1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
3  * Copyright (c) 2016-2018 Oracle. All rights reserved.
5  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
10  * COPYING in the main directory of this source tree, or the BSD-type
50  * The passed-in svc_rqst contains a struct xdr_buf which holds an
51  * XDR-encoded RPC Reply message. sendto must construct the RPC-over-RDMA
52  * transport header, post all Write WRs needed for this Reply, then post
70  * when it completes, it is guaranteed that all previous Write WRs have
73  * Write WRs are constructed and posted. Each Write segment gets its own
74  * svc_rdma_rw_ctxt, allowing the Write completion handler to find and
75  * DMA-unmap the pages under I/O for that Write segment. The Write
86  * Completion Queue do not run in parallel. Otherwise a Write completion
88  * are still DMA-mapped.
92  * - If the Send WR is posted successfully, it will either complete
95  * - If the Send WR cannot be not posted, the forward path releases
99  * where two different Write segments send portions of the same page.
119 	int node = ibdev_to_node(rdma->sc_cm_id->device);  in svc_rdma_send_ctxt_alloc()
125 	ctxt = kzalloc_node(struct_size(ctxt, sc_sges, rdma->sc_max_send_sges),  in svc_rdma_send_ctxt_alloc()
129 	buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);  in svc_rdma_send_ctxt_alloc()
132 	addr = ib_dma_map_single(rdma->sc_pd->device, buffer,  in svc_rdma_send_ctxt_alloc()
133 				 rdma->sc_max_req_size, DMA_TO_DEVICE);  in svc_rdma_send_ctxt_alloc()
134 	if (ib_dma_mapping_error(rdma->sc_pd->device, addr))  in svc_rdma_send_ctxt_alloc()
137 	svc_rdma_send_cid_init(rdma, &ctxt->sc_cid);  in svc_rdma_send_ctxt_alloc()
139 	ctxt->sc_rdma = rdma;  in svc_rdma_send_ctxt_alloc()
140 	ctxt->sc_send_wr.next = NULL;  in svc_rdma_send_ctxt_alloc()
141 	ctxt->sc_send_wr.wr_cqe = &ctxt->sc_cqe;  in svc_rdma_send_ctxt_alloc()
142 	ctxt->sc_send_wr.sg_list = ctxt->sc_sges;  in svc_rdma_send_ctxt_alloc()
143 	ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED;  in svc_rdma_send_ctxt_alloc()
144 	ctxt->sc_cqe.done = svc_rdma_wc_send;  in svc_rdma_send_ctxt_alloc()
145 	ctxt->sc_xprt_buf = buffer;  in svc_rdma_send_ctxt_alloc()
146 	xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf,  in svc_rdma_send_ctxt_alloc()
147 		     rdma->sc_max_req_size);  in svc_rdma_send_ctxt_alloc()
148 	ctxt->sc_sges[0].addr = addr;  in svc_rdma_send_ctxt_alloc()
150 	for (i = 0; i < rdma->sc_max_send_sges; i++)  in svc_rdma_send_ctxt_alloc()
151 		ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey;  in svc_rdma_send_ctxt_alloc()
163  * svc_rdma_send_ctxts_destroy - Release all send_ctxt's for an xprt
172 	while ((node = llist_del_first(&rdma->sc_send_ctxts)) != NULL) {  in svc_rdma_send_ctxts_destroy()
174 		ib_dma_unmap_single(rdma->sc_pd->device,  in svc_rdma_send_ctxts_destroy()
175 				    ctxt->sc_sges[0].addr,  in svc_rdma_send_ctxts_destroy()
176 				    rdma->sc_max_req_size,  in svc_rdma_send_ctxts_destroy()
178 		kfree(ctxt->sc_xprt_buf);  in svc_rdma_send_ctxts_destroy()
184  * svc_rdma_send_ctxt_get - Get a free send_ctxt
187  * Returns a ready-to-use send_ctxt, or NULL if none are
195 	spin_lock(&rdma->sc_send_lock);  in svc_rdma_send_ctxt_get()
196 	node = llist_del_first(&rdma->sc_send_ctxts);  in svc_rdma_send_ctxt_get()
197 	spin_unlock(&rdma->sc_send_lock);  in svc_rdma_send_ctxt_get()
204 	rpcrdma_set_xdrlen(&ctxt->sc_hdrbuf, 0);  in svc_rdma_send_ctxt_get()
205 	xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf,  in svc_rdma_send_ctxt_get()
206 			ctxt->sc_xprt_buf, NULL);  in svc_rdma_send_ctxt_get()
208 	svc_rdma_cc_init(rdma, &ctxt->sc_reply_info.wi_cc);  in svc_rdma_send_ctxt_get()
209 	ctxt->sc_send_wr.num_sge = 0;  in svc_rdma_send_ctxt_get()
210 	ctxt->sc_cur_sge_no = 0;  in svc_rdma_send_ctxt_get()
211 	ctxt->sc_page_count = 0;  in svc_rdma_send_ctxt_get()
212 	ctxt->sc_wr_chain = &ctxt->sc_send_wr;  in svc_rdma_send_ctxt_get()
213 	ctxt->sc_sqecount = 1;  in svc_rdma_send_ctxt_get()
227 	struct ib_device *device = rdma->sc_cm_id->device;  in svc_rdma_send_ctxt_release()
232 	if (ctxt->sc_page_count)  in svc_rdma_send_ctxt_release()
233 		release_pages(ctxt->sc_pages, ctxt->sc_page_count);  in svc_rdma_send_ctxt_release()
238 	for (i = 1; i < ctxt->sc_send_wr.num_sge; i++) {  in svc_rdma_send_ctxt_release()
239 		trace_svcrdma_dma_unmap_page(&ctxt->sc_cid,  in svc_rdma_send_ctxt_release()
240 					     ctxt->sc_sges[i].addr,  in svc_rdma_send_ctxt_release()
241 					     ctxt->sc_sges[i].length);  in svc_rdma_send_ctxt_release()
243 				  ctxt->sc_sges[i].addr,  in svc_rdma_send_ctxt_release()
244 				  ctxt->sc_sges[i].length,  in svc_rdma_send_ctxt_release()
248 	llist_add(&ctxt->sc_node, &rdma->sc_send_ctxts);  in svc_rdma_send_ctxt_release()
256 	svc_rdma_send_ctxt_release(ctxt->sc_rdma, ctxt);  in svc_rdma_send_ctxt_put_async()
260  * svc_rdma_send_ctxt_put - Return send_ctxt to free list
264  * Pages left in sc_pages are DMA unmapped and released.
269 	INIT_WORK(&ctxt->sc_work, svc_rdma_send_ctxt_put_async);  in svc_rdma_send_ctxt_put()
270 	queue_work(svcrdma_wq, &ctxt->sc_work);  in svc_rdma_send_ctxt_put()
274  * svc_rdma_wake_send_waiters - manage Send Queue accounting
281 	atomic_add(avail, &rdma->sc_sq_avail);  in svc_rdma_wake_send_waiters()
283 	if (unlikely(waitqueue_active(&rdma->sc_send_wait)))  in svc_rdma_wake_send_waiters()
284 		wake_up(&rdma->sc_send_wait);  in svc_rdma_wake_send_waiters()
288  * svc_rdma_wc_send - Invoked by RDMA provider for each polled Send WC
297 	struct svcxprt_rdma *rdma = cq->cq_context;  in svc_rdma_wc_send()
298 	struct ib_cqe *cqe = wc->wr_cqe;  in svc_rdma_wc_send()
302 	svc_rdma_wake_send_waiters(rdma, ctxt->sc_sqecount);  in svc_rdma_wc_send()
304 	if (unlikely(wc->status != IB_WC_SUCCESS))  in svc_rdma_wc_send()
307 	trace_svcrdma_wc_send(&ctxt->sc_cid);  in svc_rdma_wc_send()
312 	if (wc->status != IB_WC_WR_FLUSH_ERR)  in svc_rdma_wc_send()
313 		trace_svcrdma_wc_send_err(wc, &ctxt->sc_cid);  in svc_rdma_wc_send()
315 		trace_svcrdma_wc_send_flush(wc, &ctxt->sc_cid);  in svc_rdma_wc_send()
317 	svc_xprt_deferred_close(&rdma->sc_xprt);  in svc_rdma_wc_send()
321  * svc_rdma_post_send - Post a WR chain to the Send Queue
336  *   %-ENOTCONN: The connection was lost
341 	struct ib_send_wr *first_wr = ctxt->sc_wr_chain;  in svc_rdma_post_send()
342 	struct ib_send_wr *send_wr = &ctxt->sc_send_wr;  in svc_rdma_post_send()
344 	struct rpc_rdma_cid cid = ctxt->sc_cid;  in svc_rdma_post_send()
345 	int ret, sqecount = ctxt->sc_sqecount;  in svc_rdma_post_send()
350 	ib_dma_sync_single_for_device(rdma->sc_pd->device,  in svc_rdma_post_send()
351 				      send_wr->sg_list[0].addr,  in svc_rdma_post_send()
352 				      send_wr->sg_list[0].length,  in svc_rdma_post_send()
356 	while (!test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) {  in svc_rdma_post_send()
357 		if (atomic_sub_return(sqecount, &rdma->sc_sq_avail) < 0) {  in svc_rdma_post_send()
368 			wait_event(rdma->sc_send_wait,  in svc_rdma_post_send()
369 				   atomic_read(&rdma->sc_sq_avail) > 0);  in svc_rdma_post_send()
375 		ret = ib_post_send(rdma->sc_qp, first_wr, &bad_wr);  in svc_rdma_post_send()
378 			svc_xprt_deferred_close(&rdma->sc_xprt);  in svc_rdma_post_send()
390 	return -ENOTCONN;  in svc_rdma_post_send()
394  * svc_rdma_encode_read_list - Encode RPC Reply's Read chunk list
400  *   %-EMSGSIZE on XDR buffer overflow
404 	/* RPC-over-RDMA version 1 replies never have a Read list. */  in svc_rdma_encode_read_list()
405 	return xdr_stream_encode_item_absent(&sctxt->sc_stream);  in svc_rdma_encode_read_list()
409  * svc_rdma_encode_write_segment - Encode one Write segment
411  * @chunk: Write chunk to push
412  * @remaining: remaining bytes of the payload left in the Write chunk
417  *   that was consumed by the Write segment, and updates @remaining
418  *   %-EMSGSIZE on XDR buffer overflow
424 	const struct svc_rdma_segment *segment = &chunk->ch_segments[segno];  in svc_rdma_encode_write_segment()
429 	p = xdr_reserve_space(&sctxt->sc_stream, len);  in svc_rdma_encode_write_segment()
431 		return -EMSGSIZE;  in svc_rdma_encode_write_segment()
433 	length = min_t(u32, *remaining, segment->rs_length);  in svc_rdma_encode_write_segment()
434 	*remaining -= length;  in svc_rdma_encode_write_segment()
435 	xdr_encode_rdma_segment(p, segment->rs_handle, length,  in svc_rdma_encode_write_segment()
436 				segment->rs_offset);  in svc_rdma_encode_write_segment()
437 	trace_svcrdma_encode_wseg(sctxt, segno, segment->rs_handle, length,  in svc_rdma_encode_write_segment()
438 				  segment->rs_offset);  in svc_rdma_encode_write_segment()
443  * svc_rdma_encode_write_chunk - Encode one Write chunk
445  * @chunk: Write chunk to push
447  * Copy a Write chunk from the Call transport header to the
453  *   that was consumed by the Write chunk
454  *   %-EMSGSIZE on XDR buffer overflow
459 	u32 remaining = chunk->ch_payload_length;  in svc_rdma_encode_write_chunk()
464 	ret = xdr_stream_encode_item_present(&sctxt->sc_stream);  in svc_rdma_encode_write_chunk()
469 	ret = xdr_stream_encode_u32(&sctxt->sc_stream, chunk->ch_segcount);  in svc_rdma_encode_write_chunk()
474 	for (segno = 0; segno < chunk->ch_segcount; segno++) {  in svc_rdma_encode_write_chunk()
485  * svc_rdma_encode_write_list - Encode RPC Reply's Write chunk list
491  *   that was consumed by the Reply's Write list
492  *   %-EMSGSIZE on XDR buffer overflow
501 	pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) {  in svc_rdma_encode_write_list()
508 	/* Terminate the Write list */  in svc_rdma_encode_write_list()
509 	ret = xdr_stream_encode_item_absent(&sctxt->sc_stream);  in svc_rdma_encode_write_list()
517  * svc_rdma_encode_reply_chunk - Encode RPC Reply's Reply chunk
525  *   %-EMSGSIZE on XDR buffer overflow
526  *   %-E2BIG if the RPC message is larger than the Reply chunk
535 	if (pcl_is_empty(&rctxt->rc_reply_pcl))  in svc_rdma_encode_reply_chunk()
536 		return xdr_stream_encode_item_absent(&sctxt->sc_stream);  in svc_rdma_encode_reply_chunk()
538 	chunk = pcl_first_chunk(&rctxt->rc_reply_pcl);  in svc_rdma_encode_reply_chunk()
539 	if (length > chunk->ch_length)  in svc_rdma_encode_reply_chunk()
540 		return -E2BIG;  in svc_rdma_encode_reply_chunk()
542 	chunk->ch_payload_length = length;  in svc_rdma_encode_reply_chunk()
552  * svc_rdma_page_dma_map - DMA map one page
554  * @page: struct page to DMA map
559  *   %0 if DMA mapping was successful
560  *   %-EIO if the page cannot be DMA mapped
566 	struct svcxprt_rdma *rdma = args->md_rdma;  in svc_rdma_page_dma_map()
567 	struct svc_rdma_send_ctxt *ctxt = args->md_ctxt;  in svc_rdma_page_dma_map()
568 	struct ib_device *dev = rdma->sc_cm_id->device;  in svc_rdma_page_dma_map()
571 	++ctxt->sc_cur_sge_no;  in svc_rdma_page_dma_map()
577 	trace_svcrdma_dma_map_page(&ctxt->sc_cid, dma_addr, len);  in svc_rdma_page_dma_map()
578 	ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr;  in svc_rdma_page_dma_map()
579 	ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len;  in svc_rdma_page_dma_map()
580 	ctxt->sc_send_wr.num_sge++;  in svc_rdma_page_dma_map()
584 	trace_svcrdma_dma_map_err(&ctxt->sc_cid, dma_addr, len);  in svc_rdma_page_dma_map()
585 	return -EIO;  in svc_rdma_page_dma_map()
589  * svc_rdma_iov_dma_map - DMA map an iovec
591  * @iov: kvec to DMA map
594  * handles DMA-unmap and it uses ib_dma_unmap_page() exclusively.
597  *   %0 if DMA mapping was successful
598  *   %-EIO if the iovec cannot be DMA mapped
602 	if (!iov->iov_len)  in svc_rdma_iov_dma_map()
604 	return svc_rdma_page_dma_map(data, virt_to_page(iov->iov_base),  in svc_rdma_iov_dma_map()
605 				     offset_in_page(iov->iov_base),  in svc_rdma_iov_dma_map()
606 				     iov->iov_len);  in svc_rdma_iov_dma_map()
610  * svc_rdma_xb_dma_map - DMA map all segments of an xdr_buf
615  *   %0 if DMA mapping was successful
616  *   %-EIO if DMA mapping failed
618  * On failure, any DMA mappings that have been already done must be
628 	ret = svc_rdma_iov_dma_map(data, &xdr->head[0]);  in svc_rdma_xb_dma_map()
632 	ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);  in svc_rdma_xb_dma_map()
633 	pageoff = offset_in_page(xdr->page_base);  in svc_rdma_xb_dma_map()
634 	remaining = xdr->page_len;  in svc_rdma_xb_dma_map()
636 		len = min_t(u32, PAGE_SIZE - pageoff, remaining);  in svc_rdma_xb_dma_map()
642 		remaining -= len;  in svc_rdma_xb_dma_map()
646 	ret = svc_rdma_iov_dma_map(data, &xdr->tail[0]);  in svc_rdma_xb_dma_map()
650 	return xdr->len;  in svc_rdma_xb_dma_map()
660  * svc_rdma_xb_count_sges - Count how many SGEs will be needed
674 	if (xdr->head[0].iov_len)  in svc_rdma_xb_count_sges()
675 		++args->pd_num_sges;  in svc_rdma_xb_count_sges()
677 	offset = offset_in_page(xdr->page_base);  in svc_rdma_xb_count_sges()
678 	remaining = xdr->page_len;  in svc_rdma_xb_count_sges()
680 		++args->pd_num_sges;  in svc_rdma_xb_count_sges()
681 		remaining -= min_t(u32, PAGE_SIZE - offset, remaining);  in svc_rdma_xb_count_sges()
685 	if (xdr->tail[0].iov_len)  in svc_rdma_xb_count_sges()
686 		++args->pd_num_sges;  in svc_rdma_xb_count_sges()
688 	args->pd_length += xdr->len;  in svc_rdma_xb_count_sges()
693  * svc_rdma_pull_up_needed - Determine whether to use pull-up
696  * @write_pcl: Write chunk list provided by client
700  *   %true if pull-up must be used
710 		.pd_length	= sctxt->sc_hdrbuf.len,  in svc_rdma_pull_up_needed()
722 	return args.pd_num_sges >= rdma->sc_max_send_sges;  in svc_rdma_pull_up_needed()
726  * svc_rdma_xb_linearize - Copy region of xdr_buf to flat buffer
741 	if (xdr->head[0].iov_len) {  in svc_rdma_xb_linearize()
742 		memcpy(args->pd_dest, xdr->head[0].iov_base, xdr->head[0].iov_len);  in svc_rdma_xb_linearize()
743 		args->pd_dest += xdr->head[0].iov_len;  in svc_rdma_xb_linearize()
746 	ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);  in svc_rdma_xb_linearize()
747 	pageoff = offset_in_page(xdr->page_base);  in svc_rdma_xb_linearize()
748 	remaining = xdr->page_len;  in svc_rdma_xb_linearize()
750 		len = min_t(u32, PAGE_SIZE - pageoff, remaining);  in svc_rdma_xb_linearize()
751 		memcpy(args->pd_dest, page_address(*ppages) + pageoff, len);  in svc_rdma_xb_linearize()
752 		remaining -= len;  in svc_rdma_xb_linearize()
753 		args->pd_dest += len;  in svc_rdma_xb_linearize()
758 	if (xdr->tail[0].iov_len) {  in svc_rdma_xb_linearize()
759 		memcpy(args->pd_dest, xdr->tail[0].iov_base, xdr->tail[0].iov_len);  in svc_rdma_xb_linearize()
760 		args->pd_dest += xdr->tail[0].iov_len;  in svc_rdma_xb_linearize()
763 	args->pd_length += xdr->len;  in svc_rdma_xb_linearize()
768  * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer
771  * @write_pcl: Write chunk list provided by client
781  *   %0 if pull-up was successful
782  *   %-EMSGSIZE if a buffer manipulation problem occurred
790 		.pd_dest	= sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len,  in svc_rdma_pull_up_reply_msg()
799 	sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len + args.pd_length;  in svc_rdma_pull_up_reply_msg()
804 /* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message
807  * @write_pcl: Write chunk list provided by client
812  *   %0 if DMA mapping was successful.
813  *   %-EMSGSIZE if a buffer manipulation problem occurred
814  *   %-EIO if DMA mapping failed
829 	/* Set up the (persistently-mapped) transport header SGE. */  in svc_rdma_map_reply_msg()
830 	sctxt->sc_send_wr.num_sge = 1;  in svc_rdma_map_reply_msg()
831 	sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len;  in svc_rdma_map_reply_msg()
839 	/* For pull-up, svc_rdma_send() will sync the transport header.  in svc_rdma_map_reply_msg()
840 	 * No additional DMA mapping is necessary.  in svc_rdma_map_reply_msg()
856 	int i, pages = rqstp->rq_next_page - rqstp->rq_respages;  in svc_rdma_save_io_pages()
858 	ctxt->sc_page_count += pages;  in svc_rdma_save_io_pages()
860 		ctxt->sc_pages[i] = rqstp->rq_respages[i];  in svc_rdma_save_io_pages()
861 		rqstp->rq_respages[i] = NULL;  in svc_rdma_save_io_pages()
865 	rqstp->rq_next_page = rqstp->rq_respages;  in svc_rdma_save_io_pages()
869  * via RDMA Send. The RPC-over-RDMA transport header is prepared
872  * Depending on whether a Write list or Reply chunk is present,
878  * - The Reply's transport header will never be larger than a page.
885 	struct ib_send_wr *send_wr = &sctxt->sc_send_wr;  in svc_rdma_send_reply_msg()
888 	ret = svc_rdma_map_reply_msg(rdma, sctxt, &rctxt->rc_write_pcl,  in svc_rdma_send_reply_msg()
889 				     &rctxt->rc_reply_pcl, &rqstp->rq_res);  in svc_rdma_send_reply_msg()
898 	if (rctxt->rc_inv_rkey) {  in svc_rdma_send_reply_msg()
899 		send_wr->opcode = IB_WR_SEND_WITH_INV;  in svc_rdma_send_reply_msg()
900 		send_wr->ex.invalidate_rkey = rctxt->rc_inv_rkey;  in svc_rdma_send_reply_msg()
902 		send_wr->opcode = IB_WR_SEND;  in svc_rdma_send_reply_msg()
909  * svc_rdma_send_error_msg - Send an RPC/RDMA v1 error response
915  * Given the client-provided Read, Write, and Reply chunks, the
928 	__be32 *rdma_argp = rctxt->rc_recv_buf;  in svc_rdma_send_error_msg()
931 	rpcrdma_set_xdrlen(&sctxt->sc_hdrbuf, 0);  in svc_rdma_send_error_msg()
932 	xdr_init_encode(&sctxt->sc_stream, &sctxt->sc_hdrbuf,  in svc_rdma_send_error_msg()
933 			sctxt->sc_xprt_buf, NULL);  in svc_rdma_send_error_msg()
935 	p = xdr_reserve_space(&sctxt->sc_stream,  in svc_rdma_send_error_msg()
942 	*p++ = rdma->sc_fc_credits;  in svc_rdma_send_error_msg()
946 	case -EPROTONOSUPPORT:  in svc_rdma_send_error_msg()
947 		p = xdr_reserve_space(&sctxt->sc_stream, 3 * sizeof(*p));  in svc_rdma_send_error_msg()
957 		p = xdr_reserve_space(&sctxt->sc_stream, sizeof(*p));  in svc_rdma_send_error_msg()
966 	sctxt->sc_send_wr.num_sge = 1;  in svc_rdma_send_error_msg()
967 	sctxt->sc_send_wr.opcode = IB_WR_SEND;  in svc_rdma_send_error_msg()
968 	sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len;  in svc_rdma_send_error_msg()
978  * svc_rdma_sendto - Transmit an RPC reply
986  *	%-ENOMEM if a resource shortage occurred (connection is lost),
987  *	%-ENOTCONN if posting failed (connection is lost).
991 	struct svc_xprt *xprt = rqstp->rq_xprt;  in svc_rdma_sendto()
994 	struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt;  in svc_rdma_sendto()
995 	__be32 *rdma_argp = rctxt->rc_recv_buf;  in svc_rdma_sendto()
1001 	ret = -ENOTCONN;  in svc_rdma_sendto()
1005 	ret = -ENOMEM;  in svc_rdma_sendto()
1010 	ret = -EMSGSIZE;  in svc_rdma_sendto()
1011 	p = xdr_reserve_space(&sctxt->sc_stream,  in svc_rdma_sendto()
1016 	ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res);  in svc_rdma_sendto()
1021 	if (!pcl_is_empty(&rctxt->rc_reply_pcl)) {  in svc_rdma_sendto()
1022 		ret = svc_rdma_prepare_reply_chunk(rdma, &rctxt->rc_write_pcl,  in svc_rdma_sendto()
1023 						   &rctxt->rc_reply_pcl, sctxt,  in svc_rdma_sendto()
1024 						   &rqstp->rq_res);  in svc_rdma_sendto()
1032 	*p++ = rdma->sc_fc_credits;  in svc_rdma_sendto()
1033 	*p = pcl_is_empty(&rctxt->rc_reply_pcl) ? rdma_msg : rdma_nomsg;  in svc_rdma_sendto()
1051 	if (ret != -E2BIG && ret != -EINVAL)  in svc_rdma_sendto()
1065 	svc_xprt_deferred_close(&rdma->sc_xprt);  in svc_rdma_sendto()
1066 	return -ENOTCONN;  in svc_rdma_sendto()
1070  * svc_rdma_result_payload - special processing for a result payload
1072  * @offset: payload's byte offset in @rqstp->rq_res
1075  * Assign the passed-in result payload to the current Write chunk,
1076  * and advance to cur_result_payload to the next Write chunk, if
1081  *   %-E2BIG if the payload was larger than the Write chunk
1086 	struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt;  in svc_rdma_result_payload()
1089 	chunk = rctxt->rc_cur_result_payload;  in svc_rdma_result_payload()
1092 	rctxt->rc_cur_result_payload =  in svc_rdma_result_payload()
1093 		pcl_next_chunk(&rctxt->rc_write_pcl, chunk);  in svc_rdma_result_payload()
1095 	if (length > chunk->ch_length)  in svc_rdma_result_payload()
1096 		return -E2BIG;  in svc_rdma_result_payload()
1097 	chunk->ch_position = offset;  in svc_rdma_result_payload()
1098 	chunk->ch_payload_length = length;  in svc_rdma_result_payload()