Re: Interface for the new fallocate() system call

Chris Wedgwood
2007-03-29T16:35:37Z

On Thu, Mar 29, 2007 at 05:21:26PM +0530, Amit K. Arora wrote:

> int fallocate(int fd, loff_t offset, loff_t len, int mode)

Right now there are only two possible values for mode --- it's not
clear what additional values there will be in the future.

How about two syscalls? If we decide later on we need something more
complicated we can revisit this and *THEN* add another system call
which may end up being a superset of the other two.

I know that sounds somewhat icky but:

* it's fairly simple

* we get nice argument handling on all arches by dropping u32 mode
(don't we?)

* syscalls don't really cost a lot to keep about, they do cost in
terms on maintenance though, but in this case i don't see it being
all that much of a problem

* IMO badly/over designed syscalls are going to be a bigger problem
long term

Given that *NO* single fs in mainline right now can *reliably* use
this functionality for a while maybe whatever solution people come up
with next should sit in -mm for a while? At least that gives people
exposure to it and a chance to make some changes as once it's merged
to mainline it's pretty hard to change.