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1046 lines
30 KiB
1046 lines
30 KiB
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
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/* |
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* Copyright (c) 2016-2018 Oracle. All rights reserved. |
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* Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved. |
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* Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved. |
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* |
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* This software is available to you under a choice of one of two |
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* licenses. You may choose to be licensed under the terms of the GNU |
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* General Public License (GPL) Version 2, available from the file |
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* COPYING in the main directory of this source tree, or the BSD-type |
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* license below: |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer in the documentation and/or other materials provided |
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* with the distribution. |
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* |
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* Neither the name of the Network Appliance, Inc. nor the names of |
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* its contributors may be used to endorse or promote products |
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* derived from this software without specific prior written |
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* permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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* Author: Tom Tucker <[email protected]> |
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*/ |
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|
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/* Operation |
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* |
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* The main entry point is svc_rdma_sendto. This is called by the |
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* RPC server when an RPC Reply is ready to be transmitted to a client. |
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* |
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* The passed-in svc_rqst contains a struct xdr_buf which holds an |
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* XDR-encoded RPC Reply message. sendto must construct the RPC-over-RDMA |
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* transport header, post all Write WRs needed for this Reply, then post |
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* a Send WR conveying the transport header and the RPC message itself to |
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* the client. |
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* |
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* svc_rdma_sendto must fully transmit the Reply before returning, as |
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* the svc_rqst will be recycled as soon as sendto returns. Remaining |
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* resources referred to by the svc_rqst are also recycled at that time. |
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* Therefore any resources that must remain longer must be detached |
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* from the svc_rqst and released later. |
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* |
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* Page Management |
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* |
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* The I/O that performs Reply transmission is asynchronous, and may |
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* complete well after sendto returns. Thus pages under I/O must be |
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* removed from the svc_rqst before sendto returns. |
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* |
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* The logic here depends on Send Queue and completion ordering. Since |
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* the Send WR is always posted last, it will always complete last. Thus |
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* when it completes, it is guaranteed that all previous Write WRs have |
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* also completed. |
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* |
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* Write WRs are constructed and posted. Each Write segment gets its own |
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* svc_rdma_rw_ctxt, allowing the Write completion handler to find and |
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* DMA-unmap the pages under I/O for that Write segment. The Write |
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* completion handler does not release any pages. |
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* |
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* When the Send WR is constructed, it also gets its own svc_rdma_send_ctxt. |
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* The ownership of all of the Reply's pages are transferred into that |
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* ctxt, the Send WR is posted, and sendto returns. |
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* |
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* The svc_rdma_send_ctxt is presented when the Send WR completes. The |
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* Send completion handler finally releases the Reply's pages. |
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* |
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* This mechanism also assumes that completions on the transport's Send |
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* Completion Queue do not run in parallel. Otherwise a Write completion |
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* and Send completion running at the same time could release pages that |
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* are still DMA-mapped. |
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* |
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* Error Handling |
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* |
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* - If the Send WR is posted successfully, it will either complete |
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* successfully, or get flushed. Either way, the Send completion |
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* handler releases the Reply's pages. |
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* - If the Send WR cannot be not posted, the forward path releases |
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* the Reply's pages. |
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* |
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* This handles the case, without the use of page reference counting, |
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* where two different Write segments send portions of the same page. |
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*/ |
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|
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#include <linux/spinlock.h> |
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#include <asm/unaligned.h> |
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|
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#include <rdma/ib_verbs.h> |
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#include <rdma/rdma_cm.h> |
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|
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#include <linux/sunrpc/debug.h> |
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#include <linux/sunrpc/svc_rdma.h> |
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|
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#include "xprt_rdma.h" |
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#include <trace/events/rpcrdma.h> |
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|
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#define RPCDBG_FACILITY RPCDBG_SVCXPRT |
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|
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static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc); |
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|
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static inline struct svc_rdma_send_ctxt * |
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svc_rdma_next_send_ctxt(struct list_head *list) |
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{ |
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return list_first_entry_or_null(list, struct svc_rdma_send_ctxt, |
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sc_list); |
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} |
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|
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static void svc_rdma_send_cid_init(struct svcxprt_rdma *rdma, |
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struct rpc_rdma_cid *cid) |
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{ |
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cid->ci_queue_id = rdma->sc_sq_cq->res.id; |
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cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids); |
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} |
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|
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static struct svc_rdma_send_ctxt * |
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svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_send_ctxt *ctxt; |
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dma_addr_t addr; |
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void *buffer; |
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size_t size; |
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int i; |
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|
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size = sizeof(*ctxt); |
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size += rdma->sc_max_send_sges * sizeof(struct ib_sge); |
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ctxt = kmalloc(size, GFP_KERNEL); |
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if (!ctxt) |
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goto fail0; |
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buffer = kmalloc(rdma->sc_max_req_size, GFP_KERNEL); |
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if (!buffer) |
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goto fail1; |
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addr = ib_dma_map_single(rdma->sc_pd->device, buffer, |
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rdma->sc_max_req_size, DMA_TO_DEVICE); |
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if (ib_dma_mapping_error(rdma->sc_pd->device, addr)) |
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goto fail2; |
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|
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svc_rdma_send_cid_init(rdma, &ctxt->sc_cid); |
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|
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ctxt->sc_send_wr.next = NULL; |
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ctxt->sc_send_wr.wr_cqe = &ctxt->sc_cqe; |
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ctxt->sc_send_wr.sg_list = ctxt->sc_sges; |
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ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED; |
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ctxt->sc_cqe.done = svc_rdma_wc_send; |
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ctxt->sc_xprt_buf = buffer; |
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xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, |
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rdma->sc_max_req_size); |
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ctxt->sc_sges[0].addr = addr; |
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|
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for (i = 0; i < rdma->sc_max_send_sges; i++) |
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ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey; |
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return ctxt; |
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|
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fail2: |
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kfree(buffer); |
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fail1: |
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kfree(ctxt); |
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fail0: |
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return NULL; |
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} |
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|
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/** |
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* svc_rdma_send_ctxts_destroy - Release all send_ctxt's for an xprt |
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* @rdma: svcxprt_rdma being torn down |
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* |
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*/ |
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void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_send_ctxt *ctxt; |
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|
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while ((ctxt = svc_rdma_next_send_ctxt(&rdma->sc_send_ctxts))) { |
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list_del(&ctxt->sc_list); |
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ib_dma_unmap_single(rdma->sc_pd->device, |
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ctxt->sc_sges[0].addr, |
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rdma->sc_max_req_size, |
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DMA_TO_DEVICE); |
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kfree(ctxt->sc_xprt_buf); |
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kfree(ctxt); |
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} |
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} |
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|
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/** |
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* svc_rdma_send_ctxt_get - Get a free send_ctxt |
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* @rdma: controlling svcxprt_rdma |
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* |
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* Returns a ready-to-use send_ctxt, or NULL if none are |
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* available and a fresh one cannot be allocated. |
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*/ |
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struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_send_ctxt *ctxt; |
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|
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spin_lock(&rdma->sc_send_lock); |
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ctxt = svc_rdma_next_send_ctxt(&rdma->sc_send_ctxts); |
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if (!ctxt) |
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goto out_empty; |
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list_del(&ctxt->sc_list); |
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spin_unlock(&rdma->sc_send_lock); |
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out: |
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rpcrdma_set_xdrlen(&ctxt->sc_hdrbuf, 0); |
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xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf, |
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ctxt->sc_xprt_buf, NULL); |
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ctxt->sc_send_wr.num_sge = 0; |
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ctxt->sc_cur_sge_no = 0; |
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ctxt->sc_page_count = 0; |
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return ctxt; |
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out_empty: |
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spin_unlock(&rdma->sc_send_lock); |
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ctxt = svc_rdma_send_ctxt_alloc(rdma); |
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if (!ctxt) |
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return NULL; |
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goto out; |
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} |
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/** |
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* svc_rdma_send_ctxt_put - Return send_ctxt to free list |
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* @rdma: controlling svcxprt_rdma |
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* @ctxt: object to return to the free list |
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* |
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* Pages left in sc_pages are DMA unmapped and released. |
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*/ |
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void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma, |
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struct svc_rdma_send_ctxt *ctxt) |
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{ |
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struct ib_device *device = rdma->sc_cm_id->device; |
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unsigned int i; |
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|
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/* The first SGE contains the transport header, which |
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* remains mapped until @ctxt is destroyed. |
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*/ |
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for (i = 1; i < ctxt->sc_send_wr.num_sge; i++) { |
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ib_dma_unmap_page(device, |
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ctxt->sc_sges[i].addr, |
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ctxt->sc_sges[i].length, |
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DMA_TO_DEVICE); |
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trace_svcrdma_dma_unmap_page(rdma, |
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ctxt->sc_sges[i].addr, |
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ctxt->sc_sges[i].length); |
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} |
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for (i = 0; i < ctxt->sc_page_count; ++i) |
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put_page(ctxt->sc_pages[i]); |
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spin_lock(&rdma->sc_send_lock); |
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list_add(&ctxt->sc_list, &rdma->sc_send_ctxts); |
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spin_unlock(&rdma->sc_send_lock); |
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} |
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|
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/** |
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* svc_rdma_wc_send - Invoked by RDMA provider for each polled Send WC |
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* @cq: Completion Queue context |
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* @wc: Work Completion object |
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* |
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* NB: The svc_xprt/svcxprt_rdma is pinned whenever it's possible that |
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* the Send completion handler could be running. |
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*/ |
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static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) |
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{ |
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struct svcxprt_rdma *rdma = cq->cq_context; |
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struct ib_cqe *cqe = wc->wr_cqe; |
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struct svc_rdma_send_ctxt *ctxt = |
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container_of(cqe, struct svc_rdma_send_ctxt, sc_cqe); |
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trace_svcrdma_wc_send(wc, &ctxt->sc_cid); |
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atomic_inc(&rdma->sc_sq_avail); |
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wake_up(&rdma->sc_send_wait); |
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svc_rdma_send_ctxt_put(rdma, ctxt); |
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if (unlikely(wc->status != IB_WC_SUCCESS)) { |
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set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); |
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svc_xprt_enqueue(&rdma->sc_xprt); |
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} |
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} |
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|
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/** |
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* svc_rdma_send - Post a single Send WR |
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* @rdma: transport on which to post the WR |
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* @ctxt: send ctxt with a Send WR ready to post |
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* |
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* Returns zero the Send WR was posted successfully. Otherwise, a |
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* negative errno is returned. |
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*/ |
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int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt) |
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{ |
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struct ib_send_wr *wr = &ctxt->sc_send_wr; |
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int ret; |
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|
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might_sleep(); |
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|
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/* Sync the transport header buffer */ |
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ib_dma_sync_single_for_device(rdma->sc_pd->device, |
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wr->sg_list[0].addr, |
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wr->sg_list[0].length, |
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DMA_TO_DEVICE); |
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|
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/* If the SQ is full, wait until an SQ entry is available */ |
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while (1) { |
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if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) { |
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percpu_counter_inc(&svcrdma_stat_sq_starve); |
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trace_svcrdma_sq_full(rdma); |
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atomic_inc(&rdma->sc_sq_avail); |
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wait_event(rdma->sc_send_wait, |
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atomic_read(&rdma->sc_sq_avail) > 1); |
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if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) |
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return -ENOTCONN; |
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trace_svcrdma_sq_retry(rdma); |
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continue; |
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} |
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|
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trace_svcrdma_post_send(ctxt); |
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ret = ib_post_send(rdma->sc_qp, wr, NULL); |
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if (ret) |
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break; |
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return 0; |
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} |
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|
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trace_svcrdma_sq_post_err(rdma, ret); |
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set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); |
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wake_up(&rdma->sc_send_wait); |
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return ret; |
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} |
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|
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/** |
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* svc_rdma_encode_read_list - Encode RPC Reply's Read chunk list |
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* @sctxt: Send context for the RPC Reply |
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* |
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* Return values: |
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* On success, returns length in bytes of the Reply XDR buffer |
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* that was consumed by the Reply Read list |
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* %-EMSGSIZE on XDR buffer overflow |
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*/ |
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static ssize_t svc_rdma_encode_read_list(struct svc_rdma_send_ctxt *sctxt) |
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{ |
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/* RPC-over-RDMA version 1 replies never have a Read list. */ |
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return xdr_stream_encode_item_absent(&sctxt->sc_stream); |
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} |
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|
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/** |
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* svc_rdma_encode_write_segment - Encode one Write segment |
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* @sctxt: Send context for the RPC Reply |
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* @chunk: Write chunk to push |
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* @remaining: remaining bytes of the payload left in the Write chunk |
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* @segno: which segment in the chunk |
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* |
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* Return values: |
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* On success, returns length in bytes of the Reply XDR buffer |
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* that was consumed by the Write segment, and updates @remaining |
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* %-EMSGSIZE on XDR buffer overflow |
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*/ |
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static ssize_t svc_rdma_encode_write_segment(struct svc_rdma_send_ctxt *sctxt, |
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const struct svc_rdma_chunk *chunk, |
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u32 *remaining, unsigned int segno) |
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{ |
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const struct svc_rdma_segment *segment = &chunk->ch_segments[segno]; |
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const size_t len = rpcrdma_segment_maxsz * sizeof(__be32); |
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u32 length; |
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__be32 *p; |
|
|
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p = xdr_reserve_space(&sctxt->sc_stream, len); |
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if (!p) |
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return -EMSGSIZE; |
|
|
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length = min_t(u32, *remaining, segment->rs_length); |
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*remaining -= length; |
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xdr_encode_rdma_segment(p, segment->rs_handle, length, |
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segment->rs_offset); |
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trace_svcrdma_encode_wseg(sctxt, segno, segment->rs_handle, length, |
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segment->rs_offset); |
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return len; |
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} |
|
|
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/** |
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* svc_rdma_encode_write_chunk - Encode one Write chunk |
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* @sctxt: Send context for the RPC Reply |
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* @chunk: Write chunk to push |
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* |
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* Copy a Write chunk from the Call transport header to the |
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* Reply transport header. Update each segment's length field |
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* to reflect the number of bytes written in that segment. |
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* |
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* Return values: |
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* On success, returns length in bytes of the Reply XDR buffer |
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* that was consumed by the Write chunk |
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* %-EMSGSIZE on XDR buffer overflow |
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*/ |
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static ssize_t svc_rdma_encode_write_chunk(struct svc_rdma_send_ctxt *sctxt, |
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const struct svc_rdma_chunk *chunk) |
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{ |
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u32 remaining = chunk->ch_payload_length; |
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unsigned int segno; |
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ssize_t len, ret; |
|
|
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len = 0; |
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ret = xdr_stream_encode_item_present(&sctxt->sc_stream); |
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if (ret < 0) |
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return ret; |
|
len += ret; |
|
|
|
ret = xdr_stream_encode_u32(&sctxt->sc_stream, chunk->ch_segcount); |
|
if (ret < 0) |
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return ret; |
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len += ret; |
|
|
|
for (segno = 0; segno < chunk->ch_segcount; segno++) { |
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ret = svc_rdma_encode_write_segment(sctxt, chunk, &remaining, segno); |
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if (ret < 0) |
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return ret; |
|
len += ret; |
|
} |
|
|
|
return len; |
|
} |
|
|
|
/** |
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* svc_rdma_encode_write_list - Encode RPC Reply's Write chunk list |
|
* @rctxt: Reply context with information about the RPC Call |
|
* @sctxt: Send context for the RPC Reply |
|
* |
|
* Return values: |
|
* On success, returns length in bytes of the Reply XDR buffer |
|
* that was consumed by the Reply's Write list |
|
* %-EMSGSIZE on XDR buffer overflow |
|
*/ |
|
static ssize_t svc_rdma_encode_write_list(struct svc_rdma_recv_ctxt *rctxt, |
|
struct svc_rdma_send_ctxt *sctxt) |
|
{ |
|
struct svc_rdma_chunk *chunk; |
|
ssize_t len, ret; |
|
|
|
len = 0; |
|
pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) { |
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ret = svc_rdma_encode_write_chunk(sctxt, chunk); |
|
if (ret < 0) |
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return ret; |
|
len += ret; |
|
} |
|
|
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/* Terminate the Write list */ |
|
ret = xdr_stream_encode_item_absent(&sctxt->sc_stream); |
|
if (ret < 0) |
|
return ret; |
|
|
|
return len + ret; |
|
} |
|
|
|
/** |
|
* svc_rdma_encode_reply_chunk - Encode RPC Reply's Reply chunk |
|
* @rctxt: Reply context with information about the RPC Call |
|
* @sctxt: Send context for the RPC Reply |
|
* @length: size in bytes of the payload in the Reply chunk |
|
* |
|
* Return values: |
|
* On success, returns length in bytes of the Reply XDR buffer |
|
* that was consumed by the Reply's Reply chunk |
|
* %-EMSGSIZE on XDR buffer overflow |
|
* %-E2BIG if the RPC message is larger than the Reply chunk |
|
*/ |
|
static ssize_t |
|
svc_rdma_encode_reply_chunk(struct svc_rdma_recv_ctxt *rctxt, |
|
struct svc_rdma_send_ctxt *sctxt, |
|
unsigned int length) |
|
{ |
|
struct svc_rdma_chunk *chunk; |
|
|
|
if (pcl_is_empty(&rctxt->rc_reply_pcl)) |
|
return xdr_stream_encode_item_absent(&sctxt->sc_stream); |
|
|
|
chunk = pcl_first_chunk(&rctxt->rc_reply_pcl); |
|
if (length > chunk->ch_length) |
|
return -E2BIG; |
|
|
|
chunk->ch_payload_length = length; |
|
return svc_rdma_encode_write_chunk(sctxt, chunk); |
|
} |
|
|
|
struct svc_rdma_map_data { |
|
struct svcxprt_rdma *md_rdma; |
|
struct svc_rdma_send_ctxt *md_ctxt; |
|
}; |
|
|
|
/** |
|
* svc_rdma_page_dma_map - DMA map one page |
|
* @data: pointer to arguments |
|
* @page: struct page to DMA map |
|
* @offset: offset into the page |
|
* @len: number of bytes to map |
|
* |
|
* Returns: |
|
* %0 if DMA mapping was successful |
|
* %-EIO if the page cannot be DMA mapped |
|
*/ |
|
static int svc_rdma_page_dma_map(void *data, struct page *page, |
|
unsigned long offset, unsigned int len) |
|
{ |
|
struct svc_rdma_map_data *args = data; |
|
struct svcxprt_rdma *rdma = args->md_rdma; |
|
struct svc_rdma_send_ctxt *ctxt = args->md_ctxt; |
|
struct ib_device *dev = rdma->sc_cm_id->device; |
|
dma_addr_t dma_addr; |
|
|
|
++ctxt->sc_cur_sge_no; |
|
|
|
dma_addr = ib_dma_map_page(dev, page, offset, len, DMA_TO_DEVICE); |
|
if (ib_dma_mapping_error(dev, dma_addr)) |
|
goto out_maperr; |
|
|
|
trace_svcrdma_dma_map_page(rdma, dma_addr, len); |
|
ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr; |
|
ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len; |
|
ctxt->sc_send_wr.num_sge++; |
|
return 0; |
|
|
|
out_maperr: |
|
trace_svcrdma_dma_map_err(rdma, dma_addr, len); |
|
return -EIO; |
|
} |
|
|
|
/** |
|
* svc_rdma_iov_dma_map - DMA map an iovec |
|
* @data: pointer to arguments |
|
* @iov: kvec to DMA map |
|
* |
|
* ib_dma_map_page() is used here because svc_rdma_dma_unmap() |
|
* handles DMA-unmap and it uses ib_dma_unmap_page() exclusively. |
|
* |
|
* Returns: |
|
* %0 if DMA mapping was successful |
|
* %-EIO if the iovec cannot be DMA mapped |
|
*/ |
|
static int svc_rdma_iov_dma_map(void *data, const struct kvec *iov) |
|
{ |
|
if (!iov->iov_len) |
|
return 0; |
|
return svc_rdma_page_dma_map(data, virt_to_page(iov->iov_base), |
|
offset_in_page(iov->iov_base), |
|
iov->iov_len); |
|
} |
|
|
|
/** |
|
* svc_rdma_xb_dma_map - DMA map all segments of an xdr_buf |
|
* @xdr: xdr_buf containing portion of an RPC message to transmit |
|
* @data: pointer to arguments |
|
* |
|
* Returns: |
|
* %0 if DMA mapping was successful |
|
* %-EIO if DMA mapping failed |
|
* |
|
* On failure, any DMA mappings that have been already done must be |
|
* unmapped by the caller. |
|
*/ |
|
static int svc_rdma_xb_dma_map(const struct xdr_buf *xdr, void *data) |
|
{ |
|
unsigned int len, remaining; |
|
unsigned long pageoff; |
|
struct page **ppages; |
|
int ret; |
|
|
|
ret = svc_rdma_iov_dma_map(data, &xdr->head[0]); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); |
|
pageoff = offset_in_page(xdr->page_base); |
|
remaining = xdr->page_len; |
|
while (remaining) { |
|
len = min_t(u32, PAGE_SIZE - pageoff, remaining); |
|
|
|
ret = svc_rdma_page_dma_map(data, *ppages++, pageoff, len); |
|
if (ret < 0) |
|
return ret; |
|
|
|
remaining -= len; |
|
pageoff = 0; |
|
} |
|
|
|
ret = svc_rdma_iov_dma_map(data, &xdr->tail[0]); |
|
if (ret < 0) |
|
return ret; |
|
|
|
return xdr->len; |
|
} |
|
|
|
struct svc_rdma_pullup_data { |
|
u8 *pd_dest; |
|
unsigned int pd_length; |
|
unsigned int pd_num_sges; |
|
}; |
|
|
|
/** |
|
* svc_rdma_xb_count_sges - Count how many SGEs will be needed |
|
* @xdr: xdr_buf containing portion of an RPC message to transmit |
|
* @data: pointer to arguments |
|
* |
|
* Returns: |
|
* Number of SGEs needed to Send the contents of @xdr inline |
|
*/ |
|
static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, |
|
void *data) |
|
{ |
|
struct svc_rdma_pullup_data *args = data; |
|
unsigned int remaining; |
|
unsigned long offset; |
|
|
|
if (xdr->head[0].iov_len) |
|
++args->pd_num_sges; |
|
|
|
offset = offset_in_page(xdr->page_base); |
|
remaining = xdr->page_len; |
|
while (remaining) { |
|
++args->pd_num_sges; |
|
remaining -= min_t(u32, PAGE_SIZE - offset, remaining); |
|
offset = 0; |
|
} |
|
|
|
if (xdr->tail[0].iov_len) |
|
++args->pd_num_sges; |
|
|
|
args->pd_length += xdr->len; |
|
return 0; |
|
} |
|
|
|
/** |
|
* svc_rdma_pull_up_needed - Determine whether to use pull-up |
|
* @rdma: controlling transport |
|
* @sctxt: send_ctxt for the Send WR |
|
* @rctxt: Write and Reply chunks provided by client |
|
* @xdr: xdr_buf containing RPC message to transmit |
|
* |
|
* Returns: |
|
* %true if pull-up must be used |
|
* %false otherwise |
|
*/ |
|
static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, |
|
const struct svc_rdma_send_ctxt *sctxt, |
|
const struct svc_rdma_recv_ctxt *rctxt, |
|
const struct xdr_buf *xdr) |
|
{ |
|
/* Resources needed for the transport header */ |
|
struct svc_rdma_pullup_data args = { |
|
.pd_length = sctxt->sc_hdrbuf.len, |
|
.pd_num_sges = 1, |
|
}; |
|
int ret; |
|
|
|
ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, |
|
svc_rdma_xb_count_sges, &args); |
|
if (ret < 0) |
|
return false; |
|
|
|
if (args.pd_length < RPCRDMA_PULLUP_THRESH) |
|
return true; |
|
return args.pd_num_sges >= rdma->sc_max_send_sges; |
|
} |
|
|
|
/** |
|
* svc_rdma_xb_linearize - Copy region of xdr_buf to flat buffer |
|
* @xdr: xdr_buf containing portion of an RPC message to copy |
|
* @data: pointer to arguments |
|
* |
|
* Returns: |
|
* Always zero. |
|
*/ |
|
static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, |
|
void *data) |
|
{ |
|
struct svc_rdma_pullup_data *args = data; |
|
unsigned int len, remaining; |
|
unsigned long pageoff; |
|
struct page **ppages; |
|
|
|
if (xdr->head[0].iov_len) { |
|
memcpy(args->pd_dest, xdr->head[0].iov_base, xdr->head[0].iov_len); |
|
args->pd_dest += xdr->head[0].iov_len; |
|
} |
|
|
|
ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); |
|
pageoff = offset_in_page(xdr->page_base); |
|
remaining = xdr->page_len; |
|
while (remaining) { |
|
len = min_t(u32, PAGE_SIZE - pageoff, remaining); |
|
memcpy(args->pd_dest, page_address(*ppages) + pageoff, len); |
|
remaining -= len; |
|
args->pd_dest += len; |
|
pageoff = 0; |
|
ppages++; |
|
} |
|
|
|
if (xdr->tail[0].iov_len) { |
|
memcpy(args->pd_dest, xdr->tail[0].iov_base, xdr->tail[0].iov_len); |
|
args->pd_dest += xdr->tail[0].iov_len; |
|
} |
|
|
|
args->pd_length += xdr->len; |
|
return 0; |
|
} |
|
|
|
/** |
|
* svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer |
|
* @rdma: controlling transport |
|
* @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared |
|
* @rctxt: Write and Reply chunks provided by client |
|
* @xdr: prepared xdr_buf containing RPC message |
|
* |
|
* The device is not capable of sending the reply directly. |
|
* Assemble the elements of @xdr into the transport header buffer. |
|
* |
|
* Assumptions: |
|
* pull_up_needed has determined that @xdr will fit in the buffer. |
|
* |
|
* Returns: |
|
* %0 if pull-up was successful |
|
* %-EMSGSIZE if a buffer manipulation problem occurred |
|
*/ |
|
static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, |
|
struct svc_rdma_send_ctxt *sctxt, |
|
const struct svc_rdma_recv_ctxt *rctxt, |
|
const struct xdr_buf *xdr) |
|
{ |
|
struct svc_rdma_pullup_data args = { |
|
.pd_dest = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len, |
|
}; |
|
int ret; |
|
|
|
ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, |
|
svc_rdma_xb_linearize, &args); |
|
if (ret < 0) |
|
return ret; |
|
|
|
sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len + args.pd_length; |
|
trace_svcrdma_send_pullup(sctxt, args.pd_length); |
|
return 0; |
|
} |
|
|
|
/* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message |
|
* @rdma: controlling transport |
|
* @sctxt: send_ctxt for the Send WR |
|
* @rctxt: Write and Reply chunks provided by client |
|
* @xdr: prepared xdr_buf containing RPC message |
|
* |
|
* Returns: |
|
* %0 if DMA mapping was successful. |
|
* %-EMSGSIZE if a buffer manipulation problem occurred |
|
* %-EIO if DMA mapping failed |
|
* |
|
* The Send WR's num_sge field is set in all cases. |
|
*/ |
|
int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, |
|
struct svc_rdma_send_ctxt *sctxt, |
|
const struct svc_rdma_recv_ctxt *rctxt, |
|
const struct xdr_buf *xdr) |
|
{ |
|
struct svc_rdma_map_data args = { |
|
.md_rdma = rdma, |
|
.md_ctxt = sctxt, |
|
}; |
|
|
|
/* Set up the (persistently-mapped) transport header SGE. */ |
|
sctxt->sc_send_wr.num_sge = 1; |
|
sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; |
|
|
|
/* If there is a Reply chunk, nothing follows the transport |
|
* header, and we're done here. |
|
*/ |
|
if (!pcl_is_empty(&rctxt->rc_reply_pcl)) |
|
return 0; |
|
|
|
/* For pull-up, svc_rdma_send() will sync the transport header. |
|
* No additional DMA mapping is necessary. |
|
*/ |
|
if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) |
|
return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); |
|
|
|
return pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, |
|
svc_rdma_xb_dma_map, &args); |
|
} |
|
|
|
/* The svc_rqst and all resources it owns are released as soon as |
|
* svc_rdma_sendto returns. Transfer pages under I/O to the ctxt |
|
* so they are released by the Send completion handler. |
|
*/ |
|
static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, |
|
struct svc_rdma_send_ctxt *ctxt) |
|
{ |
|
int i, pages = rqstp->rq_next_page - rqstp->rq_respages; |
|
|
|
ctxt->sc_page_count += pages; |
|
for (i = 0; i < pages; i++) { |
|
ctxt->sc_pages[i] = rqstp->rq_respages[i]; |
|
rqstp->rq_respages[i] = NULL; |
|
} |
|
|
|
/* Prevent svc_xprt_release from releasing pages in rq_pages */ |
|
rqstp->rq_next_page = rqstp->rq_respages; |
|
} |
|
|
|
/* Prepare the portion of the RPC Reply that will be transmitted |
|
* via RDMA Send. The RPC-over-RDMA transport header is prepared |
|
* in sc_sges[0], and the RPC xdr_buf is prepared in following sges. |
|
* |
|
* Depending on whether a Write list or Reply chunk is present, |
|
* the server may send all, a portion of, or none of the xdr_buf. |
|
* In the latter case, only the transport header (sc_sges[0]) is |
|
* transmitted. |
|
* |
|
* RDMA Send is the last step of transmitting an RPC reply. Pages |
|
* involved in the earlier RDMA Writes are here transferred out |
|
* of the rqstp and into the sctxt's page array. These pages are |
|
* DMA unmapped by each Write completion, but the subsequent Send |
|
* completion finally releases these pages. |
|
* |
|
* Assumptions: |
|
* - The Reply's transport header will never be larger than a page. |
|
*/ |
|
static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, |
|
struct svc_rdma_send_ctxt *sctxt, |
|
const struct svc_rdma_recv_ctxt *rctxt, |
|
struct svc_rqst *rqstp) |
|
{ |
|
int ret; |
|
|
|
ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqstp->rq_res); |
|
if (ret < 0) |
|
return ret; |
|
|
|
svc_rdma_save_io_pages(rqstp, sctxt); |
|
|
|
if (rctxt->rc_inv_rkey) { |
|
sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; |
|
sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; |
|
} else { |
|
sctxt->sc_send_wr.opcode = IB_WR_SEND; |
|
} |
|
return svc_rdma_send(rdma, sctxt); |
|
} |
|
|
|
/** |
|
* svc_rdma_send_error_msg - Send an RPC/RDMA v1 error response |
|
* @rdma: controlling transport context |
|
* @sctxt: Send context for the response |
|
* @rctxt: Receive context for incoming bad message |
|
* @status: negative errno indicating error that occurred |
|
* |
|
* Given the client-provided Read, Write, and Reply chunks, the |
|
* server was not able to parse the Call or form a complete Reply. |
|
* Return an RDMA_ERROR message so the client can retire the RPC |
|
* transaction. |
|
* |
|
* The caller does not have to release @sctxt. It is released by |
|
* Send completion, or by this function on error. |
|
*/ |
|
void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, |
|
struct svc_rdma_send_ctxt *sctxt, |
|
struct svc_rdma_recv_ctxt *rctxt, |
|
int status) |
|
{ |
|
__be32 *rdma_argp = rctxt->rc_recv_buf; |
|
__be32 *p; |
|
|
|
rpcrdma_set_xdrlen(&sctxt->sc_hdrbuf, 0); |
|
xdr_init_encode(&sctxt->sc_stream, &sctxt->sc_hdrbuf, |
|
sctxt->sc_xprt_buf, NULL); |
|
|
|
p = xdr_reserve_space(&sctxt->sc_stream, |
|
rpcrdma_fixed_maxsz * sizeof(*p)); |
|
if (!p) |
|
goto put_ctxt; |
|
|
|
*p++ = *rdma_argp; |
|
*p++ = *(rdma_argp + 1); |
|
*p++ = rdma->sc_fc_credits; |
|
*p = rdma_error; |
|
|
|
switch (status) { |
|
case -EPROTONOSUPPORT: |
|
p = xdr_reserve_space(&sctxt->sc_stream, 3 * sizeof(*p)); |
|
if (!p) |
|
goto put_ctxt; |
|
|
|
*p++ = err_vers; |
|
*p++ = rpcrdma_version; |
|
*p = rpcrdma_version; |
|
trace_svcrdma_err_vers(*rdma_argp); |
|
break; |
|
default: |
|
p = xdr_reserve_space(&sctxt->sc_stream, sizeof(*p)); |
|
if (!p) |
|
goto put_ctxt; |
|
|
|
*p = err_chunk; |
|
trace_svcrdma_err_chunk(*rdma_argp); |
|
} |
|
|
|
/* Remote Invalidation is skipped for simplicity. */ |
|
sctxt->sc_send_wr.num_sge = 1; |
|
sctxt->sc_send_wr.opcode = IB_WR_SEND; |
|
sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; |
|
if (svc_rdma_send(rdma, sctxt)) |
|
goto put_ctxt; |
|
return; |
|
|
|
put_ctxt: |
|
svc_rdma_send_ctxt_put(rdma, sctxt); |
|
} |
|
|
|
/** |
|
* svc_rdma_sendto - Transmit an RPC reply |
|
* @rqstp: processed RPC request, reply XDR already in ::rq_res |
|
* |
|
* Any resources still associated with @rqstp are released upon return. |
|
* If no reply message was possible, the connection is closed. |
|
* |
|
* Returns: |
|
* %0 if an RPC reply has been successfully posted, |
|
* %-ENOMEM if a resource shortage occurred (connection is lost), |
|
* %-ENOTCONN if posting failed (connection is lost). |
|
*/ |
|
int svc_rdma_sendto(struct svc_rqst *rqstp) |
|
{ |
|
struct svc_xprt *xprt = rqstp->rq_xprt; |
|
struct svcxprt_rdma *rdma = |
|
container_of(xprt, struct svcxprt_rdma, sc_xprt); |
|
struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; |
|
__be32 *rdma_argp = rctxt->rc_recv_buf; |
|
struct svc_rdma_send_ctxt *sctxt; |
|
__be32 *p; |
|
int ret; |
|
|
|
ret = -ENOTCONN; |
|
if (svc_xprt_is_dead(xprt)) |
|
goto err0; |
|
|
|
ret = -ENOMEM; |
|
sctxt = svc_rdma_send_ctxt_get(rdma); |
|
if (!sctxt) |
|
goto err0; |
|
|
|
p = xdr_reserve_space(&sctxt->sc_stream, |
|
rpcrdma_fixed_maxsz * sizeof(*p)); |
|
if (!p) |
|
goto err1; |
|
|
|
ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); |
|
if (ret < 0) |
|
goto err2; |
|
|
|
*p++ = *rdma_argp; |
|
*p++ = *(rdma_argp + 1); |
|
*p++ = rdma->sc_fc_credits; |
|
*p = pcl_is_empty(&rctxt->rc_reply_pcl) ? rdma_msg : rdma_nomsg; |
|
|
|
if (svc_rdma_encode_read_list(sctxt) < 0) |
|
goto err1; |
|
if (svc_rdma_encode_write_list(rctxt, sctxt) < 0) |
|
goto err1; |
|
if (svc_rdma_encode_reply_chunk(rctxt, sctxt, ret) < 0) |
|
goto err1; |
|
|
|
ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp); |
|
if (ret < 0) |
|
goto err1; |
|
return 0; |
|
|
|
err2: |
|
if (ret != -E2BIG && ret != -EINVAL) |
|
goto err1; |
|
|
|
/* Send completion releases payload pages that were part |
|
* of previously posted RDMA Writes. |
|
*/ |
|
svc_rdma_save_io_pages(rqstp, sctxt); |
|
svc_rdma_send_error_msg(rdma, sctxt, rctxt, ret); |
|
return 0; |
|
|
|
err1: |
|
svc_rdma_send_ctxt_put(rdma, sctxt); |
|
err0: |
|
trace_svcrdma_send_err(rqstp, ret); |
|
set_bit(XPT_CLOSE, &xprt->xpt_flags); |
|
return -ENOTCONN; |
|
} |
|
|
|
/** |
|
* svc_rdma_result_payload - special processing for a result payload |
|
* @rqstp: svc_rqst to operate on |
|
* @offset: payload's byte offset in @xdr |
|
* @length: size of payload, in bytes |
|
* |
|
* Return values: |
|
* %0 if successful or nothing needed to be done |
|
* %-EMSGSIZE on XDR buffer overflow |
|
* %-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) |
|
*/ |
|
int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; |
|
struct svc_rdma_chunk *chunk; |
|
struct svcxprt_rdma *rdma; |
|
struct xdr_buf subbuf; |
|
int ret; |
|
|
|
chunk = rctxt->rc_cur_result_payload; |
|
if (!length || !chunk) |
|
return 0; |
|
rctxt->rc_cur_result_payload = |
|
pcl_next_chunk(&rctxt->rc_write_pcl, chunk); |
|
if (length > chunk->ch_length) |
|
return -E2BIG; |
|
|
|
chunk->ch_position = offset; |
|
chunk->ch_payload_length = length; |
|
|
|
if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) |
|
return -EMSGSIZE; |
|
|
|
rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); |
|
ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); |
|
if (ret < 0) |
|
return ret; |
|
return 0; |
|
}
|
|
|