1. A method for accessing blocks of data in a shared storage which is accessed via a storage gateway, said accessing including the steps of: establishing a metadata file system control data structure on at least one of a plurality of metadata controller nodes; providing, from one of said metadata controller nodes, permission to an application node, to access said blocks of data using metadata file control information transferred from at least one of said metadata controller nodes to said application node, said permission having a time limited duration; providing to said storage gateway a list of said disk blocks and identification of the application node which is permitted to access said blocks; requesting, by said application node, access to said blocks of data, said request being made through said storage gateway; and verifying, within said storage gateway, the validity of said request by comparison with metadata file control information communicated to said gateway from at least one of said metadata controller nodes.