Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 687 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
new file mode 100644
index 00000000..41cb63b6
--- /dev/null
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -0,0 +1,687 @@
+/*
+ * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the BSD-type
+ * license below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *      Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *      Redistributions in binary form must reproduce the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer in the documentation and/or other materials provided
+ *      with the distribution.
+ *
+ *      Neither the name of the Network Appliance, Inc. nor the names of
+ *      its contributors may be used to endorse or promote products
+ *      derived from this software without specific prior written
+ *      permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Tom Tucker <tom@opengridcomputing.com>
+ */
+
+#include <linux/sunrpc/debug.h>
+#include <linux/sunrpc/rpc_rdma.h>
+#include <linux/spinlock.h>
+#include <asm/unaligned.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <linux/sunrpc/svc_rdma.h>
+
+#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
+
+/*
+ * Replace the pages in the rq_argpages array with the pages from the SGE in
+ * the RDMA_RECV completion. The SGL should contain full pages up until the
+ * last one.
+ */
+static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
+			       struct svc_rdma_op_ctxt *ctxt,
+			       u32 byte_count)
+{
+	struct page *page;
+	u32 bc;
+	int sge_no;
+
+	/* Swap the page in the SGE with the page in argpages */
+	page = ctxt->pages[0];
+	put_page(rqstp->rq_pages[0]);
+	rqstp->rq_pages[0] = page;
+
+	/* Set up the XDR head */
+	rqstp->rq_arg.head[0].iov_base = page_address(page);
+	rqstp->rq_arg.head[0].iov_len = min(byte_count, ctxt->sge[0].length);
+	rqstp->rq_arg.len = byte_count;
+	rqstp->rq_arg.buflen = byte_count;
+
+	/* Compute bytes past head in the SGL */
+	bc = byte_count - rqstp->rq_arg.head[0].iov_len;
+
+	/* If data remains, store it in the pagelist */
+	rqstp->rq_arg.page_len = bc;
+	rqstp->rq_arg.page_base = 0;
+	rqstp->rq_arg.pages = &rqstp->rq_pages[1];
+	sge_no = 1;
+	while (bc && sge_no < ctxt->count) {
+		page = ctxt->pages[sge_no];
+		put_page(rqstp->rq_pages[sge_no]);
+		rqstp->rq_pages[sge_no] = page;
+		bc -= min(bc, ctxt->sge[sge_no].length);
+		rqstp->rq_arg.buflen += ctxt->sge[sge_no].length;
+		sge_no++;
+	}
+	rqstp->rq_respages = &rqstp->rq_pages[sge_no];
+
+	/* We should never run out of SGE because the limit is defined to
+	 * support the max allowed RPC data length
+	 */
+	BUG_ON(bc && (sge_no == ctxt->count));
+	BUG_ON((rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len)
+	       != byte_count);
+	BUG_ON(rqstp->rq_arg.len != byte_count);
+
+	/* If not all pages were used from the SGL, free the remaining ones */
+	bc = sge_no;
+	while (sge_no < ctxt->count) {
+		page = ctxt->pages[sge_no++];
+		put_page(page);
+	}
+	ctxt->count = bc;
+
+	/* Set up tail */
+	rqstp->rq_arg.tail[0].iov_base = NULL;
+	rqstp->rq_arg.tail[0].iov_len = 0;
+}
+
+/* Encode a read-chunk-list as an array of IB SGE
+ *
+ * Assumptions:
+ * - chunk[0]->position points to pages[0] at an offset of 0
+ * - pages[] is not physically or virtually contiguous and consists of
+ *   PAGE_SIZE elements.
+ *
+ * Output:
+ * - sge array pointing into pages[] array.
+ * - chunk_sge array specifying sge index and count for each
+ *   chunk in the read list
+ *
+ */
+static int map_read_chunks(struct svcxprt_rdma *xprt,
+			   struct svc_rqst *rqstp,
+			   struct svc_rdma_op_ctxt *head,
+			   struct rpcrdma_msg *rmsgp,
+			   struct svc_rdma_req_map *rpl_map,
+			   struct svc_rdma_req_map *chl_map,
+			   int ch_count,
+			   int byte_count)
+{
+	int sge_no;
+	int sge_bytes;
+	int page_off;
+	int page_no;
+	int ch_bytes;
+	int ch_no;
+	struct rpcrdma_read_chunk *ch;
+
+	sge_no = 0;
+	page_no = 0;
+	page_off = 0;
+	ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
+	ch_no = 0;
+	ch_bytes = ntohl(ch->rc_target.rs_length);
+	head->arg.head[0] = rqstp->rq_arg.head[0];
+	head->arg.tail[0] = rqstp->rq_arg.tail[0];
+	head->arg.pages = &head->pages[head->count];
+	head->hdr_count = head->count; /* save count of hdr pages */
+	head->arg.page_base = 0;
+	head->arg.page_len = ch_bytes;
+	head->arg.len = rqstp->rq_arg.len + ch_bytes;
+	head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes;
+	head->count++;
+	chl_map->ch[0].start = 0;
+	while (byte_count) {
+		rpl_map->sge[sge_no].iov_base =
+			page_address(rqstp->rq_arg.pages[page_no]) + page_off;
+		sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes);
+		rpl_map->sge[sge_no].iov_len = sge_bytes;
+		/*
+		 * Don't bump head->count here because the same page
+		 * may be used by multiple SGE.
+		 */
+		head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
+		rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
+
+		byte_count -= sge_bytes;
+		ch_bytes -= sge_bytes;
+		sge_no++;
+		/*
+		 * If all bytes for this chunk have been mapped to an
+		 * SGE, move to the next SGE
+		 */
+		if (ch_bytes == 0) {
+			chl_map->ch[ch_no].count =
+				sge_no - chl_map->ch[ch_no].start;
+			ch_no++;
+			ch++;
+			chl_map->ch[ch_no].start = sge_no;
+			ch_bytes = ntohl(ch->rc_target.rs_length);
+			/* If bytes remaining account for next chunk */
+			if (byte_count) {
+				head->arg.page_len += ch_bytes;
+				head->arg.len += ch_bytes;
+				head->arg.buflen += ch_bytes;
+			}
+		}
+		/*
+		 * If this SGE consumed all of the page, move to the
+		 * next page
+		 */
+		if ((sge_bytes + page_off) == PAGE_SIZE) {
+			page_no++;
+			page_off = 0;
+			/*
+			 * If there are still bytes left to map, bump
+			 * the page count
+			 */
+			if (byte_count)
+				head->count++;
+		} else
+			page_off += sge_bytes;
+	}
+	BUG_ON(byte_count != 0);
+	return sge_no;
+}
+
+/* Map a read-chunk-list to an XDR and fast register the page-list.
+ *
+ * Assumptions:
+ * - chunk[0]	position points to pages[0] at an offset of 0
+ * - pages[]	will be made physically contiguous by creating a one-off memory
+ *		region using the fastreg verb.
+ * - byte_count is # of bytes in read-chunk-list
+ * - ch_count	is # of chunks in read-chunk-list
+ *
+ * Output:
+ * - sge array pointing into pages[] array.
+ * - chunk_sge array specifying sge index and count for each
+ *   chunk in the read list
+ */
+static int fast_reg_read_chunks(struct svcxprt_rdma *xprt,
+				struct svc_rqst *rqstp,
+				struct svc_rdma_op_ctxt *head,
+				struct rpcrdma_msg *rmsgp,
+				struct svc_rdma_req_map *rpl_map,
+				struct svc_rdma_req_map *chl_map,
+				int ch_count,
+				int byte_count)
+{
+	int page_no;
+	int ch_no;
+	u32 offset;
+	struct rpcrdma_read_chunk *ch;
+	struct svc_rdma_fastreg_mr *frmr;
+	int ret = 0;
+
+	frmr = svc_rdma_get_frmr(xprt);
+	if (IS_ERR(frmr))
+		return -ENOMEM;
+
+	head->frmr = frmr;
+	head->arg.head[0] = rqstp->rq_arg.head[0];
+	head->arg.tail[0] = rqstp->rq_arg.tail[0];
+	head->arg.pages = &head->pages[head->count];
+	head->hdr_count = head->count; /* save count of hdr pages */
+	head->arg.page_base = 0;
+	head->arg.page_len = byte_count;
+	head->arg.len = rqstp->rq_arg.len + byte_count;
+	head->arg.buflen = rqstp->rq_arg.buflen + byte_count;
+
+	/* Fast register the page list */
+	frmr->kva = page_address(rqstp->rq_arg.pages[0]);
+	frmr->direction = DMA_FROM_DEVICE;
+	frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE);
+	frmr->map_len = byte_count;
+	frmr->page_list_len = PAGE_ALIGN(byte_count) >> PAGE_SHIFT;
+	for (page_no = 0; page_no < frmr->page_list_len; page_no++) {
+		frmr->page_list->page_list[page_no] =
+			ib_dma_map_page(xprt->sc_cm_id->device,
+					rqstp->rq_arg.pages[page_no], 0,
+					PAGE_SIZE, DMA_FROM_DEVICE);
+		if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+					 frmr->page_list->page_list[page_no]))
+			goto fatal_err;
+		atomic_inc(&xprt->sc_dma_used);
+		head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
+	}
+	head->count += page_no;
+
+	/* rq_respages points one past arg pages */
+	rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
+
+	/* Create the reply and chunk maps */
+	offset = 0;
+	ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
+	for (ch_no = 0; ch_no < ch_count; ch_no++) {
+		int len = ntohl(ch->rc_target.rs_length);
+		rpl_map->sge[ch_no].iov_base = frmr->kva + offset;
+		rpl_map->sge[ch_no].iov_len = len;
+		chl_map->ch[ch_no].count = 1;
+		chl_map->ch[ch_no].start = ch_no;
+		offset += len;
+		ch++;
+	}
+
+	ret = svc_rdma_fastreg(xprt, frmr);
+	if (ret)
+		goto fatal_err;
+
+	return ch_no;
+
+ fatal_err:
+	printk("svcrdma: error fast registering xdr for xprt %p", xprt);
+	svc_rdma_put_frmr(xprt, frmr);
+	return -EIO;
+}
+
+static int rdma_set_ctxt_sge(struct svcxprt_rdma *xprt,
+			     struct svc_rdma_op_ctxt *ctxt,
+			     struct svc_rdma_fastreg_mr *frmr,
+			     struct kvec *vec,
+			     u64 *sgl_offset,
+			     int count)
+{
+	int i;
+	unsigned long off;
+
+	ctxt->count = count;
+	ctxt->direction = DMA_FROM_DEVICE;
+	for (i = 0; i < count; i++) {
+		ctxt->sge[i].length = 0; /* in case map fails */
+		if (!frmr) {
+			BUG_ON(!virt_to_page(vec[i].iov_base));
+			off = (unsigned long)vec[i].iov_base & ~PAGE_MASK;
+			ctxt->sge[i].addr =
+				ib_dma_map_page(xprt->sc_cm_id->device,
+						virt_to_page(vec[i].iov_base),
+						off,
+						vec[i].iov_len,
+						DMA_FROM_DEVICE);
+			if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+						 ctxt->sge[i].addr))
+				return -EINVAL;
+			ctxt->sge[i].lkey = xprt->sc_dma_lkey;
+			atomic_inc(&xprt->sc_dma_used);
+		} else {
+			ctxt->sge[i].addr = (unsigned long)vec[i].iov_base;
+			ctxt->sge[i].lkey = frmr->mr->lkey;
+		}
+		ctxt->sge[i].length = vec[i].iov_len;
+		*sgl_offset = *sgl_offset + vec[i].iov_len;
+	}
+	return 0;
+}
+
+static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
+{
+	if ((rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
+	     RDMA_TRANSPORT_IWARP) &&
+	    sge_count > 1)
+		return 1;
+	else
+		return min_t(int, sge_count, xprt->sc_max_sge);
+}
+
+/*
+ * Use RDMA_READ to read data from the advertised client buffer into the
+ * XDR stream starting at rq_arg.head[0].iov_base.
+ * Each chunk in the array
+ * contains the following fields:
+ * discrim      - '1', This isn't used for data placement
+ * position     - The xdr stream offset (the same for every chunk)
+ * handle       - RMR for client memory region
+ * length       - data transfer length
+ * offset       - 64 bit tagged offset in remote memory region
+ *
+ * On our side, we need to read into a pagelist. The first page immediately
+ * follows the RPC header.
+ *
+ * This function returns:
+ * 0 - No error and no read-list found.
+ *
+ * 1 - Successful read-list processing. The data is not yet in
+ * the pagelist and therefore the RPC request must be deferred. The
+ * I/O completion will enqueue the transport again and
+ * svc_rdma_recvfrom will complete the request.
+ *
+ * <0 - Error processing/posting read-list.
+ *
+ * NOTE: The ctxt must not be touched after the last WR has been posted
+ * because the I/O completion processing may occur on another
+ * processor and free / modify the context. Ne touche pas!
+ */
+static int rdma_read_xdr(struct svcxprt_rdma *xprt,
+			 struct rpcrdma_msg *rmsgp,
+			 struct svc_rqst *rqstp,
+			 struct svc_rdma_op_ctxt *hdr_ctxt)
+{
+	struct ib_send_wr read_wr;
+	struct ib_send_wr inv_wr;
+	int err = 0;
+	int ch_no;
+	int ch_count;
+	int byte_count;
+	int sge_count;
+	u64 sgl_offset;
+	struct rpcrdma_read_chunk *ch;
+	struct svc_rdma_op_ctxt *ctxt = NULL;
+	struct svc_rdma_req_map *rpl_map;
+	struct svc_rdma_req_map *chl_map;
+
+	/* If no read list is present, return 0 */
+	ch = svc_rdma_get_read_chunk(rmsgp);
+	if (!ch)
+		return 0;
+
+	svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count);
+	if (ch_count > RPCSVC_MAXPAGES)
+		return -EINVAL;
+
+	/* Allocate temporary reply and chunk maps */
+	rpl_map = svc_rdma_get_req_map();
+	chl_map = svc_rdma_get_req_map();
+
+	if (!xprt->sc_frmr_pg_list_len)
+		sge_count = map_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
+					    rpl_map, chl_map, ch_count,
+					    byte_count);
+	else
+		sge_count = fast_reg_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
+						 rpl_map, chl_map, ch_count,
+						 byte_count);
+	if (sge_count < 0) {
+		err = -EIO;
+		goto out;
+	}
+
+	sgl_offset = 0;
+	ch_no = 0;
+
+	for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
+	     ch->rc_discrim != 0; ch++, ch_no++) {
+		u64 rs_offset;
+next_sge:
+		ctxt = svc_rdma_get_context(xprt);
+		ctxt->direction = DMA_FROM_DEVICE;
+		ctxt->frmr = hdr_ctxt->frmr;
+		ctxt->read_hdr = NULL;
+		clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+		clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
+
+		/* Prepare READ WR */
+		memset(&read_wr, 0, sizeof read_wr);
+		read_wr.wr_id = (unsigned long)ctxt;
+		read_wr.opcode = IB_WR_RDMA_READ;
+		ctxt->wr_op = read_wr.opcode;
+		read_wr.send_flags = IB_SEND_SIGNALED;
+		read_wr.wr.rdma.rkey = ntohl(ch->rc_target.rs_handle);
+		xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset,
+				 &rs_offset);
+		read_wr.wr.rdma.remote_addr = rs_offset + sgl_offset;
+		read_wr.sg_list = ctxt->sge;
+		read_wr.num_sge =
+			rdma_read_max_sge(xprt, chl_map->ch[ch_no].count);
+		err = rdma_set_ctxt_sge(xprt, ctxt, hdr_ctxt->frmr,
+					&rpl_map->sge[chl_map->ch[ch_no].start],
+					&sgl_offset,
+					read_wr.num_sge);
+		if (err) {
+			svc_rdma_unmap_dma(ctxt);
+			svc_rdma_put_context(ctxt, 0);
+			goto out;
+		}
+		if (((ch+1)->rc_discrim == 0) &&
+		    (read_wr.num_sge == chl_map->ch[ch_no].count)) {
+			/*
+			 * Mark the last RDMA_READ with a bit to
+			 * indicate all RPC data has been fetched from
+			 * the client and the RPC needs to be enqueued.
+			 */
+			set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+			if (hdr_ctxt->frmr) {
+				set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
+				/*
+				 * Invalidate the local MR used to map the data
+				 * sink.
+				 */
+				if (xprt->sc_dev_caps &
+				    SVCRDMA_DEVCAP_READ_W_INV) {
+					read_wr.opcode =
+						IB_WR_RDMA_READ_WITH_INV;
+					ctxt->wr_op = read_wr.opcode;
+					read_wr.ex.invalidate_rkey =
+						ctxt->frmr->mr->lkey;
+				} else {
+					/* Prepare INVALIDATE WR */
+					memset(&inv_wr, 0, sizeof inv_wr);
+					inv_wr.opcode = IB_WR_LOCAL_INV;
+					inv_wr.send_flags = IB_SEND_SIGNALED;
+					inv_wr.ex.invalidate_rkey =
+						hdr_ctxt->frmr->mr->lkey;
+					read_wr.next = &inv_wr;
+				}
+			}
+			ctxt->read_hdr = hdr_ctxt;
+		}
+		/* Post the read */
+		err = svc_rdma_send(xprt, &read_wr);
+		if (err) {
+			printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
+			       err);
+			set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+			svc_rdma_unmap_dma(ctxt);
+			svc_rdma_put_context(ctxt, 0);
+			goto out;
+		}
+		atomic_inc(&rdma_stat_read);
+
+		if (read_wr.num_sge < chl_map->ch[ch_no].count) {
+			chl_map->ch[ch_no].count -= read_wr.num_sge;
+			chl_map->ch[ch_no].start += read_wr.num_sge;
+			goto next_sge;
+		}
+		sgl_offset = 0;
+		err = 1;
+	}
+
+ out:
+	svc_rdma_put_req_map(rpl_map);
+	svc_rdma_put_req_map(chl_map);
+
+	/* Detach arg pages. svc_recv will replenish them */
+	for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++)
+		rqstp->rq_pages[ch_no] = NULL;
+
+	/*
+	 * Detach res pages. svc_release must see a resused count of
+	 * zero or it will attempt to put them.
+	 */
+	while (rqstp->rq_resused)
+		rqstp->rq_respages[--rqstp->rq_resused] = NULL;
+
+	return err;
+}
+
+static int rdma_read_complete(struct svc_rqst *rqstp,
+			      struct svc_rdma_op_ctxt *head)
+{
+	int page_no;
+	int ret;
+
+	BUG_ON(!head);
+
+	/* Copy RPC pages */
+	for (page_no = 0; page_no < head->count; page_no++) {
+		put_page(rqstp->rq_pages[page_no]);
+		rqstp->rq_pages[page_no] = head->pages[page_no];
+	}
+	/* Point rq_arg.pages past header */
+	rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
+	rqstp->rq_arg.page_len = head->arg.page_len;
+	rqstp->rq_arg.page_base = head->arg.page_base;
+
+	/* rq_respages starts after the last arg page */
+	rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
+	rqstp->rq_resused = 0;
+
+	/* Rebuild rq_arg head and tail. */
+	rqstp->rq_arg.head[0] = head->arg.head[0];
+	rqstp->rq_arg.tail[0] = head->arg.tail[0];
+	rqstp->rq_arg.len = head->arg.len;
+	rqstp->rq_arg.buflen = head->arg.buflen;
+
+	/* Free the context */
+	svc_rdma_put_context(head, 0);
+
+	/* XXX: What should this be? */
+	rqstp->rq_prot = IPPROTO_MAX;
+	svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
+
+	ret = rqstp->rq_arg.head[0].iov_len
+		+ rqstp->rq_arg.page_len
+		+ rqstp->rq_arg.tail[0].iov_len;
+	dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, "
+		"rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
+		ret, rqstp->rq_arg.len,	rqstp->rq_arg.head[0].iov_base,
+		rqstp->rq_arg.head[0].iov_len);
+
+	return ret;
+}
+
+/*
+ * Set up the rqstp thread context to point to the RQ buffer. If
+ * necessary, pull additional data from the client with an RDMA_READ
+ * request.
+ */
+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_op_ctxt *ctxt = NULL;
+	struct rpcrdma_msg *rmsgp;
+	int ret = 0;
+	int len;
+
+	dprintk("svcrdma: rqstp=%p\n", rqstp);
+
+	spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
+	if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
+		ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
+				  struct svc_rdma_op_ctxt,
+				  dto_q);
+		list_del_init(&ctxt->dto_q);
+	}
+	if (ctxt) {
+		spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+		return rdma_read_complete(rqstp, ctxt);
+	}
+
+	if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
+		ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next,
+				  struct svc_rdma_op_ctxt,
+				  dto_q);
+		list_del_init(&ctxt->dto_q);
+	} else {
+		atomic_inc(&rdma_stat_rq_starve);
+		clear_bit(XPT_DATA, &xprt->xpt_flags);
+		ctxt = NULL;
+	}
+	spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+	if (!ctxt) {
+		/* This is the EAGAIN path. The svc_recv routine will
+		 * return -EAGAIN, the nfsd thread will go to call into
+		 * svc_recv again and we shouldn't be on the active
+		 * transport list
+		 */
+		if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
+			goto close_out;
+
+		BUG_ON(ret);
+		goto out;
+	}
+	dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n",
+		ctxt, rdma_xprt, rqstp, ctxt->wc_status);
+	BUG_ON(ctxt->wc_status != IB_WC_SUCCESS);
+	atomic_inc(&rdma_stat_recv);
+
+	/* Build up the XDR from the receive buffers. */
+	rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);
+
+	/* Decode the RDMA header. */
+	len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);
+	rqstp->rq_xprt_hlen = len;
+
+	/* If the request is invalid, reply with an error */
+	if (len < 0) {
+		if (len == -ENOSYS)
+			svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
+		goto close_out;
+	}
+
+	/* Read read-list data. */
+	ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
+	if (ret > 0) {
+		/* read-list posted, defer until data received from client. */
+		goto defer;
+	}
+	if (ret < 0) {
+		/* Post of read-list failed, free context. */
+		svc_rdma_put_context(ctxt, 1);
+		return 0;
+	}
+
+	ret = rqstp->rq_arg.head[0].iov_len
+		+ rqstp->rq_arg.page_len
+		+ rqstp->rq_arg.tail[0].iov_len;
+	svc_rdma_put_context(ctxt, 0);
+ out:
+	dprintk("svcrdma: ret = %d, rq_arg.len =%d, "
+		"rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
+		ret, rqstp->rq_arg.len,
+		rqstp->rq_arg.head[0].iov_base,
+		rqstp->rq_arg.head[0].iov_len);
+	rqstp->rq_prot = IPPROTO_MAX;
+	svc_xprt_copy_addrs(rqstp, xprt);
+	return ret;
+
+ close_out:
+	if (ctxt)
+		svc_rdma_put_context(ctxt, 1);
+	dprintk("svcrdma: transport %p is closing\n", xprt);
+	/*
+	 * Set the close bit and enqueue it. svc_recv will see the
+	 * close bit and call svc_xprt_delete
+	 */
+	set_bit(XPT_CLOSE, &xprt->xpt_flags);
+defer:
+	return 0;
+}