Re: Libublk-rs v0.1.0

[Ming Lei <ming.lei@redhat.com>]

Hi Gabriel,

On Mon, Aug 14, 2023 at 02:23:14PM -0400, Gabriel Krisman Bertazi wrote:
> Ming Lei <ming.lei@redhat.com> writes:
> 
> > Hello,
> >
> > Libublk-rs(Rust)[1][2] 0.1.0 is released.
> 
> Hi Ming,
> 
> Do you intend to effectively deprecate the code in ubdsrv in favor of
> libublk-rs or do you intend to keep the C library?  I'm asking because
> I'm looking into how to enable ublk in distributions.

So far, there are users of C ubdsrv library, and both are maintained
and co-exist, so C library is still kept.


Thanks
Ming

> 
> Thanks,
> 
> >
> > The original idea is to use Rust to write ublk target for covering all
> > kinds of block queue limits/parameters combination easily when talking
> > with Andreas and Shinichiro about blktests in LSFMM/BPF 2023.
> >
> > Finally it is evolved into one generic library. Attributed to Rust's
> > some modern language features, libublk interfaces are pretty simple:
> >
> > - one closure(tgt_init) for user to customize device by providing all
> >   kind of parameter
> >
> > - the other closure(io handling) for user to handling IO which is
> >   completely io_uring CQE driven: a) IO command CQE from ublk driver,
> >   b) target IO CQE originated from target io handling code, c) eventfd
> >   CQE if IO is offloaded to other context
> >
> > With low level APIs, <50 LoC can build one ublk-null, and if high level
> > APIs are used, 30 LoC is enough.
> >
> > Performance is basically aligned with pure C ublk implementation[3].
> >
> > The library has been verified on null, ramdisk, loop and zoned target.
> > The plan is to support async/await in 0.2 or 0.3 so that libublk can
> > be used to build complicated target easily and efficiently.
> >
> > Thanks Andreas for reviewing and providing lots of good ideas for
> > improvement & cleanup. Thanks German Maglione for some suggestions, such
> > as eventfd support. Thanks Joe for providing excellent Rust programming
> > guide.
> >
> > Any feedback is welcome!
> >
> > [1] https://crates.io/crates/libublk 
> > [2] https://github.com/ming1/libublk-rs
> > [3] https://github.com/osandov/blktests/blob/master/src/miniublk.c
> >
> > Thanks,
> > Ming
> >
> 
> -- 
> Gabriel Krisman Bertazi
> 

-- 
Ming