WARNING in xfs_lwr.c, xfs_write()

[Stewart Smith]

On Sun, 23 May 2010 23:12:24 -0500, Stan Hoeppner <stan at hardwarefreak.com> wrote:
> "The whole notion of "direct IO" is totally braindamaged. Just say no.
> 
> 	This is your brain: O
> 	This is your brain on O_DIRECT: .
> 
> 	Any questions?"
> 
> 
> 		Linus
> 
> From:  http://lkml.org/lkml/2007/1/10/235

and the alternative is......

\0

(null).


We can have very explicit knowledge about buffers and IO in
userspace. Much better than you are ever going to have guessing it in
kernel IO paths. There currently exists *no* usable and reliable way of
transmitting this information to the kernel other than O_DIRECT.
-- 
Stewart Smith