1. A computer system which provides a client node with a file system mounted into a virtual namespace, comprising: at least one file server which provides the file system; a root node which mounts the file system provided by the file server into the virtual namespace; and a network which couples the file server and the root node, wherein: the root node has an interface coupled to the network, a processor coupled to the interface, and a memory coupled to the processor; and the root node is configured to: obtain access information set to a directory above a point in the virtual namespace at which the file system is to be mounted when mounting the file system into the virtual namespace; judge whether the obtained access information is to be inherited; and set, to the file system to be mounted, the obtained access information that is to be inherited.