--- /dev/null
+/*
+ * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
+ * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the BSD-type
+ * license below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * Neither the name of the Network Appliance, Inc. nor the names of
+ * its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Tom Tucker <tom@opengridcomputing.com>
+ */
+
+#include <linux/sunrpc/debug.h>
+#include <linux/sunrpc/rpc_rdma.h>
+#include <linux/spinlock.h>
+#include <asm/unaligned.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <linux/sunrpc/svc_rdma.h>
+
+#define RPCDBG_FACILITY RPCDBG_SVCXPRT
+
+/*
+ * Replace the pages in the rq_argpages array with the pages from the SGE in
+ * the RDMA_RECV completion. The SGL should contain full pages up until the
+ * last one.
+ */
+static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *ctxt,
+ u32 byte_count)
+{
+ struct rpcrdma_msg *rmsgp;
+ struct page *page;
+ u32 bc;
+ int sge_no;
+
+ /* Swap the page in the SGE with the page in argpages */
+ page = ctxt->pages[0];
+ put_page(rqstp->rq_pages[0]);
+ rqstp->rq_pages[0] = page;
+
+ /* Set up the XDR head */
+ rqstp->rq_arg.head[0].iov_base = page_address(page);
+ rqstp->rq_arg.head[0].iov_len =
+ min_t(size_t, byte_count, ctxt->sge[0].length);
+ rqstp->rq_arg.len = byte_count;
+ rqstp->rq_arg.buflen = byte_count;
+
+ /* Compute bytes past head in the SGL */
+ bc = byte_count - rqstp->rq_arg.head[0].iov_len;
+
+ /* If data remains, store it in the pagelist */
+ rqstp->rq_arg.page_len = bc;
+ rqstp->rq_arg.page_base = 0;
+
+ /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */
+ rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
+ if (be32_to_cpu(rmsgp->rm_type) == RDMA_NOMSG)
+ rqstp->rq_arg.pages = &rqstp->rq_pages[0];
+ else
+ rqstp->rq_arg.pages = &rqstp->rq_pages[1];
+
+ sge_no = 1;
+ while (bc && sge_no < ctxt->count) {
+ page = ctxt->pages[sge_no];
+ put_page(rqstp->rq_pages[sge_no]);
+ rqstp->rq_pages[sge_no] = page;
+ bc -= min_t(u32, bc, ctxt->sge[sge_no].length);
+ rqstp->rq_arg.buflen += ctxt->sge[sge_no].length;
+ sge_no++;
+ }
+ rqstp->rq_respages = &rqstp->rq_pages[sge_no];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+ /* If not all pages were used from the SGL, free the remaining ones */
+ bc = sge_no;
+ while (sge_no < ctxt->count) {
+ page = ctxt->pages[sge_no++];
+ put_page(page);
+ }
+ ctxt->count = bc;
+
+ /* Set up tail */
+ rqstp->rq_arg.tail[0].iov_base = NULL;
+ rqstp->rq_arg.tail[0].iov_len = 0;
+}
+
+static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
+{
+ if (rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
+ RDMA_TRANSPORT_IWARP)
+ return 1;
+ else
+ return min_t(int, sge_count, xprt->sc_max_sge);
+}
+
+/* Issue an RDMA_READ using the local lkey to map the data sink */
+int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
+ struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *head,
+ int *page_no,
+ u32 *page_offset,
+ u32 rs_handle,
+ u32 rs_length,
+ u64 rs_offset,
+ bool last)
+{
+ struct ib_send_wr read_wr;
+ int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
+ struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
+ int ret, read, pno;
+ u32 pg_off = *page_offset;
+ u32 pg_no = *page_no;
+
+ ctxt->direction = DMA_FROM_DEVICE;
+ ctxt->read_hdr = head;
+ pages_needed =
+ min_t(int, pages_needed, rdma_read_max_sge(xprt, pages_needed));
+ read = min_t(int, pages_needed << PAGE_SHIFT, rs_length);
+
+ for (pno = 0; pno < pages_needed; pno++) {
+ int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
+
+ head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
+ head->arg.page_len += len;
+ head->arg.len += len;
+ if (!pg_off)
+ head->count++;
+ rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+ ctxt->sge[pno].addr =
+ ib_dma_map_page(xprt->sc_cm_id->device,
+ head->arg.pages[pg_no], pg_off,
+ PAGE_SIZE - pg_off,
+ DMA_FROM_DEVICE);
+ ret = ib_dma_mapping_error(xprt->sc_cm_id->device,
+ ctxt->sge[pno].addr);
+ if (ret)
+ goto err;
+ atomic_inc(&xprt->sc_dma_used);
+
+ /* The lkey here is either a local dma lkey or a dma_mr lkey */
+ ctxt->sge[pno].lkey = xprt->sc_dma_lkey;
+ ctxt->sge[pno].length = len;
+ ctxt->count++;
+
+ /* adjust offset and wrap to next page if needed */
+ pg_off += len;
+ if (pg_off == PAGE_SIZE) {
+ pg_off = 0;
+ pg_no++;
+ }
+ rs_length -= len;
+ }
+
+ if (last && rs_length == 0)
+ set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+ else
+ clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+
+ memset(&read_wr, 0, sizeof(read_wr));
+ read_wr.wr_id = (unsigned long)ctxt;
+ read_wr.opcode = IB_WR_RDMA_READ;
+ ctxt->wr_op = read_wr.opcode;
+ read_wr.send_flags = IB_SEND_SIGNALED;
+ read_wr.wr.rdma.rkey = rs_handle;
+ read_wr.wr.rdma.remote_addr = rs_offset;
+ read_wr.sg_list = ctxt->sge;
+ read_wr.num_sge = pages_needed;
+
+ ret = svc_rdma_send(xprt, &read_wr);
+ if (ret) {
+ pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
+ set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+ goto err;
+ }
+
+ /* return current location in page array */
+ *page_no = pg_no;
+ *page_offset = pg_off;
+ ret = read;
+ atomic_inc(&rdma_stat_read);
+ return ret;
+ err:
+ svc_rdma_unmap_dma(ctxt);
+ svc_rdma_put_context(ctxt, 0);
+ return ret;
+}
+
+/* Issue an RDMA_READ using an FRMR to map the data sink */
+int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
+ struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *head,
+ int *page_no,
+ u32 *page_offset,
+ u32 rs_handle,
+ u32 rs_length,
+ u64 rs_offset,
+ bool last)
+{
+ struct ib_send_wr read_wr;
+ struct ib_send_wr inv_wr;
+ struct ib_send_wr fastreg_wr;
+ u8 key;
+ int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
+ struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
+ struct svc_rdma_fastreg_mr *frmr = svc_rdma_get_frmr(xprt);
+ int ret, read, pno;
+ u32 pg_off = *page_offset;
+ u32 pg_no = *page_no;
+
+ if (IS_ERR(frmr))
+ return -ENOMEM;
+
+ ctxt->direction = DMA_FROM_DEVICE;
+ ctxt->frmr = frmr;
+ pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len);
+ read = min_t(int, pages_needed << PAGE_SHIFT, rs_length);
+
+ frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]);
+ frmr->direction = DMA_FROM_DEVICE;
+ frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE);
+ frmr->map_len = pages_needed << PAGE_SHIFT;
+ frmr->page_list_len = pages_needed;
+
+ for (pno = 0; pno < pages_needed; pno++) {
+ int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
+
+ head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
+ head->arg.page_len += len;
+ head->arg.len += len;
+ if (!pg_off)
+ head->count++;
+ rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+ frmr->page_list->page_list[pno] =
+ ib_dma_map_page(xprt->sc_cm_id->device,
+ head->arg.pages[pg_no], 0,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ ret = ib_dma_mapping_error(xprt->sc_cm_id->device,
+ frmr->page_list->page_list[pno]);
+ if (ret)
+ goto err;
+ atomic_inc(&xprt->sc_dma_used);
+
+ /* adjust offset and wrap to next page if needed */
+ pg_off += len;
+ if (pg_off == PAGE_SIZE) {
+ pg_off = 0;
+ pg_no++;
+ }
+ rs_length -= len;
+ }
+
+ if (last && rs_length == 0)
+ set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+ else
+ clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+
+ /* Bump the key */
+ key = (u8)(frmr->mr->lkey & 0x000000FF);
+ ib_update_fast_reg_key(frmr->mr, ++key);
+
+ ctxt->sge[0].addr = (unsigned long)frmr->kva + *page_offset;
+ ctxt->sge[0].lkey = frmr->mr->lkey;
+ ctxt->sge[0].length = read;
+ ctxt->count = 1;
+ ctxt->read_hdr = head;
+
+ /* Prepare FASTREG WR */
+ memset(&fastreg_wr, 0, sizeof(fastreg_wr));
+ fastreg_wr.opcode = IB_WR_FAST_REG_MR;
+ fastreg_wr.send_flags = IB_SEND_SIGNALED;
+ fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva;
+ fastreg_wr.wr.fast_reg.page_list = frmr->page_list;
+ fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len;
+ fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
+ fastreg_wr.wr.fast_reg.length = frmr->map_len;
+ fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags;
+ fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey;
+ fastreg_wr.next = &read_wr;
+
+ /* Prepare RDMA_READ */
+ memset(&read_wr, 0, sizeof(read_wr));
+ read_wr.send_flags = IB_SEND_SIGNALED;
+ read_wr.wr.rdma.rkey = rs_handle;
+ read_wr.wr.rdma.remote_addr = rs_offset;
+ read_wr.sg_list = ctxt->sge;
+ read_wr.num_sge = 1;
+ if (xprt->sc_dev_caps & SVCRDMA_DEVCAP_READ_W_INV) {
+ read_wr.opcode = IB_WR_RDMA_READ_WITH_INV;
+ read_wr.wr_id = (unsigned long)ctxt;
+ read_wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey;
+ } else {
+ read_wr.opcode = IB_WR_RDMA_READ;
+ read_wr.next = &inv_wr;
+ /* Prepare invalidate */
+ memset(&inv_wr, 0, sizeof(inv_wr));
+ inv_wr.wr_id = (unsigned long)ctxt;
+ inv_wr.opcode = IB_WR_LOCAL_INV;
+ inv_wr.send_flags = IB_SEND_SIGNALED | IB_SEND_FENCE;
+ inv_wr.ex.invalidate_rkey = frmr->mr->lkey;
+ }
+ ctxt->wr_op = read_wr.opcode;
+
+ /* Post the chain */
+ ret = svc_rdma_send(xprt, &fastreg_wr);
+ if (ret) {
+ pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
+ set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+ goto err;
+ }
+
+ /* return current location in page array */
+ *page_no = pg_no;
+ *page_offset = pg_off;
+ ret = read;
+ atomic_inc(&rdma_stat_read);
+ return ret;
+ err:
+ svc_rdma_unmap_dma(ctxt);
+ svc_rdma_put_context(ctxt, 0);
+ svc_rdma_put_frmr(xprt, frmr);
+ return ret;
+}
+
+static unsigned int
+rdma_rcl_chunk_count(struct rpcrdma_read_chunk *ch)
+{
+ unsigned int count;
+
+ for (count = 0; ch->rc_discrim != xdr_zero; ch++)
+ count++;
+ return count;
+}
+
+/* If there was additional inline content, append it to the end of arg.pages.
+ * Tail copy has to be done after the reader function has determined how many
+ * pages are needed for RDMA READ.
+ */
+static int
+rdma_copy_tail(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head,
+ u32 position, u32 byte_count, u32 page_offset, int page_no)
+{
+ char *srcp, *destp;
+ int ret;
+
+ ret = 0;
+ srcp = head->arg.head[0].iov_base + position;
+ byte_count = head->arg.head[0].iov_len - position;
+ if (byte_count > PAGE_SIZE) {
+ dprintk("svcrdma: large tail unsupported\n");
+ return 0;
+ }
+
+ /* Fit as much of the tail on the current page as possible */
+ if (page_offset != PAGE_SIZE) {
+ destp = page_address(rqstp->rq_arg.pages[page_no]);
+ destp += page_offset;
+ while (byte_count--) {
+ *destp++ = *srcp++;
+ page_offset++;
+ if (page_offset == PAGE_SIZE && byte_count)
+ goto more;
+ }
+ goto done;
+ }
+
+more:
+ /* Fit the rest on the next page */
+ page_no++;
+ destp = page_address(rqstp->rq_arg.pages[page_no]);
+ while (byte_count--)
+ *destp++ = *srcp++;
+
+ rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+done:
+ byte_count = head->arg.head[0].iov_len - position;
+ head->arg.page_len += byte_count;
+ head->arg.len += byte_count;
+ head->arg.buflen += byte_count;
+ return 1;
+}
+
+static int rdma_read_chunks(struct svcxprt_rdma *xprt,
+ struct rpcrdma_msg *rmsgp,
+ struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *head)
+{
+ int page_no, ret;
+ struct rpcrdma_read_chunk *ch;
+ u32 handle, page_offset, byte_count;
+ u32 position;
+ u64 rs_offset;
+ bool last;
+
+ /* If no read list is present, return 0 */
+ ch = svc_rdma_get_read_chunk(rmsgp);
+ if (!ch)
+ return 0;
+
+ if (rdma_rcl_chunk_count(ch) > RPCSVC_MAXPAGES)
+ return -EINVAL;
+
+ /* The request is completed when the RDMA_READs complete. The
+ * head context keeps all the pages that comprise the
+ * request.
+ */
+ head->arg.head[0] = rqstp->rq_arg.head[0];
+ head->arg.tail[0] = rqstp->rq_arg.tail[0];
+ head->hdr_count = head->count;
+ head->arg.page_base = 0;
+ head->arg.page_len = 0;
+ head->arg.len = rqstp->rq_arg.len;
+ head->arg.buflen = rqstp->rq_arg.buflen;
+
+ ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
+ position = be32_to_cpu(ch->rc_position);
+
+ /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */
+ if (position == 0) {
+ head->arg.pages = &head->pages[0];
+ page_offset = head->byte_len;
+ } else {
+ head->arg.pages = &head->pages[head->count];
+ page_offset = 0;
+ }
+
+ ret = 0;
+ page_no = 0;
+ for (; ch->rc_discrim != xdr_zero; ch++) {
+ if (be32_to_cpu(ch->rc_position) != position)
+ goto err;
+
+ handle = be32_to_cpu(ch->rc_target.rs_handle),
+ byte_count = be32_to_cpu(ch->rc_target.rs_length);
+ xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset,
+ &rs_offset);
+
+ while (byte_count > 0) {
+ last = (ch + 1)->rc_discrim == xdr_zero;
+ ret = xprt->sc_reader(xprt, rqstp, head,
+ &page_no, &page_offset,
+ handle, byte_count,
+ rs_offset, last);
+ if (ret < 0)
+ goto err;
+ byte_count -= ret;
+ rs_offset += ret;
+ head->arg.buflen += ret;
+ }
+ }
+
+ /* Read list may need XDR round-up (see RFC 5666, s. 3.7) */
+ if (page_offset & 3) {
+ u32 pad = 4 - (page_offset & 3);
+
+ head->arg.page_len += pad;
+ head->arg.len += pad;
+ head->arg.buflen += pad;
+ page_offset += pad;
+ }
+
+ ret = 1;
+ if (position && position < head->arg.head[0].iov_len)
+ ret = rdma_copy_tail(rqstp, head, position,
+ byte_count, page_offset, page_no);
+ head->arg.head[0].iov_len = position;
+ head->position = position;
+
+ err:
+ /* Detach arg pages. svc_recv will replenish them */
+ for (page_no = 0;
+ &rqstp->rq_pages[page_no] < rqstp->rq_respages; page_no++)
+ rqstp->rq_pages[page_no] = NULL;
+
+ return ret;
+}
+
+static int rdma_read_complete(struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *head)
+{
+ int page_no;
+ int ret;
+
+ /* Copy RPC pages */
+ for (page_no = 0; page_no < head->count; page_no++) {
+ put_page(rqstp->rq_pages[page_no]);
+ rqstp->rq_pages[page_no] = head->pages[page_no];
+ }
+
+ /* Adjustments made for RDMA_NOMSG type requests */
+ if (head->position == 0) {
+ if (head->arg.len <= head->sge[0].length) {
+ head->arg.head[0].iov_len = head->arg.len -
+ head->byte_len;
+ head->arg.page_len = 0;
+ } else {
+ head->arg.head[0].iov_len = head->sge[0].length -
+ head->byte_len;
+ head->arg.page_len = head->arg.len -
+ head->sge[0].length;
+ }
+ }
+
+ /* Point rq_arg.pages past header */
+ rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
+ rqstp->rq_arg.page_len = head->arg.page_len;
+ rqstp->rq_arg.page_base = head->arg.page_base;
+
+ /* rq_respages starts after the last arg page */
+ rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+ /* Rebuild rq_arg head and tail. */
+ rqstp->rq_arg.head[0] = head->arg.head[0];
+ rqstp->rq_arg.tail[0] = head->arg.tail[0];
+ rqstp->rq_arg.len = head->arg.len;
+ rqstp->rq_arg.buflen = head->arg.buflen;
+
+ /* Free the context */
+ svc_rdma_put_context(head, 0);
+
+ /* XXX: What should this be? */
+ rqstp->rq_prot = IPPROTO_MAX;
+ svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
+
+ ret = rqstp->rq_arg.head[0].iov_len
+ + rqstp->rq_arg.page_len
+ + rqstp->rq_arg.tail[0].iov_len;
+ dprintk("svcrdma: deferred read ret=%d, rq_arg.len=%u, "
+ "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zu\n",
+ ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base,
+ rqstp->rq_arg.head[0].iov_len);
+
+ return ret;
+}
+
+/*
+ * Set up the rqstp thread context to point to the RQ buffer. If
+ * necessary, pull additional data from the client with an RDMA_READ
+ * request.
+ */
+int svc_rdma_recvfrom(struct svc_rqst *rqstp)
+{
+ struct svc_xprt *xprt = rqstp->rq_xprt;
+ struct svcxprt_rdma *rdma_xprt =
+ container_of(xprt, struct svcxprt_rdma, sc_xprt);
+ struct svc_rdma_op_ctxt *ctxt = NULL;
+ struct rpcrdma_msg *rmsgp;
+ int ret = 0;
+ int len;
+
+ dprintk("svcrdma: rqstp=%p\n", rqstp);
+
+ spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
+ if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
+ ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
+ struct svc_rdma_op_ctxt,
+ dto_q);
+ list_del_init(&ctxt->dto_q);
+ spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+ return rdma_read_complete(rqstp, ctxt);
+ } else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
+ ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next,
+ struct svc_rdma_op_ctxt,
+ dto_q);
+ list_del_init(&ctxt->dto_q);
+ } else {
+ atomic_inc(&rdma_stat_rq_starve);
+ clear_bit(XPT_DATA, &xprt->xpt_flags);
+ ctxt = NULL;
+ }
+ spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+ if (!ctxt) {
+ /* This is the EAGAIN path. The svc_recv routine will
+ * return -EAGAIN, the nfsd thread will go to call into
+ * svc_recv again and we shouldn't be on the active
+ * transport list
+ */
+ if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
+ goto close_out;
+
+ goto out;
+ }
+ dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n",
+ ctxt, rdma_xprt, rqstp, ctxt->wc_status);
+ atomic_inc(&rdma_stat_recv);
+
+ /* Build up the XDR from the receive buffers. */
+ rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);
+
+ /* Decode the RDMA header. */
+ len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);
+ rqstp->rq_xprt_hlen = len;
+
+ /* If the request is invalid, reply with an error */
+ if (len < 0) {
+ if (len == -ENOSYS)
+ svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
+ goto close_out;
+ }
+
+ /* Read read-list data. */
+ ret = rdma_read_chunks(rdma_xprt, rmsgp, rqstp, ctxt);
+ if (ret > 0) {
+ /* read-list posted, defer until data received from client. */
+ goto defer;
+ } else if (ret < 0) {
+ /* Post of read-list failed, free context. */
+ svc_rdma_put_context(ctxt, 1);
+ return 0;
+ }
+
+ ret = rqstp->rq_arg.head[0].iov_len
+ + rqstp->rq_arg.page_len
+ + rqstp->rq_arg.tail[0].iov_len;
+ svc_rdma_put_context(ctxt, 0);
+ out:
+ dprintk("svcrdma: ret=%d, rq_arg.len=%u, "
+ "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zd\n",
+ ret, rqstp->rq_arg.len,
+ rqstp->rq_arg.head[0].iov_base,
+ rqstp->rq_arg.head[0].iov_len);
+ rqstp->rq_prot = IPPROTO_MAX;
+ svc_xprt_copy_addrs(rqstp, xprt);
+ return ret;
+
+ close_out:
+ if (ctxt)
+ svc_rdma_put_context(ctxt, 1);
+ dprintk("svcrdma: transport %p is closing\n", xprt);
+ /*
+ * Set the close bit and enqueue it. svc_recv will see the
+ * close bit and call svc_xprt_delete
+ */
+ set_bit(XPT_CLOSE, &xprt->xpt_flags);
+defer:
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff