On Mon, 2008-07-07 at 14:43 -0400, Chuck Lever wrote: > On Jul 7, 2008, at 2:20 PM, Trond Myklebust wrote: > > On Thu, 2008-07-03 at 16:45 -0400, J. Bruce Fields wrote: > >> On Mon, Jun 30, 2008 at 06:38:35PM -0400, Chuck Lever wrote: > >>> Hi Trond- > >>> > >>> Seven patches that implement kernel RPC service registration via > >>> rpcbind v4. > >>> This allows the kernel to advertise IPv4-only services on hosts > >>> with IPv6 > >>> addresses, for example. > >> > >> This is Trond's baliwick, but I read through all 7 quickly and they > >> looked good to me.... > > > > They look more or less OK to me too, however I'm a bit unhappy about > > the > > RPC_TASK_ONESHOT name: it isn't at all descriptive. > > Open to suggestions. I thought RPC_TASK_FAIL_WITHOUT_CONNECTION was a > bit wordy ;-) RPC_TASK_CONNECT_ONCE ? > > I also have questions about the change to a TCP socket here. Why not > > just implement connected UDP sockets? > > Changing rpcb_register() to use a TCP socket is less work overall, and > we get a positive hand shake between the kernel and user space when > the TCP connection is opened. > > Other services might also want to use TCP+ONESHOT for several short > requests over a real network with actual packet loss, but they might > find CUDP+ONESHOT less practical/reliable (or even forbidden in the > case of NFSv4). So we would end up with something of a one-off > implementation for rpcb_register. I don't see what that has to do with anything: the connection failed codepath in call_connect_status() should be the same in both the TCP and the UDP case. > The downside of using TCP in this case is that it's more overhead: 8 > packets instead of two for registration in the common case, and it > leaves a single privileged port in TIME_WAIT for each registered > service. I don't think this matters much as registration happens > quite infrequently. The problem is that registration usually happens at boot time, which is also when most of the NFS 'mount' requests will be eating privileged ports. -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
