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3cbe01a94c
linux-next/net/sunrpc/xprtrdma/svc_rdma_sendto.c
Jeff Layton 3cbe01a94c svcrdma: fix offset calculation for non-page aligned sge entries 
The xdr_off value in dma_map_xdr gets passed to ib_dma_map_page as the
offset into the page to be mapped. This calculation does not correctly
take into account the case where the data starts at some offset into
the page. Increment the xdr_off by the page_base to ensure that it is
respected.

Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-03-28 18:02:13 -04:00

750 lines
21 KiB
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/*
* 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
/* Encode an XDR as an array of IB SGE
*
* Assumptions:
* - head[0] is physically contiguous.
* - tail[0] is physically contiguous.
* - pages[] is not physically or virtually contiguous and consists of
* PAGE_SIZE elements.
*
* Output:
* SGE[0] reserved for RCPRDMA header
* SGE[1] data from xdr->head[]
* SGE[2..sge_count-2] data from xdr->pages[]
* SGE[sge_count-1] data from xdr->tail.
*
* The max SGE we need is the length of the XDR / pagesize + one for
* head + one for tail + one for RPCRDMA header. Since RPCSVC_MAXPAGES
* reserves a page for both the request and the reply header, and this
* array is only concerned with the reply we are assured that we have
* on extra page for the RPCRMDA header.
*/
static int fast_reg_xdr(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
struct svc_rdma_req_map *vec)
{
int sge_no;
u32 sge_bytes;
u32 page_bytes;
u32 page_off;
int page_no = 0;
u8 *frva;
struct svc_rdma_fastreg_mr *frmr;
frmr = svc_rdma_get_frmr(xprt);
if (IS_ERR(frmr))
return -ENOMEM;
vec->frmr = frmr;
/* Skip the RPCRDMA header */
sge_no = 1;
/* Map the head. */
frva = (void *)((unsigned long)(xdr->head[0].iov_base) & PAGE_MASK);
vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
vec->count = 2;
sge_no++;
/* Map the XDR head */
frmr->kva = frva;
frmr->direction = DMA_TO_DEVICE;
frmr->access_flags = 0;
frmr->map_len = PAGE_SIZE;
frmr->page_list_len = 1;
page_off = (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
frmr->page_list->page_list[page_no] =
ib_dma_map_page(xprt->sc_cm_id->device,
virt_to_page(xdr->head[0].iov_base),
page_off,
PAGE_SIZE - page_off,
DMA_TO_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);
/* Map the XDR page list */
page_off = xdr->page_base;
page_bytes = xdr->page_len + page_off;
if (!page_bytes)
goto encode_tail;
/* Map the pages */
vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
vec->sge[sge_no].iov_len = page_bytes;
sge_no++;
while (page_bytes) {
struct page *page;
page = xdr->pages[page_no++];
sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
page_bytes -= sge_bytes;
frmr->page_list->page_list[page_no] =
ib_dma_map_page(xprt->sc_cm_id->device,
page, page_off,
sge_bytes, DMA_TO_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);
page_off = 0; /* reset for next time through loop */
frmr->map_len += PAGE_SIZE;
frmr->page_list_len++;
}
vec->count++;
encode_tail:
/* Map tail */
if (0 == xdr->tail[0].iov_len)
goto done;
vec->count++;
vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
if (((unsigned long)xdr->tail[0].iov_base & PAGE_MASK) ==
((unsigned long)xdr->head[0].iov_base & PAGE_MASK)) {
/*
* If head and tail use the same page, we don't need
* to map it again.
*/
vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
} else {
void *va;
/* Map another page for the tail */
page_off = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
va = (void *)((unsigned long)xdr->tail[0].iov_base & PAGE_MASK);
vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
frmr->page_list->page_list[page_no] =
ib_dma_map_page(xprt->sc_cm_id->device, virt_to_page(va),
page_off,
PAGE_SIZE,
DMA_TO_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);
frmr->map_len += PAGE_SIZE;
frmr->page_list_len++;
}
done:
if (svc_rdma_fastreg(xprt, frmr))
goto fatal_err;
return 0;
fatal_err:
printk("svcrdma: Error fast registering memory for xprt %p\n", xprt);
vec->frmr = NULL;
svc_rdma_put_frmr(xprt, frmr);
return -EIO;
}
static int map_xdr(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
struct svc_rdma_req_map *vec)
{
int sge_no;
u32 sge_bytes;
u32 page_bytes;
u32 page_off;
int page_no;
BUG_ON(xdr->len !=
(xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len));
if (xprt->sc_frmr_pg_list_len)
return fast_reg_xdr(xprt, xdr, vec);
/* Skip the first sge, this is for the RPCRDMA header */
sge_no = 1;
/* Head SGE */
vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
sge_no++;
/* pages SGE */
page_no = 0;
page_bytes = xdr->page_len;
page_off = xdr->page_base;
while (page_bytes) {
vec->sge[sge_no].iov_base =
page_address(xdr->pages[page_no]) + page_off;
sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
page_bytes -= sge_bytes;
vec->sge[sge_no].iov_len = sge_bytes;
sge_no++;
page_no++;
page_off = 0; /* reset for next time through loop */
}
/* Tail SGE */
if (xdr->tail[0].iov_len) {
vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
sge_no++;
}
dprintk("svcrdma: map_xdr: sge_no %d page_no %d "
"page_base %u page_len %u head_len %zu tail_len %zu\n",
sge_no, page_no, xdr->page_base, xdr->page_len,
xdr->head[0].iov_len, xdr->tail[0].iov_len);
vec->count = sge_no;
return 0;
}
static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
u32 xdr_off, size_t len, int dir)
{
struct page *page;
dma_addr_t dma_addr;
if (xdr_off < xdr->head[0].iov_len) {
/* This offset is in the head */
xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
page = virt_to_page(xdr->head[0].iov_base);
} else {
xdr_off -= xdr->head[0].iov_len;
if (xdr_off < xdr->page_len) {
/* This offset is in the page list */
xdr_off += xdr->page_base;
page = xdr->pages[xdr_off >> PAGE_SHIFT];
xdr_off &= ~PAGE_MASK;
} else {
/* This offset is in the tail */
xdr_off -= xdr->page_len;
xdr_off += (unsigned long)
xdr->tail[0].iov_base & ~PAGE_MASK;
page = virt_to_page(xdr->tail[0].iov_base);
}
}
dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off,
min_t(size_t, PAGE_SIZE, len), dir);
return dma_addr;
}
/* Assumptions:
* - We are using FRMR
* - or -
* - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
*/
static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
u32 rmr, u64 to,
u32 xdr_off, int write_len,
struct svc_rdma_req_map *vec)
{
struct ib_send_wr write_wr;
struct ib_sge *sge;
int xdr_sge_no;
int sge_no;
int sge_bytes;
int sge_off;
int bc;
struct svc_rdma_op_ctxt *ctxt;
BUG_ON(vec->count > RPCSVC_MAXPAGES);
dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
"write_len=%d, vec->sge=%p, vec->count=%lu\n",
rmr, (unsigned long long)to, xdr_off,
write_len, vec->sge, vec->count);
ctxt = svc_rdma_get_context(xprt);
ctxt->direction = DMA_TO_DEVICE;
sge = ctxt->sge;
/* Find the SGE associated with xdr_off */
for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count;
xdr_sge_no++) {
if (vec->sge[xdr_sge_no].iov_len > bc)
break;
bc -= vec->sge[xdr_sge_no].iov_len;
}
sge_off = bc;
bc = write_len;
sge_no = 0;
/* Copy the remaining SGE */
while (bc != 0) {
sge_bytes = min_t(size_t,
bc, vec->sge[xdr_sge_no].iov_len-sge_off);
sge[sge_no].length = sge_bytes;
if (!vec->frmr) {
sge[sge_no].addr =
dma_map_xdr(xprt, &rqstp->rq_res, xdr_off,
sge_bytes, DMA_TO_DEVICE);
xdr_off += sge_bytes;
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
sge[sge_no].addr))
goto err;
atomic_inc(&xprt->sc_dma_used);
sge[sge_no].lkey = xprt->sc_dma_lkey;
} else {
sge[sge_no].addr = (unsigned long)
vec->sge[xdr_sge_no].iov_base + sge_off;
sge[sge_no].lkey = vec->frmr->mr->lkey;
}
ctxt->count++;
ctxt->frmr = vec->frmr;
sge_off = 0;
sge_no++;
xdr_sge_no++;
BUG_ON(xdr_sge_no > vec->count);
bc -= sge_bytes;
}
/* Prepare WRITE WR */
memset(&write_wr, 0, sizeof write_wr);
ctxt->wr_op = IB_WR_RDMA_WRITE;
write_wr.wr_id = (unsigned long)ctxt;
write_wr.sg_list = &sge[0];
write_wr.num_sge = sge_no;
write_wr.opcode = IB_WR_RDMA_WRITE;
write_wr.send_flags = IB_SEND_SIGNALED;
write_wr.wr.rdma.rkey = rmr;
write_wr.wr.rdma.remote_addr = to;
/* Post It */
atomic_inc(&rdma_stat_write);
if (svc_rdma_send(xprt, &write_wr))
goto err;
return 0;
err:
svc_rdma_unmap_dma(ctxt);
svc_rdma_put_frmr(xprt, vec->frmr);
svc_rdma_put_context(ctxt, 0);
/* Fatal error, close transport */
return -EIO;
}
static int send_write_chunks(struct svcxprt_rdma *xprt,
struct rpcrdma_msg *rdma_argp,
struct rpcrdma_msg *rdma_resp,
struct svc_rqst *rqstp,
struct svc_rdma_req_map *vec)
{
u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
int write_len;
int max_write;
u32 xdr_off;
int chunk_off;
int chunk_no;
struct rpcrdma_write_array *arg_ary;
struct rpcrdma_write_array *res_ary;
int ret;
arg_ary = svc_rdma_get_write_array(rdma_argp);
if (!arg_ary)
return 0;
res_ary = (struct rpcrdma_write_array *)
&rdma_resp->rm_body.rm_chunks[1];
if (vec->frmr)
max_write = vec->frmr->map_len;
else
max_write = xprt->sc_max_sge * PAGE_SIZE;
/* Write chunks start at the pagelist */
for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
xfer_len && chunk_no < arg_ary->wc_nchunks;
chunk_no++) {
struct rpcrdma_segment *arg_ch;
u64 rs_offset;
arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
write_len = min(xfer_len, ntohl(arg_ch->rs_length));
/* Prepare the response chunk given the length actually
* written */
xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset);
svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
arg_ch->rs_handle,
arg_ch->rs_offset,
write_len);
chunk_off = 0;
while (write_len) {
int this_write;
this_write = min(write_len, max_write);
ret = send_write(xprt, rqstp,
ntohl(arg_ch->rs_handle),
rs_offset + chunk_off,
xdr_off,
this_write,
vec);
if (ret) {
dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
ret);
return -EIO;
}
chunk_off += this_write;
xdr_off += this_write;
xfer_len -= this_write;
write_len -= this_write;
}
}
/* Update the req with the number of chunks actually used */
svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
}
static int send_reply_chunks(struct svcxprt_rdma *xprt,
struct rpcrdma_msg *rdma_argp,
struct rpcrdma_msg *rdma_resp,
struct svc_rqst *rqstp,
struct svc_rdma_req_map *vec)
{
u32 xfer_len = rqstp->rq_res.len;
int write_len;
int max_write;
u32 xdr_off;
int chunk_no;
int chunk_off;
int nchunks;
struct rpcrdma_segment *ch;
struct rpcrdma_write_array *arg_ary;
struct rpcrdma_write_array *res_ary;
int ret;
arg_ary = svc_rdma_get_reply_array(rdma_argp);
if (!arg_ary)
return 0;
/* XXX: need to fix when reply lists occur with read-list and or
* write-list */
res_ary = (struct rpcrdma_write_array *)
&rdma_resp->rm_body.rm_chunks[2];
if (vec->frmr)
max_write = vec->frmr->map_len;
else
max_write = xprt->sc_max_sge * PAGE_SIZE;
/* xdr offset starts at RPC message */
nchunks = ntohl(arg_ary->wc_nchunks);
for (xdr_off = 0, chunk_no = 0;
xfer_len && chunk_no < nchunks;
chunk_no++) {
u64 rs_offset;
ch = &arg_ary->wc_array[chunk_no].wc_target;
write_len = min(xfer_len, htonl(ch->rs_length));
/* Prepare the reply chunk given the length actually
* written */
xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset);
svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
ch->rs_handle, ch->rs_offset,
write_len);
chunk_off = 0;
while (write_len) {
int this_write;
this_write = min(write_len, max_write);
ret = send_write(xprt, rqstp,
ntohl(ch->rs_handle),
rs_offset + chunk_off,
xdr_off,
this_write,
vec);
if (ret) {
dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
ret);
return -EIO;
}
chunk_off += this_write;
xdr_off += this_write;
xfer_len -= this_write;
write_len -= this_write;
}
}
/* Update the req with the number of chunks actually used */
svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
return rqstp->rq_res.len;
}
/* This function prepares the portion of the RPCRDMA message to be
* sent in the RDMA_SEND. This function is called after data sent via
* RDMA has already been transmitted. There are three cases:
* - The RPCRDMA header, RPC header, and payload are all sent in a
* single RDMA_SEND. This is the "inline" case.
* - The RPCRDMA header and some portion of the RPC header and data
* are sent via this RDMA_SEND and another portion of the data is
* sent via RDMA.
* - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
* header and data are all transmitted via RDMA.
* In all three cases, this function prepares the RPCRDMA header in
* sge[0], the 'type' parameter indicates the type to place in the
* RPCRDMA header, and the 'byte_count' field indicates how much of
* the XDR to include in this RDMA_SEND. NB: The offset of the payload
* to send is zero in the XDR.
*/
static int send_reply(struct svcxprt_rdma *rdma,
struct svc_rqst *rqstp,
struct page *page,
struct rpcrdma_msg *rdma_resp,
struct svc_rdma_op_ctxt *ctxt,
struct svc_rdma_req_map *vec,
int byte_count)
{
struct ib_send_wr send_wr;
struct ib_send_wr inv_wr;
int sge_no;
int sge_bytes;
int page_no;
int pages;
int ret;
/* Post a recv buffer to handle another request. */
ret = svc_rdma_post_recv(rdma);
if (ret) {
printk(KERN_INFO
"svcrdma: could not post a receive buffer, err=%d."
"Closing transport %p.\n", ret, rdma);
set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
svc_rdma_put_frmr(rdma, vec->frmr);
svc_rdma_put_context(ctxt, 0);
return -ENOTCONN;
}
/* Prepare the context */
ctxt->pages[0] = page;
ctxt->count = 1;
ctxt->frmr = vec->frmr;
if (vec->frmr)
set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
else
clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
/* Prepare the SGE for the RPCRDMA Header */
ctxt->sge[0].lkey = rdma->sc_dma_lkey;
ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
ctxt->sge[0].addr =
ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
ctxt->sge[0].length, DMA_TO_DEVICE);
if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
goto err;
atomic_inc(&rdma->sc_dma_used);
ctxt->direction = DMA_TO_DEVICE;
/* Map the payload indicated by 'byte_count' */
for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
int xdr_off = 0;
sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
byte_count -= sge_bytes;
if (!vec->frmr) {
ctxt->sge[sge_no].addr =
dma_map_xdr(rdma, &rqstp->rq_res, xdr_off,
sge_bytes, DMA_TO_DEVICE);
xdr_off += sge_bytes;
if (ib_dma_mapping_error(rdma->sc_cm_id->device,
ctxt->sge[sge_no].addr))
goto err;
atomic_inc(&rdma->sc_dma_used);
ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
} else {
ctxt->sge[sge_no].addr = (unsigned long)
vec->sge[sge_no].iov_base;
ctxt->sge[sge_no].lkey = vec->frmr->mr->lkey;
}
ctxt->sge[sge_no].length = sge_bytes;
}
BUG_ON(byte_count != 0);
/* Save all respages in the ctxt and remove them from the
* respages array. They are our pages until the I/O
* completes.
*/
pages = rqstp->rq_next_page - rqstp->rq_respages;
for (page_no = 0; page_no < pages; page_no++) {
ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
ctxt->count++;
rqstp->rq_respages[page_no] = NULL;
/*
* If there are more pages than SGE, terminate SGE
* list so that svc_rdma_unmap_dma doesn't attempt to
* unmap garbage.
*/
if (page_no+1 >= sge_no)
ctxt->sge[page_no+1].length = 0;
}
rqstp->rq_next_page = rqstp->rq_respages + 1;
BUG_ON(sge_no > rdma->sc_max_sge);
memset(&send_wr, 0, sizeof send_wr);
ctxt->wr_op = IB_WR_SEND;
send_wr.wr_id = (unsigned long)ctxt;
send_wr.sg_list = ctxt->sge;
send_wr.num_sge = sge_no;
send_wr.opcode = IB_WR_SEND;
send_wr.send_flags = IB_SEND_SIGNALED;
if (vec->frmr) {
/* 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 =
vec->frmr->mr->lkey;
send_wr.next = &inv_wr;
}
ret = svc_rdma_send(rdma, &send_wr);
if (ret)
goto err;
return 0;
err:
svc_rdma_unmap_dma(ctxt);
svc_rdma_put_frmr(rdma, vec->frmr);
svc_rdma_put_context(ctxt, 1);
return -EIO;
}
void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
{
}
/*
* Return the start of an xdr buffer.
*/
static void *xdr_start(struct xdr_buf *xdr)
{
return xdr->head[0].iov_base -
(xdr->len -
xdr->page_len -
xdr->tail[0].iov_len -
xdr->head[0].iov_len);
}
int svc_rdma_sendto(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt = rqstp->rq_xprt;
struct svcxprt_rdma *rdma =
container_of(xprt, struct svcxprt_rdma, sc_xprt);
struct rpcrdma_msg *rdma_argp;
struct rpcrdma_msg *rdma_resp;
struct rpcrdma_write_array *reply_ary;
enum rpcrdma_proc reply_type;
int ret;
int inline_bytes;
struct page *res_page;
struct svc_rdma_op_ctxt *ctxt;
struct svc_rdma_req_map *vec;
dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
/* Get the RDMA request header. */
rdma_argp = xdr_start(&rqstp->rq_arg);
/* Build an req vec for the XDR */
ctxt = svc_rdma_get_context(rdma);
ctxt->direction = DMA_TO_DEVICE;
vec = svc_rdma_get_req_map();
ret = map_xdr(rdma, &rqstp->rq_res, vec);
if (ret)
goto err0;
inline_bytes = rqstp->rq_res.len;
/* Create the RDMA response header */
res_page = svc_rdma_get_page();
rdma_resp = page_address(res_page);
reply_ary = svc_rdma_get_reply_array(rdma_argp);
if (reply_ary)
reply_type = RDMA_NOMSG;
else
reply_type = RDMA_MSG;
svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
rdma_resp, reply_type);
/* Send any write-chunk data and build resp write-list */
ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
rqstp, vec);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
ret);
goto err1;
}
inline_bytes -= ret;
/* Send any reply-list data and update resp reply-list */
ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
rqstp, vec);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
ret);
goto err1;
}
inline_bytes -= ret;
ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
inline_bytes);
svc_rdma_put_req_map(vec);
dprintk("svcrdma: send_reply returns %d\n", ret);
return ret;
err1:
put_page(res_page);
err0:
svc_rdma_put_req_map(vec);
svc_rdma_put_context(ctxt, 0);
return ret;
}
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