// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
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/*
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* Copyright (c) 2014-2017 Oracle. All rights reserved.
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* Copyright (c) 2003-2007 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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/*
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* rpc_rdma.c
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*
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* This file contains the guts of the RPC RDMA protocol, and
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* does marshaling/unmarshaling, etc. It is also where interfacing
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* to the Linux RPC framework lives.
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*/
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#include <linux/highmem.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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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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# define RPCDBG_FACILITY RPCDBG_TRANS
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#endif
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/* Returns size of largest RPC-over-RDMA header in a Call message
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*
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* The largest Call header contains a full-size Read list and a
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* minimal Reply chunk.
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*/
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static unsigned int rpcrdma_max_call_header_size(unsigned int maxsegs)
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{
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unsigned int size;
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/* Fixed header fields and list discriminators */
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size = RPCRDMA_HDRLEN_MIN;
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/* Maximum Read list size */
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size += maxsegs * rpcrdma_readchunk_maxsz * sizeof(__be32);
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/* Minimal Read chunk size */
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size += sizeof(__be32); /* segment count */
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size += rpcrdma_segment_maxsz * sizeof(__be32);
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size += sizeof(__be32); /* list discriminator */
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return size;
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}
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/* Returns size of largest RPC-over-RDMA header in a Reply message
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*
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* There is only one Write list or one Reply chunk per Reply
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* message. The larger list is the Write list.
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*/
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static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs)
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{
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unsigned int size;
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/* Fixed header fields and list discriminators */
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size = RPCRDMA_HDRLEN_MIN;
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/* Maximum Write list size */
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size += sizeof(__be32); /* segment count */
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size += maxsegs * rpcrdma_segment_maxsz * sizeof(__be32);
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size += sizeof(__be32); /* list discriminator */
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return size;
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}
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/**
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* rpcrdma_set_max_header_sizes - Initialize inline payload sizes
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* @ep: endpoint to initialize
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*
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* The max_inline fields contain the maximum size of an RPC message
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* so the marshaling code doesn't have to repeat this calculation
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* for every RPC.
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*/
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void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep)
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{
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unsigned int maxsegs = ep->re_max_rdma_segs;
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ep->re_max_inline_send =
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ep->re_inline_send - rpcrdma_max_call_header_size(maxsegs);
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ep->re_max_inline_recv =
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ep->re_inline_recv - rpcrdma_max_reply_header_size(maxsegs);
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}
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/* The client can send a request inline as long as the RPCRDMA header
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* plus the RPC call fit under the transport's inline limit. If the
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* combined call message size exceeds that limit, the client must use
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* a Read chunk for this operation.
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*
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* A Read chunk is also required if sending the RPC call inline would
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* exceed this device's max_sge limit.
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*/
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static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt,
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struct rpc_rqst *rqst)
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{
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struct xdr_buf *xdr = &rqst->rq_snd_buf;
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struct rpcrdma_ep *ep = r_xprt->rx_ep;
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unsigned int count, remaining, offset;
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if (xdr->len > ep->re_max_inline_send)
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return false;
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if (xdr->page_len) {
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remaining = xdr->page_len;
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offset = offset_in_page(xdr->page_base);
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count = RPCRDMA_MIN_SEND_SGES;
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while (remaining) {
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remaining -= min_t(unsigned int,
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PAGE_SIZE - offset, remaining);
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offset = 0;
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if (++count > ep->re_attr.cap.max_send_sge)
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return false;
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}
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}
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return true;
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}
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/* The client can't know how large the actual reply will be. Thus it
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* plans for the largest possible reply for that particular ULP
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* operation. If the maximum combined reply message size exceeds that
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* limit, the client must provide a write list or a reply chunk for
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* this request.
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*/
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static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
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struct rpc_rqst *rqst)
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{
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return rqst->rq_rcv_buf.buflen <= r_xprt->rx_ep->re_max_inline_recv;
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}
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/* The client is required to provide a Reply chunk if the maximum
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* size of the non-payload part of the RPC Reply is larger than
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* the inline threshold.
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*/
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static bool
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rpcrdma_nonpayload_inline(const struct rpcrdma_xprt *r_xprt,
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const struct rpc_rqst *rqst)
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{
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const struct xdr_buf *buf = &rqst->rq_rcv_buf;
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return (buf->head[0].iov_len + buf->tail[0].iov_len) <
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r_xprt->rx_ep->re_max_inline_recv;
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}
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/* ACL likes to be lazy in allocating pages. For TCP, these
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* pages can be allocated during receive processing. Not true
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* for RDMA, which must always provision receive buffers
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* up front.
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*/
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static noinline int
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rpcrdma_alloc_sparse_pages(struct xdr_buf *buf)
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{
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struct page **ppages;
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int len;
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len = buf->page_len;
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ppages = buf->pages + (buf->page_base >> PAGE_SHIFT);
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while (len > 0) {
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if (!*ppages)
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*ppages = alloc_page(GFP_NOWAIT | __GFP_NOWARN);
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if (!*ppages)
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return -ENOBUFS;
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ppages++;
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len -= PAGE_SIZE;
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}
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return 0;
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}
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/* Split @vec on page boundaries into SGEs. FMR registers pages, not
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* a byte range. Other modes coalesce these SGEs into a single MR
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* when they can.
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*
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* Returns pointer to next available SGE, and bumps the total number
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* of SGEs consumed.
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*/
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static struct rpcrdma_mr_seg *
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rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
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unsigned int *n)
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{
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u32 remaining, page_offset;
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char *base;
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base = vec->iov_base;
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page_offset = offset_in_page(base);
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remaining = vec->iov_len;
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while (remaining) {
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seg->mr_page = NULL;
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seg->mr_offset = base;
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seg->mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining);
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remaining -= seg->mr_len;
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base += seg->mr_len;
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++seg;
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++(*n);
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page_offset = 0;
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}
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return seg;
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}
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/* Convert @xdrbuf into SGEs no larger than a page each. As they
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* are registered, these SGEs are then coalesced into RDMA segments
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* when the selected memreg mode supports it.
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*
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* Returns positive number of SGEs consumed, or a negative errno.
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*/
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static int
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rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf,
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unsigned int pos, enum rpcrdma_chunktype type,
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struct rpcrdma_mr_seg *seg)
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{
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unsigned long page_base;
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unsigned int len, n;
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struct page **ppages;
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n = 0;
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if (pos == 0)
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seg = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, &n);
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len = xdrbuf->page_len;
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ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
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page_base = offset_in_page(xdrbuf->page_base);
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while (len) {
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seg->mr_page = *ppages;
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seg->mr_offset = (char *)page_base;
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seg->mr_len = min_t(u32, PAGE_SIZE - page_base, len);
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len -= seg->mr_len;
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++ppages;
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++seg;
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++n;
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page_base = 0;
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}
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/* When encoding a Read chunk, the tail iovec contains an
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* XDR pad and may be omitted.
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*/
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if (type == rpcrdma_readch && r_xprt->rx_ep->re_implicit_roundup)
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goto out;
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/* When encoding a Write chunk, some servers need to see an
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* extra segment for non-XDR-aligned Write chunks. The upper
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* layer provides space in the tail iovec that may be used
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* for this purpose.
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*/
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if (type == rpcrdma_writech && r_xprt->rx_ep->re_implicit_roundup)
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goto out;
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if (xdrbuf->tail[0].iov_len)
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seg = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, &n);
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out:
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if (unlikely(n > RPCRDMA_MAX_SEGS))
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return -EIO;
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return n;
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}
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static int
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encode_rdma_segment(struct xdr_stream *xdr, struct rpcrdma_mr *mr)
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{
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__be32 *p;
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p = xdr_reserve_space(xdr, 4 * sizeof(*p));
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if (unlikely(!p))
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return -EMSGSIZE;
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xdr_encode_rdma_segment(p, mr->mr_handle, mr->mr_length, mr->mr_offset);
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return 0;
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}
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static int
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encode_read_segment(struct xdr_stream *xdr, struct rpcrdma_mr *mr,
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u32 position)
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{
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__be32 *p;
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p = xdr_reserve_space(xdr, 6 * sizeof(*p));
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if (unlikely(!p))
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return -EMSGSIZE;
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*p++ = xdr_one; /* Item present */
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xdr_encode_read_segment(p, position, mr->mr_handle, mr->mr_length,
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mr->mr_offset);
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return 0;
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}
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static struct rpcrdma_mr_seg *rpcrdma_mr_prepare(struct rpcrdma_xprt *r_xprt,
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struct rpcrdma_req *req,
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struct rpcrdma_mr_seg *seg,
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int nsegs, bool writing,
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struct rpcrdma_mr **mr)
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{
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*mr = rpcrdma_mr_pop(&req->rl_free_mrs);
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if (!*mr) {
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*mr = rpcrdma_mr_get(r_xprt);
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if (!*mr)
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goto out_getmr_err;
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trace_xprtrdma_mr_get(req);
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(*mr)->mr_req = req;
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}
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rpcrdma_mr_push(*mr, &req->rl_registered);
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return frwr_map(r_xprt, seg, nsegs, writing, req->rl_slot.rq_xid, *mr);
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out_getmr_err:
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trace_xprtrdma_nomrs(req);
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xprt_wait_for_buffer_space(&r_xprt->rx_xprt);
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rpcrdma_mrs_refresh(r_xprt);
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return ERR_PTR(-EAGAIN);
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}
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/* Register and XDR encode the Read list. Supports encoding a list of read
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* segments that belong to a single read chunk.
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*
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* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
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*
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* Read chunklist (a linked list):
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* N elements, position P (same P for all chunks of same arg!):
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* 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
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*
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* Returns zero on success, or a negative errno if a failure occurred.
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* @xdr is advanced to the next position in the stream.
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*
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* Only a single @pos value is currently supported.
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*/
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static int rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
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struct rpcrdma_req *req,
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struct rpc_rqst *rqst,
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enum rpcrdma_chunktype rtype)
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{
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struct xdr_stream *xdr = &req->rl_stream;
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struct rpcrdma_mr_seg *seg;
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struct rpcrdma_mr *mr;
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unsigned int pos;
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int nsegs;
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if (rtype == rpcrdma_noch_pullup || rtype == rpcrdma_noch_mapped)
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goto done;
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pos = rqst->rq_snd_buf.head[0].iov_len;
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if (rtype == rpcrdma_areadch)
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pos = 0;
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seg = req->rl_segments;
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nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_snd_buf, pos,
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rtype, seg);
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if (nsegs < 0)
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return nsegs;
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do {
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seg = rpcrdma_mr_prepare(r_xprt, req, seg, nsegs, false, &mr);
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if (IS_ERR(seg))
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return PTR_ERR(seg);
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if (encode_read_segment(xdr, mr, pos) < 0)
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return -EMSGSIZE;
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trace_xprtrdma_chunk_read(rqst->rq_task, pos, mr, nsegs);
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r_xprt->rx_stats.read_chunk_count++;
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nsegs -= mr->mr_nents;
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} while (nsegs);
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done:
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if (xdr_stream_encode_item_absent(xdr) < 0)
|
return -EMSGSIZE;
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return 0;
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}
|
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/* Register and XDR encode the Write list. Supports encoding a list
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* containing one array of plain segments that belong to a single
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* write chunk.
|
*
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* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
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*
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* Write chunklist (a list of (one) counted array):
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* N elements:
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* 1 - N - HLOO - HLOO - ... - HLOO - 0
|
*
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* Returns zero on success, or a negative errno if a failure occurred.
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* @xdr is advanced to the next position in the stream.
|
*
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* Only a single Write chunk is currently supported.
|
*/
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static int rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt,
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struct rpcrdma_req *req,
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struct rpc_rqst *rqst,
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enum rpcrdma_chunktype wtype)
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{
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struct xdr_stream *xdr = &req->rl_stream;
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struct rpcrdma_mr_seg *seg;
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struct rpcrdma_mr *mr;
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int nsegs, nchunks;
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__be32 *segcount;
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if (wtype != rpcrdma_writech)
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goto done;
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seg = req->rl_segments;
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nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_rcv_buf,
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rqst->rq_rcv_buf.head[0].iov_len,
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wtype, seg);
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if (nsegs < 0)
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return nsegs;
|
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if (xdr_stream_encode_item_present(xdr) < 0)
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return -EMSGSIZE;
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segcount = xdr_reserve_space(xdr, sizeof(*segcount));
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if (unlikely(!segcount))
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return -EMSGSIZE;
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/* Actual value encoded below */
|
|
nchunks = 0;
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do {
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seg = rpcrdma_mr_prepare(r_xprt, req, seg, nsegs, true, &mr);
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if (IS_ERR(seg))
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return PTR_ERR(seg);
|
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if (encode_rdma_segment(xdr, mr) < 0)
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return -EMSGSIZE;
|
|
trace_xprtrdma_chunk_write(rqst->rq_task, mr, nsegs);
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r_xprt->rx_stats.write_chunk_count++;
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r_xprt->rx_stats.total_rdma_request += mr->mr_length;
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nchunks++;
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nsegs -= mr->mr_nents;
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} while (nsegs);
|
|
/* Update count of segments in this Write chunk */
|
*segcount = cpu_to_be32(nchunks);
|
|
done:
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if (xdr_stream_encode_item_absent(xdr) < 0)
|
return -EMSGSIZE;
|
return 0;
|
}
|
|
/* Register and XDR encode the Reply chunk. Supports encoding an array
|
* of plain segments that belong to a single write (reply) chunk.
|
*
|
* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
|
*
|
* Reply chunk (a counted array):
|
* N elements:
|
* 1 - N - HLOO - HLOO - ... - HLOO
|
*
|
* Returns zero on success, or a negative errno if a failure occurred.
|
* @xdr is advanced to the next position in the stream.
|
*/
|
static int rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct rpc_rqst *rqst,
|
enum rpcrdma_chunktype wtype)
|
{
|
struct xdr_stream *xdr = &req->rl_stream;
|
struct rpcrdma_mr_seg *seg;
|
struct rpcrdma_mr *mr;
|
int nsegs, nchunks;
|
__be32 *segcount;
|
|
if (wtype != rpcrdma_replych) {
|
if (xdr_stream_encode_item_absent(xdr) < 0)
|
return -EMSGSIZE;
|
return 0;
|
}
|
|
seg = req->rl_segments;
|
nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_rcv_buf, 0, wtype, seg);
|
if (nsegs < 0)
|
return nsegs;
|
|
if (xdr_stream_encode_item_present(xdr) < 0)
|
return -EMSGSIZE;
|
segcount = xdr_reserve_space(xdr, sizeof(*segcount));
|
if (unlikely(!segcount))
|
return -EMSGSIZE;
|
/* Actual value encoded below */
|
|
nchunks = 0;
|
do {
|
seg = rpcrdma_mr_prepare(r_xprt, req, seg, nsegs, true, &mr);
|
if (IS_ERR(seg))
|
return PTR_ERR(seg);
|
|
if (encode_rdma_segment(xdr, mr) < 0)
|
return -EMSGSIZE;
|
|
trace_xprtrdma_chunk_reply(rqst->rq_task, mr, nsegs);
|
r_xprt->rx_stats.reply_chunk_count++;
|
r_xprt->rx_stats.total_rdma_request += mr->mr_length;
|
nchunks++;
|
nsegs -= mr->mr_nents;
|
} while (nsegs);
|
|
/* Update count of segments in the Reply chunk */
|
*segcount = cpu_to_be32(nchunks);
|
|
return 0;
|
}
|
|
static void rpcrdma_sendctx_done(struct kref *kref)
|
{
|
struct rpcrdma_req *req =
|
container_of(kref, struct rpcrdma_req, rl_kref);
|
struct rpcrdma_rep *rep = req->rl_reply;
|
|
rpcrdma_complete_rqst(rep);
|
rep->rr_rxprt->rx_stats.reply_waits_for_send++;
|
}
|
|
/**
|
* rpcrdma_sendctx_unmap - DMA-unmap Send buffer
|
* @sc: sendctx containing SGEs to unmap
|
*
|
*/
|
void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc)
|
{
|
struct rpcrdma_regbuf *rb = sc->sc_req->rl_sendbuf;
|
struct ib_sge *sge;
|
|
if (!sc->sc_unmap_count)
|
return;
|
|
/* The first two SGEs contain the transport header and
|
* the inline buffer. These are always left mapped so
|
* they can be cheaply re-used.
|
*/
|
for (sge = &sc->sc_sges[2]; sc->sc_unmap_count;
|
++sge, --sc->sc_unmap_count)
|
ib_dma_unmap_page(rdmab_device(rb), sge->addr, sge->length,
|
DMA_TO_DEVICE);
|
|
kref_put(&sc->sc_req->rl_kref, rpcrdma_sendctx_done);
|
}
|
|
/* Prepare an SGE for the RPC-over-RDMA transport header.
|
*/
|
static void rpcrdma_prepare_hdr_sge(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req, u32 len)
|
{
|
struct rpcrdma_sendctx *sc = req->rl_sendctx;
|
struct rpcrdma_regbuf *rb = req->rl_rdmabuf;
|
struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
|
|
sge->addr = rdmab_addr(rb);
|
sge->length = len;
|
sge->lkey = rdmab_lkey(rb);
|
|
ib_dma_sync_single_for_device(rdmab_device(rb), sge->addr, sge->length,
|
DMA_TO_DEVICE);
|
}
|
|
/* The head iovec is straightforward, as it is usually already
|
* DMA-mapped. Sync the content that has changed.
|
*/
|
static bool rpcrdma_prepare_head_iov(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req, unsigned int len)
|
{
|
struct rpcrdma_sendctx *sc = req->rl_sendctx;
|
struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
|
struct rpcrdma_regbuf *rb = req->rl_sendbuf;
|
|
if (!rpcrdma_regbuf_dma_map(r_xprt, rb))
|
return false;
|
|
sge->addr = rdmab_addr(rb);
|
sge->length = len;
|
sge->lkey = rdmab_lkey(rb);
|
|
ib_dma_sync_single_for_device(rdmab_device(rb), sge->addr, sge->length,
|
DMA_TO_DEVICE);
|
return true;
|
}
|
|
/* If there is a page list present, DMA map and prepare an
|
* SGE for each page to be sent.
|
*/
|
static bool rpcrdma_prepare_pagelist(struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
struct rpcrdma_sendctx *sc = req->rl_sendctx;
|
struct rpcrdma_regbuf *rb = req->rl_sendbuf;
|
unsigned int page_base, len, remaining;
|
struct page **ppages;
|
struct ib_sge *sge;
|
|
ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
|
page_base = offset_in_page(xdr->page_base);
|
remaining = xdr->page_len;
|
while (remaining) {
|
sge = &sc->sc_sges[req->rl_wr.num_sge++];
|
len = min_t(unsigned int, PAGE_SIZE - page_base, remaining);
|
sge->addr = ib_dma_map_page(rdmab_device(rb), *ppages,
|
page_base, len, DMA_TO_DEVICE);
|
if (ib_dma_mapping_error(rdmab_device(rb), sge->addr))
|
goto out_mapping_err;
|
|
sge->length = len;
|
sge->lkey = rdmab_lkey(rb);
|
|
sc->sc_unmap_count++;
|
ppages++;
|
remaining -= len;
|
page_base = 0;
|
}
|
|
return true;
|
|
out_mapping_err:
|
trace_xprtrdma_dma_maperr(sge->addr);
|
return false;
|
}
|
|
/* The tail iovec may include an XDR pad for the page list,
|
* as well as additional content, and may not reside in the
|
* same page as the head iovec.
|
*/
|
static bool rpcrdma_prepare_tail_iov(struct rpcrdma_req *req,
|
struct xdr_buf *xdr,
|
unsigned int page_base, unsigned int len)
|
{
|
struct rpcrdma_sendctx *sc = req->rl_sendctx;
|
struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
|
struct rpcrdma_regbuf *rb = req->rl_sendbuf;
|
struct page *page = virt_to_page(xdr->tail[0].iov_base);
|
|
sge->addr = ib_dma_map_page(rdmab_device(rb), page, page_base, len,
|
DMA_TO_DEVICE);
|
if (ib_dma_mapping_error(rdmab_device(rb), sge->addr))
|
goto out_mapping_err;
|
|
sge->length = len;
|
sge->lkey = rdmab_lkey(rb);
|
++sc->sc_unmap_count;
|
return true;
|
|
out_mapping_err:
|
trace_xprtrdma_dma_maperr(sge->addr);
|
return false;
|
}
|
|
/* Copy the tail to the end of the head buffer.
|
*/
|
static void rpcrdma_pullup_tail_iov(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
unsigned char *dst;
|
|
dst = (unsigned char *)xdr->head[0].iov_base;
|
dst += xdr->head[0].iov_len + xdr->page_len;
|
memmove(dst, xdr->tail[0].iov_base, xdr->tail[0].iov_len);
|
r_xprt->rx_stats.pullup_copy_count += xdr->tail[0].iov_len;
|
}
|
|
/* Copy pagelist content into the head buffer.
|
*/
|
static void rpcrdma_pullup_pagelist(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
unsigned int len, page_base, remaining;
|
struct page **ppages;
|
unsigned char *src, *dst;
|
|
dst = (unsigned char *)xdr->head[0].iov_base;
|
dst += xdr->head[0].iov_len;
|
ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
|
page_base = offset_in_page(xdr->page_base);
|
remaining = xdr->page_len;
|
while (remaining) {
|
src = page_address(*ppages);
|
src += page_base;
|
len = min_t(unsigned int, PAGE_SIZE - page_base, remaining);
|
memcpy(dst, src, len);
|
r_xprt->rx_stats.pullup_copy_count += len;
|
|
ppages++;
|
dst += len;
|
remaining -= len;
|
page_base = 0;
|
}
|
}
|
|
/* Copy the contents of @xdr into @rl_sendbuf and DMA sync it.
|
* When the head, pagelist, and tail are small, a pull-up copy
|
* is considerably less costly than DMA mapping the components
|
* of @xdr.
|
*
|
* Assumptions:
|
* - the caller has already verified that the total length
|
* of the RPC Call body will fit into @rl_sendbuf.
|
*/
|
static bool rpcrdma_prepare_noch_pullup(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
if (unlikely(xdr->tail[0].iov_len))
|
rpcrdma_pullup_tail_iov(r_xprt, req, xdr);
|
|
if (unlikely(xdr->page_len))
|
rpcrdma_pullup_pagelist(r_xprt, req, xdr);
|
|
/* The whole RPC message resides in the head iovec now */
|
return rpcrdma_prepare_head_iov(r_xprt, req, xdr->len);
|
}
|
|
static bool rpcrdma_prepare_noch_mapped(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
struct kvec *tail = &xdr->tail[0];
|
|
if (!rpcrdma_prepare_head_iov(r_xprt, req, xdr->head[0].iov_len))
|
return false;
|
if (xdr->page_len)
|
if (!rpcrdma_prepare_pagelist(req, xdr))
|
return false;
|
if (tail->iov_len)
|
if (!rpcrdma_prepare_tail_iov(req, xdr,
|
offset_in_page(tail->iov_base),
|
tail->iov_len))
|
return false;
|
|
if (req->rl_sendctx->sc_unmap_count)
|
kref_get(&req->rl_kref);
|
return true;
|
}
|
|
static bool rpcrdma_prepare_readch(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req,
|
struct xdr_buf *xdr)
|
{
|
if (!rpcrdma_prepare_head_iov(r_xprt, req, xdr->head[0].iov_len))
|
return false;
|
|
/* If there is a Read chunk, the page list is being handled
|
* via explicit RDMA, and thus is skipped here.
|
*/
|
|
/* Do not include the tail if it is only an XDR pad */
|
if (xdr->tail[0].iov_len > 3) {
|
unsigned int page_base, len;
|
|
/* If the content in the page list is an odd length,
|
* xdr_write_pages() adds a pad at the beginning of
|
* the tail iovec. Force the tail's non-pad content to
|
* land at the next XDR position in the Send message.
|
*/
|
page_base = offset_in_page(xdr->tail[0].iov_base);
|
len = xdr->tail[0].iov_len;
|
page_base += len & 3;
|
len -= len & 3;
|
if (!rpcrdma_prepare_tail_iov(req, xdr, page_base, len))
|
return false;
|
kref_get(&req->rl_kref);
|
}
|
|
return true;
|
}
|
|
/**
|
* rpcrdma_prepare_send_sges - Construct SGEs for a Send WR
|
* @r_xprt: controlling transport
|
* @req: context of RPC Call being marshalled
|
* @hdrlen: size of transport header, in bytes
|
* @xdr: xdr_buf containing RPC Call
|
* @rtype: chunk type being encoded
|
*
|
* Returns 0 on success; otherwise a negative errno is returned.
|
*/
|
inline int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
|
struct rpcrdma_req *req, u32 hdrlen,
|
struct xdr_buf *xdr,
|
enum rpcrdma_chunktype rtype)
|
{
|
int ret;
|
|
ret = -EAGAIN;
|
req->rl_sendctx = rpcrdma_sendctx_get_locked(r_xprt);
|
if (!req->rl_sendctx)
|
goto out_nosc;
|
req->rl_sendctx->sc_unmap_count = 0;
|
req->rl_sendctx->sc_req = req;
|
kref_init(&req->rl_kref);
|
req->rl_wr.wr_cqe = &req->rl_sendctx->sc_cqe;
|
req->rl_wr.sg_list = req->rl_sendctx->sc_sges;
|
req->rl_wr.num_sge = 0;
|
req->rl_wr.opcode = IB_WR_SEND;
|
|
rpcrdma_prepare_hdr_sge(r_xprt, req, hdrlen);
|
|
ret = -EIO;
|
switch (rtype) {
|
case rpcrdma_noch_pullup:
|
if (!rpcrdma_prepare_noch_pullup(r_xprt, req, xdr))
|
goto out_unmap;
|
break;
|
case rpcrdma_noch_mapped:
|
if (!rpcrdma_prepare_noch_mapped(r_xprt, req, xdr))
|
goto out_unmap;
|
break;
|
case rpcrdma_readch:
|
if (!rpcrdma_prepare_readch(r_xprt, req, xdr))
|
goto out_unmap;
|
break;
|
case rpcrdma_areadch:
|
break;
|
default:
|
goto out_unmap;
|
}
|
|
return 0;
|
|
out_unmap:
|
rpcrdma_sendctx_unmap(req->rl_sendctx);
|
out_nosc:
|
trace_xprtrdma_prepsend_failed(&req->rl_slot, ret);
|
return ret;
|
}
|
|
/**
|
* rpcrdma_marshal_req - Marshal and send one RPC request
|
* @r_xprt: controlling transport
|
* @rqst: RPC request to be marshaled
|
*
|
* For the RPC in "rqst", this function:
|
* - Chooses the transfer mode (eg., RDMA_MSG or RDMA_NOMSG)
|
* - Registers Read, Write, and Reply chunks
|
* - Constructs the transport header
|
* - Posts a Send WR to send the transport header and request
|
*
|
* Returns:
|
* %0 if the RPC was sent successfully,
|
* %-ENOTCONN if the connection was lost,
|
* %-EAGAIN if the caller should call again with the same arguments,
|
* %-ENOBUFS if the caller should call again after a delay,
|
* %-EMSGSIZE if the transport header is too small,
|
* %-EIO if a permanent problem occurred while marshaling.
|
*/
|
int
|
rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
|
{
|
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
|
struct xdr_stream *xdr = &req->rl_stream;
|
enum rpcrdma_chunktype rtype, wtype;
|
struct xdr_buf *buf = &rqst->rq_snd_buf;
|
bool ddp_allowed;
|
__be32 *p;
|
int ret;
|
|
if (unlikely(rqst->rq_rcv_buf.flags & XDRBUF_SPARSE_PAGES)) {
|
ret = rpcrdma_alloc_sparse_pages(&rqst->rq_rcv_buf);
|
if (ret)
|
return ret;
|
}
|
|
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
|
xdr_init_encode(xdr, &req->rl_hdrbuf, rdmab_data(req->rl_rdmabuf),
|
rqst);
|
|
/* Fixed header fields */
|
ret = -EMSGSIZE;
|
p = xdr_reserve_space(xdr, 4 * sizeof(*p));
|
if (!p)
|
goto out_err;
|
*p++ = rqst->rq_xid;
|
*p++ = rpcrdma_version;
|
*p++ = r_xprt->rx_buf.rb_max_requests;
|
|
/* When the ULP employs a GSS flavor that guarantees integrity
|
* or privacy, direct data placement of individual data items
|
* is not allowed.
|
*/
|
ddp_allowed = !test_bit(RPCAUTH_AUTH_DATATOUCH,
|
&rqst->rq_cred->cr_auth->au_flags);
|
|
/*
|
* Chunks needed for results?
|
*
|
* o If the expected result is under the inline threshold, all ops
|
* return as inline.
|
* o Large read ops return data as write chunk(s), header as
|
* inline.
|
* o Large non-read ops return as a single reply chunk.
|
*/
|
if (rpcrdma_results_inline(r_xprt, rqst))
|
wtype = rpcrdma_noch;
|
else if ((ddp_allowed && rqst->rq_rcv_buf.flags & XDRBUF_READ) &&
|
rpcrdma_nonpayload_inline(r_xprt, rqst))
|
wtype = rpcrdma_writech;
|
else
|
wtype = rpcrdma_replych;
|
|
/*
|
* Chunks needed for arguments?
|
*
|
* o If the total request is under the inline threshold, all ops
|
* are sent as inline.
|
* o Large write ops transmit data as read chunk(s), header as
|
* inline.
|
* o Large non-write ops are sent with the entire message as a
|
* single read chunk (protocol 0-position special case).
|
*
|
* This assumes that the upper layer does not present a request
|
* that both has a data payload, and whose non-data arguments
|
* by themselves are larger than the inline threshold.
|
*/
|
if (rpcrdma_args_inline(r_xprt, rqst)) {
|
*p++ = rdma_msg;
|
rtype = buf->len < rdmab_length(req->rl_sendbuf) ?
|
rpcrdma_noch_pullup : rpcrdma_noch_mapped;
|
} else if (ddp_allowed && buf->flags & XDRBUF_WRITE) {
|
*p++ = rdma_msg;
|
rtype = rpcrdma_readch;
|
} else {
|
r_xprt->rx_stats.nomsg_call_count++;
|
*p++ = rdma_nomsg;
|
rtype = rpcrdma_areadch;
|
}
|
|
/* This implementation supports the following combinations
|
* of chunk lists in one RPC-over-RDMA Call message:
|
*
|
* - Read list
|
* - Write list
|
* - Reply chunk
|
* - Read list + Reply chunk
|
*
|
* It might not yet support the following combinations:
|
*
|
* - Read list + Write list
|
*
|
* It does not support the following combinations:
|
*
|
* - Write list + Reply chunk
|
* - Read list + Write list + Reply chunk
|
*
|
* This implementation supports only a single chunk in each
|
* Read or Write list. Thus for example the client cannot
|
* send a Call message with a Position Zero Read chunk and a
|
* regular Read chunk at the same time.
|
*/
|
ret = rpcrdma_encode_read_list(r_xprt, req, rqst, rtype);
|
if (ret)
|
goto out_err;
|
ret = rpcrdma_encode_write_list(r_xprt, req, rqst, wtype);
|
if (ret)
|
goto out_err;
|
ret = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, wtype);
|
if (ret)
|
goto out_err;
|
|
ret = rpcrdma_prepare_send_sges(r_xprt, req, req->rl_hdrbuf.len,
|
buf, rtype);
|
if (ret)
|
goto out_err;
|
|
trace_xprtrdma_marshal(req, rtype, wtype);
|
return 0;
|
|
out_err:
|
trace_xprtrdma_marshal_failed(rqst, ret);
|
r_xprt->rx_stats.failed_marshal_count++;
|
frwr_reset(req);
|
return ret;
|
}
|
|
static void __rpcrdma_update_cwnd_locked(struct rpc_xprt *xprt,
|
struct rpcrdma_buffer *buf,
|
u32 grant)
|
{
|
buf->rb_credits = grant;
|
xprt->cwnd = grant << RPC_CWNDSHIFT;
|
}
|
|
static void rpcrdma_update_cwnd(struct rpcrdma_xprt *r_xprt, u32 grant)
|
{
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
|
|
spin_lock(&xprt->transport_lock);
|
__rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, grant);
|
spin_unlock(&xprt->transport_lock);
|
}
|
|
/**
|
* rpcrdma_reset_cwnd - Reset the xprt's congestion window
|
* @r_xprt: controlling transport instance
|
*
|
* Prepare @r_xprt for the next connection by reinitializing
|
* its credit grant to one (see RFC 8166, Section 3.3.3).
|
*/
|
void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt)
|
{
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
|
|
spin_lock(&xprt->transport_lock);
|
xprt->cong = 0;
|
__rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, 1);
|
spin_unlock(&xprt->transport_lock);
|
}
|
|
/**
|
* rpcrdma_inline_fixup - Scatter inline received data into rqst's iovecs
|
* @rqst: controlling RPC request
|
* @srcp: points to RPC message payload in receive buffer
|
* @copy_len: remaining length of receive buffer content
|
* @pad: Write chunk pad bytes needed (zero for pure inline)
|
*
|
* The upper layer has set the maximum number of bytes it can
|
* receive in each component of rq_rcv_buf. These values are set in
|
* the head.iov_len, page_len, tail.iov_len, and buflen fields.
|
*
|
* Unlike the TCP equivalent (xdr_partial_copy_from_skb), in
|
* many cases this function simply updates iov_base pointers in
|
* rq_rcv_buf to point directly to the received reply data, to
|
* avoid copying reply data.
|
*
|
* Returns the count of bytes which had to be memcopied.
|
*/
|
static unsigned long
|
rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
|
{
|
unsigned long fixup_copy_count;
|
int i, npages, curlen;
|
char *destp;
|
struct page **ppages;
|
int page_base;
|
|
/* The head iovec is redirected to the RPC reply message
|
* in the receive buffer, to avoid a memcopy.
|
*/
|
rqst->rq_rcv_buf.head[0].iov_base = srcp;
|
rqst->rq_private_buf.head[0].iov_base = srcp;
|
|
/* The contents of the receive buffer that follow
|
* head.iov_len bytes are copied into the page list.
|
*/
|
curlen = rqst->rq_rcv_buf.head[0].iov_len;
|
if (curlen > copy_len)
|
curlen = copy_len;
|
srcp += curlen;
|
copy_len -= curlen;
|
|
ppages = rqst->rq_rcv_buf.pages +
|
(rqst->rq_rcv_buf.page_base >> PAGE_SHIFT);
|
page_base = offset_in_page(rqst->rq_rcv_buf.page_base);
|
fixup_copy_count = 0;
|
if (copy_len && rqst->rq_rcv_buf.page_len) {
|
int pagelist_len;
|
|
pagelist_len = rqst->rq_rcv_buf.page_len;
|
if (pagelist_len > copy_len)
|
pagelist_len = copy_len;
|
npages = PAGE_ALIGN(page_base + pagelist_len) >> PAGE_SHIFT;
|
for (i = 0; i < npages; i++) {
|
curlen = PAGE_SIZE - page_base;
|
if (curlen > pagelist_len)
|
curlen = pagelist_len;
|
|
destp = kmap_atomic(ppages[i]);
|
memcpy(destp + page_base, srcp, curlen);
|
flush_dcache_page(ppages[i]);
|
kunmap_atomic(destp);
|
srcp += curlen;
|
copy_len -= curlen;
|
fixup_copy_count += curlen;
|
pagelist_len -= curlen;
|
if (!pagelist_len)
|
break;
|
page_base = 0;
|
}
|
|
/* Implicit padding for the last segment in a Write
|
* chunk is inserted inline at the front of the tail
|
* iovec. The upper layer ignores the content of
|
* the pad. Simply ensure inline content in the tail
|
* that follows the Write chunk is properly aligned.
|
*/
|
if (pad)
|
srcp -= pad;
|
}
|
|
/* The tail iovec is redirected to the remaining data
|
* in the receive buffer, to avoid a memcopy.
|
*/
|
if (copy_len || pad) {
|
rqst->rq_rcv_buf.tail[0].iov_base = srcp;
|
rqst->rq_private_buf.tail[0].iov_base = srcp;
|
}
|
|
if (fixup_copy_count)
|
trace_xprtrdma_fixup(rqst, fixup_copy_count);
|
return fixup_copy_count;
|
}
|
|
/* 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
|
rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep)
|
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
|
{
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
|
struct xdr_stream *xdr = &rep->rr_stream;
|
__be32 *p;
|
|
if (rep->rr_proc != rdma_msg)
|
return false;
|
|
/* Peek at stream contents without advancing. */
|
p = xdr_inline_decode(xdr, 0);
|
|
/* Chunk lists */
|
if (xdr_item_is_present(p++))
|
return false;
|
if (xdr_item_is_present(p++))
|
return false;
|
if (xdr_item_is_present(p++))
|
return false;
|
|
/* RPC header */
|
if (*p++ != rep->rr_xid)
|
return false;
|
if (*p != cpu_to_be32(RPC_CALL))
|
return false;
|
|
/* No bc service. */
|
if (xprt->bc_serv == NULL)
|
return false;
|
|
/* Now that we are sure this is a backchannel call,
|
* advance to the RPC header.
|
*/
|
p = xdr_inline_decode(xdr, 3 * sizeof(*p));
|
if (unlikely(!p))
|
goto out_short;
|
|
rpcrdma_bc_receive_call(r_xprt, rep);
|
return true;
|
|
out_short:
|
pr_warn("RPC/RDMA short backward direction call\n");
|
return true;
|
}
|
#else /* CONFIG_SUNRPC_BACKCHANNEL */
|
{
|
return false;
|
}
|
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
|
|
static int decode_rdma_segment(struct xdr_stream *xdr, u32 *length)
|
{
|
u32 handle;
|
u64 offset;
|
__be32 *p;
|
|
p = xdr_inline_decode(xdr, 4 * sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
|
xdr_decode_rdma_segment(p, &handle, length, &offset);
|
trace_xprtrdma_decode_seg(handle, *length, offset);
|
return 0;
|
}
|
|
static int decode_write_chunk(struct xdr_stream *xdr, u32 *length)
|
{
|
u32 segcount, seglength;
|
__be32 *p;
|
|
p = xdr_inline_decode(xdr, sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
|
*length = 0;
|
segcount = be32_to_cpup(p);
|
while (segcount--) {
|
if (decode_rdma_segment(xdr, &seglength))
|
return -EIO;
|
*length += seglength;
|
}
|
|
return 0;
|
}
|
|
/* In RPC-over-RDMA Version One replies, a Read list is never
|
* expected. This decoder is a stub that returns an error if
|
* a Read list is present.
|
*/
|
static int decode_read_list(struct xdr_stream *xdr)
|
{
|
__be32 *p;
|
|
p = xdr_inline_decode(xdr, sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
if (unlikely(xdr_item_is_present(p)))
|
return -EIO;
|
return 0;
|
}
|
|
/* Supports only one Write chunk in the Write list
|
*/
|
static int decode_write_list(struct xdr_stream *xdr, u32 *length)
|
{
|
u32 chunklen;
|
bool first;
|
__be32 *p;
|
|
*length = 0;
|
first = true;
|
do {
|
p = xdr_inline_decode(xdr, sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
if (xdr_item_is_absent(p))
|
break;
|
if (!first)
|
return -EIO;
|
|
if (decode_write_chunk(xdr, &chunklen))
|
return -EIO;
|
*length += chunklen;
|
first = false;
|
} while (true);
|
return 0;
|
}
|
|
static int decode_reply_chunk(struct xdr_stream *xdr, u32 *length)
|
{
|
__be32 *p;
|
|
p = xdr_inline_decode(xdr, sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
|
*length = 0;
|
if (xdr_item_is_present(p))
|
if (decode_write_chunk(xdr, length))
|
return -EIO;
|
return 0;
|
}
|
|
static int
|
rpcrdma_decode_msg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep,
|
struct rpc_rqst *rqst)
|
{
|
struct xdr_stream *xdr = &rep->rr_stream;
|
u32 writelist, replychunk, rpclen;
|
char *base;
|
|
/* Decode the chunk lists */
|
if (decode_read_list(xdr))
|
return -EIO;
|
if (decode_write_list(xdr, &writelist))
|
return -EIO;
|
if (decode_reply_chunk(xdr, &replychunk))
|
return -EIO;
|
|
/* RDMA_MSG sanity checks */
|
if (unlikely(replychunk))
|
return -EIO;
|
|
/* Build the RPC reply's Payload stream in rqst->rq_rcv_buf */
|
base = (char *)xdr_inline_decode(xdr, 0);
|
rpclen = xdr_stream_remaining(xdr);
|
r_xprt->rx_stats.fixup_copy_count +=
|
rpcrdma_inline_fixup(rqst, base, rpclen, writelist & 3);
|
|
r_xprt->rx_stats.total_rdma_reply += writelist;
|
return rpclen + xdr_align_size(writelist);
|
}
|
|
static noinline int
|
rpcrdma_decode_nomsg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep)
|
{
|
struct xdr_stream *xdr = &rep->rr_stream;
|
u32 writelist, replychunk;
|
|
/* Decode the chunk lists */
|
if (decode_read_list(xdr))
|
return -EIO;
|
if (decode_write_list(xdr, &writelist))
|
return -EIO;
|
if (decode_reply_chunk(xdr, &replychunk))
|
return -EIO;
|
|
/* RDMA_NOMSG sanity checks */
|
if (unlikely(writelist))
|
return -EIO;
|
if (unlikely(!replychunk))
|
return -EIO;
|
|
/* Reply chunk buffer already is the reply vector */
|
r_xprt->rx_stats.total_rdma_reply += replychunk;
|
return replychunk;
|
}
|
|
static noinline int
|
rpcrdma_decode_error(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep,
|
struct rpc_rqst *rqst)
|
{
|
struct xdr_stream *xdr = &rep->rr_stream;
|
__be32 *p;
|
|
p = xdr_inline_decode(xdr, sizeof(*p));
|
if (unlikely(!p))
|
return -EIO;
|
|
switch (*p) {
|
case err_vers:
|
p = xdr_inline_decode(xdr, 2 * sizeof(*p));
|
if (!p)
|
break;
|
dprintk("RPC: %s: server reports "
|
"version error (%u-%u), xid %08x\n", __func__,
|
be32_to_cpup(p), be32_to_cpu(*(p + 1)),
|
be32_to_cpu(rep->rr_xid));
|
break;
|
case err_chunk:
|
dprintk("RPC: %s: server reports "
|
"header decoding error, xid %08x\n", __func__,
|
be32_to_cpu(rep->rr_xid));
|
break;
|
default:
|
dprintk("RPC: %s: server reports "
|
"unrecognized error %d, xid %08x\n", __func__,
|
be32_to_cpup(p), be32_to_cpu(rep->rr_xid));
|
}
|
|
return -EIO;
|
}
|
|
/* Perform XID lookup, reconstruction of the RPC reply, and
|
* RPC completion while holding the transport lock to ensure
|
* the rep, rqst, and rq_task pointers remain stable.
|
*/
|
void rpcrdma_complete_rqst(struct rpcrdma_rep *rep)
|
{
|
struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
|
struct rpc_rqst *rqst = rep->rr_rqst;
|
int status;
|
|
switch (rep->rr_proc) {
|
case rdma_msg:
|
status = rpcrdma_decode_msg(r_xprt, rep, rqst);
|
break;
|
case rdma_nomsg:
|
status = rpcrdma_decode_nomsg(r_xprt, rep);
|
break;
|
case rdma_error:
|
status = rpcrdma_decode_error(r_xprt, rep, rqst);
|
break;
|
default:
|
status = -EIO;
|
}
|
if (status < 0)
|
goto out_badheader;
|
|
out:
|
spin_lock(&xprt->queue_lock);
|
xprt_complete_rqst(rqst->rq_task, status);
|
xprt_unpin_rqst(rqst);
|
spin_unlock(&xprt->queue_lock);
|
return;
|
|
out_badheader:
|
trace_xprtrdma_reply_hdr(rep);
|
r_xprt->rx_stats.bad_reply_count++;
|
rqst->rq_task->tk_status = status;
|
status = 0;
|
goto out;
|
}
|
|
static void rpcrdma_reply_done(struct kref *kref)
|
{
|
struct rpcrdma_req *req =
|
container_of(kref, struct rpcrdma_req, rl_kref);
|
|
rpcrdma_complete_rqst(req->rl_reply);
|
}
|
|
/**
|
* rpcrdma_reply_handler - Process received RPC/RDMA messages
|
* @rep: Incoming rpcrdma_rep object to process
|
*
|
* Errors must result in the RPC task either being awakened, or
|
* allowed to timeout, to discover the errors at that time.
|
*/
|
void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
|
{
|
struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
|
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
|
struct rpcrdma_req *req;
|
struct rpc_rqst *rqst;
|
u32 credits;
|
__be32 *p;
|
|
/* Any data means we had a useful conversation, so
|
* then we don't need to delay the next reconnect.
|
*/
|
if (xprt->reestablish_timeout)
|
xprt->reestablish_timeout = 0;
|
|
/* Fixed transport header fields */
|
xdr_init_decode(&rep->rr_stream, &rep->rr_hdrbuf,
|
rep->rr_hdrbuf.head[0].iov_base, NULL);
|
p = xdr_inline_decode(&rep->rr_stream, 4 * sizeof(*p));
|
if (unlikely(!p))
|
goto out_shortreply;
|
rep->rr_xid = *p++;
|
rep->rr_vers = *p++;
|
credits = be32_to_cpu(*p++);
|
rep->rr_proc = *p++;
|
|
if (rep->rr_vers != rpcrdma_version)
|
goto out_badversion;
|
|
if (rpcrdma_is_bcall(r_xprt, rep))
|
return;
|
|
/* Match incoming rpcrdma_rep to an rpcrdma_req to
|
* get context for handling any incoming chunks.
|
*/
|
spin_lock(&xprt->queue_lock);
|
rqst = xprt_lookup_rqst(xprt, rep->rr_xid);
|
if (!rqst)
|
goto out_norqst;
|
xprt_pin_rqst(rqst);
|
spin_unlock(&xprt->queue_lock);
|
|
if (credits == 0)
|
credits = 1; /* don't deadlock */
|
else if (credits > r_xprt->rx_ep->re_max_requests)
|
credits = r_xprt->rx_ep->re_max_requests;
|
rpcrdma_post_recvs(r_xprt, credits + (buf->rb_bc_srv_max_requests << 1),
|
false);
|
if (buf->rb_credits != credits)
|
rpcrdma_update_cwnd(r_xprt, credits);
|
|
req = rpcr_to_rdmar(rqst);
|
if (req->rl_reply) {
|
trace_xprtrdma_leaked_rep(rqst, req->rl_reply);
|
rpcrdma_recv_buffer_put(req->rl_reply);
|
}
|
req->rl_reply = rep;
|
rep->rr_rqst = rqst;
|
|
trace_xprtrdma_reply(rqst->rq_task, rep, req, credits);
|
|
if (rep->rr_wc_flags & IB_WC_WITH_INVALIDATE)
|
frwr_reminv(rep, &req->rl_registered);
|
if (!list_empty(&req->rl_registered))
|
frwr_unmap_async(r_xprt, req);
|
/* LocalInv completion will complete the RPC */
|
else
|
kref_put(&req->rl_kref, rpcrdma_reply_done);
|
return;
|
|
out_badversion:
|
trace_xprtrdma_reply_vers(rep);
|
goto out;
|
|
out_norqst:
|
spin_unlock(&xprt->queue_lock);
|
trace_xprtrdma_reply_rqst(rep);
|
goto out;
|
|
out_shortreply:
|
trace_xprtrdma_reply_short(rep);
|
|
out:
|
rpcrdma_recv_buffer_put(rep);
|
}
|
