Minimum size to read from disk is configurable in rozofsmount
Up to now the rozofsmount was always reading a full buffer size(256K) from disk
whatever the size the VFS read was requesting.
It is now possible to configure the minimum size to read from disk with
"-o rozofsminreadsize=N". By default this value is the size of the buffer(256K).
The rozofsmount will either read from disk the VFS requested size or the
configured value when the requested size is lower than the configured value.
The minimum configured value is 8K (1 block) and  the given value is rounded up
to a multiple of 8K.
With 8K one read from disk only the data to answer to the VFS request. Such a
configuration may be used in specific usages where there is no need to do read
ahead and where reading 256K to only use 8K from it results in a waste of CPU
and bandwith.