Re: O_DIRECT foolish question

[Chris Wedgwood <cw@f00f.org>]

On Wed, Feb 12, 2003 at 05:29:52PM -0500, Bruno Diniz de Paula wrote:

> But I am using multiples of page size in both buffer alignment and
> buffer size (2nd and 3rd parameters of read).  The issue is that
> when I try to read files with sizes that are NOT multiples of block
> size (and therefore also not multiples of page size), the read
> syscall returns 0, with no errors.

What filesystem?

Can you send an strace of this occurring?

> So the question remains, am I able to read just files whose size is
> a multiple of block size?

No.

You ideally should be able to read any length file with O_DIRECT.
Even a 1-byte file.



  --cw