On Mon, Jun 12, 2017 at 11:16 PM, Florian Westphal <[email protected]> wrote: > Cong Wang <[email protected]> wrote: >> On Thu, Jun 1, 2017 at 1:52 AM, Florian Westphal <[email protected]> wrote: >> > Joe described it nicely, problem is that after unload we may have >> > conntracks that still have a nf_conn_help extension attached that >> > has a pointer to a structure that resided in the (unloaded) module. >> >> Why not hold a refcnt for its module? > > That would work as well. > > I'm not sure its nice to disallow rmmod of helper modules if they are > used by a connection however.
I am _not_ suggesting to disallow rmmod. > > Right now you can "rmmod nf_conntrack_foo" at any time and this should > work just fine without first having to flush affected conntracks > manually. My point is that since netns wq could invoke code of that module, why it doesn't hold a refcnt of that module? I am not familiar with netfilter code base so not sure if that is hard to do or not, but it looks more elegant than this barrier.
