diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f527453..acdc076 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -666,6 +666,9 @@
 	void **slot;
 	unsigned int found;
 
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
 	if (available_free_memory(sbi, EXTENT_CACHE))
 		return;
 
@@ -714,6 +717,9 @@
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct extent_tree *et;
 
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
 	down_read(&sbi->extent_tree_lock);
 	et = radix_tree_lookup(&sbi->extent_tree_root, inode->i_ino);
 	if (!et) {
@@ -749,6 +755,9 @@
 static bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
 							struct extent_info *ei)
 {
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return f2fs_lookup_extent_tree(inode, pgofs, ei);
+
 	return lookup_extent_info(inode, pgofs, ei);
 }
 
@@ -765,6 +774,10 @@
 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
 							dn->ofs_in_node;
 
+	if (test_opt(F2FS_I_SB(dn->inode), EXTENT_CACHE))
+		return f2fs_update_extent_tree(dn->inode, fofs,
+							dn->data_blkaddr);
+
 	if (update_extent_info(dn->inode, fofs, dn->data_blkaddr))
 		sync_inode_page(dn);
 }
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 28dd26a..b508744 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -335,6 +335,7 @@
 no_delete:
 	stat_dec_inline_dir(inode);
 	stat_dec_inline_inode(inode);
+	f2fs_destroy_extent_tree(inode);
 	invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino);
 	if (xnid)
 		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index daee4ab..29c04ed 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -277,6 +277,9 @@
 
 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 {
+	/* try to shrink extent cache when there is no enough memory */
+	f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
+
 	/* check the # of cached NAT entries and prefree segments */
 	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
 			excess_prefree_segs(sbi) ||
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3ce4d7c..e649f21 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1079,6 +1079,8 @@
 	INIT_LIST_HEAD(&sbi->dir_inode_list);
 	spin_lock_init(&sbi->dir_inode_lock);
 
+	init_extent_cache_info(sbi);
+
 	init_ino_entry_info(sbi);
 
 	/* setup f2fs internal modules */
@@ -1285,10 +1287,13 @@
 	err = create_checkpoint_caches();
 	if (err)
 		goto free_segment_manager_caches;
+	err = create_extent_cache();
+	if (err)
+		goto free_checkpoint_caches;
 	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
 	if (!f2fs_kset) {
 		err = -ENOMEM;
-		goto free_checkpoint_caches;
+		goto free_extent_cache;
 	}
 	err = register_filesystem(&f2fs_fs_type);
 	if (err)
@@ -1299,6 +1304,8 @@
 
 free_kset:
 	kset_unregister(f2fs_kset);
+free_extent_cache:
+	destroy_extent_cache();
 free_checkpoint_caches:
 	destroy_checkpoint_caches();
 free_segment_manager_caches: