From: Chuck Lever Date: Fri, 15 Dec 2017 01:57:31 +0000 (-0500) Subject: xprtrdma: Split xprt_rdma_send_request X-Git-Tag: v4.16-rc1~150^2~5^2~22 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=cf73daf52750fca4b4af0ca812f542891c228066;p=linux.git xprtrdma: Split xprt_rdma_send_request Clean up. @rqst is set up differently for backchannel Replies. For example, rqst->rq_task and task->tk_client are both NULL. So it is easier to understand and maintain this code path if it is separated. Also, we can get rid of the confusing rl_connect_cookie hack in rpcrdma_bc_receive_call. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index 11fb38f4d70d..6c66a4f85507 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -187,13 +187,7 @@ size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt) return maxmsg - RPCRDMA_HDRLEN_MIN; } -/** - * 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) +static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst) { struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); struct rpcrdma_req *req = rpcr_to_rdmar(rqst); @@ -220,6 +214,43 @@ int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst) return 0; } +/** + * xprt_rdma_bc_send_reply - marshal and send a backchannel reply + * @rqst: RPC rqst with a backchannel RPC reply in rq_snd_buf + * + * Caller holds the transport's write lock. + * + * Returns: + * %0 if the RPC message has been sent + * %-ENOTCONN if the caller should reconnect and call again + * %-EIO if a permanent error occurred and the request was not + * sent. Do not try to send this message again. + */ +int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst) +{ + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); + struct rpcrdma_req *req = rpcr_to_rdmar(rqst); + int rc; + + if (!xprt_connected(rqst->rq_xprt)) + goto drop_connection; + + rc = rpcrdma_bc_marshal_reply(rqst); + if (rc < 0) + goto failed_marshal; + + if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req)) + goto drop_connection; + return 0; + +failed_marshal: + if (rc != -ENOTCONN) + return rc; +drop_connection: + xprt_disconnect_done(rqst->rq_xprt); + return -ENOTCONN; +} + /** * xprt_rdma_bc_destroy - Release resources for handling backchannel requests * @xprt: transport associated with these backchannel resources @@ -330,9 +361,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, __func__, rep, req); req->rl_reply = rep; - /* Defeat the retransmit detection logic in send_request */ - req->rl_connect_cookie = 0; - /* Queue rqst for ULP's callback service */ bc_serv = xprt->bc_serv; spin_lock(&bc_serv->sv_cb_lock); diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index dd7c0aab7535..9207aeacd2c3 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -754,11 +754,6 @@ rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst) __be32 *p; int ret; -#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 - rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0); xdr_init_encode(xdr, &req->rl_hdrbuf, req->rl_rdmabuf->rg_base); diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index d0cd6d411b64..be8c4e62d3f2 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -699,22 +699,12 @@ xprt_rdma_free(struct rpc_task *task) * * Caller holds the transport's write lock. * - * Return values: - * 0: The request has been sent - * ENOTCONN: Caller needs to invoke connect logic then call again - * ENOBUFS: Call again later to send the request - * EIO: A permanent error occurred. The request was not sent, - * and don't try it again - * - * send_request invokes the meat of RPC RDMA. It must do the following: - * - * 1. Marshal the RPC request into an RPC RDMA request, which means - * putting a header in front of data, and creating IOVs for RDMA - * from those in the request. - * 2. In marshaling, detect opportunities for RDMA, and use them. - * 3. Post a recv message to set up asynch completion, then send - * the request (rpcrdma_ep_post). - * 4. No partial sends are possible in the RPC-RDMA protocol (as in UDP). + * Returns: + * %0 if the RPC message has been sent + * %-ENOTCONN if the caller should reconnect and call again + * %-ENOBUFS if the caller should call again later + * %-EIO if a permanent error occurred and the request was not + * sent. Do not try to send this message again. */ static int xprt_rdma_send_request(struct rpc_task *task) @@ -725,6 +715,11 @@ xprt_rdma_send_request(struct rpc_task *task) struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); int rc = 0; +#if defined(CONFIG_SUNRPC_BACKCHANNEL) + if (unlikely(!rqst->rq_buffer)) + return xprt_rdma_bc_send_reply(rqst); +#endif /* CONFIG_SUNRPC_BACKCHANNEL */ + if (!xprt_connected(xprt)) goto drop_connection; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index ed7e51304bc2..e084130d3d84 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -666,7 +666,7 @@ int xprt_rdma_bc_up(struct svc_serv *, struct net *); size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); -int rpcrdma_bc_marshal_reply(struct rpc_rqst *); +int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst); void xprt_rdma_bc_free_rqst(struct rpc_rqst *); void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); #endif /* CONFIG_SUNRPC_BACKCHANNEL */