Re: O_DIRECT, ext3fs, kernel 2.4.32... again

From: Nathan Scott
Date: Wed May 03 2006 - 02:35:21 EST


On Wed, May 03, 2006 at 07:27:52AM +0200, DervishD wrote:
> ...
> Are the differences too large?

Yep.

> I know that this change would be intrusive and probably large,
> but IMHO is a quite important bug, because it prevents apps to
> selectively disable O_DIRECT (the flag is accepted by open(), so
> there's no reason the app should bother about which caused the
> read()/write() failures. In fact, is very difficult to know that
> those failures are caused by partial/buggy support of O_DIRECT flag).

You could open for direct, do a direct read, and see if it fails.
If it fails, clear O_DIRECT on the fd via fcntl(F_SETFL) then do
regular buffered IO instead... a bit hacky, but should work fine
I think.

cheers.

--
Nathan
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