On Fri, May 20, 2016 at 6:21 PM, Sage Weil <sage@xxxxxxxxxxxx> wrote: > On Fri, 20 May 2016, Junwang Zhao wrote: >> On Thu, May 19, 2016 at 8:08 PM, Sage Weil <sage@xxxxxxxxxxxx> wrote: >> > On Thu, 19 May 2016, Junwang Zhao wrote: >> >> Hi Sage, Haomai, >> >> Please check [1] and give some feedback, I am not sure about >> >> 52436ded943b8f567adb584c50b789431b788a85 >> >> >> >> [1] https://github.com/zhjwpku/ceph/commits/wip-addr-work >> > >> > Great! I made several suggestions, and I have a question for everyone: >> > what should we do if we have a "new" addr (say, for the v2 msgr protocol) >> > and we need to encode it for a client that doesn't have the ADDR2 feature? >> > Right now we are still stuffing the sockaddr_storage in their with >> > whatever sockaddr data we have, but it is indistinguishable from a legacy >> > address. Perhaps it sould encode as blank? (e.g., entity_addr_t())? Or >> > blank, except with a magic nonce (0xffffffff maybe) so that you can tell >> > that it is non-blank but not terribly useful/usable? >> >> I don't quite get this, can you explain this more specific? I now >> consider the first encoded __u32 as the distinguish flag for the client >> to identify legacy or not, a little bit confused :( > > Yeah, it is. Look forward a bit to where we have a new, incompatible wire > protocol, and TYPE_MSGR2 = 2 (to go with TYPE_LEGACY = 1). How should we > encode a msgr2 addr for a client that doesn't have the new ADDR2 feature? > Currently, we'll set the legacy __u32 type = 0, and then encode same nonce > and sockaddr, but that makes the msgr2 addr appear to be legacy addr to > the legacy client. > > Instead, I'm suggesting that if type != TYPE_LEGACY and the target doesn't > have the ADDR2 feature, we encode type = 0, nonce = -1 (or some other > poison placeholder), and an empty sockaddr. That way the legacy code will > see an addr that is not blank and also looks unusable (blank sockaddr, > weird nonce). > Thanks, understand now :) >> BTW, i have add entity_addrvec_t[1], you may want to have a look. >> >> [1] https://github.com/zhjwpku/ceph/commits/wip-addr-work > > A few comments, but looks good! Updated, I add a entity_addr_t::decode_legacy_addr_after_marker() helper to eliminate the duplication, have a look when you got some time. > > I will work on getting the discussion for the msgr2 protocol going next > week, as we'll be needing that sooner rather than later. > Look forward to that! Thanks! > Thanks! > sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
