Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:47995 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752291AbaGJURH (ORCPT ); Thu, 10 Jul 2014 16:17:07 -0400 Date: Thu, 10 Jul 2014 16:17:02 -0400 From: "J. Bruce Fields" To: Steve Wise Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org, tom@ogc.us Subject: Re: [PATCH] svcrdma: send_write() must not overflow the device's max sge Message-ID: <20140710201702.GG26561@fieldses.org> References: <20140709184914.22217.59770.stgit@build.ogc.int> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140709184914.22217.59770.stgit@build.ogc.int> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Jul 09, 2014 at 01:49:15PM -0500, Steve Wise wrote: > Function send_write() must stop creating sges when it reaches the device > max and return the amount sent in the RDMA Write to the caller. Queueing up for 3.17, thanks.--b. > > Signed-off-by: Steve Wise > --- > > net/sunrpc/xprtrdma/svc_rdma_sendto.c | 39 +++++++++++++-------------------- > 1 files changed, 15 insertions(+), 24 deletions(-) > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c > index 49fd21a..9f1b506 100644 > --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c > +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c > @@ -192,6 +192,8 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, > xdr_sge_no++; > BUG_ON(xdr_sge_no > vec->count); > bc -= sge_bytes; > + if (sge_no == xprt->sc_max_sge) > + break; > } > > /* Prepare WRITE WR */ > @@ -209,7 +211,7 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, > atomic_inc(&rdma_stat_write); > if (svc_rdma_send(xprt, &write_wr)) > goto err; > - return 0; > + return write_len - bc; > err: > svc_rdma_unmap_dma(ctxt); > svc_rdma_put_context(ctxt, 0); > @@ -225,7 +227,6 @@ static int send_write_chunks(struct svcxprt_rdma *xprt, > { > u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len; > int write_len; > - int max_write; > u32 xdr_off; > int chunk_off; > int chunk_no; > @@ -239,8 +240,6 @@ static int send_write_chunks(struct svcxprt_rdma *xprt, > res_ary = (struct rpcrdma_write_array *) > &rdma_resp->rm_body.rm_chunks[1]; > > - max_write = xprt->sc_max_sge * PAGE_SIZE; > - > /* Write chunks start at the pagelist */ > for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0; > xfer_len && chunk_no < arg_ary->wc_nchunks; > @@ -260,23 +259,21 @@ static int send_write_chunks(struct svcxprt_rdma *xprt, > write_len); > chunk_off = 0; > while (write_len) { > - int this_write; > - this_write = min(write_len, max_write); > ret = send_write(xprt, rqstp, > ntohl(arg_ch->rs_handle), > rs_offset + chunk_off, > xdr_off, > - this_write, > + write_len, > vec); > - if (ret) { > + if (ret <= 0) { > dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", > ret); > return -EIO; > } > - chunk_off += this_write; > - xdr_off += this_write; > - xfer_len -= this_write; > - write_len -= this_write; > + chunk_off += ret; > + xdr_off += ret; > + xfer_len -= ret; > + write_len -= ret; > } > } > /* Update the req with the number of chunks actually used */ > @@ -293,7 +290,6 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt, > { > u32 xfer_len = rqstp->rq_res.len; > int write_len; > - int max_write; > u32 xdr_off; > int chunk_no; > int chunk_off; > @@ -311,8 +307,6 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt, > res_ary = (struct rpcrdma_write_array *) > &rdma_resp->rm_body.rm_chunks[2]; > > - max_write = xprt->sc_max_sge * PAGE_SIZE; > - > /* xdr offset starts at RPC message */ > nchunks = ntohl(arg_ary->wc_nchunks); > for (xdr_off = 0, chunk_no = 0; > @@ -330,24 +324,21 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt, > write_len); > chunk_off = 0; > while (write_len) { > - int this_write; > - > - this_write = min(write_len, max_write); > ret = send_write(xprt, rqstp, > ntohl(ch->rs_handle), > rs_offset + chunk_off, > xdr_off, > - this_write, > + write_len, > vec); > - if (ret) { > + if (ret <= 0) { > dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", > ret); > return -EIO; > } > - chunk_off += this_write; > - xdr_off += this_write; > - xfer_len -= this_write; > - write_len -= this_write; > + chunk_off += ret; > + xdr_off += ret; > + xfer_len -= ret; > + write_len -= ret; > } > } > /* Update the req with the number of chunks actually used */ >