Re: [PATCH 0/5] fallocate system call

Chris Wedgwood
2007-04-30T05:26:08Z

On Mon, Apr 30, 2007 at 10:47:02AM +1000, David Chinner wrote:

> For FA_ALLOCATE, it's supposed to change the file size if we
> allocate past EOF, right?

I would argue no. Use truncate for that.

> For FA_DEALLOCATE, does it change the filesize at all?

Same as above.

> Or does
> it just punch a hole in the file?

Yes.

> FWIW, we definitely need a FA_PREALLOCATE mode (FA_ALLOCATE but does
> not change file size) so we can preallocate beyond EOF for apps
> which use O_APPEND (i.e. changing file size would cause problems for
> them).

FA_ALLOCATE should be able to allocate past-EOF I would argue.