diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_sendto.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 745 |
1 files changed, 745 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c new file mode 100644 index 00000000..42eb7ba0 --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -0,0 +1,745 @@ +/* + * 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 */ + 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 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. + */ + for (page_no = 0; page_no < rqstp->rq_resused; 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; + } + 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; +} |