>  [<ffffffff811cf152>] btrfs_commit_super+0x90/0xd9
>  [<ffffffff811cf1e5>] close_ctree+0x4a/0x35c
>  [<ffffffff810648f5>] ? up_write+0x23/0x3b
>  [<ffffffff8112d83b>] ? invalidate_inodes+0x134/0x146
>  [<ffffffff811b5989>] btrfs_put_super+0x1d/0x2c
>  [<ffffffff8111c08d>] generic_shutdown_super+0x56/0xd7
>  [<ffffffff8111c163>] kill_anon_super+0x16/0x54
>  [<ffffffff8111b895>] ? deactivate_super+0x3d/0x4a
>  [<ffffffff8111b405>] deactivate_locked_super+0x26/0x46
>  [<ffffffff8111b89d>] deactivate_super+0x45/0x4a
>  [<ffffffff81131d6a>] mntput_no_expire+0xd6/0x104
>  [<ffffffff81132e8f>] sys_umount+0x2c1/0x2ec
>  [<ffffffff81002ddb>] system_call_fastpath+0x16/0x1b
> INFO: lockdep is turned off.
> 
> btrfs_remove_delayed_node() is called while trans_mutex is held.

Could you test the attached patch for me?

Thanks
Miao

[-- Attachment #2: 0001-btrfs-implement-delayed-inode-items-operation-v4.patch --]
[-- Type: text/plain, Size: 82351 bytes --]

>From d3b93038967483d37f3deeca866bcd1ec2760b55 Mon Sep 17 00:00:00 2001
From: Miao Xie <miaox@cn.fujitsu.com>
Date: Tue, 15 Feb 2011 16:20:15 +0800
Subject: [PATCH] btrfs: implement delayed inode items operation - v4

Changelog V3 -> V4:
- Fix nested lock, which is reported by Itaru Kitayama

Changelog V2 -> V3:
- Fix the race between the delayed worker and the task which does delayed items
  balance, which is reported by Tsutomu Itoh.
- Modify the patch address David Sterba's comment.
- Fix the bug of the cpu recursion spinlock, reported by Chris Mason

Changelog V1 -> V2:
- break up the global rb-tree, use a list to manage the delayed nodes,
  which is created for every directory and file, and used to manage the
  delayed directory name index items and the delayed inode item.
- introduce a worker to deal with the delayed nodes.

Compare with Ext3/4, the performance of file creation and deletion on btrfs
is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
such as inode item, directory name item, directory name index and so on.

If we can do some delayed b+ tree insertion or deletion, we can improve the
performance, so we made this patch which implemented delayed directory name
index insertion/deletion and delayed inode update.

Implementation:
- introduce a delayed root object into the filesystem, that use two lists to
  manage the delayed nodes which are created for every file/directory.
  One is used to manage all the delayed nodes that have delayed items. And the
  other is used to manage the delayed nodes which is waiting to be dealt with
  by the work thread.
- Every delayed node has two rb-tree, one is used to manage the directory name
  index which is going to be inserted into b+ tree, and the other is used to
  manage the directory name index which is going to be deleted from b+ tree.
- introduce a worker to deal with the delayed operation. This worker is used
  to deal with the works of the delayed directory name index items insertion
  and deletion and the delayed inode update.
  When the delayed items is beyond the lower limit, we create works for some
  delayed nodes and insert them into the work queue of the worker, and then
  go back.
  When the delayed items is beyond the upper bound, we create works for all
  the delayed nodes that haven't been dealt with, and insert them into the work
  queue of the worker, and then wait for that the untreated items is below some
  threshold value.
- When we want to insert a directory name index into b+ tree, we just add the
  information into the delayed inserting rb-tree.
  And then we check the number of the delayed items and do delayed items
  balance. (The balance policy is above.)
- When we want to delete a directory name index from the b+ tree, we search it
  in the inserting rb-tree at first. If we look it up, just drop it. If not,
  add the key of it into the delayed deleting rb-tree.
  Similar to the delayed inserting rb-tree, we also check the number of the
  delayed items and do delayed items balance.
  (The same to inserting manipulation)
- When we want to update the metadata of some inode, we cached the data of the
  inode into the delayed node. the worker will flush it into the b+ tree after
  dealing with the delayed insertion and deletion.
- We will move the delayed node to the tail of the list after we access the
  delayed node, By this way, we can cache more delayed items and merge more
  inode updates.
- If we want to commit transaction, we will deal with all the delayed node.
- the delayed node will be freed when we free the btrfs inode.
- Before we log the inode items, we commit all the directory name index items
  and the delayed inode update.

I did a quick test by the benchmark tool[1] and found we can improve the
performance of file creation by ~15%, and file deletion by ~20%.

Before applying this patch:
Create files:
	Total files: 50000
	Total time: 1.096108
	Average time: 0.000022
Delete files:
	Total files: 50000
	Total time: 1.510403
	Average time: 0.000030

After applying this patch:
Create files:
	Total files: 50000
	Total time: 0.932899
	Average time: 0.000019
Delete files:
	Total files: 50000
	Total time: 1.215732
	Average time: 0.000024

[1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 fs/btrfs/Makefile           |    2 +-
 fs/btrfs/btrfs_inode.h      |    5 +
 fs/btrfs/ctree.c            |   14 +-
 fs/btrfs/ctree.h            |   27 +-
 fs/btrfs/delayed-inode.c    | 1614 +++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/delayed-inode.h    |  139 ++++
 fs/btrfs/dir-item.c         |   32 +-
 fs/btrfs/disk-io.c          |   26 +-
 fs/btrfs/extent-tree.c      |   18 +-
 fs/btrfs/free-space-cache.c |    6 +-
 fs/btrfs/inode.c            |  108 ++-
 fs/btrfs/ioctl.c            |    2 +-
 fs/btrfs/super.c            |   10 +-
 fs/btrfs/transaction.c      |   49 ++-
 fs/btrfs/transaction.h      |    2 +
 fs/btrfs/tree-log.c         |    7 +
 16 files changed, 1970 insertions(+), 91 deletions(-)
 create mode 100644 fs/btrfs/delayed-inode.c
 create mode 100644 fs/btrfs/delayed-inode.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 31610ea..a8411c2 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -7,4 +7,4 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
 	   extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
 	   export.o tree-log.o acl.o free-space-cache.o zlib.o lzo.o \
-	   compression.o delayed-ref.o relocation.o
+	   compression.o delayed-ref.o relocation.o delayed-inode.o
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index ccc991c..ef3baa8 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -22,6 +22,7 @@
 #include "extent_map.h"
 #include "extent_io.h"
 #include "ordered-data.h"
+#include "delayed-inode.h"
 
 /* in memory btrfs inode */
 struct btrfs_inode {
@@ -159,9 +160,13 @@ struct btrfs_inode {
 	 */
 	unsigned force_compress:4;
 
+	struct btrfs_delayed_node *delayed_node;
+
 	struct inode vfs_inode;
 };
 
+extern unsigned char btrfs_filetype_table[];
+
 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 {
 	return container_of(inode, struct btrfs_inode, vfs_inode);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b5baff0..6e3e4c3 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,11 +38,6 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct extent_buffer *src_buf);
 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		   struct btrfs_path *path, int level, int slot);
-static int setup_items_for_insert(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root, struct btrfs_path *path,
-			struct btrfs_key *cpu_key, u32 *data_size,
-			u32 total_data, u32 total_size, int nr);
-
 
 struct btrfs_path *btrfs_alloc_path(void)
 {
@@ -3688,11 +3683,10 @@ out:
  * to save stack depth by doing the bulk of the work in a function
  * that doesn't call btrfs_search_slot
  */
-static noinline_for_stack int
-setup_items_for_insert(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root, struct btrfs_path *path,
-		      struct btrfs_key *cpu_key, u32 *data_size,
-		      u32 total_data, u32 total_size, int nr)
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr)
 {
 	struct btrfs_item *item;
 	int i;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 28188a7..8a58888 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -859,6 +859,7 @@ struct btrfs_block_group_cache {
 struct reloc_control;
 struct btrfs_device;
 struct btrfs_fs_devices;
+struct btrfs_delayed_root;
 struct btrfs_fs_info {
 	u8 fsid[BTRFS_FSID_SIZE];
 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
@@ -885,7 +886,10 @@ struct btrfs_fs_info {
 	/* logical->physical extent mapping */
 	struct btrfs_mapping_tree mapping_tree;
 
-	/* block reservation for extent, checksum and root tree */
+	/*
+	 * block reservation for extent, checksum, root tree and
+	 * delayed dir index item
+	 */
 	struct btrfs_block_rsv global_block_rsv;
 	/* block reservation for delay allocation */
 	struct btrfs_block_rsv delalloc_block_rsv;
@@ -1012,6 +1016,7 @@ struct btrfs_fs_info {
 	 * for the sys_munmap function call path
 	 */
 	struct btrfs_workers fixup_workers;
+	struct btrfs_workers delayed_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;
 	int thread_pool_size;
@@ -1069,6 +1074,8 @@ struct btrfs_fs_info {
 
 	/* filesystem state */
 	u64 fs_state;
+
+	struct btrfs_delayed_root *delayed_root;
 };
 
 /*
@@ -2086,6 +2093,13 @@ static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
 }
 
 /* extent-tree.c */
+static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
+						 int num_items)
+{
+	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
+		3 * num_items;
+}
+
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root, unsigned long count);
@@ -2277,6 +2291,8 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_set_path_blocking(struct btrfs_path *p);
+void btrfs_clear_path_blocking(struct btrfs_path *p,
+			       struct extent_buffer *held);
 void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -2288,6 +2304,10 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 	return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
+int setup_items_for_insert(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct btrfs_path *path,
+			   struct btrfs_key *cpu_key, u32 *data_size,
+			   u32 total_data, u32 total_size, int nr);
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
@@ -2349,7 +2369,7 @@ int btrfs_set_root_node(struct btrfs_root_item *item,
 /* dir-item.c */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, const char *name,
-			  int name_len, u64 dir,
+			  int name_len, struct inode *dir,
 			  struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
@@ -2517,6 +2537,9 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct inode *inode);
+int btrfs_update_inode_nodelayed(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *root,
+				 struct inode *inode);
 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
 void btrfs_orphan_cleanup(struct btrfs_root *root);
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
new file mode 100644
index 0000000..495a6af
--- /dev/null
+++ b/fs/btrfs/delayed-inode.c
@@ -0,0 +1,1614 @@
+/*
+ * 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,
+				u64 root_id, u64 inode_id)
+{
+	delayed_node->root_id = root_id;
+	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;
+	delayed_node->block_rsv = NULL;
+}
+
+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;
+
+	if (btrfs_inode->delayed_node) {
+		node = btrfs_inode->delayed_node;
+		atomic_inc(&node->refs);	/* can be accessed */
+		return node;
+	}
+
+	node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	btrfs_init_delayed_node(node, root->objectid, inode->i_ino);
+
+	btrfs_inode->delayed_node = node;
+	node->delayed_root = btrfs_get_delayed_root(root);
+	atomic_inc(&node->refs);	/* cached in the btrfs inode */
+	atomic_inc(&node->refs);	/* can be accessed */
+
+	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 = node->delayed_root;
+	struct list_head *p;
+	struct btrfs_delayed_node *next = NULL;
+
+	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->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))
+		kmem_cache_free(delayed_node_cache, delayed_node);
+}
+
+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;
+	}
+	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->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->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);
+		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;
+		node->block_rsv = dst_rsv;
+	}
+
+	return ret;
+}
+
+static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
+						struct btrfs_delayed_node *node)
+{
+	if (!node->bytes_reserved)
+		return;
+
+	btrfs_block_rsv_release(root, node->block_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)
+{
+	if (delayed_node && delayed_node->inode_dirty) {
+		BUG_ON(!delayed_node->delayed_root);
+		delayed_node->inode_dirty = 0;
+		delayed_node->count--;
+		atomic_dec(&delayed_node->delayed_root->items);
+		if (atomic_read(&delayed_node->delayed_root->items) <
+		    BTRFS_DELAYED_BACKGROUND &&
+		    waitqueue_active(&delayed_node->delayed_root->wait))
+			wake_up(&delayed_node->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) {
+		/*
+		 * check root, if root is not the one which the delayed item
+		 * wants to be inserted to, we get the right root.
+		 */
+		if (root->objectid != curr_node->root_id) {
+			root = btrfs_get_fs_root(root, curr_node->root_id);
+			BUG_ON(IS_ERR_OR_NULL(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;
+}
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode)
+{
+	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
+	struct btrfs_path *path;
+	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);
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		btrfs_release_delayed_node(delayed_node);
+		return -ENOMEM;
+	}
+	path->leave_spinning = 1;
+
+	ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
+	if (!ret)
+		ret = btrfs_delete_delayed_items(trans, path, root,
+						 delayed_node);
+	if (!ret)
+		ret = btrfs_update_delayed_inode(trans, root, path,
+						 delayed_node);
+	btrfs_free_path(path);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_remove_delayed_node(struct inode *inode)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node = BTRFS_I(inode)->delayed_node;
+	int ret;
+
+	if (!delayed_node)
+		return 0;
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = btrfs_commit_inode_delayed_items(trans, root, inode);
+	if (ret)
+		goto out;
+
+	BUG_ON(delayed_node->in_list);
+	BUG_ON(delayed_node->count);
+
+	BTRFS_I(inode)->delayed_node = NULL;
+	btrfs_release_delayed_node(delayed_node);
+out:
+	btrfs_end_transaction_dmeta(trans, root);
+
+	return ret;
+}
+
+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;
+
+	root = async_node->root;
+	BUG_ON(!root);
+
+	trans = btrfs_join_transaction(root, 0);
+	if (IS_ERR(trans))
+		goto free_path;
+
+	delayed_node = async_node->delayed_node;
+
+	root = btrfs_get_fs_root(async_node->root, delayed_node->root_id);
+	BUG_ON(IS_ERR_OR_NULL(root));
+
+	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(delayed_node->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_id,
+				(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_id,
+				(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;
+}
+
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode)
+{
+	struct btrfs_delayed_node *delayed_node;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (delayed_node)
+		mutex_lock(&delayed_node->mutex);
+
+	return delayed_node;
+}
+
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node)
+{
+	if (!node)
+		return;
+
+	mutex_unlock(&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(&node->refs);
+}
+
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index)
+{
+	if (!delayed_node)
+		return 0;
+
+	if (IS_ERR(*item))
+		return 0;
+
+	if (!(*item))
+		*item = __btrfs_first_delayed_deletion_item(delayed_node);
+
+	while (*item) {
+		if ((*item)->key.offset < index) {
+			*item = __btrfs_next_delayed_item(*item);
+			continue;
+		} else if ((*item)->key.offset > index)
+			break;
+
+		*item = __btrfs_next_delayed_item(*item);
+		if (!(*item))
+			*item = ERR_PTR(-ERANGE);
+		return 1;
+	}
+
+	if (!(*item))
+		*item = ERR_PTR(-ERANGE);
+	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 btrfs_delayed_node *delayed_node)
+{
+	struct btrfs_dir_item *di;
+	struct btrfs_delayed_item *item;
+	struct btrfs_key location;
+	char *name;
+	int name_len;
+	int over = 0;
+	unsigned char d_type;
+
+	if (!delayed_node)
+		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.
+	 */
+	item = __btrfs_first_delayed_insertion_item(delayed_node);
+	while (item) {
+		if (item->key.offset < filp->f_pos) {
+			item = __btrfs_next_delayed_item(item);
+			continue;
+		}
+
+		filp->f_pos = item->key.offset;
+
+		di = (struct btrfs_dir_item *)item->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, item->key.offset,
+			       location.objectid, d_type);
+
+		if (over)
+			return 1;
+		item = __btrfs_next_delayed_item(item);
+	}
+	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(&delayed_node->delayed_root->items);
+release_node:
+	mutex_unlock(&delayed_node->mutex);
+	btrfs_release_delayed_node(delayed_node);
+	return ret;
+}
+
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode)
+{
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_delayed_node *delayed_node;
+	struct btrfs_delayed_item *curr_item, *prev_item;
+
+	delayed_node = btrfs_get_delayed_node(inode);
+	if (!delayed_node)
+		return 0;
+
+	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);
+
+	btrfs_release_delayed_node(delayed_node);
+
+	return 0;
+}
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
new file mode 100644
index 0000000..d4134bc
--- /dev/null
+++ b/fs/btrfs/delayed-inode.h
@@ -0,0 +1,139 @@
+/*
+ * 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.
+ */
+
+#ifndef __DELAYED_TREE_OPERATION_H
+#define __DELAYED_TREE_OPERATION_H
+
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include "ctree.h"
+
+/* types of the delayed item */
+#define BTRFS_DELAYED_INSERTION_ITEM	1
+#define BTRFS_DELAYED_DELETION_ITEM	2
+
+struct btrfs_delayed_root {
+	spinlock_t lock;
+	struct list_head node_list;
+	/*
+	 * Used for delayed nodes which is waiting to be dealt with by the
+	 * worker. If the delayed node is inserted into the work queue, we
+	 * drop it from this list.
+	 */
+	struct list_head prepare_list;
+	atomic_t items;		/* for delayed items */
+	int nodes;		/* for delayed nodes */
+	wait_queue_head_t wait;
+};
+
+struct btrfs_delayed_node {
+	u64 root_id;
+	u64 inode_id;
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_root *delayed_root;
+	/* Used to add the node into the delayed root's node list. */
+	struct list_head n_list;
+	/*
+	 * Used to add the node into the prepare list, the nodes in this list
+	 * is waiting to be dealt with by the async worker.
+	 */
+	struct list_head p_list;
+	struct rb_root ins_root;
+	struct rb_root del_root;
+	struct mutex mutex;
+	struct btrfs_inode_item inode_item;
+	atomic_t refs;
+	u64 index_cnt;
+	bool in_list;
+	bool inode_dirty;
+	int count;
+};
+
+struct btrfs_delayed_item {
+	struct rb_node rb_node;
+	struct btrfs_key key;
+	struct list_head tree_list;	/* used for batch insert/delete items */
+	u64 bytes_reserved;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_delayed_node *delayed_node;
+	int ins_or_del;
+	u32 data_len;
+	char data[0];
+};
+
+static inline void btrfs_init_delayed_root(
+				struct btrfs_delayed_root *delayed_root)
+{
+	atomic_set(&delayed_root->items, 0);
+	delayed_root->nodes = 0;
+	spin_lock_init(&delayed_root->lock);
+	init_waitqueue_head(&delayed_root->wait);
+	INIT_LIST_HEAD(&delayed_root->node_list);
+	INIT_LIST_HEAD(&delayed_root->prepare_list);
+}
+
+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);
+
+int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
+				   struct btrfs_root *root, struct inode *dir,
+				   u64 index);
+
+int btrfs_inode_delayed_dir_index_count(struct inode *inode);
+
+int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+
+void btrfs_balance_delayed_items(struct btrfs_root *root);
+
+int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct inode *inode);
+/* Used for evicting the inode. */
+int btrfs_remove_delayed_node(struct inode *inode);
+int btrfs_kill_delayed_inode_items(struct btrfs_trans_handle *trans,
+				   struct inode *inode);
+
+
+int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root, struct inode *inode);
+
+/* Used for readdir() */
+struct btrfs_delayed_node *btrfs_get_locked_delayed_node(struct inode *inode);
+void btrfs_put_locked_delayed_node(struct btrfs_delayed_node *node);
+int btrfs_should_delete_dir_index(struct btrfs_delayed_node *delayed_node,
+				  struct btrfs_delayed_item **item,
+				  u64 index);
+int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
+				    filldir_t filldir,
+				    struct btrfs_delayed_node *delayed_node);
+
+/* for init */
+int __init btrfs_delayed_inode_init(void);
+void btrfs_delayed_inode_exit(void);
+#endif
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f0cad5a..696c793 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -124,8 +124,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  * to use for the second index (if one is created).
  */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, const char *name, int name_len, u64 dir,
-			  struct btrfs_key *location, u8 type, u64 index)
+			  *root, const char *name, int name_len,
+			  struct inode *dir, struct btrfs_key *location,
+			  u8 type, u64 index)
 {
 	int ret = 0;
 	int ret2 = 0;
@@ -137,13 +138,17 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	struct btrfs_disk_key disk_key;
 	u32 data_size;
 
-	key.objectid = dir;
+	key.objectid = dir->i_ino;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
 
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->leave_spinning = 1;
 
+	btrfs_cpu_key_to_disk(&disk_key, location);
+
 	data_size = sizeof(*dir_item) + name_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 					name, name_len);
@@ -155,7 +160,6 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	}
 
 	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
 	btrfs_set_dir_data_len(leaf, dir_item, 0);
@@ -174,24 +178,8 @@ second_insert:
 	}
 	btrfs_release_path(root, path);
 
-	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-	key.offset = index;
-	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
-					name, name_len);
-	if (IS_ERR(dir_item)) {
-		ret2 = PTR_ERR(dir_item);
-		goto out;
-	}
-	leaf = path->nodes[0];
-	btrfs_cpu_key_to_disk(&disk_key, location);
-	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
-	btrfs_set_dir_type(leaf, dir_item, type);
-	btrfs_set_dir_data_len(leaf, dir_item, 0);
-	btrfs_set_dir_name_len(leaf, dir_item, name_len);
-	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
-	name_ptr = (unsigned long)(dir_item + 1);
-	write_extent_buffer(leaf, name, name_ptr, name_len);
-	btrfs_mark_buffer_dirty(leaf);
+	ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir,
+					      &disk_key, type, index);
 out:
 	btrfs_free_path(path);
 	if (ret)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3e1ea3e..ea3c145 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1676,6 +1676,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	INIT_LIST_HEAD(&fs_info->ordered_extents);
 	spin_lock_init(&fs_info->ordered_extent_lock);
+	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+					GFP_NOFS);
+	if (!fs_info->delayed_root) {
+		err = -ENOMEM;
+		goto fail_iput;
+	}
+	btrfs_init_delayed_root(fs_info->delayed_root);
 
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
@@ -1743,7 +1750,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	bh = btrfs_read_dev_super(fs_devices->latest_bdev);
 	if (!bh) {
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
@@ -1755,7 +1762,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	disk_super = &fs_info->super_copy;
 	if (!btrfs_super_root(disk_super))
-		goto fail_iput;
+		goto fail_alloc;
 
 	/* check FS state, whether FS is broken. */
 	fs_info->fs_state |= btrfs_super_flags(disk_super);
@@ -1765,7 +1772,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	ret = btrfs_parse_options(tree_root, options);
 	if (ret) {
 		err = ret;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super) &
@@ -1775,7 +1782,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported optional features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super);
@@ -1791,7 +1798,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		       "unsupported option features (%Lx).\n",
 		       (unsigned long long)features);
 		err = -EINVAL;
-		goto fail_iput;
+		goto fail_alloc;
 	}
 
 	btrfs_init_workers(&fs_info->generic_worker,
@@ -1838,6 +1845,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 			   &fs_info->generic_worker);
 	btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
 			   1, &fs_info->generic_worker);
+	btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
+			   fs_info->thread_pool_size,
+			   &fs_info->generic_worker);
 
 	/*
 	 * endios are largely parallel and should have a very
@@ -1859,6 +1869,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_write_workers, 1);
 	btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
+	btrfs_start_workers(&fs_info->delayed_workers, 1);
 
 	fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
 	fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -2104,6 +2115,9 @@ fail_sb_buffer:
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
+fail_alloc:
+	kfree(fs_info->delayed_root);
 fail_iput:
 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 	iput(fs_info->btree_inode);
@@ -2551,6 +2565,7 @@ int close_ctree(struct btrfs_root *root)
 	del_fs_roots(fs_info);
 
 	iput(fs_info->btree_inode);
+	kfree(fs_info->delayed_root);
 
 	btrfs_stop_workers(&fs_info->generic_worker);
 	btrfs_stop_workers(&fs_info->fixup_workers);
@@ -2562,6 +2577,7 @@ int close_ctree(struct btrfs_root *root)
 	btrfs_stop_workers(&fs_info->endio_write_workers);
 	btrfs_stop_workers(&fs_info->endio_freespace_worker);
 	btrfs_stop_workers(&fs_info->submit_workers);
+	btrfs_stop_workers(&fs_info->delayed_workers);
 
 	btrfs_close_devices(fs_info->fs_devices);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 100e409..aed763f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3897,12 +3897,6 @@ static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
 }
 
-static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
-{
-	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
-		3 * num_items;
-}
-
 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 int num_items)
@@ -3913,7 +3907,7 @@ int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
 	if (num_items == 0 || root->fs_info->chunk_root == root)
 		return 0;
 
-	num_bytes = calc_trans_metadata_size(root, num_items);
+	num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
 	ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
 				  num_bytes);
 	if (!ret) {
@@ -3952,14 +3946,14 @@ int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * If all of the metadata space is used, we can commit
 	 * transaction and use space it freed.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
 void btrfs_orphan_release_metadata(struct inode *inode)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes = calc_trans_metadata_size(root, 4);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 4);
 	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
 }
 
@@ -3973,7 +3967,7 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
 	 * two for root back/forward refs, two for directory entries
 	 * and one for root of the snapshot.
 	 */
-	u64 num_bytes = calc_trans_metadata_size(root, 5);
+	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
 	dst_rsv->space_info = src_rsv->space_info;
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
@@ -4000,7 +3994,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
 	if (nr_extents > BTRFS_I(inode)->reserved_extents) {
 		nr_extents -= BTRFS_I(inode)->reserved_extents;
-		to_reserve = calc_trans_metadata_size(root, nr_extents);
+		to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
 	} else {
 		nr_extents = 0;
 		to_reserve = 0;
@@ -4047,7 +4041,7 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 
 	to_free = calc_csum_metadata_size(inode, num_bytes);
 	if (nr_extents > 0)
-		to_free += calc_trans_metadata_size(root, nr_extents);
+		to_free += btrfs_calc_trans_metadata_size(root, nr_extents);
 
 	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
 				to_free);
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index a039065..5d4d2fa 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -775,7 +775,11 @@ out_free:
 		BTRFS_I(inode)->generation = 0;
 	}
 	kfree(checksums);
-	btrfs_update_inode(trans, root, inode);
+	/*
+	 * This function is called when committing current transaction, so
+	 * we can not delay to update in-btree inode item.
+	 */
+	btrfs_update_inode_nodelayed(trans, root, inode);
 	iput(inode);
 	return ret;
 }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7027953..0f841aa 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2598,26 +2598,41 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root, struct inode *inode)
 {
+	int ret;
+
+	ret = btrfs_delayed_update_inode(trans, root, inode);
+	if (!ret)
+		btrfs_set_inode_last_trans(trans, inode);
+
+	return ret;
+}
+
+noinline int btrfs_update_inode_nodelayed(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct inode *inode)
+{
 	struct btrfs_inode_item *inode_item;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
 	int ret;
 
 	path = btrfs_alloc_path();
-	BUG_ON(!path);
+	if (!path)
+		return -ENOMEM;
+
 	path->leave_spinning = 1;
-	ret = btrfs_lookup_inode(trans, root, path,
-				 &BTRFS_I(inode)->location, 1);
+	ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
+				 1);
 	if (ret) {
 		if (ret > 0)
-			ret = -ENOENT;
+			ret = -ENOMEM;
 		goto failed;
 	}
 
 	btrfs_unlock_up_safe(path, 1);
 	leaf = path->nodes[0];
 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
-				  struct btrfs_inode_item);
+				    struct btrfs_inode_item);
 
 	fill_inode_item(trans, leaf, inode_item, inode);
 	btrfs_mark_buffer_dirty(leaf);
@@ -2628,7 +2643,6 @@ failed:
 	return ret;
 }
 
-
 /*
  * unlink helper that gets used here in inode.c and in the tree logging
  * recovery code.  It remove a link in a directory with a given name, and
@@ -2680,18 +2694,9 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto err;
 	}
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
-		goto err;
-	}
-	if (!di) {
-		ret = -ENOENT;
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
+	if (ret)
 		goto err;
-	}
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
-	btrfs_release_path(root, path);
 
 	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
 					 inode, dir->i_ino);
@@ -2867,6 +2872,14 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 	index = btrfs_inode_ref_index(path->nodes[0], ref);
 	btrfs_release_path(root, path);
 
+	/*
+	 * This is a commit root search, if we can lookup inode item and other
+	 * relative items in the commit root, it means the transaction of
+	 * dir/file creation has been committed, and the dir index item that we
+	 * delay to insert has also been inserted into the commit root. So
+	 * we needn't worry about the delayed insertion of the dir index item
+	 * here.
+	 */
 	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
 				dentry->d_name.name, dentry->d_name.len, 0);
 	if (IS_ERR(di)) {
@@ -2972,24 +2985,16 @@ int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 		btrfs_release_path(root, path);
 		index = key.offset;
 	}
+	btrfs_release_path(root, path);
 
-	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-					 index, name, name_len, -1);
-	BUG_ON(!di || IS_ERR(di));
-
-	leaf = path->nodes[0];
-	btrfs_dir_item_key_to_cpu(leaf, di, &key);
-	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
-	ret = btrfs_delete_one_dir_name(trans, root, path, di);
+	ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
 	BUG_ON(ret);
-	btrfs_release_path(root, path);
 
 	btrfs_i_size_write(dir, dir->i_size - name_len * 2);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 	ret = btrfs_update_inode(trans, root, dir);
 	BUG_ON(ret);
 
-	btrfs_free_path(path);
 	return 0;
 }
 
@@ -3249,6 +3254,15 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	if (root->ref_cows || root == root->fs_info->tree_root)
 		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
 
+	/*
+	 * This function is also used to drop the items in the log tree before
+	 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
+	 * it is used to drop the loged items. So we shouldn't kill the delayed
+	 * items.
+	 */
+	if (min_type == 0 && root == BTRFS_I(inode)->root)
+		btrfs_kill_delayed_inode_items(trans, inode);
+
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
 	path->reada = -1;
@@ -4182,7 +4196,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
 	return d_splice_alias(inode, dentry);
 }
 
-static unsigned char btrfs_filetype_table[] = {
+unsigned char btrfs_filetype_table[] = {
 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
 };
 
@@ -4196,6 +4210,8 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	struct btrfs_path *path;
+	struct btrfs_delayed_node *delayed_node = NULL;
+	struct btrfs_delayed_item *delayed_item = NULL;
 	int ret;
 	u32 nritems;
 	struct extent_buffer *leaf;
@@ -4210,6 +4226,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	char tmp_name[32];
 	char *name_ptr;
 	int name_len;
+	int is_curr = 0;	/* filp->f_pos points to the current index? */
 
 	/* FIXME, use a real flag for deciding about the key type */
 	if (root->fs_info->tree_root == root)
@@ -4234,8 +4251,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 		filp->f_pos = 2;
 	}
 	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
 	path->reada = 2;
 
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		delayed_node = btrfs_get_locked_delayed_node(inode);
+
 	btrfs_set_key_type(&key, key_type);
 	key.offset = filp->f_pos;
 	key.objectid = inode->i_ino;
@@ -4273,8 +4295,13 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 			break;
 		if (found_key.offset < filp->f_pos)
 			continue;
+		if (key_type == BTRFS_DIR_INDEX_KEY &&
+		    btrfs_should_delete_dir_index(delayed_node, &delayed_item,
+						  found_key.offset))
+			continue;
 
 		filp->f_pos = found_key.offset;
+		is_curr = 1;
 
 		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 		di_cur = 0;
@@ -4324,6 +4351,15 @@ skip:
 		}
 	}
 
+	if (key_type == BTRFS_DIR_INDEX_KEY) {
+		if (is_curr)
+			filp->f_pos++;
+		ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
+						      delayed_node);
+		if (ret)
+			goto nopos;
+	}
+
 	/* Reached end of directory/root. Bump pos past the last item. */
 	if (key_type == BTRFS_DIR_INDEX_KEY)
 		/*
@@ -4336,6 +4372,8 @@ skip:
 nopos:
 	ret = 0;
 err:
+	if (key_type == BTRFS_DIR_INDEX_KEY)
+		btrfs_put_locked_delayed_node(delayed_node);
 	btrfs_free_path(path);
 	return ret;
 }
@@ -4481,9 +4519,12 @@ int btrfs_set_inode_index(struct inode *dir, u64 *index)
 	int ret = 0;
 
 	if (BTRFS_I(dir)->index_cnt == (u64)-1) {
-		ret = btrfs_set_inode_index_count(dir);
-		if (ret)
-			return ret;
+		ret = btrfs_inode_delayed_dir_index_count(dir);
+		if (ret) {
+			ret = btrfs_set_inode_index_count(dir);
+			if (ret)
+				return ret;
+		}
 	}
 
 	*index = BTRFS_I(dir)->index_cnt;
@@ -4641,7 +4682,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
 
 	if (ret == 0) {
 		ret = btrfs_insert_dir_item(trans, root, name, name_len,
-					    parent_inode->i_ino, &key,
+					    parent_inode, &key,
 					    btrfs_inode_type(inode), index);
 		BUG_ON(ret);
 
@@ -6642,6 +6683,8 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->dummy_inode = 0;
 	ei->force_compress = BTRFS_COMPRESS_NONE;
 
+	ei->delayed_node = NULL;
+
 	inode = &ei->vfs_inode;
 	extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
 	extent_io_tree_init(&ei->io_tree, &inode->i_data, GFP_NOFS);
@@ -6725,6 +6768,7 @@ void btrfs_destroy_inode(struct inode *inode)
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 free:
+	btrfs_remove_delayed_node(inode);
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..b200e07 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -333,7 +333,7 @@ static noinline int create_subvol(struct btrfs_root *root,
 	BUG_ON(ret);
 
 	ret = btrfs_insert_dir_item(trans, root,
-				    name, namelen, dir->i_ino, &key,
+				    name, namelen, dir, &key,
 				    BTRFS_FT_DIR, index);
 	if (ret)
 		goto fail;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db0a827..593ce8a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -40,6 +40,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include "compat.h"
+#include "delayed-inode.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1163,10 +1164,14 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_extent_io;
 
-	err = btrfs_interface_init();
+	err = btrfs_delayed_inode_init();
 	if (err)
 		goto free_extent_map;
 
+	err = btrfs_interface_init();
+	if (err)
+		goto free_delayed_inode;
+
 	err = register_filesystem(&btrfs_fs_type);
 	if (err)
 		goto unregister_ioctl;
@@ -1176,6 +1181,8 @@ static int __init init_btrfs_fs(void)
 
 unregister_ioctl:
 	btrfs_interface_exit();
+free_delayed_inode:
+	btrfs_delayed_inode_exit();
 free_extent_map:
 	extent_map_exit();
 free_extent_io:
@@ -1192,6 +1199,7 @@ free_sysfs:
 static void __exit exit_btrfs_fs(void)
 {
 	btrfs_destroy_cachep();
+	btrfs_delayed_inode_exit();
 	extent_map_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3d73c8d..31b328b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -478,19 +478,46 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 1, 1);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 1, 1);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
 }
 
 int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root)
 {
-	return __btrfs_end_transaction(trans, root, 0, 0);
+	int ret;
+
+	ret = __btrfs_end_transaction(trans, root, 0, 0);
+	if (ret)
+		return ret;
+
+	btrfs_balance_delayed_items(root);
+	return 0;
+}
+
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root)
+{
+	return __btrfs_end_transaction(trans, root, 1, 1);
 }
 
 /*
@@ -958,7 +985,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	BUG_ON(ret);
 	ret = btrfs_insert_dir_item(trans, parent_root,
 				dentry->d_name.name, dentry->d_name.len,
-				parent_inode->i_ino, &key,
+				parent_inode, &key,
 				BTRFS_FT_DIR, index);
 	BUG_ON(ret);
 
@@ -1027,6 +1054,14 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 	int ret;
 
 	list_for_each_entry(pending, head, list) {
+		/*
+		 * We must deal with the delayed items before creating
+		 * snapshots, or we will create a snapthot with inconsistent
+		 * information.
+		*/
+		ret = btrfs_run_delayed_items(trans, fs_info->fs_root);
+		BUG_ON(ret);
+
 		ret = create_pending_snapshot(trans, fs_info, pending);
 		BUG_ON(ret);
 	}
@@ -1279,6 +1314,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 			BUG_ON(ret);
 		}
 
+		ret = btrfs_run_delayed_items(trans, root);
+		BUG_ON(ret);
+
 		/*
 		 * rename don't use btrfs_join_transaction, so, once we
 		 * set the transaction to blocked above, we aren't going
@@ -1305,6 +1343,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	ret = create_pending_snapshots(trans, root->fs_info);
 	BUG_ON(ret);
 
+	ret = btrfs_run_delayed_items(trans, root);
+	BUG_ON(ret);
+
 	ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
 	BUG_ON(ret);
 
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 229a594..a4a441f 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -115,6 +115,8 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 				   int wait_for_unblock);
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root);
+int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root);
 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root);
 void btrfs_throttle(struct btrfs_root *root);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a4bbb85..e8a2e95 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2775,6 +2775,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		max_key.type = (u8)-1;
 	max_key.offset = (u64)-1;
 
+	ret = btrfs_commit_inode_delayed_items(trans, root, inode);
+	if (ret) {
+		btrfs_free_path(path);
+		btrfs_free_path(dst_path);
+		return ret;
+	}
+
 	mutex_lock(&BTRFS_I(inode)->log_mutex);
 
 	/*
-- 
1.7.3.1


^ permalink raw reply related	[flat|nested] 17+ messages in thread

* RE: [PATCH V3] btrfs: implement delayed inode items operation
@ 2011-03-09 15:03 Itaru Kitayama
  2011-03-10  6:21 ` Miao Xie
  0 siblings, 1 reply; 17+ messages in thread
From: Itaru Kitayama @ 2011-03-09 15:03 UTC (permalink / raw)
  To: miaox; +Cc: linux-btrfs

Hi Miao,

My virtual machine hangs upon reboot.

INFO: task umount:1952 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
umount        D 00000000fffd44dc  3024  1952   1714 0x00000000
 ffff880051ea99e8 0000000000000046 ffff880000000000 ffff880051ea9fd8
 00000000001d4240 ffff88005cd958d0 ffff88005cd95e60 ffff88005cd95e58
 ffff880051ea8000 ffff880051ea9fd8 00000000001d4240 00000000001d4240
Call Trace:
 [<ffffffff811d2697>] ? start_transaction+0x7b/0x1f8
 [<ffffffff814b5593>] __mutex_lock_common+0x28c/0x444
 [<ffffffff811d2697>] ? start_transaction+0x7b/0x1f8
 [<ffffffff814b5800>] mutex_lock_nested+0x39/0x3e
 [<ffffffff811d2697>] start_transaction+0x7b/0x1f8
 [<ffffffff811d2857>] btrfs_join_transaction+0x15/0x17
 [<ffffffff8120e873>] btrfs_remove_delayed_node+0x36/0xa1
 [<ffffffff811d32ae>] btrfs_destroy_inode+0x2ae/0x2cc
 [<ffffffff8112d1c9>] destroy_inode+0x2f/0x45
 [<ffffffff8112da86>] iput+0x239/0x23e
 [<ffffffff811c7992>] btrfs_write_dirty_block_groups+0x22a/0x47c
 [<ffffffff811d0f46>] commit_cowonly_roots+0xd9/0x198
 [<ffffffff811d20fc>] btrfs_commit_transaction+0x3a0/0x658
 [<ffffffff814b5176>] ? __mutex_unlock_slowpath+0x129/0x13a
 [<ffffffff810603de>] ? autoremove_wake_function+0x0/0x39
 [<ffffffff811cf152>] btrfs_commit_super+0x90/0xd9
 [<ffffffff811cf1e5>] close_ctree+0x4a/0x35c
 [<ffffffff810648f5>] ? up_write+0x23/0x3b
 [<ffffffff8112d83b>] ? invalidate_inodes+0x134/0x146
 [<ffffffff811b5989>] btrfs_put_super+0x1d/0x2c
 [<ffffffff8111c08d>] generic_shutdown_super+0x56/0xd7
 [<ffffffff8111c163>] kill_anon_super+0x16/0x54
 [<ffffffff8111b895>] ? deactivate_super+0x3d/0x4a
 [<ffffffff8111b405>] deactivate_locked_super+0x26/0x46
 [<ffffffff8111b89d>] deactivate_super+0x45/0x4a
 [<ffffffff81131d6a>] mntput_no_expire+0xd6/0x104
 [<ffffffff81132e8f>] sys_umount+0x2c1/0x2ec
 [<ffffffff81002ddb>] system_call_fastpath+0x16/0x1b
INFO: lockdep is turned off.

btrfs_remove_delayed_node() is called while trans_mutex is held.

Itaru


^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, other threads:[~2011-03-18  9:18 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-03-03  6:06 [PATCH V3] btrfs: implement delayed inode items operation Miao Xie
2011-03-05  7:01 ` Itaru Kitayama
2011-03-06 23:25   ` Tsutomu Itoh
2011-03-07  1:57     ` Miao Xie
2011-03-10  3:07       ` Itaru Kitayama
2011-03-08 16:56 ` David Sterba
2011-03-09  5:40   ` Miao Xie
2011-03-11 15:24     ` David Sterba
2011-03-09 15:03 Itaru Kitayama
2011-03-10  6:21 ` Miao Xie
2011-03-16  9:48   ` Itaru Kitayama
2011-03-16 14:24     ` Miao Xie
2011-03-16 17:49       ` Chris Mason
2011-03-17  1:37         ` Itaru Kitayama
2011-03-18  3:37     ` Miao Xie
2011-03-18  8:59       ` Itaru Kitayama
2011-03-18  9:18         ` Miao Xie

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