Re: clearing 'flag unwritten extents'

[Roger Willcocks <willcor@xxxxxxxxx>]

> once [the flag unwritten extents option is] set unwritten extents may
> have been used, and there's no going back at that point.

I'd like to understand this a bit more - is this a security issue or
an architectural one?

AIUI, the 'flag unwritten extents' option allows non-root users to
preallocate unwritten extents (root can always create them). Clearing
the option would just prevent the creation of new unwritten extents.
The system would still do the right thing with previously flagged
extents. Or am I missing something?

--
Roger


On 11/10/05, Nathan Scott <nathans@xxxxxxx> wrote:
> On Thu, Nov 10, 2005 at 07:11:32PM +0000, Roger Willcocks wrote:
> > xfs_db has an option (version extflg) for setting the 'flag unwritten
> > extents' bit in the superblock(s), but no way of clearing it.
> >
> > Is this deliberate?
>
> Yes, once set unwritten extents may have been used, and there's
> no going back at that point.
>
> cheers.
>
> --
> Nathan
>