On Thu, 25 Jan 2024, Chuck Lever III wrote: > > > > On Jan 24, 2024, at 6:24 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > > On Wed, 2024-01-24 at 10:52 +0100, Lorenzo Bianconi wrote: > >> [...] > >>> > >>> That's a great question. We do need to properly support the -H option to > >>> rpc.nfsd. What we do today is look up the hostname or address using > >>> getaddrinfo, and then open a listening socket for that address and then > >>> pass that fd down to the kernel, which I think then takes the socket and > >>> sticks it on sv_permsocks. > >>> > >>> All of that seems a bit klunky. Ideally, I'd say the best thing would be > >>> to allow userland to pass the sockaddr we look up directly via netlink, > >>> and then let the kernel open the socket. That will probably mean > >>> refactoring some of the svc_xprt_create machinery to take a sockaddr, > >>> but I don't think it looks too hard to do. > >> > >> Do we already have a specific use case for it? I think we can even add it > >> later when we have a defined use case for it on top of the current series. > >> > > > > Yes: > > > > rpc.nfsd -H makes nfsd listen on a particular address and port. By > > passing down the sockaddr instead of an already-opened socket > > descriptor, we can achieve the goal without having to open sockets in > > userland. > > Tearing down a listener that was created that way would be a > use case for: Only if it was actually useful. Have you *ever* wanted to do that? Or heard from anyone else who did? NeilBrown > > > Do we ever want/need to remove listening sockets? > > Normal practice when making any changes is to stop and restart where > > "stop" removes all sockets, unexports all filesystems, disables all > > versions. > > > > -- > Chuck Lever > > >
