diff --git a/fs/hmdfs/file_local.c b/fs/hmdfs/file_local.c
index aaab5837b71b0b779272a2dbf851c5f6bd00bfb9..41f65cfa4184023e0cfcba5d5f9ad4a85d18e4d3 100644
--- a/fs/hmdfs/file_local.c
+++ b/fs/hmdfs/file_local.c
@@ -20,17 +20,6 @@
 #include "hmdfs_share.h"
 #include "hmdfs_trace.h"
 
-static inline void update_upper_file(struct file *upper_file, struct file *lower_file)
-{
-	loff_t upper_size = i_size_read(upper_file->f_inode);
-	loff_t lower_size = i_size_read(lower_file->f_inode);
-
-	if (upper_file->f_inode->i_mapping && upper_size != lower_size) {
-		i_size_write(upper_file->f_inode, lower_size);
-		truncate_inode_pages(upper_file->f_inode->i_mapping, 0);
-	}
-}
-
 int hmdfs_file_open_local(struct inode *inode, struct file *file)
 {
 	int err = 0;
@@ -60,7 +49,7 @@ int hmdfs_file_open_local(struct inode *inode, struct file *file)
 	} else {
 		gfi->lower_file = lower_file;
 		file->private_data = gfi;
-		update_upper_file(file, lower_file);
+		hmdfs_update_upper_file(file, lower_file);
 		if (file->f_flags & (O_RDWR | O_WRONLY))
 			atomic_inc(&info->write_opened);
 	}
diff --git a/fs/hmdfs/file_merge.c b/fs/hmdfs/file_merge.c
index cbe9358247ce443e8099d8d1dd7c5857bf47aded..8952674a23d4c4fc8e7729dc1290e88cb3766ace 100644
--- a/fs/hmdfs/file_merge.c
+++ b/fs/hmdfs/file_merge.c
@@ -567,6 +567,7 @@ int hmdfs_file_open_merge(struct inode *inode, struct file *file)
 	} else {
 		gfi->lower_file = lower_file;
 		file->private_data = gfi;
+		hmdfs_update_upper_file(file, lower_file);
 	}
 	dput(parent);
 out_err:
diff --git a/fs/hmdfs/inode.c b/fs/hmdfs/inode.c
index 0b3ec919c3e7808e1d11dcdc0c14df3ac6fc5591..93d29cc3e905b21136e31637fc8bf1e97f30be89 100644
--- a/fs/hmdfs/inode.c
+++ b/fs/hmdfs/inode.c
@@ -342,3 +342,15 @@ struct inode *hmdfs_iget_locked_root(struct super_block *sb, uint64_t root_ino,
 
 	return iget5_locked(sb, ia.ino.ino_output, iget_test, iget_set, &ia);
 }
+
+
+void hmdfs_update_upper_file(struct file *upper_file, struct file *lower_file)
+{
+	loff_t upper_size = i_size_read(upper_file->f_inode);
+	loff_t lower_size = i_size_read(lower_file->f_inode);
+
+	if (upper_file->f_inode->i_mapping && upper_size != lower_size) {
+		i_size_write(upper_file->f_inode, lower_size);
+		truncate_inode_pages(upper_file->f_inode->i_mapping, 0);
+	}
+}
\ No newline at end of file
diff --git a/fs/hmdfs/inode.h b/fs/hmdfs/inode.h
index 8877a53a0110cb6d6a98350ae2ac3eba5a30675a..fb9bd2929d581e6e48dee17bd369962869440e02 100644
--- a/fs/hmdfs/inode.h
+++ b/fs/hmdfs/inode.h
@@ -259,5 +259,6 @@ struct inode *hmdfs_iget5_locked_cloud(struct super_block *sb,
 				       struct hmdfs_peer *peer,
 				       struct hmdfs_lookup_cloud_ret *res);
 
+void hmdfs_update_upper_file(struct file *upper_file, struct file *lower_file);
 uint32_t make_ino_raw_cloud(uint8_t *cloud_id);
 #endif // INODE_H