On Sat, Dec 22, 2018 at 08:46:55PM +0300, Vasily Averin wrote: > On 12/21/18 4:00 AM, bfields@xxxxxxxxxxxx wrote: > > On Tue, Dec 18, 2018 at 02:55:15PM +0000, Trond Myklebust wrote: > >> No. We don't care about xpt_flags for the back channel because there is > >> no "server transport". The actual transport is stored in the 'struct > >> rpc_rqst', and is the struct rpc_xprt corresponding to the client > >> socket or RDMA channel. > >> > >> IOW: All we really need in svc_process_common() is to be able to run > >> rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(), and that can be passed > >> either as a pointer to the struct svc_xprt_ops itself. > > > > For what it's worth, I'd rather get rid of that op--it's an awfully > > roundabout way just to do "svc_putnl(resv, 0);" in the tcp case. > > Do you mean that svc_create_xprt(serv, "tcp-bc", ...) was used ONLY to call > svc_tcp_prep_reply_hdr() in svc_process_common() ? > And according call for rdma-bc does nothing useful at all? Right, in the rdma case it's: void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp) { } > I've just tried to remove svc_create_xprt() from xs_tcp_bc_up() and > just provide pointer to svc_tcp_prep_reply_hdr() in > svc_process_common() via per-netns sunrpc_net -- and seems it was > enough, my testcase worked correctly. > > Am I missed something probably? Should we really remove > svc_create_xprt( "tcp/rdma-bc"...) related stuff? ? Haven't looked carefully, but off the top of my head I can't see why that wouldn't work. I also tried some patches that replace that op by a flag bit (doesn't address the original problem here, just seemed like a simplification): git://linux-nfs.org/~bfields/linux-topics.git but I don't if that's compatible with what you've done. --b.