Re: [PATCH] fuse: Add support for fuse stacked I/O

From: Andy Lutomirski
Date: Fri Jan 15 2016 - 11:31:51 EST

On Jan 14, 2016 11:19 AM, "Linus Torvalds"
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Jan 14, 2016 at 10:57 AM, Nikhilesh Reddy <reddyn@xxxxxxxxxxxxxx> wrote:
> >
> > *I will send out a properly formatted patch shortly.*
> So before you do that, can you explain in what cases fuse just wants
> to pass through the IO?
> Why aren't such cases just using unionfs or something?
> In other words, I think that patch needs an explanation for the
> *reason* for the new functionality.

Also, clarifying the functionality would be nice. What is the
"underlying" fs you speak of? What f_cred gets used? Who opens the
underlying file, whatever that is?

Is the intent overlay-style stacking or is it something else entirely?