Adding an Uncacheable File Data Attribute to NFSv4.2

Network File System version 4.2 (NFSv4.2) clients commonly perform client-side caching of file data in order to improve performance. On some systems, applications may influence client data caching behavior, but there is no standardized mechanism for a server or administrator to indicate that particular file data should not be cached by clients for reasons of performance or correctness. This document introduces a new file data caching attribute for NFSv4.2. Files marked with this attribute are intended to be accessed with client-side caching of file data suppressed, in order to support workloads that require predictable data visibility. This document extends NFSv4.2 (see RFC7862).