Re: [PATCH net-next] devlink: Require devlink lock during device reload

Jakub Kicinski
2021-11-09T16:20:48Z

On Tue, 9 Nov 2021 11:33:35 -0400 Jason Gunthorpe wrote:
> > > I once sketched out fixing this by removing the need to hold the
> > > per_net_rwsem just for list iteration, which in turn avoids holding it
> > > over the devlink reload paths. It seemed like a reasonable step toward
> > > finer grained locking.
> >
> > Seems to me the locking is just a symptom.
>
> My fear is this reload during net ns destruction is devlink uAPI now
> and, yes it may be only a symptom, but the root cause may be unfixable
> uAPI constraints.

If I'm reading this right it locks up 100% of the time, what is a uAPI
for? DoS? ;)

Hence my questions about the actual use cases.