On Thu, 2009-02-12 at 15:43 -0500, Chuck Lever wrote: > On Feb 12, 2009, at 3:27 PM, Trond Myklebust wrote: > > On Thu, 2009-02-12 at 15:11 -0500, Chuck Lever wrote: > >> On Feb 12, 2009, at 2:43 PM, Trond Myklebust wrote: > >>> On Thu, 2009-02-12 at 14:35 -0500, Chuck Lever wrote: > >>>> I wasn't sure exactly where the compared addresses came from. I > >>>> had > >>>> assumed that they all came through the listener, so we wouldn't > >>>> need > >>>> this kind of translation. It shouldn't be difficult to map > >>>> addresses > >>>> passed in via nlmclnt_init() to AF_INET6. > >>>> > >>>> But this is the kind of thing that makes "falling back" to an > >>>> AF_INET > >>>> listener a little challenging. We will have to record what flavor > >>>> the > >>>> listener is and do a translation depending on what listener family > >>>> was > >>>> actually created. > >>> > >>> Why? Should we care whether we're receiving IPv4 addresses or IPv6 > >>> v4-mapped addresses? They're the same thing... > >> > >> The problem is the listener family is now decided at run-time. If an > >> AF_INET6 listener can't be created, an AF_INET listener is created > >> instead, even if CONFIG_IPV6 || CONFIG_IPV6_MODULE is enabled. If an > >> AF_INET listener is created, we get only IPv4 addresses in svc_rqst- > >>> rq_addr. > > > > You're missing my point. Why should we care if it's one or the > > other? In > > the NFSv4 case, we v4map all IPv4 addresses _unconditionally_ if it > > turns out that CONFIG_IPV6 is enabled. > > > > IOW: we always compare IPv6 addresses. > > The reason we might care in this case is nlm_cmp_addr() is executed > more frequently than nfs_sockaddr_match_ipaddr(). > > Mapping the server address in nlmclnt_init() means we translate the > server address once and are done with it. We never have to map > incoming AF_INET addresses in NLM requests, and we don't have the > extra conditionals every time we go through nlm_cmp_addr(). > > This keeps nlm_cmp_addr() as simple as it can be: it compares only two > AF_INET addresses or two AF_INET6 addresses. I don't see how that changes the general principle. All it means is that you should be caching v4 mapped addresses instead of ipv4 addresses. That would allow you to simplify nlm_cmp_addr() even further... Trond -- 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
