Re: [Gluster-devel] fallocate

[Anand Avati]

On Sat, Nov 16, 2013 at 4:45 PM, Emmanuel Dreyfus <address@hidden> wrote:

Anand Avati <address@hidden> wrote:

> If you call fallocate() over an existing region with data it shouldn't be
> wiped with 0s. You can also call fallocate() on a hole (in case file was
> ftruncate()ed to a large size) and that region should get "allocated" (i.e
> future write to an fallocated() region should NOT fail with ENOSPC).

It seems it can be emulated, should it be atomic?

I am not aware of any app which depends on it being atomic (though Linux implementations probably are)

 

> BTW, does NetBSD have the equivalent of open_by_handle[_at]() and
> name_to_handle[_at]() system calls?

That is extended API set 2. With the exception of fexecve(2), I
implemented them in NetBSD-current, which means they will be available
in NetBSD-7.0. Are they also mandatory in glusterfs-3.5? Is they are,
then emulating fallocate() in userland is useless, I would better work
on it in kernel for the next release.

Oh that's interesting, can I get pointers to see how NetBSD implements open_by_handle() and name_to_handle()?

Thanks,

Avati