Re: [RFC Patch 08/09] NFS/RDMA client - rpcrdma protocol handling

[Chuck Lever <chuck.lever@oracle.com>]

[-- Attachment #1: Type: text/plain, Size: 39853 bytes --]

Hi Tom!


Talpey, Thomas wrote:
> 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>
> 
> ---
> 
> Index: linux-2.6.22/net/sunrpc/xprtrdma/rpc_rdma.c
> ===================================================================
> --- linux-2.6.22.orig/net/sunrpc/xprtrdma/rpc_rdma.c
> +++ linux-2.6.22/net/sunrpc/xprtrdma/rpc_rdma.c
> @@ -1,9 +1,882 @@
>  /*
> - * 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/nfs2.h>
> +#include <linux/nfs3.h>
> +#include <linux/nfs4.h>

I haven't looked closely at this yet, but is there really a dependency 
in here on NFS?  I don't see NFS dependencies in other parts of the RPC 
client or server, save the legacy debugging interface 
(/proc/sys/sunrpc/nfs_debug and friends).


> +#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 first,
> +       enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
> +{
> +       int len, n = 0, p;
> +
> +       if (first == 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;
> +               ++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 = PAGE_SIZE - xdrbuf->page_base;
> +               len = xdrbuf->page_len - seg[n].mr_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 = ((len > PAGE_SIZE) ? PAGE_SIZE : len);
> +                       len -= seg[n].mr_len;
> +                       ++n;
> +                       ++p;
> +               }
> +       }
> +
> +       if (xdrbuf->tail[0].iov_len && type != rpcrdma_writech) {
> +               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;
> +               ++n;
> +       }
> +       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;
> +
> +       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;
> +       rpcx_to_rdmax(rqst->rq_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);
> +                       rpcx_to_rdmax(rqst->rq_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;
> +}
> +
> +/*
> + * Totally imperfect, temporary attempt to detect nfs reads...
> + * e.g. establish a hint via xdr_inline_pages, etc.
> + */
> +static int
> +is_nfs_read(struct rpc_rqst *rqst)
> +{
> +       u32 *p;
> +
> +       if (rqst->rq_task->tk_client->cl_prog != NFS_PROGRAM)
> +               return 0;
> +       switch (rqst->rq_task->tk_client->cl_vers) {
> +       case 4:
> +               /* Must dig into the COMPOUND. */
> +               /* Back up from the end of what a read request would be */
> +               /* PUTFH, fh, OP_READ, stateid(16), offset(8), count(4) */
> +               p = (u32 *)(rqst->rq_snd_buf.head[0].iov_base +
> +                           rqst->rq_snd_buf.head[0].iov_len);
> +               /* test read and count */
> +               return (rqst->rq_snd_buf.head[0].iov_len > 40 &&
> +                       p[-8] == __constant_htonl(OP_READ) &&
> +
> +                       p[-1] == htonl(rqst->rq_rcv_buf.page_len));
> +       case 3:
> +               return rqst->rq_task->tk_msg.rpc_proc->p_proc == NFS3PROC_READ;
> +       case 2:
> +               return rqst->rq_task->tk_msg.rpc_proc->p_proc == NFSPROC_READ;
> +       }
> +       return 0;
> +}
> +
> +/*
> + * 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 (is_nfs_read(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 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--) {
> +               ifdebug(FACILITY) {
> +                       u64 off;
> +                       xdr_decode_hyper((u32 *)&cur_wchunk->wc_target.rs_offset, &off);
> +                       dprintk("RPC:       %s: chunk %d@0x%llx:0x%x\n",
> +                               __func__, ntohl(cur_wchunk->wc_target.rs_length),
> +                               off, ntohl(cur_wchunk->wc_target.rs_handle));
> +               }
> +               total_len += ntohl(cur_wchunk->wc_target.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;
> +                       if ((copy_len -= curlen) == 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:
> +               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;
> +
> +       default:
> +       badheader:
> +               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);
> +}
> 
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> NFS maillist  -  NFS@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/nfs


[-- Attachment #2: chuck.lever.vcf --]
[-- Type: text/x-vcard, Size: 315 bytes --]

begin:vcard
fn:Chuck Lever
n:Lever;Chuck
org:Oracle Corporation;Corporate Architecture: Linux Projects Group
adr:;;1015 Granger Avenue;Ann Arbor;MI;48104;USA
email;internet:chuck dot lever at nospam oracle dot com
title:Principal Member of Staff
tel;work:+1 248 614 5091
x-mozilla-html:FALSE
version:2.1
end:vcard


[-- Attachment #3: Type: text/plain, Size: 286 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

[-- Attachment #4: Type: text/plain, Size: 140 bytes --]

_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs