In this ticket a number of functions are defined, for each function 3 steps must be followed:

1. Determine if the live restore file handle should support that functionality
2. If yes, split off a ticket to implement it.
3. Update the technical design to indicate the support (y/n) and why that decision was made.

The functions are as follows:
    fh_advise
    fh_sync_nowait
    fh_unmap
    fh_map_preload
    fh_map_discard
fh_map
    fh_extend
    fh_extend_nolock;