Some information about direct-io support on ubifs

[Michael Nazzareno Trimarchi]

Hi all

I would like to have some information on how to implement direct-io
support in ubifs. I have tried to mount squashfs image as file in
ubifs using loopback and direct-io but it seems that loop can not
handle when this is on top of ubifs. From what I understand from the
code it seems that the requirement is that the direct-io is
implemented in the filesystem where the file is stored. I have
simulated using nand sim. The idea is to reduce the buffering. I'm
open to have other suggestions regarding this too.

Michael