From: Tom Tucker Subject: [PATCH,RFC 07/09] svcrdma: Modify the RPC recv path to use FRMR when available Date: Wed, 13 Aug 2008 11:15:41 -0500 Message-ID: <48A308AD.20508@opengridcomputing.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linux-nfs@vger.kernel.org To: "J. Bruce Fields" Return-path: Received: from smtp.opengridcomputing.com ([209.198.142.2]:36751 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755423AbYHMQPm (ORCPT ); Wed, 13 Aug 2008 12:15:42 -0400 Sender: linux-nfs-owner@vger.kernel.org List-ID: RPCRDMA requests that specify a read-list are fetched with RDMA_READ. Using an FRMR to map the data sink improves NFSRDMA security on transports that place the RDMA_READ data sink LKEY on the wire because the valid lifetime of the MR is only the duration of the RDMA_READ. The LKEY is invalidated when the last RDMA_READ WR completes. Mapping the data sink also allows for very large amounts to data to be fetched with a single WR, so if the client is also using FRMR, the entire RPC read-list can be fetched with a single WR. Signed-off-by: Tom Tucker --- include/linux/sunrpc/svc_rdma.h | 1 + net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 187 ++++++++++++++++++++++++++---- net/sunrpc/xprtrdma/svc_rdma_transport.c | 5 +- 3 files changed, 171 insertions(+), 22 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 6899b71..5069e25 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -217,6 +217,7 @@ extern int svc_rdma_post_recv(struct svcxprt_rdma *); extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *); extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *); extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int); +extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt); extern struct svc_rdma_req_map *svc_rdma_get_req_map(void); extern void svc_rdma_put_req_map(struct svc_rdma_req_map *); extern int svc_rdma_fastreg(struct svcxprt_rdma *, struct svc_rdma_fastreg_mr *); diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index 74de31a..a475657 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -116,7 +116,7 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp, * * Assumptions: * - chunk[0]->position points to pages[0] at an offset of 0 - * - pages[] is not physically or virtually contigous and consists of + * - pages[] is not physically or virtually contiguous and consists of * PAGE_SIZE elements. * * Output: @@ -125,7 +125,7 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp, * chunk in the read list * */ -static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, +static int map_read_chunks(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head, struct rpcrdma_msg *rmsgp, @@ -211,26 +211,128 @@ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, return sge_no; } -static void rdma_set_ctxt_sge(struct svcxprt_rdma *xprt, - struct svc_rdma_op_ctxt *ctxt, - struct kvec *vec, - u64 *sgl_offset, - int count) +/* Map a read-chunk-list to an XDR and fast register the page-list. + * + * Assumptions: + * - chunk[0] position points to pages[0] at an offset of 0 + * - pages[] will be made physically contiguous by creating a one-off memory + * region using the fastreg verb. + * - byte_count is # of bytes in read-chunk-list + * - ch_count is # of chunks in read-chunk-list + * + * Output: + * - sge array pointing into pages[] array. + * - chunk_sge array specifying sge index and count for each + * chunk in the read list + */ +static int fast_reg_read_chunks(struct svcxprt_rdma *xprt, + struct svc_rqst *rqstp, + struct svc_rdma_op_ctxt *head, + struct rpcrdma_msg *rmsgp, + struct svc_rdma_req_map *rpl_map, + struct svc_rdma_req_map *chl_map, + int ch_count, + int byte_count) +{ + int page_no; + int ch_no; + u32 offset; + struct rpcrdma_read_chunk *ch; + struct svc_rdma_fastreg_mr *frmr; + int ret = 0; + + frmr = svc_rdma_get_frmr(xprt); + if (IS_ERR(frmr)) + return -ENOMEM; + + head->frmr = frmr; + head->arg.head[0] = rqstp->rq_arg.head[0]; + head->arg.tail[0] = rqstp->rq_arg.tail[0]; + head->arg.pages = &head->pages[head->count]; + head->hdr_count = head->count; /* save count of hdr pages */ + head->arg.page_base = 0; + head->arg.page_len = byte_count; + head->arg.len = rqstp->rq_arg.len + byte_count; + head->arg.buflen = rqstp->rq_arg.buflen + byte_count; + + /* Fast register the page list */ + frmr->kva = page_address(rqstp->rq_arg.pages[0]); + frmr->direction = DMA_FROM_DEVICE; + frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE); + frmr->map_len = byte_count; + frmr->page_list_len = PAGE_ALIGN(byte_count) >> PAGE_SHIFT; + for (page_no = 0; page_no < frmr->page_list_len; page_no++) { + frmr->page_list->page_list[page_no] = + ib_dma_map_single(xprt->sc_cm_id->device, + page_address(rqstp->rq_arg.pages[page_no]), + PAGE_SIZE, DMA_TO_DEVICE); + if (ib_dma_mapping_error(xprt->sc_cm_id->device, + frmr->page_list->page_list[page_no])) + goto fatal_err; + atomic_inc(&xprt->sc_dma_used); + head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no]; + } + head->count += page_no; + + /* rq_respages points one past arg pages */ + rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; + + /* Create the reply and chunk maps */ + offset = 0; + ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + for (ch_no = 0; ch_no < ch_count; ch_no++) { + rpl_map->sge[ch_no].iov_base = frmr->kva + offset; + rpl_map->sge[ch_no].iov_len = ch->rc_target.rs_length; + chl_map->ch[ch_no].count = 1; + chl_map->ch[ch_no].start = ch_no; + offset += ch->rc_target.rs_length; + ch++; + } + + ret = svc_rdma_fastreg(xprt, frmr); + if (ret) + goto fatal_err; + + return ch_no; + + fatal_err: + printk("svcrdma: error fast registering xdr for xprt %p", xprt); + svc_rdma_put_frmr(xprt, frmr); + return -EIO; +} + +static int rdma_set_ctxt_sge(struct svcxprt_rdma *xprt, + struct svc_rdma_op_ctxt *ctxt, + struct svc_rdma_fastreg_mr *frmr, + struct kvec *vec, + u64 *sgl_offset, + int count) { int i; ctxt->count = count; ctxt->direction = DMA_FROM_DEVICE; for (i = 0; i < count; i++) { - atomic_inc(&xprt->sc_dma_used); - ctxt->sge[i].addr = - ib_dma_map_single(xprt->sc_cm_id->device, - vec[i].iov_base, vec[i].iov_len, - DMA_FROM_DEVICE); + ctxt->sge[i].length = 0; /* in case map fails */ + if (!frmr) { + ctxt->sge[i].addr = + ib_dma_map_single(xprt->sc_cm_id->device, + vec[i].iov_base, + vec[i].iov_len, + DMA_FROM_DEVICE); + if (ib_dma_mapping_error(xprt->sc_cm_id->device, + ctxt->sge[i].addr)) + return -EINVAL; + ctxt->sge[i].lkey = xprt->sc_dma_lkey; + atomic_inc(&xprt->sc_dma_used); + } else { + ctxt->sge[i].addr = (unsigned long)vec[i].iov_base; + ctxt->sge[i].lkey = frmr->mr->lkey; + } ctxt->sge[i].length = vec[i].iov_len; - ctxt->sge[i].lkey = xprt->sc_phys_mr->lkey; *sgl_offset = *sgl_offset + vec[i].iov_len; } + return 0; } static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) @@ -278,6 +380,7 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, struct svc_rdma_op_ctxt *hdr_ctxt) { struct ib_send_wr read_wr; + struct ib_send_wr inv_wr; int err = 0; int ch_no; int ch_count; @@ -301,9 +404,20 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count); if (ch_count > RPCSVC_MAXPAGES) return -EINVAL; - sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp, - rpl_map, chl_map, - ch_count, byte_count); + + if (!xprt->sc_frmr_pg_list_len) + sge_count = map_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp, + rpl_map, chl_map, ch_count, + byte_count); + else + sge_count = fast_reg_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp, + rpl_map, chl_map, ch_count, + byte_count); + if (sge_count < 0) { + err = -EIO; + goto out; + } + sgl_offset = 0; ch_no = 0; @@ -312,13 +426,16 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, next_sge: ctxt = svc_rdma_get_context(xprt); ctxt->direction = DMA_FROM_DEVICE; + ctxt->frmr = hdr_ctxt->frmr; + ctxt->read_hdr = NULL; clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); + clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags); /* Prepare READ WR */ memset(&read_wr, 0, sizeof read_wr); - ctxt->wr_op = IB_WR_RDMA_READ; read_wr.wr_id = (unsigned long)ctxt; read_wr.opcode = IB_WR_RDMA_READ; + ctxt->wr_op = read_wr.opcode; read_wr.send_flags = IB_SEND_SIGNALED; read_wr.wr.rdma.rkey = ch->rc_target.rs_handle; read_wr.wr.rdma.remote_addr = @@ -327,10 +444,15 @@ next_sge: read_wr.sg_list = ctxt->sge; read_wr.num_sge = rdma_read_max_sge(xprt, chl_map->ch[ch_no].count); - rdma_set_ctxt_sge(xprt, ctxt, - &rpl_map->sge[chl_map->ch[ch_no].start], - &sgl_offset, - read_wr.num_sge); + err = rdma_set_ctxt_sge(xprt, ctxt, hdr_ctxt->frmr, + &rpl_map->sge[chl_map->ch[ch_no].start], + &sgl_offset, + read_wr.num_sge); + if (err) { + svc_rdma_unmap_dma(ctxt); + svc_rdma_put_context(ctxt, 0); + goto out; + } if (((ch+1)->rc_discrim == 0) && (read_wr.num_sge == chl_map->ch[ch_no].count)) { /* @@ -339,6 +461,29 @@ next_sge: * the client and the RPC needs to be enqueued. */ set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); + if (hdr_ctxt->frmr) { + set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags); + /* + * Invalidate the local MR used to map the data + * sink. + */ + if (xprt->sc_dev_caps & + SVCRDMA_DEVCAP_READ_W_INV) { + read_wr.opcode = + IB_WR_RDMA_READ_WITH_INV; + ctxt->wr_op = read_wr.opcode; + read_wr.ex.invalidate_rkey = + ctxt->frmr->mr->lkey; + } else { + /* Prepare INVALIDATE WR */ + memset(&inv_wr, 0, sizeof inv_wr); + inv_wr.opcode = IB_WR_LOCAL_INV; + inv_wr.send_flags = IB_SEND_SIGNALED; + inv_wr.ex.invalidate_rkey = + hdr_ctxt->frmr->mr->lkey; + read_wr.next = &inv_wr; + } + } ctxt->read_hdr = hdr_ctxt; } /* Post the read */ diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 1f561c0..360070e 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -105,7 +105,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) return ctxt; } -static void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt) +void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt) { struct svcxprt_rdma *xprt = ctxt->xprt; int i; @@ -367,9 +367,12 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt) break; case IB_WR_RDMA_READ: + case IB_WR_RDMA_READ_WITH_INV: if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) { struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr; BUG_ON(!read_hdr); + if (test_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags)) + svc_rdma_put_frmr(xprt, ctxt->frmr); spin_lock_bh(&xprt->sc_rq_dto_lock); set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); list_add_tail(&read_hdr->dto_q,