Re: [PATCH 2/5] nvme: don't hold nvmf_transports_rwsem for more than transport lookups

[Sagi Grimberg]

> > diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
> > index 7ae732a77fe8..febf82639b40 100644
> > --- a/drivers/nvme/host/fabrics.c
> > +++ b/drivers/nvme/host/fabrics.c
> > @@ -957,16 +957,17 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count)
> >   
> >   	down_read(&nvmf_transports_rwsem);
> >   	ops = nvmf_lookup_transport(opts);
> > +	up_read(&nvmf_transports_rwsem);
>
> And what protects us from the transport getting unregister right here
> from anothet thread waiting to acquire nvmf_transports_rwsem?

I think having the module_get inside as well would protect against it.