Return-Path: Received: from mail-qg0-f54.google.com ([209.85.192.54]:33377 "EHLO mail-qg0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753891AbbGIUmb (ORCPT ); Thu, 9 Jul 2015 16:42:31 -0400 Subject: [PATCH v1 05/12] xprtrdma: Account for RPC/RDMA header size when deciding to inline From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Thu, 09 Jul 2015 16:42:27 -0400 Message-ID: <20150709204227.26247.51111.stgit@manet.1015granger.net> In-Reply-To: <20150709203242.26247.4848.stgit@manet.1015granger.net> References: <20150709203242.26247.4848.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: When marshaling RPC/RDMA requests, ensure the combined size of RPC/RDMA header and RPC header do not exceed the inline threshold. Endpoints typically reject RPC/RDMA messages that exceed the size of their receive buffers. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/rpc_rdma.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 84ea37d..8cf9402 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -71,6 +71,31 @@ static const char transfertypes[][12] = { }; #endif +/* The client can send a request inline as long as the RPCRDMA header + * plus the RPC call fit under the transport's inline limit. If the + * combined call message size exceeds that limit, the client must use + * the read chunk list for this operation. + */ +static bool rpcrdma_args_inline(struct rpc_rqst *rqst) +{ + unsigned int callsize = RPCRDMA_HDRLEN_MIN + rqst->rq_snd_buf.len; + + return callsize <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst); +} + +/* The client can’t know how large the actual reply will be. Thus it + * plans for the largest possible reply for that particular ULP + * operation. If the maximum combined reply message size exceeds that + * limit, the client must provide a write list or a reply chunk for + * this request. + */ +static bool rpcrdma_results_inline(struct rpc_rqst *rqst) +{ + unsigned int repsize = RPCRDMA_HDRLEN_MIN + rqst->rq_rcv_buf.buflen; + + return repsize <= RPCRDMA_INLINE_READ_THRESHOLD(rqst); +} + /* * Chunk assembly from upper layer xdr_buf. * @@ -418,7 +443,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) * a READ, then use write chunks to separate the file data * into pages; otherwise use reply chunks. */ - if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst)) + if (rpcrdma_results_inline(rqst)) wtype = rpcrdma_noch; else if (rqst->rq_rcv_buf.page_len == 0) wtype = rpcrdma_replych; @@ -441,7 +466,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) * implies the op is a write. * TBD check NFSv4 setacl */ - if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst)) + if (rpcrdma_args_inline(rqst)) rtype = rpcrdma_noch; else if (rqst->rq_snd_buf.page_len == 0) rtype = rpcrdma_areadch;