davem@redhat.com said:
quoted
Er, surely the same goes for sys_sendfile? Why have a new system
call rather than just swapping the 'in' and 'out' fds?
There is an assumption that one is a linear stream of output (in this
case a socket) and the other one is a page cache based file.
That's an implementation detail and it's not clear we should be exposing it
to the user. It's not entirely insane to contemplate socket->socket or
file->file sendfile either -- would we invent new system calls for those
too? File descriptors are file descriptors.
It would be nice to extend sys_sendfile to work properly in both ways
in a manner that Linus would accept, want to work on that?
Yeah -- I'll add it to the TODO list. Scheduled for some time in 2007 :)
More seriously though, I'd hope that whoever implemented what you call
'sys_receivefile' would solve this issue, as 'sys_receivefile' isn't really
useful as anything more than a handy nomenclature for describing the
process in question.
--
dwmw2