dentry1          2904 fs/dcache.c    void d_exchange(struct dentry *dentry1, struct dentry *dentry2)
dentry1          2908 fs/dcache.c    	WARN_ON(!dentry1->d_inode);
dentry1          2910 fs/dcache.c    	WARN_ON(IS_ROOT(dentry1));
dentry1          2913 fs/dcache.c    	__d_move(dentry1, dentry2, true);