Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935310AbdCJJ0y (ORCPT ); Fri, 10 Mar 2017 04:26:54 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:39210 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934408AbdCJJ0u (ORCPT ); Fri, 10 Mar 2017 04:26:50 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chuck Lever , Anna Schumaker Subject: [PATCH 4.9 141/153] xprtrdma: Fix Read chunk padding Date: Fri, 10 Mar 2017 10:09:34 +0100 Message-Id: <20170310083955.688169221@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170310083947.108106897@linuxfoundation.org> References: <20170310083947.108106897@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2108 Lines: 59 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever commit 24abdf1be15c478e2821d6fc903a4a4440beff02 upstream. When pad optimization is disabled, rpcrdma_convert_iovs still does not add explicit XDR round-up padding to a Read chunk. Commit 677eb17e94ed ("xprtrdma: Fix XDR tail buffer marshalling") incorrectly short-circuited the test for whether round-up padding is needed that appears later in rpcrdma_convert_iovs. However, if this is indeed a regular Read chunk (and not a Position-Zero Read chunk), the tail iovec _always_ contains the chunk's padding, and never anything else. So, it's easy to just skip the tail when padding optimization is enabled, and add the tail in a subsequent Read chunk segment, if disabled. Fixes: 677eb17e94ed ("xprtrdma: Fix XDR tail buffer marshalling") Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtrdma/rpc_rdma.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -226,8 +226,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdr if (len && n == RPCRDMA_MAX_SEGS) goto out_overflow; - /* When encoding the read list, the tail is always sent inline */ - if (type == rpcrdma_readch) + /* When encoding a Read chunk, the tail iovec contains an + * XDR pad and may be omitted. + */ + if (type == rpcrdma_readch && xprt_rdma_pad_optimize) return n; /* When encoding the Write list, some servers need to see an extra @@ -238,10 +240,6 @@ rpcrdma_convert_iovs(struct xdr_buf *xdr return n; if (xdrbuf->tail[0].iov_len) { - /* the rpcrdma protocol allows us to omit any trailing - * xdr pad bytes, saving the server an RDMA operation. */ - if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize) - return n; n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n); if (n == RPCRDMA_MAX_SEGS) goto out_overflow;