Evolving the Vnode interface

The vnode interface has succeeded in supporting a wide range of file system implementations over its 6-year history. During that time it has also had to accommodate evolution in file system semantics, and in the relationship between the file system and the virtual memory system. The effects of this evolution have been less than elegant, and pressures for further evolution are mounting. The evolution of the interface is reviewed in order to identify the problems it has caused, and a more robust revision of the interface design proposed. This design also permits new file systems to be implemented in terms of pre-existing file system implementations; it is more like the Streams interface in this respect. The current state of a prototype implementation is described and its performance characterized. MELENE (lazily). We are very well as we are. Life without a care − every want supplied by a kind and fatherly monarch, who, despot though he be, has no other thought than to make his people happy − what have we to gain by the great change that is in store for us? Gilbert & Sullivan, Utopia, Ltd.