> 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: > 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
