[PATCH 2/2] ubifs: Allow O_DIRECT

[Artem Bityutskiy]

On Wed, 2015-08-19 at 22:35 +0200, Richard Weinberger wrote:
> Currently UBIFS does not support direct IO, but some applications
> blindly use the O_DIRECT flag.
> Instead of failing upon open() we can do better and fall back
> to buffered IO.
> 
> Cc: Dongsheng Yang <yangds.fnst at cn.fujitsu.com>
> Cc: dedekind1 at gmail.com
> Suggested-by: Dave Chinner <david at fromorbit.com>
> Signed-off-by: Richard Weinberger <richard at nod.at>

Richard,

The idea was to explicitly reject what we do not support. Let's say I
am an app which requires O_DIRECT, and which does not want to work with
non-O_DIRECT. What would I do to ensure O_DIRECT?

Could you please check what other file-systems which do not support
O_DIRECT do in this case? Do they also fall-back to normal IO instead
of explicitly failing? If yes, we can do what is considered to be the
"standard" behavior.

Thanks!