Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f170.google.com ([209.85.223.170]:46580 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751757AbbAMQDa (ORCPT ); Tue, 13 Jan 2015 11:03:30 -0500 From: Chuck Lever Subject: [PATCH v2 07/10] svcrdma: rc_position sanity checking To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Tue, 13 Jan 2015 11:03:28 -0500 Message-ID: <20150113160328.8118.43894.stgit@klimt.1015granger.net> In-Reply-To: <20150113155904.8118.57718.stgit@klimt.1015granger.net> References: <20150113155904.8118.57718.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: An RPC/RDMA client may send large RPC arguments via a read list. This is a list of scatter/gather elements which convey RPC call arguments too large to fit in a small RDMA SEND. Each entry in the read list has a "position" field, whose value is the byte offset in the XDR stream where the data in that entry is to be inserted. Entries which share the same "position" value make up the same RPC argument. The receiver inserts entries with the same position field value in list order into the XDR stream. Currently the Linux NFS/RDMA server cannot handle receiving read chunks in more than one position, mostly because no current client sends read lists with elements in more than one position. As a sanity check, ensure that all received chunks have the same "rc_position." Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index c3aebc1..a67dd1a 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -365,6 +365,7 @@ static int rdma_read_chunks(struct svcxprt_rdma *xprt, int page_no, ret; struct rpcrdma_read_chunk *ch; u32 handle, page_offset, byte_count; + u32 position; u64 rs_offset; bool last; @@ -389,10 +390,17 @@ static int rdma_read_chunks(struct svcxprt_rdma *xprt, head->arg.len = rqstp->rq_arg.len; head->arg.buflen = rqstp->rq_arg.buflen; - page_no = 0; page_offset = 0; - for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; - ch->rc_discrim != 0; ch++) { - handle = be32_to_cpu(ch->rc_target.rs_handle); + ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + position = be32_to_cpu(ch->rc_position); + + ret = 0; + page_no = 0; + page_offset = 0; + for (; ch->rc_discrim != xdr_zero; ch++) { + if (be32_to_cpu(ch->rc_position) != position) + goto err; + + handle = be32_to_cpu(ch->rc_target.rs_handle), byte_count = be32_to_cpu(ch->rc_target.rs_length); xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset, &rs_offset);