Re: [PATCH RFC v2 00/19] fuse: fuse-over-io-uring

[Kent Overstreet <kent.overstreet@linux.dev>]

On Thu, May 30, 2024 at 06:17:29PM +0200, Bernd Schubert wrote:
> 
> 
> On 5/30/24 18:10, Kent Overstreet wrote:
> > On Thu, May 30, 2024 at 06:02:21PM +0200, Bernd Schubert wrote:
> >> Hmm, initially I had thought about writing my own ring buffer, but then 
> >> io-uring got IORING_OP_URING_CMD, which seems to have exactly what we
> >> need? From interface point of view, io-uring seems easy to use here, 
> >> has everything we need and kind of the same thing is used for ublk - 
> >> what speaks against io-uring? And what other suggestion do you have?
> >>
> >> I guess the same concern would also apply to ublk_drv. 
> >>
> >> Well, decoupling from io-uring might help to get for zero-copy, as there
> >> doesn't seem to be an agreement with Mings approaches (sorry I'm only
> >> silently following for now).
> >>
> >> From our side, a customer has pointed out security concerns for io-uring. 
> >> My thinking so far was to implemented the required io-uring pieces into 
> >> an module and access it with ioctls... Which would also allow to
> >> backport it to RHEL8/RHEL9.
> > 
> > Well, I've been starting to sketch out a ringbuffer() syscall, which
> > would work on any (supported) file descriptor and give you a ringbuffer
> > for reading or writing (or call it twice for both).
> > 
> > That seems to be what fuse really wants, no? You're already using a file
> > descriptor and your own RPC format, you just want a faster
> > communications channel.
> 
> Fine with me, if you have something better/simpler with less security
> concerns - why not. We just need a community agreement on that.
> 
> Do you have something I could look at?

Like I said it's at the early sketch stage, I haven't written any code
yet. But I'm envisioning something very simple - just a syscall that
gives you a mapped buffer of a specified size with head and tail pointers.

But this has been kicking around for awhile, so if you're interested I
could probably have something for you to try out in the next few days.