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902 lines
25 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_recvfrom. This is called from |
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* svc_recv when the transport indicates there is incoming data to |
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* be read. "Data Ready" is signaled when an RDMA Receive completes, |
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* or when a set of RDMA Reads complete. |
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* |
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* An svc_rqst is passed in. This structure contains an array of |
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* free pages (rq_pages) that will contain the incoming RPC message. |
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* |
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* Short messages are moved directly into svc_rqst::rq_arg, and |
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* the RPC Call is ready to be processed by the Upper Layer. |
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* svc_rdma_recvfrom returns the length of the RPC Call message, |
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* completing the reception of the RPC Call. |
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* |
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* However, when an incoming message has Read chunks, |
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* svc_rdma_recvfrom must post RDMA Reads to pull the RPC Call's |
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* data payload from the client. svc_rdma_recvfrom sets up the |
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* RDMA Reads using pages in svc_rqst::rq_pages, which are |
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* transferred to an svc_rdma_recv_ctxt for the duration of the |
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* I/O. svc_rdma_recvfrom then returns zero, since the RPC message |
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* is still not yet ready. |
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* |
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* When the Read chunk payloads have become available on the |
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* server, "Data Ready" is raised again, and svc_recv calls |
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* svc_rdma_recvfrom again. This second call may use a different |
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* svc_rqst than the first one, thus any information that needs |
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* to be preserved across these two calls is kept in an |
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* svc_rdma_recv_ctxt. |
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* |
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* The second call to svc_rdma_recvfrom performs final assembly |
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* of the RPC Call message, using the RDMA Read sink pages kept in |
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* the svc_rdma_recv_ctxt. The xdr_buf is copied from the |
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* svc_rdma_recv_ctxt to the second svc_rqst. The second call returns |
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* the length of the completed RPC Call message. |
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* |
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* Page Management |
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* |
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* Pages under I/O must be transferred from the first svc_rqst to an |
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* svc_rdma_recv_ctxt before the first svc_rdma_recvfrom call returns. |
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* |
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* The first svc_rqst supplies pages for RDMA Reads. These are moved |
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* from rqstp::rq_pages into ctxt::pages. The consumed elements of |
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* the rq_pages array are set to NULL and refilled with the first |
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* svc_rdma_recvfrom call returns. |
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* |
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* During the second svc_rdma_recvfrom call, RDMA Read sink pages |
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* are transferred from the svc_rdma_recv_ctxt to the second svc_rqst |
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* (see rdma_read_complete() below). |
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*/ |
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|
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <asm/unaligned.h> |
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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/xdr.h> |
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#include <linux/sunrpc/debug.h> |
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#include <linux/sunrpc/rpc_rdma.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_receive(struct ib_cq *cq, struct ib_wc *wc); |
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|
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static inline struct svc_rdma_recv_ctxt * |
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svc_rdma_next_recv_ctxt(struct list_head *list) |
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{ |
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return list_first_entry_or_null(list, struct svc_rdma_recv_ctxt, |
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rc_list); |
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} |
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|
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static void svc_rdma_recv_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_rq_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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static struct svc_rdma_recv_ctxt * |
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svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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dma_addr_t addr; |
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void *buffer; |
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ctxt = kmalloc(sizeof(*ctxt), 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_FROM_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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svc_rdma_recv_cid_init(rdma, &ctxt->rc_cid); |
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pcl_init(&ctxt->rc_call_pcl); |
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pcl_init(&ctxt->rc_read_pcl); |
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pcl_init(&ctxt->rc_write_pcl); |
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pcl_init(&ctxt->rc_reply_pcl); |
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ctxt->rc_recv_wr.next = NULL; |
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ctxt->rc_recv_wr.wr_cqe = &ctxt->rc_cqe; |
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ctxt->rc_recv_wr.sg_list = &ctxt->rc_recv_sge; |
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ctxt->rc_recv_wr.num_sge = 1; |
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ctxt->rc_cqe.done = svc_rdma_wc_receive; |
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ctxt->rc_recv_sge.addr = addr; |
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ctxt->rc_recv_sge.length = rdma->sc_max_req_size; |
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ctxt->rc_recv_sge.lkey = rdma->sc_pd->local_dma_lkey; |
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ctxt->rc_recv_buf = buffer; |
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ctxt->rc_temp = false; |
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return ctxt; |
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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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static void svc_rdma_recv_ctxt_destroy(struct svcxprt_rdma *rdma, |
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struct svc_rdma_recv_ctxt *ctxt) |
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{ |
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ib_dma_unmap_single(rdma->sc_pd->device, ctxt->rc_recv_sge.addr, |
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ctxt->rc_recv_sge.length, DMA_FROM_DEVICE); |
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kfree(ctxt->rc_recv_buf); |
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kfree(ctxt); |
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} |
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|
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/** |
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* svc_rdma_recv_ctxts_destroy - Release all recv_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_recv_ctxts_destroy(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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struct llist_node *node; |
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while ((node = llist_del_first(&rdma->sc_recv_ctxts))) { |
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ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node); |
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svc_rdma_recv_ctxt_destroy(rdma, ctxt); |
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} |
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} |
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/** |
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* svc_rdma_recv_ctxt_get - Allocate a recv_ctxt |
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* @rdma: controlling svcxprt_rdma |
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* |
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* Returns a recv_ctxt or (rarely) NULL if none are available. |
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*/ |
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struct svc_rdma_recv_ctxt *svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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struct llist_node *node; |
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node = llist_del_first(&rdma->sc_recv_ctxts); |
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if (!node) |
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goto out_empty; |
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ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node); |
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out: |
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ctxt->rc_page_count = 0; |
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return ctxt; |
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out_empty: |
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ctxt = svc_rdma_recv_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_recv_ctxt_put - Return recv_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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*/ |
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void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma, |
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struct svc_rdma_recv_ctxt *ctxt) |
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{ |
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unsigned int i; |
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for (i = 0; i < ctxt->rc_page_count; i++) |
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put_page(ctxt->rc_pages[i]); |
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pcl_free(&ctxt->rc_call_pcl); |
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pcl_free(&ctxt->rc_read_pcl); |
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pcl_free(&ctxt->rc_write_pcl); |
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pcl_free(&ctxt->rc_reply_pcl); |
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if (!ctxt->rc_temp) |
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llist_add(&ctxt->rc_node, &rdma->sc_recv_ctxts); |
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else |
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svc_rdma_recv_ctxt_destroy(rdma, ctxt); |
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} |
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/** |
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* svc_rdma_release_rqst - Release transport-specific per-rqst resources |
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* @rqstp: svc_rqst being released |
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* |
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* Ensure that the recv_ctxt is released whether or not a Reply |
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* was sent. For example, the client could close the connection, |
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* or svc_process could drop an RPC, before the Reply is sent. |
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*/ |
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void svc_rdma_release_rqst(struct svc_rqst *rqstp) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt = rqstp->rq_xprt_ctxt; |
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struct svc_xprt *xprt = rqstp->rq_xprt; |
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struct svcxprt_rdma *rdma = |
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container_of(xprt, struct svcxprt_rdma, sc_xprt); |
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rqstp->rq_xprt_ctxt = NULL; |
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if (ctxt) |
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svc_rdma_recv_ctxt_put(rdma, ctxt); |
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} |
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static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma, |
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struct svc_rdma_recv_ctxt *ctxt) |
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{ |
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int ret; |
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trace_svcrdma_post_recv(ctxt); |
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ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL); |
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if (ret) |
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goto err_post; |
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return 0; |
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err_post: |
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trace_svcrdma_rq_post_err(rdma, ret); |
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svc_rdma_recv_ctxt_put(rdma, ctxt); |
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return ret; |
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} |
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static int svc_rdma_post_recv(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) |
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return 0; |
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ctxt = svc_rdma_recv_ctxt_get(rdma); |
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if (!ctxt) |
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return -ENOMEM; |
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return __svc_rdma_post_recv(rdma, ctxt); |
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} |
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/** |
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* svc_rdma_post_recvs - Post initial set of Recv WRs |
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* @rdma: fresh svcxprt_rdma |
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* |
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* Returns true if successful, otherwise false. |
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*/ |
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bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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unsigned int i; |
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int ret; |
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for (i = 0; i < rdma->sc_max_requests; i++) { |
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ctxt = svc_rdma_recv_ctxt_get(rdma); |
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if (!ctxt) |
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return false; |
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ctxt->rc_temp = true; |
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ret = __svc_rdma_post_recv(rdma, ctxt); |
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if (ret) |
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return false; |
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} |
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return true; |
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} |
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/** |
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* svc_rdma_wc_receive - Invoked by RDMA provider for each polled Receive 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 Receive completion handler could be running. |
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*/ |
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static void svc_rdma_wc_receive(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_recv_ctxt *ctxt; |
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/* WARNING: Only wc->wr_cqe and wc->status are reliable */ |
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ctxt = container_of(cqe, struct svc_rdma_recv_ctxt, rc_cqe); |
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trace_svcrdma_wc_receive(wc, &ctxt->rc_cid); |
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if (wc->status != IB_WC_SUCCESS) |
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goto flushed; |
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if (svc_rdma_post_recv(rdma)) |
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goto post_err; |
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/* All wc fields are now known to be valid */ |
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ctxt->rc_byte_len = wc->byte_len; |
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spin_lock(&rdma->sc_rq_dto_lock); |
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list_add_tail(&ctxt->rc_list, &rdma->sc_rq_dto_q); |
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/* Note the unlock pairs with the smp_rmb in svc_xprt_ready: */ |
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set_bit(XPT_DATA, &rdma->sc_xprt.xpt_flags); |
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spin_unlock(&rdma->sc_rq_dto_lock); |
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if (!test_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags)) |
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svc_xprt_enqueue(&rdma->sc_xprt); |
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return; |
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flushed: |
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post_err: |
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svc_rdma_recv_ctxt_put(rdma, ctxt); |
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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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* svc_rdma_flush_recv_queues - Drain pending Receive work |
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* @rdma: svcxprt_rdma being shut down |
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* |
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*/ |
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void svc_rdma_flush_recv_queues(struct svcxprt_rdma *rdma) |
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{ |
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struct svc_rdma_recv_ctxt *ctxt; |
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while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_read_complete_q))) { |
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list_del(&ctxt->rc_list); |
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svc_rdma_recv_ctxt_put(rdma, ctxt); |
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} |
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while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_rq_dto_q))) { |
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list_del(&ctxt->rc_list); |
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svc_rdma_recv_ctxt_put(rdma, ctxt); |
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} |
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} |
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static void svc_rdma_build_arg_xdr(struct svc_rqst *rqstp, |
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struct svc_rdma_recv_ctxt *ctxt) |
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{ |
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struct xdr_buf *arg = &rqstp->rq_arg; |
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|
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arg->head[0].iov_base = ctxt->rc_recv_buf; |
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arg->head[0].iov_len = ctxt->rc_byte_len; |
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arg->tail[0].iov_base = NULL; |
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arg->tail[0].iov_len = 0; |
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arg->page_len = 0; |
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arg->page_base = 0; |
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arg->buflen = ctxt->rc_byte_len; |
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arg->len = ctxt->rc_byte_len; |
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} |
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|
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/** |
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* xdr_count_read_segments - Count number of Read segments in Read list |
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* @rctxt: Ingress receive context |
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* @p: Start of an un-decoded Read list |
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* |
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* Before allocating anything, ensure the ingress Read list is safe |
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* to use. |
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* |
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* The segment count is limited to how many segments can fit in the |
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* transport header without overflowing the buffer. That's about 40 |
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* Read segments for a 1KB inline threshold. |
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* |
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* Return values: |
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* %true: Read list is valid. @rctxt's xdr_stream is updated to point |
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* to the first byte past the Read list. rc_read_pcl and |
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* rc_call_pcl cl_count fields are set to the number of |
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* Read segments in the list. |
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* %false: Read list is corrupt. @rctxt's xdr_stream is left in an |
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* unknown state. |
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*/ |
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static bool xdr_count_read_segments(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) |
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{ |
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rctxt->rc_call_pcl.cl_count = 0; |
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rctxt->rc_read_pcl.cl_count = 0; |
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while (xdr_item_is_present(p)) { |
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u32 position, handle, length; |
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u64 offset; |
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|
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p = xdr_inline_decode(&rctxt->rc_stream, |
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rpcrdma_readseg_maxsz * sizeof(*p)); |
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if (!p) |
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return false; |
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|
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xdr_decode_read_segment(p, &position, &handle, |
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&length, &offset); |
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if (position) { |
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if (position & 3) |
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return false; |
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++rctxt->rc_read_pcl.cl_count; |
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} else { |
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++rctxt->rc_call_pcl.cl_count; |
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} |
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|
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p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
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if (!p) |
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return false; |
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} |
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return true; |
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} |
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|
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/* Sanity check the Read list. |
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* |
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* Sanity checks: |
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* - Read list does not overflow Receive buffer. |
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* - Chunk size limited by largest NFS data payload. |
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* |
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* Return values: |
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* %true: Read list is valid. @rctxt's xdr_stream is updated |
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* to point to the first byte past the Read list. |
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* %false: Read list is corrupt. @rctxt's xdr_stream is left |
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* in an unknown state. |
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*/ |
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static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt) |
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{ |
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__be32 *p; |
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|
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p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
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if (!p) |
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return false; |
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if (!xdr_count_read_segments(rctxt, p)) |
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return false; |
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if (!pcl_alloc_call(rctxt, p)) |
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return false; |
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return pcl_alloc_read(rctxt, p); |
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} |
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|
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static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt) |
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{ |
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u32 segcount; |
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__be32 *p; |
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|
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if (xdr_stream_decode_u32(&rctxt->rc_stream, &segcount)) |
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return false; |
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|
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/* A bogus segcount causes this buffer overflow check to fail. */ |
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p = xdr_inline_decode(&rctxt->rc_stream, |
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segcount * rpcrdma_segment_maxsz * sizeof(*p)); |
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return p != NULL; |
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} |
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|
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/** |
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* xdr_count_write_chunks - Count number of Write chunks in Write list |
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* @rctxt: Received header and decoding state |
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* @p: start of an un-decoded Write list |
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* |
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* Before allocating anything, ensure the ingress Write list is |
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* safe to use. |
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* |
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* Return values: |
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* %true: Write list is valid. @rctxt's xdr_stream is updated |
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* to point to the first byte past the Write list, and |
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* the number of Write chunks is in rc_write_pcl.cl_count. |
|
* %false: Write list is corrupt. @rctxt's xdr_stream is left |
|
* in an indeterminate state. |
|
*/ |
|
static bool xdr_count_write_chunks(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) |
|
{ |
|
rctxt->rc_write_pcl.cl_count = 0; |
|
while (xdr_item_is_present(p)) { |
|
if (!xdr_check_write_chunk(rctxt)) |
|
return false; |
|
++rctxt->rc_write_pcl.cl_count; |
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
|
if (!p) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
/* Sanity check the Write list. |
|
* |
|
* Implementation limits: |
|
* - This implementation currently supports only one Write chunk. |
|
* |
|
* Sanity checks: |
|
* - Write list does not overflow Receive buffer. |
|
* - Chunk size limited by largest NFS data payload. |
|
* |
|
* Return values: |
|
* %true: Write list is valid. @rctxt's xdr_stream is updated |
|
* to point to the first byte past the Write list. |
|
* %false: Write list is corrupt. @rctxt's xdr_stream is left |
|
* in an unknown state. |
|
*/ |
|
static bool xdr_check_write_list(struct svc_rdma_recv_ctxt *rctxt) |
|
{ |
|
__be32 *p; |
|
|
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
|
if (!p) |
|
return false; |
|
if (!xdr_count_write_chunks(rctxt, p)) |
|
return false; |
|
if (!pcl_alloc_write(rctxt, &rctxt->rc_write_pcl, p)) |
|
return false; |
|
|
|
rctxt->rc_cur_result_payload = pcl_first_chunk(&rctxt->rc_write_pcl); |
|
return true; |
|
} |
|
|
|
/* Sanity check the Reply chunk. |
|
* |
|
* Sanity checks: |
|
* - Reply chunk does not overflow Receive buffer. |
|
* - Chunk size limited by largest NFS data payload. |
|
* |
|
* Return values: |
|
* %true: Reply chunk is valid. @rctxt's xdr_stream is updated |
|
* to point to the first byte past the Reply chunk. |
|
* %false: Reply chunk is corrupt. @rctxt's xdr_stream is left |
|
* in an unknown state. |
|
*/ |
|
static bool xdr_check_reply_chunk(struct svc_rdma_recv_ctxt *rctxt) |
|
{ |
|
__be32 *p; |
|
|
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
|
if (!p) |
|
return false; |
|
|
|
if (!xdr_item_is_present(p)) |
|
return true; |
|
if (!xdr_check_write_chunk(rctxt)) |
|
return false; |
|
|
|
rctxt->rc_reply_pcl.cl_count = 1; |
|
return pcl_alloc_write(rctxt, &rctxt->rc_reply_pcl, p); |
|
} |
|
|
|
/* RPC-over-RDMA Version One private extension: Remote Invalidation. |
|
* Responder's choice: requester signals it can handle Send With |
|
* Invalidate, and responder chooses one R_key to invalidate. |
|
* |
|
* If there is exactly one distinct R_key in the received transport |
|
* header, set rc_inv_rkey to that R_key. Otherwise, set it to zero. |
|
*/ |
|
static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, |
|
struct svc_rdma_recv_ctxt *ctxt) |
|
{ |
|
struct svc_rdma_segment *segment; |
|
struct svc_rdma_chunk *chunk; |
|
u32 inv_rkey; |
|
|
|
ctxt->rc_inv_rkey = 0; |
|
|
|
if (!rdma->sc_snd_w_inv) |
|
return; |
|
|
|
inv_rkey = 0; |
|
pcl_for_each_chunk(chunk, &ctxt->rc_call_pcl) { |
|
pcl_for_each_segment(segment, chunk) { |
|
if (inv_rkey == 0) |
|
inv_rkey = segment->rs_handle; |
|
else if (inv_rkey != segment->rs_handle) |
|
return; |
|
} |
|
} |
|
pcl_for_each_chunk(chunk, &ctxt->rc_read_pcl) { |
|
pcl_for_each_segment(segment, chunk) { |
|
if (inv_rkey == 0) |
|
inv_rkey = segment->rs_handle; |
|
else if (inv_rkey != segment->rs_handle) |
|
return; |
|
} |
|
} |
|
pcl_for_each_chunk(chunk, &ctxt->rc_write_pcl) { |
|
pcl_for_each_segment(segment, chunk) { |
|
if (inv_rkey == 0) |
|
inv_rkey = segment->rs_handle; |
|
else if (inv_rkey != segment->rs_handle) |
|
return; |
|
} |
|
} |
|
pcl_for_each_chunk(chunk, &ctxt->rc_reply_pcl) { |
|
pcl_for_each_segment(segment, chunk) { |
|
if (inv_rkey == 0) |
|
inv_rkey = segment->rs_handle; |
|
else if (inv_rkey != segment->rs_handle) |
|
return; |
|
} |
|
} |
|
ctxt->rc_inv_rkey = inv_rkey; |
|
} |
|
|
|
/** |
|
* svc_rdma_xdr_decode_req - Decode the transport header |
|
* @rq_arg: xdr_buf containing ingress RPC/RDMA message |
|
* @rctxt: state of decoding |
|
* |
|
* On entry, xdr->head[0].iov_base points to first byte of the |
|
* RPC-over-RDMA transport header. |
|
* |
|
* On successful exit, head[0] points to first byte past the |
|
* RPC-over-RDMA header. For RDMA_MSG, this is the RPC message. |
|
* |
|
* The length of the RPC-over-RDMA header is returned. |
|
* |
|
* Assumptions: |
|
* - The transport header is entirely contained in the head iovec. |
|
*/ |
|
static int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg, |
|
struct svc_rdma_recv_ctxt *rctxt) |
|
{ |
|
__be32 *p, *rdma_argp; |
|
unsigned int hdr_len; |
|
|
|
rdma_argp = rq_arg->head[0].iov_base; |
|
xdr_init_decode(&rctxt->rc_stream, rq_arg, rdma_argp, NULL); |
|
|
|
p = xdr_inline_decode(&rctxt->rc_stream, |
|
rpcrdma_fixed_maxsz * sizeof(*p)); |
|
if (unlikely(!p)) |
|
goto out_short; |
|
p++; |
|
if (*p != rpcrdma_version) |
|
goto out_version; |
|
p += 2; |
|
rctxt->rc_msgtype = *p; |
|
switch (rctxt->rc_msgtype) { |
|
case rdma_msg: |
|
break; |
|
case rdma_nomsg: |
|
break; |
|
case rdma_done: |
|
goto out_drop; |
|
case rdma_error: |
|
goto out_drop; |
|
default: |
|
goto out_proc; |
|
} |
|
|
|
if (!xdr_check_read_list(rctxt)) |
|
goto out_inval; |
|
if (!xdr_check_write_list(rctxt)) |
|
goto out_inval; |
|
if (!xdr_check_reply_chunk(rctxt)) |
|
goto out_inval; |
|
|
|
rq_arg->head[0].iov_base = rctxt->rc_stream.p; |
|
hdr_len = xdr_stream_pos(&rctxt->rc_stream); |
|
rq_arg->head[0].iov_len -= hdr_len; |
|
rq_arg->len -= hdr_len; |
|
trace_svcrdma_decode_rqst(rctxt, rdma_argp, hdr_len); |
|
return hdr_len; |
|
|
|
out_short: |
|
trace_svcrdma_decode_short_err(rctxt, rq_arg->len); |
|
return -EINVAL; |
|
|
|
out_version: |
|
trace_svcrdma_decode_badvers_err(rctxt, rdma_argp); |
|
return -EPROTONOSUPPORT; |
|
|
|
out_drop: |
|
trace_svcrdma_decode_drop_err(rctxt, rdma_argp); |
|
return 0; |
|
|
|
out_proc: |
|
trace_svcrdma_decode_badproc_err(rctxt, rdma_argp); |
|
return -EINVAL; |
|
|
|
out_inval: |
|
trace_svcrdma_decode_parse_err(rctxt, rdma_argp); |
|
return -EINVAL; |
|
} |
|
|
|
static void rdma_read_complete(struct svc_rqst *rqstp, |
|
struct svc_rdma_recv_ctxt *head) |
|
{ |
|
int page_no; |
|
|
|
/* Move Read chunk pages to rqstp so that they will be released |
|
* when svc_process is done with them. |
|
*/ |
|
for (page_no = 0; page_no < head->rc_page_count; page_no++) { |
|
put_page(rqstp->rq_pages[page_no]); |
|
rqstp->rq_pages[page_no] = head->rc_pages[page_no]; |
|
} |
|
head->rc_page_count = 0; |
|
|
|
/* Point rq_arg.pages past header */ |
|
rqstp->rq_arg.pages = &rqstp->rq_pages[head->rc_hdr_count]; |
|
rqstp->rq_arg.page_len = head->rc_arg.page_len; |
|
|
|
/* rq_respages starts after the last arg page */ |
|
rqstp->rq_respages = &rqstp->rq_pages[page_no]; |
|
rqstp->rq_next_page = rqstp->rq_respages + 1; |
|
|
|
/* Rebuild rq_arg head and tail. */ |
|
rqstp->rq_arg.head[0] = head->rc_arg.head[0]; |
|
rqstp->rq_arg.tail[0] = head->rc_arg.tail[0]; |
|
rqstp->rq_arg.len = head->rc_arg.len; |
|
rqstp->rq_arg.buflen = head->rc_arg.buflen; |
|
} |
|
|
|
static void svc_rdma_send_error(struct svcxprt_rdma *rdma, |
|
struct svc_rdma_recv_ctxt *rctxt, |
|
int status) |
|
{ |
|
struct svc_rdma_send_ctxt *sctxt; |
|
|
|
sctxt = svc_rdma_send_ctxt_get(rdma); |
|
if (!sctxt) |
|
return; |
|
svc_rdma_send_error_msg(rdma, sctxt, rctxt, status); |
|
} |
|
|
|
/* By convention, backchannel calls arrive via rdma_msg type |
|
* messages, and never populate the chunk lists. This makes |
|
* the RPC/RDMA header small and fixed in size, so it is |
|
* straightforward to check the RPC header's direction field. |
|
*/ |
|
static bool svc_rdma_is_reverse_direction_reply(struct svc_xprt *xprt, |
|
struct svc_rdma_recv_ctxt *rctxt) |
|
{ |
|
__be32 *p = rctxt->rc_recv_buf; |
|
|
|
if (!xprt->xpt_bc_xprt) |
|
return false; |
|
|
|
if (rctxt->rc_msgtype != rdma_msg) |
|
return false; |
|
|
|
if (!pcl_is_empty(&rctxt->rc_call_pcl)) |
|
return false; |
|
if (!pcl_is_empty(&rctxt->rc_read_pcl)) |
|
return false; |
|
if (!pcl_is_empty(&rctxt->rc_write_pcl)) |
|
return false; |
|
if (!pcl_is_empty(&rctxt->rc_reply_pcl)) |
|
return false; |
|
|
|
/* RPC call direction */ |
|
if (*(p + 8) == cpu_to_be32(RPC_CALL)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
/** |
|
* svc_rdma_recvfrom - Receive an RPC call |
|
* @rqstp: request structure into which to receive an RPC Call |
|
* |
|
* Returns: |
|
* The positive number of bytes in the RPC Call message, |
|
* %0 if there were no Calls ready to return, |
|
* %-EINVAL if the Read chunk data is too large, |
|
* %-ENOMEM if rdma_rw context pool was exhausted, |
|
* %-ENOTCONN if posting failed (connection is lost), |
|
* %-EIO if rdma_rw initialization failed (DMA mapping, etc). |
|
* |
|
* Called in a loop when XPT_DATA is set. XPT_DATA is cleared only |
|
* when there are no remaining ctxt's to process. |
|
* |
|
* The next ctxt is removed from the "receive" lists. |
|
* |
|
* - If the ctxt completes a Read, then finish assembling the Call |
|
* message and return the number of bytes in the message. |
|
* |
|
* - If the ctxt completes a Receive, then construct the Call |
|
* message from the contents of the Receive buffer. |
|
* |
|
* - If there are no Read chunks in this message, then finish |
|
* assembling the Call message and return the number of bytes |
|
* in the message. |
|
* |
|
* - If there are Read chunks in this message, post Read WRs to |
|
* pull that payload and return 0. |
|
*/ |
|
int svc_rdma_recvfrom(struct svc_rqst *rqstp) |
|
{ |
|
struct svc_xprt *xprt = rqstp->rq_xprt; |
|
struct svcxprt_rdma *rdma_xprt = |
|
container_of(xprt, struct svcxprt_rdma, sc_xprt); |
|
struct svc_rdma_recv_ctxt *ctxt; |
|
int ret; |
|
|
|
rqstp->rq_xprt_ctxt = NULL; |
|
|
|
spin_lock(&rdma_xprt->sc_rq_dto_lock); |
|
ctxt = svc_rdma_next_recv_ctxt(&rdma_xprt->sc_read_complete_q); |
|
if (ctxt) { |
|
list_del(&ctxt->rc_list); |
|
spin_unlock(&rdma_xprt->sc_rq_dto_lock); |
|
rdma_read_complete(rqstp, ctxt); |
|
goto complete; |
|
} |
|
ctxt = svc_rdma_next_recv_ctxt(&rdma_xprt->sc_rq_dto_q); |
|
if (!ctxt) { |
|
/* No new incoming requests, terminate the loop */ |
|
clear_bit(XPT_DATA, &xprt->xpt_flags); |
|
spin_unlock(&rdma_xprt->sc_rq_dto_lock); |
|
return 0; |
|
} |
|
list_del(&ctxt->rc_list); |
|
spin_unlock(&rdma_xprt->sc_rq_dto_lock); |
|
percpu_counter_inc(&svcrdma_stat_recv); |
|
|
|
ib_dma_sync_single_for_cpu(rdma_xprt->sc_pd->device, |
|
ctxt->rc_recv_sge.addr, ctxt->rc_byte_len, |
|
DMA_FROM_DEVICE); |
|
svc_rdma_build_arg_xdr(rqstp, ctxt); |
|
|
|
/* Prevent svc_xprt_release from releasing pages in rq_pages |
|
* if we return 0 or an error. |
|
*/ |
|
rqstp->rq_respages = rqstp->rq_pages; |
|
rqstp->rq_next_page = rqstp->rq_respages; |
|
|
|
ret = svc_rdma_xdr_decode_req(&rqstp->rq_arg, ctxt); |
|
if (ret < 0) |
|
goto out_err; |
|
if (ret == 0) |
|
goto out_drop; |
|
rqstp->rq_xprt_hlen = ret; |
|
|
|
if (svc_rdma_is_reverse_direction_reply(xprt, ctxt)) |
|
goto out_backchannel; |
|
|
|
svc_rdma_get_inv_rkey(rdma_xprt, ctxt); |
|
|
|
if (!pcl_is_empty(&ctxt->rc_read_pcl) || |
|
!pcl_is_empty(&ctxt->rc_call_pcl)) |
|
goto out_readlist; |
|
|
|
complete: |
|
rqstp->rq_xprt_ctxt = ctxt; |
|
rqstp->rq_prot = IPPROTO_MAX; |
|
svc_xprt_copy_addrs(rqstp, xprt); |
|
return rqstp->rq_arg.len; |
|
|
|
out_readlist: |
|
ret = svc_rdma_process_read_list(rdma_xprt, rqstp, ctxt); |
|
if (ret < 0) |
|
goto out_readfail; |
|
return 0; |
|
|
|
out_err: |
|
svc_rdma_send_error(rdma_xprt, ctxt, ret); |
|
svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
|
return 0; |
|
|
|
out_readfail: |
|
if (ret == -EINVAL) |
|
svc_rdma_send_error(rdma_xprt, ctxt, ret); |
|
svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
|
return ret; |
|
|
|
out_backchannel: |
|
svc_rdma_handle_bc_reply(rqstp, ctxt); |
|
out_drop: |
|
svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
|
return 0; |
|
}
|
|
|