RPCRDMA: rpc rdma protocol implementation
This implements the marshaling and unmarshaling of the rpcrdma transport
headers. Connection management is also addressed.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index b0587f3..12db635 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1,9 +1,868 @@
/*
- * Placeholders for subsequent patches
+ * Copyright (c) 2003-2007 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.
+ */
+
+/*
+ * rpc_rdma.c
+ *
+ * This file contains the guts of the RPC RDMA protocol, and
+ * does marshaling/unmarshaling, etc. It is also where interfacing
+ * to the Linux RPC framework lives.
*/
#include "xprt_rdma.h"
-void rpcrdma_conn_func(struct rpcrdma_ep *a) { }
-void rpcrdma_reply_handler(struct rpcrdma_rep *a) { }
-int rpcrdma_marshal_req(struct rpc_rqst *a) { return EINVAL; }
+#include <linux/highmem.h>
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY RPCDBG_TRANS
+#endif
+
+enum rpcrdma_chunktype {
+ rpcrdma_noch = 0,
+ rpcrdma_readch,
+ rpcrdma_areadch,
+ rpcrdma_writech,
+ rpcrdma_replych
+};
+
+#ifdef RPC_DEBUG
+static const char transfertypes[][12] = {
+ "pure inline", /* no chunks */
+ " read chunk", /* some argument via rdma read */
+ "*read chunk", /* entire request via rdma read */
+ "write chunk", /* some result via rdma write */
+ "reply chunk" /* entire reply via rdma write */
+};
+#endif
+
+/*
+ * Chunk assembly from upper layer xdr_buf.
+ *
+ * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
+ * elements. Segments are then coalesced when registered, if possible
+ * within the selected memreg mode.
+ *
+ * Note, this routine is never called if the connection's memory
+ * registration strategy is 0 (bounce buffers).
+ */
+
+static int
+rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, int pos,
+ enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
+{
+ int len, n = 0, p;
+
+ if (pos == 0 && xdrbuf->head[0].iov_len) {
+ seg[n].mr_page = NULL;
+ seg[n].mr_offset = xdrbuf->head[0].iov_base;
+ seg[n].mr_len = xdrbuf->head[0].iov_len;
+ pos += xdrbuf->head[0].iov_len;
+ ++n;
+ }
+
+ if (xdrbuf->page_len && (xdrbuf->pages[0] != NULL)) {
+ if (n == nsegs)
+ return 0;
+ seg[n].mr_page = xdrbuf->pages[0];
+ seg[n].mr_offset = (void *)(unsigned long) xdrbuf->page_base;
+ seg[n].mr_len = min_t(u32,
+ PAGE_SIZE - xdrbuf->page_base, xdrbuf->page_len);
+ len = xdrbuf->page_len - seg[n].mr_len;
+ pos += len;
+ ++n;
+ p = 1;
+ while (len > 0) {
+ if (n == nsegs)
+ return 0;
+ seg[n].mr_page = xdrbuf->pages[p];
+ seg[n].mr_offset = NULL;
+ seg[n].mr_len = min_t(u32, PAGE_SIZE, len);
+ len -= seg[n].mr_len;
+ ++n;
+ ++p;
+ }
+ }
+
+ if (pos < xdrbuf->len && xdrbuf->tail[0].iov_len) {
+ if (n == nsegs)
+ return 0;
+ seg[n].mr_page = NULL;
+ seg[n].mr_offset = xdrbuf->tail[0].iov_base;
+ seg[n].mr_len = xdrbuf->tail[0].iov_len;
+ pos += xdrbuf->tail[0].iov_len;
+ ++n;
+ }
+
+ if (pos < xdrbuf->len)
+ dprintk("RPC: %s: marshaled only %d of %d\n",
+ __func__, pos, xdrbuf->len);
+
+ return n;
+}
+
+/*
+ * Create read/write chunk lists, and reply chunks, for RDMA
+ *
+ * Assume check against THRESHOLD has been done, and chunks are required.
+ * Assume only encoding one list entry for read|write chunks. The NFSv3
+ * protocol is simple enough to allow this as it only has a single "bulk
+ * result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The
+ * RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.)
+ *
+ * When used for a single reply chunk (which is a special write
+ * chunk used for the entire reply, rather than just the data), it
+ * is used primarily for READDIR and READLINK which would otherwise
+ * be severely size-limited by a small rdma inline read max. The server
+ * response will come back as an RDMA Write, followed by a message
+ * of type RDMA_NOMSG carrying the xid and length. As a result, reply
+ * chunks do not provide data alignment, however they do not require
+ * "fixup" (moving the response to the upper layer buffer) either.
+ *
+ * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
+ *
+ * Read chunklist (a linked list):
+ * N elements, position P (same P for all chunks of same arg!):
+ * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
+ *
+ * Write chunklist (a list of (one) counted array):
+ * N elements:
+ * 1 - N - HLOO - HLOO - ... - HLOO - 0
+ *
+ * Reply chunk (a counted array):
+ * N elements:
+ * 1 - N - HLOO - HLOO - ... - HLOO
+ */
+
+static unsigned int
+rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
+ struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
+{
+ struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_task->tk_xprt);
+ int nsegs, nchunks = 0;
+ int pos;
+ struct rpcrdma_mr_seg *seg = req->rl_segments;
+ struct rpcrdma_read_chunk *cur_rchunk = NULL;
+ struct rpcrdma_write_array *warray = NULL;
+ struct rpcrdma_write_chunk *cur_wchunk = NULL;
+ u32 *iptr = headerp->rm_body.rm_chunks;
+
+ if (type == rpcrdma_readch || type == rpcrdma_areadch) {
+ /* a read chunk - server will RDMA Read our memory */
+ cur_rchunk = (struct rpcrdma_read_chunk *) iptr;
+ } else {
+ /* a write or reply chunk - server will RDMA Write our memory */
+ *iptr++ = xdr_zero; /* encode a NULL read chunk list */
+ if (type == rpcrdma_replych)
+ *iptr++ = xdr_zero; /* a NULL write chunk list */
+ warray = (struct rpcrdma_write_array *) iptr;
+ cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1);
+ }
+
+ if (type == rpcrdma_replych || type == rpcrdma_areadch)
+ pos = 0;
+ else
+ pos = target->head[0].iov_len;
+
+ nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS);
+ if (nsegs == 0)
+ return 0;
+
+ do {
+ /* bind/register the memory, then build chunk from result. */
+ int n = rpcrdma_register_external(seg, nsegs,
+ cur_wchunk != NULL, r_xprt);
+ if (n <= 0)
+ goto out;
+ if (cur_rchunk) { /* read */
+ cur_rchunk->rc_discrim = xdr_one;
+ /* all read chunks have the same "position" */
+ cur_rchunk->rc_position = htonl(pos);
+ cur_rchunk->rc_target.rs_handle = htonl(seg->mr_rkey);
+ cur_rchunk->rc_target.rs_length = htonl(seg->mr_len);
+ xdr_encode_hyper(
+ (u32 *)&cur_rchunk->rc_target.rs_offset,
+ seg->mr_base);
+ dprintk("RPC: %s: read chunk "
+ "elem %d@0x%llx:0x%x pos %d (%s)\n", __func__,
+ seg->mr_len, seg->mr_base, seg->mr_rkey, pos,
+ n < nsegs ? "more" : "last");
+ cur_rchunk++;
+ r_xprt->rx_stats.read_chunk_count++;
+ } else { /* write/reply */
+ cur_wchunk->wc_target.rs_handle = htonl(seg->mr_rkey);
+ cur_wchunk->wc_target.rs_length = htonl(seg->mr_len);
+ xdr_encode_hyper(
+ (u32 *)&cur_wchunk->wc_target.rs_offset,
+ seg->mr_base);
+ dprintk("RPC: %s: %s chunk "
+ "elem %d@0x%llx:0x%x (%s)\n", __func__,
+ (type == rpcrdma_replych) ? "reply" : "write",
+ seg->mr_len, seg->mr_base, seg->mr_rkey,
+ n < nsegs ? "more" : "last");
+ cur_wchunk++;
+ if (type == rpcrdma_replych)
+ r_xprt->rx_stats.reply_chunk_count++;
+ else
+ r_xprt->rx_stats.write_chunk_count++;
+ r_xprt->rx_stats.total_rdma_request += seg->mr_len;
+ }
+ nchunks++;
+ seg += n;
+ nsegs -= n;
+ } while (nsegs);
+
+ /* success. all failures return above */
+ req->rl_nchunks = nchunks;
+
+ BUG_ON(nchunks == 0);
+
+ /*
+ * finish off header. If write, marshal discrim and nchunks.
+ */
+ if (cur_rchunk) {
+ iptr = (u32 *) cur_rchunk;
+ *iptr++ = xdr_zero; /* finish the read chunk list */
+ *iptr++ = xdr_zero; /* encode a NULL write chunk list */
+ *iptr++ = xdr_zero; /* encode a NULL reply chunk */
+ } else {
+ warray->wc_discrim = xdr_one;
+ warray->wc_nchunks = htonl(nchunks);
+ iptr = (u32 *) cur_wchunk;
+ if (type == rpcrdma_writech) {
+ *iptr++ = xdr_zero; /* finish the write chunk list */
+ *iptr++ = xdr_zero; /* encode a NULL reply chunk */
+ }
+ }
+
+ /*
+ * Return header size.
+ */
+ return (unsigned char *)iptr - (unsigned char *)headerp;
+
+out:
+ for (pos = 0; nchunks--;)
+ pos += rpcrdma_deregister_external(
+ &req->rl_segments[pos], r_xprt, NULL);
+ return 0;
+}
+
+/*
+ * Copy write data inline.
+ * This function is used for "small" requests. Data which is passed
+ * to RPC via iovecs (or page list) is copied directly into the
+ * pre-registered memory buffer for this request. For small amounts
+ * of data, this is efficient. The cutoff value is tunable.
+ */
+static int
+rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
+{
+ int i, npages, curlen;
+ int copy_len;
+ unsigned char *srcp, *destp;
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
+
+ destp = rqst->rq_svec[0].iov_base;
+ curlen = rqst->rq_svec[0].iov_len;
+ destp += curlen;
+ /*
+ * Do optional padding where it makes sense. Alignment of write
+ * payload can help the server, if our setting is accurate.
+ */
+ pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
+ if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
+ pad = 0; /* don't pad this request */
+
+ dprintk("RPC: %s: pad %d destp 0x%p len %d hdrlen %d\n",
+ __func__, pad, destp, rqst->rq_slen, curlen);
+
+ copy_len = rqst->rq_snd_buf.page_len;
+ r_xprt->rx_stats.pullup_copy_count += copy_len;
+ npages = PAGE_ALIGN(rqst->rq_snd_buf.page_base+copy_len) >> PAGE_SHIFT;
+ for (i = 0; copy_len && i < npages; i++) {
+ if (i == 0)
+ curlen = PAGE_SIZE - rqst->rq_snd_buf.page_base;
+ else
+ curlen = PAGE_SIZE;
+ if (curlen > copy_len)
+ curlen = copy_len;
+ dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n",
+ __func__, i, destp, copy_len, curlen);
+ srcp = kmap_atomic(rqst->rq_snd_buf.pages[i],
+ KM_SKB_SUNRPC_DATA);
+ if (i == 0)
+ memcpy(destp, srcp+rqst->rq_snd_buf.page_base, curlen);
+ else
+ memcpy(destp, srcp, curlen);
+ kunmap_atomic(srcp, KM_SKB_SUNRPC_DATA);
+ rqst->rq_svec[0].iov_len += curlen;
+ destp += curlen;
+ copy_len -= curlen;
+ }
+ if (rqst->rq_snd_buf.tail[0].iov_len) {
+ curlen = rqst->rq_snd_buf.tail[0].iov_len;
+ if (destp != rqst->rq_snd_buf.tail[0].iov_base) {
+ memcpy(destp,
+ rqst->rq_snd_buf.tail[0].iov_base, curlen);
+ r_xprt->rx_stats.pullup_copy_count += curlen;
+ }
+ dprintk("RPC: %s: tail destp 0x%p len %d curlen %d\n",
+ __func__, destp, copy_len, curlen);
+ rqst->rq_svec[0].iov_len += curlen;
+ }
+ /* header now contains entire send message */
+ return pad;
+}
+
+/*
+ * Marshal a request: the primary job of this routine is to choose
+ * the transfer modes. See comments below.
+ *
+ * Uses multiple RDMA IOVs for a request:
+ * [0] -- RPC RDMA header, which uses memory from the *start* of the
+ * preregistered buffer that already holds the RPC data in
+ * its middle.
+ * [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
+ * [2] -- optional padding.
+ * [3] -- if padded, header only in [1] and data here.
+ */
+
+int
+rpcrdma_marshal_req(struct rpc_rqst *rqst)
+{
+ struct rpc_xprt *xprt = rqst->rq_task->tk_xprt;
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+ struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+ char *base;
+ size_t hdrlen, rpclen, padlen;
+ enum rpcrdma_chunktype rtype, wtype;
+ struct rpcrdma_msg *headerp;
+
+ /*
+ * rpclen gets amount of data in first buffer, which is the
+ * pre-registered buffer.
+ */
+ base = rqst->rq_svec[0].iov_base;
+ rpclen = rqst->rq_svec[0].iov_len;
+
+ /* build RDMA header in private area at front */
+ headerp = (struct rpcrdma_msg *) req->rl_base;
+ /* don't htonl XID, it's already done in request */
+ headerp->rm_xid = rqst->rq_xid;
+ headerp->rm_vers = xdr_one;
+ headerp->rm_credit = htonl(r_xprt->rx_buf.rb_max_requests);
+ headerp->rm_type = __constant_htonl(RDMA_MSG);
+
+ /*
+ * Chunks needed for results?
+ *
+ * o If the expected result is under the inline threshold, all ops
+ * return as inline (but see later).
+ * o Large non-read ops return as a single reply chunk.
+ * o Large read ops return data as write chunk(s), header as inline.
+ *
+ * Note: the NFS code sending down multiple result segments implies
+ * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
+ */
+
+ /*
+ * This code can handle read chunks, write chunks OR reply
+ * chunks -- only one type. If the request is too big to fit
+ * inline, then we will choose read chunks. If the request is
+ * a READ, then use write chunks to separate the file data
+ * into pages; otherwise use reply chunks.
+ */
+ if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
+ wtype = rpcrdma_noch;
+ else if (rqst->rq_rcv_buf.page_len == 0)
+ wtype = rpcrdma_replych;
+ else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
+ 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 non-write ops are sent with the entire message as a
+ * single read chunk (protocol 0-position special case).
+ * o Large write ops transmit data as read chunk(s), header as
+ * inline.
+ *
+ * Note: the NFS code sending down multiple argument segments
+ * implies the op is a write.
+ * TBD check NFSv4 setacl
+ */
+ if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
+ rtype = rpcrdma_noch;
+ else if (rqst->rq_snd_buf.page_len == 0)
+ rtype = rpcrdma_areadch;
+ else
+ rtype = rpcrdma_readch;
+
+ /* The following simplification is not true forever */
+ if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
+ wtype = rpcrdma_noch;
+ BUG_ON(rtype != rpcrdma_noch && wtype != rpcrdma_noch);
+
+ if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS &&
+ (rtype != rpcrdma_noch || wtype != rpcrdma_noch)) {
+ /* forced to "pure inline"? */
+ dprintk("RPC: %s: too much data (%d/%d) for inline\n",
+ __func__, rqst->rq_rcv_buf.len, rqst->rq_snd_buf.len);
+ return -1;
+ }
+
+ hdrlen = 28; /*sizeof *headerp;*/
+ padlen = 0;
+
+ /*
+ * Pull up any extra send data into the preregistered buffer.
+ * When padding is in use and applies to the transfer, insert
+ * it and change the message type.
+ */
+ if (rtype == rpcrdma_noch) {
+
+ padlen = rpcrdma_inline_pullup(rqst,
+ RPCRDMA_INLINE_PAD_VALUE(rqst));
+
+ if (padlen) {
+ headerp->rm_type = __constant_htonl(RDMA_MSGP);
+ headerp->rm_body.rm_padded.rm_align =
+ htonl(RPCRDMA_INLINE_PAD_VALUE(rqst));
+ headerp->rm_body.rm_padded.rm_thresh =
+ __constant_htonl(RPCRDMA_INLINE_PAD_THRESH);
+ headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
+ headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
+ headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
+ hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
+ BUG_ON(wtype != rpcrdma_noch);
+
+ } else {
+ headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
+ headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
+ headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
+ /* new length after pullup */
+ rpclen = rqst->rq_svec[0].iov_len;
+ /*
+ * Currently we try to not actually use read inline.
+ * Reply chunks have the desirable property that
+ * they land, packed, directly in the target buffers
+ * without headers, so they require no fixup. The
+ * additional RDMA Write op sends the same amount
+ * of data, streams on-the-wire and adds no overhead
+ * on receive. Therefore, we request a reply chunk
+ * for non-writes wherever feasible and efficient.
+ */
+ if (wtype == rpcrdma_noch &&
+ r_xprt->rx_ia.ri_memreg_strategy > RPCRDMA_REGISTER)
+ wtype = rpcrdma_replych;
+ }
+ }
+
+ /*
+ * Marshal chunks. This routine will return the header length
+ * consumed by marshaling.
+ */
+ if (rtype != rpcrdma_noch) {
+ hdrlen = rpcrdma_create_chunks(rqst,
+ &rqst->rq_snd_buf, headerp, rtype);
+ wtype = rtype; /* simplify dprintk */
+
+ } else if (wtype != rpcrdma_noch) {
+ hdrlen = rpcrdma_create_chunks(rqst,
+ &rqst->rq_rcv_buf, headerp, wtype);
+ }
+
+ if (hdrlen == 0)
+ return -1;
+
+ dprintk("RPC: %s: %s: hdrlen %zd rpclen %zd padlen %zd\n"
+ " headerp 0x%p base 0x%p lkey 0x%x\n",
+ __func__, transfertypes[wtype], hdrlen, rpclen, padlen,
+ headerp, base, req->rl_iov.lkey);
+
+ /*
+ * initialize send_iov's - normally only two: rdma chunk header and
+ * single preregistered RPC header buffer, but if padding is present,
+ * then use a preregistered (and zeroed) pad buffer between the RPC
+ * header and any write data. In all non-rdma cases, any following
+ * data has been copied into the RPC header buffer.
+ */
+ req->rl_send_iov[0].addr = req->rl_iov.addr;
+ req->rl_send_iov[0].length = hdrlen;
+ req->rl_send_iov[0].lkey = req->rl_iov.lkey;
+
+ req->rl_send_iov[1].addr = req->rl_iov.addr + (base - req->rl_base);
+ req->rl_send_iov[1].length = rpclen;
+ req->rl_send_iov[1].lkey = req->rl_iov.lkey;
+
+ req->rl_niovs = 2;
+
+ if (padlen) {
+ struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+
+ req->rl_send_iov[2].addr = ep->rep_pad.addr;
+ req->rl_send_iov[2].length = padlen;
+ req->rl_send_iov[2].lkey = ep->rep_pad.lkey;
+
+ req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
+ req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
+ req->rl_send_iov[3].lkey = req->rl_iov.lkey;
+
+ req->rl_niovs = 4;
+ }
+
+ return 0;
+}
+
+/*
+ * Chase down a received write or reply chunklist to get length
+ * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
+ */
+static int
+rpcrdma_count_chunks(struct rpcrdma_rep *rep, int max, int wrchunk, u32 **iptrp)
+{
+ unsigned int i, total_len;
+ struct rpcrdma_write_chunk *cur_wchunk;
+
+ i = ntohl(**iptrp); /* get array count */
+ if (i > max)
+ return -1;
+ cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
+ total_len = 0;
+ while (i--) {
+ struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
+ ifdebug(FACILITY) {
+ u64 off;
+ xdr_decode_hyper((u32 *)&seg->rs_offset, &off);
+ dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n",
+ __func__,
+ ntohl(seg->rs_length),
+ off,
+ ntohl(seg->rs_handle));
+ }
+ total_len += ntohl(seg->rs_length);
+ ++cur_wchunk;
+ }
+ /* check and adjust for properly terminated write chunk */
+ if (wrchunk) {
+ u32 *w = (u32 *) cur_wchunk;
+ if (*w++ != xdr_zero)
+ return -1;
+ cur_wchunk = (struct rpcrdma_write_chunk *) w;
+ }
+ if ((char *) cur_wchunk > rep->rr_base + rep->rr_len)
+ return -1;
+
+ *iptrp = (u32 *) cur_wchunk;
+ return total_len;
+}
+
+/*
+ * Scatter inline received data back into provided iov's.
+ */
+static void
+rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len)
+{
+ int i, npages, curlen, olen;
+ char *destp;
+
+ curlen = rqst->rq_rcv_buf.head[0].iov_len;
+ if (curlen > copy_len) { /* write chunk header fixup */
+ curlen = copy_len;
+ rqst->rq_rcv_buf.head[0].iov_len = curlen;
+ }
+
+ dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n",
+ __func__, srcp, copy_len, curlen);
+
+ /* Shift pointer for first receive segment only */
+ rqst->rq_rcv_buf.head[0].iov_base = srcp;
+ srcp += curlen;
+ copy_len -= curlen;
+
+ olen = copy_len;
+ i = 0;
+ rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
+ if (copy_len && rqst->rq_rcv_buf.page_len) {
+ npages = PAGE_ALIGN(rqst->rq_rcv_buf.page_base +
+ rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
+ for (; i < npages; i++) {
+ if (i == 0)
+ curlen = PAGE_SIZE - rqst->rq_rcv_buf.page_base;
+ else
+ curlen = PAGE_SIZE;
+ if (curlen > copy_len)
+ curlen = copy_len;
+ dprintk("RPC: %s: page %d"
+ " srcp 0x%p len %d curlen %d\n",
+ __func__, i, srcp, copy_len, curlen);
+ destp = kmap_atomic(rqst->rq_rcv_buf.pages[i],
+ KM_SKB_SUNRPC_DATA);
+ if (i == 0)
+ memcpy(destp + rqst->rq_rcv_buf.page_base,
+ srcp, curlen);
+ else
+ memcpy(destp, srcp, curlen);
+ flush_dcache_page(rqst->rq_rcv_buf.pages[i]);
+ kunmap_atomic(destp, KM_SKB_SUNRPC_DATA);
+ srcp += curlen;
+ copy_len -= curlen;
+ if (copy_len == 0)
+ break;
+ }
+ rqst->rq_rcv_buf.page_len = olen - copy_len;
+ } else
+ rqst->rq_rcv_buf.page_len = 0;
+
+ if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) {
+ curlen = copy_len;
+ if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
+ curlen = rqst->rq_rcv_buf.tail[0].iov_len;
+ if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
+ memcpy(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
+ dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n",
+ __func__, srcp, copy_len, curlen);
+ rqst->rq_rcv_buf.tail[0].iov_len = curlen;
+ copy_len -= curlen; ++i;
+ } else
+ rqst->rq_rcv_buf.tail[0].iov_len = 0;
+
+ if (copy_len)
+ dprintk("RPC: %s: %d bytes in"
+ " %d extra segments (%d lost)\n",
+ __func__, olen, i, copy_len);
+
+ /* TBD avoid a warning from call_decode() */
+ rqst->rq_private_buf = rqst->rq_rcv_buf;
+}
+
+/*
+ * This function is called when an async event is posted to
+ * the connection which changes the connection state. All it
+ * does at this point is mark the connection up/down, the rpc
+ * timers do the rest.
+ */
+void
+rpcrdma_conn_func(struct rpcrdma_ep *ep)
+{
+ struct rpc_xprt *xprt = ep->rep_xprt;
+
+ spin_lock_bh(&xprt->transport_lock);
+ if (ep->rep_connected > 0) {
+ if (!xprt_test_and_set_connected(xprt))
+ xprt_wake_pending_tasks(xprt, 0);
+ } else {
+ if (xprt_test_and_clear_connected(xprt))
+ xprt_wake_pending_tasks(xprt, ep->rep_connected);
+ }
+ spin_unlock_bh(&xprt->transport_lock);
+}
+
+/*
+ * This function is called when memory window unbind which we are waiting
+ * for completes. Just use rr_func (zeroed by upcall) to signal completion.
+ */
+static void
+rpcrdma_unbind_func(struct rpcrdma_rep *rep)
+{
+ wake_up(&rep->rr_unbind);
+}
+
+/*
+ * Called as a tasklet to do req/reply match and complete a request
+ * 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_msg *headerp;
+ struct rpcrdma_req *req;
+ struct rpc_rqst *rqst;
+ struct rpc_xprt *xprt = rep->rr_xprt;
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+ u32 *iptr;
+ int i, rdmalen, status;
+
+ /* Check status. If bad, signal disconnect and return rep to pool */
+ if (rep->rr_len == ~0U) {
+ rpcrdma_recv_buffer_put(rep);
+ if (r_xprt->rx_ep.rep_connected == 1) {
+ r_xprt->rx_ep.rep_connected = -EIO;
+ rpcrdma_conn_func(&r_xprt->rx_ep);
+ }
+ return;
+ }
+ if (rep->rr_len < 28) {
+ dprintk("RPC: %s: short/invalid reply\n", __func__);
+ goto repost;
+ }
+ headerp = (struct rpcrdma_msg *) rep->rr_base;
+ if (headerp->rm_vers != xdr_one) {
+ dprintk("RPC: %s: invalid version %d\n",
+ __func__, ntohl(headerp->rm_vers));
+ goto repost;
+ }
+
+ /* Get XID and try for a match. */
+ spin_lock(&xprt->transport_lock);
+ rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
+ if (rqst == NULL) {
+ spin_unlock(&xprt->transport_lock);
+ dprintk("RPC: %s: reply 0x%p failed "
+ "to match any request xid 0x%08x len %d\n",
+ __func__, rep, headerp->rm_xid, rep->rr_len);
+repost:
+ r_xprt->rx_stats.bad_reply_count++;
+ rep->rr_func = rpcrdma_reply_handler;
+ if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
+ rpcrdma_recv_buffer_put(rep);
+
+ return;
+ }
+
+ /* get request object */
+ req = rpcr_to_rdmar(rqst);
+
+ dprintk("RPC: %s: reply 0x%p completes request 0x%p\n"
+ " RPC request 0x%p xid 0x%08x\n",
+ __func__, rep, req, rqst, headerp->rm_xid);
+
+ BUG_ON(!req || req->rl_reply);
+
+ /* from here on, the reply is no longer an orphan */
+ req->rl_reply = rep;
+
+ /* check for expected message types */
+ /* The order of some of these tests is important. */
+ switch (headerp->rm_type) {
+ case __constant_htonl(RDMA_MSG):
+ /* never expect read chunks */
+ /* never expect reply chunks (two ways to check) */
+ /* never expect write chunks without having offered RDMA */
+ if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
+ (headerp->rm_body.rm_chunks[1] == xdr_zero &&
+ headerp->rm_body.rm_chunks[2] != xdr_zero) ||
+ (headerp->rm_body.rm_chunks[1] != xdr_zero &&
+ req->rl_nchunks == 0))
+ goto badheader;
+ if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
+ /* count any expected write chunks in read reply */
+ /* start at write chunk array count */
+ iptr = &headerp->rm_body.rm_chunks[2];
+ rdmalen = rpcrdma_count_chunks(rep,
+ req->rl_nchunks, 1, &iptr);
+ /* check for validity, and no reply chunk after */
+ if (rdmalen < 0 || *iptr++ != xdr_zero)
+ goto badheader;
+ rep->rr_len -=
+ ((unsigned char *)iptr - (unsigned char *)headerp);
+ status = rep->rr_len + rdmalen;
+ r_xprt->rx_stats.total_rdma_reply += rdmalen;
+ } else {
+ /* else ordinary inline */
+ iptr = (u32 *)((unsigned char *)headerp + 28);
+ rep->rr_len -= 28; /*sizeof *headerp;*/
+ status = rep->rr_len;
+ }
+ /* Fix up the rpc results for upper layer */
+ rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len);
+ break;
+
+ case __constant_htonl(RDMA_NOMSG):
+ /* never expect read or write chunks, always reply chunks */
+ if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
+ headerp->rm_body.rm_chunks[1] != xdr_zero ||
+ headerp->rm_body.rm_chunks[2] != xdr_one ||
+ req->rl_nchunks == 0)
+ goto badheader;
+ iptr = (u32 *)((unsigned char *)headerp + 28);
+ rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
+ if (rdmalen < 0)
+ goto badheader;
+ r_xprt->rx_stats.total_rdma_reply += rdmalen;
+ /* Reply chunk buffer already is the reply vector - no fixup. */
+ status = rdmalen;
+ break;
+
+badheader:
+ default:
+ dprintk("%s: invalid rpcrdma reply header (type %d):"
+ " chunks[012] == %d %d %d"
+ " expected chunks <= %d\n",
+ __func__, ntohl(headerp->rm_type),
+ headerp->rm_body.rm_chunks[0],
+ headerp->rm_body.rm_chunks[1],
+ headerp->rm_body.rm_chunks[2],
+ req->rl_nchunks);
+ status = -EIO;
+ r_xprt->rx_stats.bad_reply_count++;
+ break;
+ }
+
+ /* If using mw bind, start the deregister process now. */
+ /* (Note: if mr_free(), cannot perform it here, in tasklet context) */
+ if (req->rl_nchunks) switch (r_xprt->rx_ia.ri_memreg_strategy) {
+ case RPCRDMA_MEMWINDOWS:
+ for (i = 0; req->rl_nchunks-- > 1;)
+ i += rpcrdma_deregister_external(
+ &req->rl_segments[i], r_xprt, NULL);
+ /* Optionally wait (not here) for unbinds to complete */
+ rep->rr_func = rpcrdma_unbind_func;
+ (void) rpcrdma_deregister_external(&req->rl_segments[i],
+ r_xprt, rep);
+ break;
+ case RPCRDMA_MEMWINDOWS_ASYNC:
+ for (i = 0; req->rl_nchunks--;)
+ i += rpcrdma_deregister_external(&req->rl_segments[i],
+ r_xprt, NULL);
+ break;
+ default:
+ break;
+ }
+
+ dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
+ __func__, xprt, rqst, status);
+ xprt_complete_rqst(rqst->rq_task, status);
+ spin_unlock(&xprt->transport_lock);
+}