From 82011c80b3ec0e05940a2ee2c76c1df9fd2b1ce8 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 5 Jan 2021 10:15:09 -0500 Subject: [PATCH] SUNRPC: Move svc_xprt_received() call sites Currently, XPT_BUSY is not cleared until xpo_recvfrom returns. That effectively blocks the receipt and handling of the next RPC message until the current one has been taken off the transport. This strict ordering is a requirement for socket transports. For our kernel RPC/RDMA transport implementation, however, dequeuing an ingress message is nothing more than a list_del(). The transport can safely be marked un-busy as soon as that is done. To keep the changes simpler, this patch just moves the svc_xprt_received() call site from svc_handle_xprt() into the transports, so that the actual optimization can be done in a subsequent patch. Signed-off-by: Chuck Lever --- net/sunrpc/svc_xprt.c | 7 ++++--- net/sunrpc/svcsock.c | 9 +++++++-- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 6 ++++++ 3 files changed, 17 insertions(+), 5 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 9d1374e82e90..42565f0c7d5a 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -820,8 +820,10 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) newxpt->xpt_cred = get_cred(xprt->xpt_cred); svc_add_new_temp_xprt(serv, newxpt); trace_svc_xprt_accept(newxpt, serv->sv_name); - } else + } else { module_put(xprt->xpt_class->xcl_owner); + } + svc_xprt_received(xprt); } else if (svc_xprt_reserve_slot(rqstp, xprt)) { /* XPT_DATA|XPT_DEFERRED case: */ dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", @@ -836,8 +838,6 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) rqstp->rq_reserved = serv->sv_max_mesg; atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); } - /* clear XPT_BUSY: */ - svc_xprt_received(xprt); out: trace_svc_handle_xprt(xprt, len); return len; @@ -1248,6 +1248,7 @@ static noinline int svc_deferred_recv(struct svc_rqst *rqstp) rqstp->rq_xprt_hlen = dr->xprt_hlen; rqstp->rq_daddr = dr->daddr; rqstp->rq_respages = rqstp->rq_pages; + svc_xprt_received(rqstp->rq_xprt); return (dr->argslen<<2) - dr->xprt_hlen; } diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 22454b2df5be..9eb5b6b89077 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -519,6 +519,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) if (serv->sv_stats) serv->sv_stats->netudpcnt++; + svc_xprt_received(rqstp->rq_xprt); return len; out_recv_err: @@ -527,7 +528,7 @@ out_recv_err: set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); } trace_svcsock_udp_recv_err(&svsk->sk_xprt, err); - return 0; + goto out_clear_busy; out_cmsg_err: net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n", cmh->cmsg_level, cmh->cmsg_type); @@ -536,6 +537,8 @@ out_bh_enable: local_bh_enable(); out_free: kfree_skb(skb); +out_clear_busy: + svc_xprt_received(rqstp->rq_xprt); return 0; } @@ -1033,6 +1036,7 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) if (serv->sv_stats) serv->sv_stats->nettcpcnt++; + svc_xprt_received(rqstp->rq_xprt); return rqstp->rq_arg.len; err_incomplete: @@ -1050,13 +1054,14 @@ error: if (len != -EAGAIN) goto err_delete; trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0); - return 0; + goto err_noclose; err_nuts: svsk->sk_datalen = 0; err_delete: trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len); svc_xprt_deferred_close(&svsk->sk_xprt); err_noclose: + svc_xprt_received(rqstp->rq_xprt); return 0; /* record not complete */ } diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index 8d93d26e0318..9cb5a09c4a01 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -846,6 +846,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) /* No new incoming requests, terminate the loop */ clear_bit(XPT_DATA, &xprt->xpt_flags); spin_unlock(&rdma_xprt->sc_rq_dto_lock); + svc_xprt_received(xprt); return 0; } list_del(&ctxt->rc_list); @@ -883,28 +884,33 @@ complete: rqstp->rq_xprt_ctxt = ctxt; rqstp->rq_prot = IPPROTO_MAX; svc_xprt_copy_addrs(rqstp, xprt); + svc_xprt_received(xprt); return rqstp->rq_arg.len; out_readlist: ret = svc_rdma_process_read_list(rdma_xprt, rqstp, ctxt); if (ret < 0) goto out_readfail; + svc_xprt_received(xprt); return 0; out_err: svc_rdma_send_error(rdma_xprt, ctxt, ret); svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); + svc_xprt_received(xprt); return 0; out_readfail: if (ret == -EINVAL) svc_rdma_send_error(rdma_xprt, ctxt, ret); svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); + svc_xprt_received(xprt); return ret; out_backchannel: svc_rdma_handle_bc_reply(rqstp, ctxt); out_drop: svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); + svc_xprt_received(xprt); return 0; }