// 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 <tom@opengridcomputing.com>
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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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#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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#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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#include "xprt_rdma.h"
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#include <trace/events/rpcrdma.h>
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#define RPCDBG_FACILITY RPCDBG_SVCXPRT
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static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc);
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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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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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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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* 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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static struct svc_rdma_recv_ctxt *
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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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ctxt->rc_read_payload_length = 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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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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ib_dma_sync_single_for_cpu(rdma->sc_pd->device,
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ctxt->rc_recv_sge.addr,
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wc->byte_len, DMA_FROM_DEVICE);
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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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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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/* This accommodates the largest possible Write chunk.
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*/
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#define MAX_BYTES_WRITE_CHUNK ((u32)(RPCSVC_MAXPAGES << PAGE_SHIFT))
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/* This accommodates the largest possible Position-Zero
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* Read chunk or Reply chunk.
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*/
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#define MAX_BYTES_SPECIAL_CHUNK ((u32)((RPCSVC_MAXPAGES + 2) << PAGE_SHIFT))
|
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/* Sanity check the Read list.
|
*
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* Implementation limits:
|
* - This implementation supports only one Read chunk.
|
*
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* Sanity checks:
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* - Read list does not overflow Receive buffer.
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* - Segment size limited by largest NFS data payload.
|
*
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* The segment count is limited to how many segments can
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* fit in the transport header without overflowing the
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* buffer. That's about 40 Read segments for a 1KB inline
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* 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
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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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static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt)
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{
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u32 position, len;
|
bool first;
|
__be32 *p;
|
|
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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|
len = 0;
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first = true;
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while (xdr_item_is_present(p)) {
|
p = xdr_inline_decode(&rctxt->rc_stream,
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rpcrdma_readseg_maxsz * sizeof(*p));
|
if (!p)
|
return false;
|
|
if (first) {
|
position = be32_to_cpup(p);
|
first = false;
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} else if (be32_to_cpup(p) != position) {
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return false;
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}
|
p += 2;
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len += be32_to_cpup(p);
|
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
|
if (!p)
|
return false;
|
}
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return len <= MAX_BYTES_SPECIAL_CHUNK;
|
}
|
|
/* The segment count is limited to how many segments can
|
* fit in the transport header without overflowing the
|
* buffer. That's about 60 Write segments for a 1KB inline
|
* threshold.
|
*/
|
static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt, u32 maxlen)
|
{
|
u32 i, segcount, total;
|
__be32 *p;
|
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
|
if (!p)
|
return false;
|
segcount = be32_to_cpup(p);
|
|
total = 0;
|
for (i = 0; i < segcount; i++) {
|
u32 handle, length;
|
u64 offset;
|
|
p = xdr_inline_decode(&rctxt->rc_stream,
|
rpcrdma_segment_maxsz * sizeof(*p));
|
if (!p)
|
return false;
|
|
xdr_decode_rdma_segment(p, &handle, &length, &offset);
|
trace_svcrdma_decode_wseg(handle, length, offset);
|
|
total += length;
|
}
|
return total <= maxlen;
|
}
|
|
/* 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)
|
{
|
u32 chcount = 0;
|
__be32 *p;
|
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
|
if (!p)
|
return false;
|
rctxt->rc_write_list = p;
|
while (xdr_item_is_present(p)) {
|
if (!xdr_check_write_chunk(rctxt, MAX_BYTES_WRITE_CHUNK))
|
return false;
|
++chcount;
|
p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
|
if (!p)
|
return false;
|
}
|
if (!chcount)
|
rctxt->rc_write_list = NULL;
|
return chcount < 2;
|
}
|
|
/* 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;
|
rctxt->rc_reply_chunk = NULL;
|
if (xdr_item_is_present(p)) {
|
if (!xdr_check_write_chunk(rctxt, MAX_BYTES_SPECIAL_CHUNK))
|
return false;
|
rctxt->rc_reply_chunk = p;
|
}
|
return true;
|
}
|
|
/* 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.
|
*
|
* Perform this operation while the received transport header is
|
* still in the CPU cache.
|
*/
|
static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma,
|
struct svc_rdma_recv_ctxt *ctxt)
|
{
|
__be32 inv_rkey, *p;
|
u32 i, segcount;
|
|
ctxt->rc_inv_rkey = 0;
|
|
if (!rdma->sc_snd_w_inv)
|
return;
|
|
inv_rkey = xdr_zero;
|
p = ctxt->rc_recv_buf;
|
p += rpcrdma_fixed_maxsz;
|
|
/* Read list */
|
while (xdr_item_is_present(p++)) {
|
p++; /* position */
|
if (inv_rkey == xdr_zero)
|
inv_rkey = *p;
|
else if (inv_rkey != *p)
|
return;
|
p += 4;
|
}
|
|
/* Write list */
|
while (xdr_item_is_present(p++)) {
|
segcount = be32_to_cpup(p++);
|
for (i = 0; i < segcount; i++) {
|
if (inv_rkey == xdr_zero)
|
inv_rkey = *p;
|
else if (inv_rkey != *p)
|
return;
|
p += 4;
|
}
|
}
|
|
/* Reply chunk */
|
if (xdr_item_is_present(p++)) {
|
segcount = be32_to_cpup(p++);
|
for (i = 0; i < segcount; i++) {
|
if (inv_rkey == xdr_zero)
|
inv_rkey = *p;
|
else if (inv_rkey != *p)
|
return;
|
p += 4;
|
}
|
}
|
|
ctxt->rc_inv_rkey = be32_to_cpu(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;
|
switch (*p) {
|
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_backchannel_reply(struct svc_xprt *xprt,
|
__be32 *rdma_resp)
|
{
|
__be32 *p;
|
|
if (!xprt->xpt_bc_xprt)
|
return false;
|
|
p = rdma_resp + 3;
|
if (*p++ != rdma_msg)
|
return false;
|
|
if (*p++ != xdr_zero)
|
return false;
|
if (*p++ != xdr_zero)
|
return false;
|
if (*p++ != xdr_zero)
|
return false;
|
|
/* XID sanity */
|
if (*p++ != *rdma_resp)
|
return false;
|
/* call direction */
|
if (*p == 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;
|
__be32 *p;
|
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);
|
|
atomic_inc(&rdma_stat_recv);
|
|
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;
|
|
p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
|
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_backchannel_reply(xprt, p))
|
goto out_backchannel;
|
|
svc_rdma_get_inv_rkey(rdma_xprt, ctxt);
|
|
p += rpcrdma_fixed_maxsz;
|
if (*p != xdr_zero)
|
goto out_readchunk;
|
|
complete:
|
rqstp->rq_xprt_ctxt = ctxt;
|
rqstp->rq_prot = IPPROTO_MAX;
|
svc_xprt_copy_addrs(rqstp, xprt);
|
return rqstp->rq_arg.len;
|
|
out_readchunk:
|
ret = svc_rdma_recv_read_chunk(rdma_xprt, rqstp, ctxt, p);
|
if (ret < 0)
|
goto out_postfail;
|
return 0;
|
|
out_err:
|
svc_rdma_send_error(rdma_xprt, ctxt, ret);
|
svc_rdma_recv_ctxt_put(rdma_xprt, ctxt);
|
return 0;
|
|
out_postfail:
|
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;
|
}
|
