From 5413e8a0ee5fb73665748a88650d206b8c7c7fac Mon Sep 17 00:00:00 2001
From: Zheng Liu <wenqing.lz@taobao.com>
Date: Wed, 19 Sep 2012 14:19:24 -0400
Subject: [PATCH] ext4: add extent status tree data structures

This patch adds two structures that supports status extent tree and
status_extent_info to inode_info.

Reviewed-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Reviewed-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
 fs/ext4/ext4.h           |  5 +++++
 fs/ext4/extents_status.h | 25 +++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 fs/ext4/extents_status.h

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8b6902c4d7be..fed591e09673 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -812,6 +812,8 @@ struct ext4_ext_cache {
 	__u32		ec_len; /* must be 32bit to return holes */
 };
 
+#include "extents_status.h"
+
 /*
  * fourth extended file system inode data in memory
  */
@@ -889,6 +891,9 @@ struct ext4_inode_info {
 	struct list_head i_prealloc_list;
 	spinlock_t i_prealloc_lock;
 
+	/* extents status tree */
+	struct ext4_es_tree i_es_tree;
+
 	/* ialloc */
 	ext4_group_t	i_last_alloc_group;
 
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
new file mode 100644
index 000000000000..8be2ab9c9425
--- /dev/null
+++ b/fs/ext4/extents_status.h
@@ -0,0 +1,25 @@
+/*
+ *  fs/ext4/extents_status.h
+ *
+ * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
+ * Modified by
+ *	Allison Henderson <achender@linux.vnet.ibm.com>
+ *	Zheng Liu <wenqing.lz@taobao.com>
+ *
+ */
+
+#ifndef _EXT4_EXTENTS_STATUS_H
+#define _EXT4_EXTENTS_STATUS_H
+
+struct extent_status {
+	struct rb_node rb_node;
+	ext4_lblk_t start;	/* first block extent covers */
+	ext4_lblk_t len;	/* length of extent in block */
+};
+
+struct ext4_es_tree {
+	struct rb_root root;
+	struct extent_status *cache_es;	/* recently accessed extent */
+};
+
+#endif /* _EXT4_EXTENTS_STATUS_H */
-- 
2.39.5