diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c')
-rw-r--r-- | kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c new file mode 100644 index 000000000..f9f13a32d --- /dev/null +++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -0,0 +1,672 @@ +/* + * 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; +} |