new helper: ihold()

Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 314c0d3..bd39885 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2312,7 +2312,7 @@
 
 	inode->i_ctime = ext4_current_time(inode);
 	ext4_inc_count(handle, inode);
-	atomic_inc(&inode->i_count);
+	ihold(inode);
 
 	err = ext4_add_entry(handle, dentry, inode);
 	if (!err) {