Return-Path: Received: from mail-io0-f194.google.com ([209.85.223.194]:36277 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752382AbdFPPUr (ORCPT ); Fri, 16 Jun 2017 11:20:47 -0400 Subject: [PATCH v2 03/19] svcrdma: Avoid Send Queue overflow From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Fri, 16 Jun 2017 11:20:45 -0400 Message-ID: <20170616152045.14210.12739.stgit@klimt.1015granger.net> In-Reply-To: <20170616151535.14210.34926.stgit@klimt.1015granger.net> References: <20170616151535.14210.34926.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: Sanity case: Catch the case where more Work Requests are being posted to the Send Queue than there are Send Queue Entries. This might happen if a client sends a chunk with more segments than there are SQEs for the transport. The server can't send that reply, so the transport will deadlock unless the client drops the RPC. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma_rw.c | 5 +++++ net/sunrpc/xprtrdma/svc_rdma_sendto.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index 0cf6202..3b35364 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -232,6 +232,9 @@ static int svc_rdma_post_chunk_ctxt(struct svc_rdma_chunk_ctxt *cc) struct ib_cqe *cqe; int ret; + if (cc->cc_sqecount > rdma->sc_sq_depth) + return -EINVAL; + first_wr = NULL; cqe = &cc->cc_cqe; list_for_each(tmp, &cc->cc_rwctxts) { @@ -425,6 +428,7 @@ static int svc_rdma_send_xdr_pagelist(struct svc_rdma_write_info *info, * * Returns a non-negative number of bytes the chunk consumed, or * %-E2BIG if the payload was larger than the Write chunk, + * %-EINVAL if client provided too many segments, * %-ENOMEM if rdma_rw context pool was exhausted, * %-ENOTCONN if posting failed (connection is lost), * %-EIO if rdma_rw initialization failed (DMA mapping, etc). @@ -465,6 +469,7 @@ int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, __be32 *wr_ch, * * Returns a non-negative number of bytes the chunk consumed, or * %-E2BIG if the payload was larger than the Reply chunk, + * %-EINVAL if client provided too many segments, * %-ENOMEM if rdma_rw context pool was exhausted, * %-ENOTCONN if posting failed (connection is lost), * %-EIO if rdma_rw initialization failed (DMA mapping, etc). diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 5ba6d91..19fd01e 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -684,7 +684,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) return 0; err2: - if (ret != -E2BIG) + if (ret != -E2BIG || ret != -EINVAL) goto err1; ret = svc_rdma_post_recv(rdma, GFP_KERNEL);