This is an intermidiate patch to reduce redandunt mark_inode_dirty() calls
by calling inode_inc_link_count() and inode_dec_link_count() functions.
Signed-off-by: NJiro SEKIBA <jir@unicus.jp>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>