From 83128a60ca74e996c5e0336c4fff0579f4a8c909 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sat, 24 Oct 2015 17:27:59 -0400 Subject: [PATCH] xprtrdma: Add support for sending backward direction RPC replies Backward direction RPC replies are sent via the client transport's send_request method, the same way forward direction RPC calls are sent. Signed-off-by: Chuck Lever Reviewed-by: Sagi Grimberg Tested-By: Devesh Sharma Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/backchannel.c | 45 +++++++++++++++++++++++++++++++ net/sunrpc/xprtrdma/rpc_rdma.c | 5 ++++ net/sunrpc/xprtrdma/xprt_rdma.h | 1 + 3 files changed, 51 insertions(+) diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index 3165ed639eec..ffc4853a068e 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -169,6 +169,51 @@ out_err: return -ENOMEM; } +/** + * rpcrdma_bc_marshal_reply - Send backwards direction reply + * @rqst: buffer containing RPC reply data + * + * Returns zero on success. + */ +int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst) +{ + struct rpc_xprt *xprt = rqst->rq_xprt; + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); + struct rpcrdma_req *req = rpcr_to_rdmar(rqst); + struct rpcrdma_msg *headerp; + size_t rpclen; + + headerp = rdmab_to_msg(req->rl_rdmabuf); + headerp->rm_xid = rqst->rq_xid; + headerp->rm_vers = rpcrdma_version; + headerp->rm_credit = + cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_max_requests); + headerp->rm_type = rdma_msg; + headerp->rm_body.rm_chunks[0] = xdr_zero; + headerp->rm_body.rm_chunks[1] = xdr_zero; + headerp->rm_body.rm_chunks[2] = xdr_zero; + + rpclen = rqst->rq_svec[0].iov_len; + + pr_info("RPC: %s: rpclen %zd headerp 0x%p lkey 0x%x\n", + __func__, rpclen, headerp, rdmab_lkey(req->rl_rdmabuf)); + pr_info("RPC: %s: RPC/RDMA: %*ph\n", + __func__, (int)RPCRDMA_HDRLEN_MIN, headerp); + pr_info("RPC: %s: RPC: %*ph\n", + __func__, (int)rpclen, rqst->rq_svec[0].iov_base); + + req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf); + req->rl_send_iov[0].length = RPCRDMA_HDRLEN_MIN; + req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf); + + req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf); + req->rl_send_iov[1].length = rpclen; + req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf); + + req->rl_niovs = 2; + return 0; +} + /** * xprt_rdma_bc_destroy - Release resources for handling backchannel requests * @xprt: transport associated with these backchannel resources diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 95774fcc1b43..b7a21e551888 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -441,6 +441,11 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) enum rpcrdma_chunktype rtype, wtype; struct rpcrdma_msg *headerp; +#if defined(CONFIG_SUNRPC_BACKCHANNEL) + if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state)) + return rpcrdma_bc_marshal_reply(rqst); +#endif + /* * rpclen gets amount of data in first buffer, which is the * pre-registered buffer. diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 55d2660df56a..e2d23ea23df9 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -520,6 +520,7 @@ void xprt_rdma_cleanup(void); #if defined(CONFIG_SUNRPC_BACKCHANNEL) int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); +int rpcrdma_bc_marshal_reply(struct rpc_rqst *); void xprt_rdma_bc_free_rqst(struct rpc_rqst *); void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); #endif /* CONFIG_SUNRPC_BACKCHANNEL */ -- 2.39.5