Fcntl's

["Nicholas S Castellano" <entropy@terminator.rs.itd.umich.edu>]

>(1) Questions: I'd like to hear more comments regarding my FUTIME fcntl
>    proposal.

I already commented on this and I'm still trying to get my foot out of
my mouth...

>(2) An idea that could be very convenient for file systems that try
>    to keep the fragmentation low: what about an Fcntl opcode to inform
>    the driver about the amount of bytes that *will* be written to the
>    file? Desktops and copy programs (like cp) could use this.

Not a bad idea, but it might be better to steal the "file extend
quantity" concept from VMS:  instead of specifying the total size of
the file to be written (which in many cases is difficult or impossible
to determine in advance) the program specifies the number of blocks to
be allocated when the currently allocated space is filled, and the
file system can try to allocate these as contiguous blocks if it
wishes.  When the file is closed any unused blocks are released.

cheers,
entropy