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RDS/IB: Receive datagrams via IB
Header parsing, ring refill. It puts the incoming data into an rds_incoming struct, which is passed up to rds-core. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andy Grover
David S. Miller
parent
6a0979df32
commit
1e23b3ee0e
869
net/rds/ib_recv.c
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869
net/rds/ib_recv.c
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@ -0,0 +1,869 @@
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/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/dma-mapping.h>
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#include <rdma/rdma_cm.h>
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#include "rds.h"
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#include "ib.h"
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static struct kmem_cache *rds_ib_incoming_slab;
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static struct kmem_cache *rds_ib_frag_slab;
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static atomic_t rds_ib_allocation = ATOMIC_INIT(0);
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static void rds_ib_frag_drop_page(struct rds_page_frag *frag)
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{
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rdsdebug("frag %p page %p\n", frag, frag->f_page);
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__free_page(frag->f_page);
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frag->f_page = NULL;
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}
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static void rds_ib_frag_free(struct rds_page_frag *frag)
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{
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rdsdebug("frag %p page %p\n", frag, frag->f_page);
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BUG_ON(frag->f_page != NULL);
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kmem_cache_free(rds_ib_frag_slab, frag);
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}
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/*
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* We map a page at a time. Its fragments are posted in order. This
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* is called in fragment order as the fragments get send completion events.
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* Only the last frag in the page performs the unmapping.
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*
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* It's OK for ring cleanup to call this in whatever order it likes because
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* DMA is not in flight and so we can unmap while other ring entries still
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* hold page references in their frags.
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*/
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static void rds_ib_recv_unmap_page(struct rds_ib_connection *ic,
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struct rds_ib_recv_work *recv)
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{
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struct rds_page_frag *frag = recv->r_frag;
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rdsdebug("recv %p frag %p page %p\n", recv, frag, frag->f_page);
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if (frag->f_mapped)
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ib_dma_unmap_page(ic->i_cm_id->device,
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frag->f_mapped,
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RDS_FRAG_SIZE, DMA_FROM_DEVICE);
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frag->f_mapped = 0;
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}
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void rds_ib_recv_init_ring(struct rds_ib_connection *ic)
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{
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struct rds_ib_recv_work *recv;
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u32 i;
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for (i = 0, recv = ic->i_recvs; i < ic->i_recv_ring.w_nr; i++, recv++) {
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struct ib_sge *sge;
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recv->r_ibinc = NULL;
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recv->r_frag = NULL;
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recv->r_wr.next = NULL;
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recv->r_wr.wr_id = i;
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recv->r_wr.sg_list = recv->r_sge;
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recv->r_wr.num_sge = RDS_IB_RECV_SGE;
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sge = rds_ib_data_sge(ic, recv->r_sge);
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sge->addr = 0;
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sge->length = RDS_FRAG_SIZE;
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sge->lkey = ic->i_mr->lkey;
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sge = rds_ib_header_sge(ic, recv->r_sge);
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sge->addr = ic->i_recv_hdrs_dma + (i * sizeof(struct rds_header));
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sge->length = sizeof(struct rds_header);
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sge->lkey = ic->i_mr->lkey;
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}
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}
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static void rds_ib_recv_clear_one(struct rds_ib_connection *ic,
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struct rds_ib_recv_work *recv)
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{
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if (recv->r_ibinc) {
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rds_inc_put(&recv->r_ibinc->ii_inc);
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recv->r_ibinc = NULL;
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}
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if (recv->r_frag) {
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rds_ib_recv_unmap_page(ic, recv);
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if (recv->r_frag->f_page)
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rds_ib_frag_drop_page(recv->r_frag);
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rds_ib_frag_free(recv->r_frag);
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recv->r_frag = NULL;
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}
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}
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void rds_ib_recv_clear_ring(struct rds_ib_connection *ic)
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{
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u32 i;
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for (i = 0; i < ic->i_recv_ring.w_nr; i++)
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rds_ib_recv_clear_one(ic, &ic->i_recvs[i]);
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if (ic->i_frag.f_page)
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rds_ib_frag_drop_page(&ic->i_frag);
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}
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static int rds_ib_recv_refill_one(struct rds_connection *conn,
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struct rds_ib_recv_work *recv,
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gfp_t kptr_gfp, gfp_t page_gfp)
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{
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struct rds_ib_connection *ic = conn->c_transport_data;
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dma_addr_t dma_addr;
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struct ib_sge *sge;
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int ret = -ENOMEM;
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if (recv->r_ibinc == NULL) {
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if (atomic_read(&rds_ib_allocation) >= rds_ib_sysctl_max_recv_allocation) {
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rds_ib_stats_inc(s_ib_rx_alloc_limit);
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goto out;
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}
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recv->r_ibinc = kmem_cache_alloc(rds_ib_incoming_slab,
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kptr_gfp);
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if (recv->r_ibinc == NULL)
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goto out;
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atomic_inc(&rds_ib_allocation);
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INIT_LIST_HEAD(&recv->r_ibinc->ii_frags);
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rds_inc_init(&recv->r_ibinc->ii_inc, conn, conn->c_faddr);
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}
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if (recv->r_frag == NULL) {
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recv->r_frag = kmem_cache_alloc(rds_ib_frag_slab, kptr_gfp);
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if (recv->r_frag == NULL)
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goto out;
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INIT_LIST_HEAD(&recv->r_frag->f_item);
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recv->r_frag->f_page = NULL;
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}
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if (ic->i_frag.f_page == NULL) {
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ic->i_frag.f_page = alloc_page(page_gfp);
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if (ic->i_frag.f_page == NULL)
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goto out;
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ic->i_frag.f_offset = 0;
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}
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dma_addr = ib_dma_map_page(ic->i_cm_id->device,
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ic->i_frag.f_page,
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ic->i_frag.f_offset,
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RDS_FRAG_SIZE,
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DMA_FROM_DEVICE);
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if (ib_dma_mapping_error(ic->i_cm_id->device, dma_addr))
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goto out;
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/*
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* Once we get the RDS_PAGE_LAST_OFF frag then rds_ib_frag_unmap()
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* must be called on this recv. This happens as completions hit
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* in order or on connection shutdown.
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*/
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recv->r_frag->f_page = ic->i_frag.f_page;
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recv->r_frag->f_offset = ic->i_frag.f_offset;
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recv->r_frag->f_mapped = dma_addr;
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sge = rds_ib_data_sge(ic, recv->r_sge);
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sge->addr = dma_addr;
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sge->length = RDS_FRAG_SIZE;
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sge = rds_ib_header_sge(ic, recv->r_sge);
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sge->addr = ic->i_recv_hdrs_dma + (recv - ic->i_recvs) * sizeof(struct rds_header);
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sge->length = sizeof(struct rds_header);
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get_page(recv->r_frag->f_page);
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if (ic->i_frag.f_offset < RDS_PAGE_LAST_OFF) {
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ic->i_frag.f_offset += RDS_FRAG_SIZE;
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} else {
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put_page(ic->i_frag.f_page);
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ic->i_frag.f_page = NULL;
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ic->i_frag.f_offset = 0;
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}
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ret = 0;
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out:
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return ret;
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}
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/*
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* This tries to allocate and post unused work requests after making sure that
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* they have all the allocations they need to queue received fragments into
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* sockets. The i_recv_mutex is held here so that ring_alloc and _unalloc
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* pairs don't go unmatched.
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*
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* -1 is returned if posting fails due to temporary resource exhaustion.
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*/
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int rds_ib_recv_refill(struct rds_connection *conn, gfp_t kptr_gfp,
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gfp_t page_gfp, int prefill)
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{
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struct rds_ib_connection *ic = conn->c_transport_data;
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struct rds_ib_recv_work *recv;
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struct ib_recv_wr *failed_wr;
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unsigned int posted = 0;
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int ret = 0;
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u32 pos;
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while ((prefill || rds_conn_up(conn))
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&& rds_ib_ring_alloc(&ic->i_recv_ring, 1, &pos)) {
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if (pos >= ic->i_recv_ring.w_nr) {
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printk(KERN_NOTICE "Argh - ring alloc returned pos=%u\n",
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pos);
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ret = -EINVAL;
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break;
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}
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recv = &ic->i_recvs[pos];
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ret = rds_ib_recv_refill_one(conn, recv, kptr_gfp, page_gfp);
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if (ret) {
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ret = -1;
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break;
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}
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/* XXX when can this fail? */
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ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
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rdsdebug("recv %p ibinc %p page %p addr %lu ret %d\n", recv,
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recv->r_ibinc, recv->r_frag->f_page,
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(long) recv->r_frag->f_mapped, ret);
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if (ret) {
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rds_ib_conn_error(conn, "recv post on "
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"%pI4 returned %d, disconnecting and "
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"reconnecting\n", &conn->c_faddr,
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ret);
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ret = -1;
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break;
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}
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posted++;
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}
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/* We're doing flow control - update the window. */
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if (ic->i_flowctl && posted)
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rds_ib_advertise_credits(conn, posted);
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if (ret)
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rds_ib_ring_unalloc(&ic->i_recv_ring, 1);
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return ret;
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}
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void rds_ib_inc_purge(struct rds_incoming *inc)
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{
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struct rds_ib_incoming *ibinc;
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struct rds_page_frag *frag;
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struct rds_page_frag *pos;
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ibinc = container_of(inc, struct rds_ib_incoming, ii_inc);
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rdsdebug("purging ibinc %p inc %p\n", ibinc, inc);
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list_for_each_entry_safe(frag, pos, &ibinc->ii_frags, f_item) {
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list_del_init(&frag->f_item);
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rds_ib_frag_drop_page(frag);
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rds_ib_frag_free(frag);
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}
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}
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void rds_ib_inc_free(struct rds_incoming *inc)
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{
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struct rds_ib_incoming *ibinc;
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ibinc = container_of(inc, struct rds_ib_incoming, ii_inc);
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rds_ib_inc_purge(inc);
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rdsdebug("freeing ibinc %p inc %p\n", ibinc, inc);
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BUG_ON(!list_empty(&ibinc->ii_frags));
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kmem_cache_free(rds_ib_incoming_slab, ibinc);
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atomic_dec(&rds_ib_allocation);
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BUG_ON(atomic_read(&rds_ib_allocation) < 0);
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}
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int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
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size_t size)
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{
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struct rds_ib_incoming *ibinc;
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struct rds_page_frag *frag;
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struct iovec *iov = first_iov;
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unsigned long to_copy;
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unsigned long frag_off = 0;
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unsigned long iov_off = 0;
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int copied = 0;
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int ret;
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u32 len;
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ibinc = container_of(inc, struct rds_ib_incoming, ii_inc);
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frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
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len = be32_to_cpu(inc->i_hdr.h_len);
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while (copied < size && copied < len) {
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if (frag_off == RDS_FRAG_SIZE) {
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frag = list_entry(frag->f_item.next,
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struct rds_page_frag, f_item);
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frag_off = 0;
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}
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while (iov_off == iov->iov_len) {
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iov_off = 0;
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iov++;
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}
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to_copy = min(iov->iov_len - iov_off, RDS_FRAG_SIZE - frag_off);
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to_copy = min_t(size_t, to_copy, size - copied);
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to_copy = min_t(unsigned long, to_copy, len - copied);
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rdsdebug("%lu bytes to user [%p, %zu] + %lu from frag "
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"[%p, %lu] + %lu\n",
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to_copy, iov->iov_base, iov->iov_len, iov_off,
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frag->f_page, frag->f_offset, frag_off);
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/* XXX needs + offset for multiple recvs per page */
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ret = rds_page_copy_to_user(frag->f_page,
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frag->f_offset + frag_off,
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iov->iov_base + iov_off,
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to_copy);
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if (ret) {
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copied = ret;
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break;
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}
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iov_off += to_copy;
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frag_off += to_copy;
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copied += to_copy;
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}
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return copied;
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}
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/* ic starts out kzalloc()ed */
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void rds_ib_recv_init_ack(struct rds_ib_connection *ic)
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{
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struct ib_send_wr *wr = &ic->i_ack_wr;
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struct ib_sge *sge = &ic->i_ack_sge;
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sge->addr = ic->i_ack_dma;
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sge->length = sizeof(struct rds_header);
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sge->lkey = ic->i_mr->lkey;
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wr->sg_list = sge;
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wr->num_sge = 1;
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wr->opcode = IB_WR_SEND;
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wr->wr_id = RDS_IB_ACK_WR_ID;
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wr->send_flags = IB_SEND_SIGNALED | IB_SEND_SOLICITED;
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}
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/*
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* You'd think that with reliable IB connections you wouldn't need to ack
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* messages that have been received. The problem is that IB hardware generates
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* an ack message before it has DMAed the message into memory. This creates a
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* potential message loss if the HCA is disabled for any reason between when it
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* sends the ack and before the message is DMAed and processed. This is only a
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* potential issue if another HCA is available for fail-over.
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*
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* When the remote host receives our ack they'll free the sent message from
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* their send queue. To decrease the latency of this we always send an ack
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* immediately after we've received messages.
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*
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* For simplicity, we only have one ack in flight at a time. This puts
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* pressure on senders to have deep enough send queues to absorb the latency of
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* a single ack frame being in flight. This might not be good enough.
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*
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* This is implemented by have a long-lived send_wr and sge which point to a
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* statically allocated ack frame. This ack wr does not fall under the ring
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* accounting that the tx and rx wrs do. The QP attribute specifically makes
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* room for it beyond the ring size. Send completion notices its special
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* wr_id and avoids working with the ring in that case.
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*/
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static void rds_ib_set_ack(struct rds_ib_connection *ic, u64 seq,
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int ack_required)
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{
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rds_ib_set_64bit(&ic->i_ack_next, seq);
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if (ack_required) {
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smp_mb__before_clear_bit();
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set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
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}
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}
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static u64 rds_ib_get_ack(struct rds_ib_connection *ic)
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{
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clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
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smp_mb__after_clear_bit();
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return ic->i_ack_next;
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}
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static void rds_ib_send_ack(struct rds_ib_connection *ic, unsigned int adv_credits)
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{
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struct rds_header *hdr = ic->i_ack;
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struct ib_send_wr *failed_wr;
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u64 seq;
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int ret;
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seq = rds_ib_get_ack(ic);
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rdsdebug("send_ack: ic %p ack %llu\n", ic, (unsigned long long) seq);
|
||||
rds_message_populate_header(hdr, 0, 0, 0);
|
||||
hdr->h_ack = cpu_to_be64(seq);
|
||||
hdr->h_credit = adv_credits;
|
||||
rds_message_make_checksum(hdr);
|
||||
ic->i_ack_queued = jiffies;
|
||||
|
||||
ret = ib_post_send(ic->i_cm_id->qp, &ic->i_ack_wr, &failed_wr);
|
||||
if (unlikely(ret)) {
|
||||
/* Failed to send. Release the WR, and
|
||||
* force another ACK.
|
||||
*/
|
||||
clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
|
||||
set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
|
||||
|
||||
rds_ib_stats_inc(s_ib_ack_send_failure);
|
||||
/* Need to finesse this later. */
|
||||
BUG();
|
||||
} else
|
||||
rds_ib_stats_inc(s_ib_ack_sent);
|
||||
}
|
||||
|
||||
/*
|
||||
* There are 3 ways of getting acknowledgements to the peer:
|
||||
* 1. We call rds_ib_attempt_ack from the recv completion handler
|
||||
* to send an ACK-only frame.
|
||||
* However, there can be only one such frame in the send queue
|
||||
* at any time, so we may have to postpone it.
|
||||
* 2. When another (data) packet is transmitted while there's
|
||||
* an ACK in the queue, we piggyback the ACK sequence number
|
||||
* on the data packet.
|
||||
* 3. If the ACK WR is done sending, we get called from the
|
||||
* send queue completion handler, and check whether there's
|
||||
* another ACK pending (postponed because the WR was on the
|
||||
* queue). If so, we transmit it.
|
||||
*
|
||||
* We maintain 2 variables:
|
||||
* - i_ack_flags, which keeps track of whether the ACK WR
|
||||
* is currently in the send queue or not (IB_ACK_IN_FLIGHT)
|
||||
* - i_ack_next, which is the last sequence number we received
|
||||
*
|
||||
* Potentially, send queue and receive queue handlers can run concurrently.
|
||||
*
|
||||
* Reconnecting complicates this picture just slightly. When we
|
||||
* reconnect, we may be seeing duplicate packets. The peer
|
||||
* is retransmitting them, because it hasn't seen an ACK for
|
||||
* them. It is important that we ACK these.
|
||||
*
|
||||
* ACK mitigation adds a header flag "ACK_REQUIRED"; any packet with
|
||||
* this flag set *MUST* be acknowledged immediately.
|
||||
*/
|
||||
|
||||
/*
|
||||
* When we get here, we're called from the recv queue handler.
|
||||
* Check whether we ought to transmit an ACK.
|
||||
*/
|
||||
void rds_ib_attempt_ack(struct rds_ib_connection *ic)
|
||||
{
|
||||
unsigned int adv_credits;
|
||||
|
||||
if (!test_bit(IB_ACK_REQUESTED, &ic->i_ack_flags))
|
||||
return;
|
||||
|
||||
if (test_and_set_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags)) {
|
||||
rds_ib_stats_inc(s_ib_ack_send_delayed);
|
||||
return;
|
||||
}
|
||||
|
||||
/* Can we get a send credit? */
|
||||
if (!rds_ib_send_grab_credits(ic, 1, &adv_credits, 0)) {
|
||||
rds_ib_stats_inc(s_ib_tx_throttle);
|
||||
clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
|
||||
return;
|
||||
}
|
||||
|
||||
clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
|
||||
rds_ib_send_ack(ic, adv_credits);
|
||||
}
|
||||
|
||||
/*
|
||||
* We get here from the send completion handler, when the
|
||||
* adapter tells us the ACK frame was sent.
|
||||
*/
|
||||
void rds_ib_ack_send_complete(struct rds_ib_connection *ic)
|
||||
{
|
||||
clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
|
||||
rds_ib_attempt_ack(ic);
|
||||
}
|
||||
|
||||
/*
|
||||
* This is called by the regular xmit code when it wants to piggyback
|
||||
* an ACK on an outgoing frame.
|
||||
*/
|
||||
u64 rds_ib_piggyb_ack(struct rds_ib_connection *ic)
|
||||
{
|
||||
if (test_and_clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags))
|
||||
rds_ib_stats_inc(s_ib_ack_send_piggybacked);
|
||||
return rds_ib_get_ack(ic);
|
||||
}
|
||||
|
||||
/*
|
||||
* It's kind of lame that we're copying from the posted receive pages into
|
||||
* long-lived bitmaps. We could have posted the bitmaps and rdma written into
|
||||
* them. But receiving new congestion bitmaps should be a *rare* event, so
|
||||
* hopefully we won't need to invest that complexity in making it more
|
||||
* efficient. By copying we can share a simpler core with TCP which has to
|
||||
* copy.
|
||||
*/
|
||||
static void rds_ib_cong_recv(struct rds_connection *conn,
|
||||
struct rds_ib_incoming *ibinc)
|
||||
{
|
||||
struct rds_cong_map *map;
|
||||
unsigned int map_off;
|
||||
unsigned int map_page;
|
||||
struct rds_page_frag *frag;
|
||||
unsigned long frag_off;
|
||||
unsigned long to_copy;
|
||||
unsigned long copied;
|
||||
uint64_t uncongested = 0;
|
||||
void *addr;
|
||||
|
||||
/* catch completely corrupt packets */
|
||||
if (be32_to_cpu(ibinc->ii_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
|
||||
return;
|
||||
|
||||
map = conn->c_fcong;
|
||||
map_page = 0;
|
||||
map_off = 0;
|
||||
|
||||
frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
|
||||
frag_off = 0;
|
||||
|
||||
copied = 0;
|
||||
|
||||
while (copied < RDS_CONG_MAP_BYTES) {
|
||||
uint64_t *src, *dst;
|
||||
unsigned int k;
|
||||
|
||||
to_copy = min(RDS_FRAG_SIZE - frag_off, PAGE_SIZE - map_off);
|
||||
BUG_ON(to_copy & 7); /* Must be 64bit aligned. */
|
||||
|
||||
addr = kmap_atomic(frag->f_page, KM_SOFTIRQ0);
|
||||
|
||||
src = addr + frag_off;
|
||||
dst = (void *)map->m_page_addrs[map_page] + map_off;
|
||||
for (k = 0; k < to_copy; k += 8) {
|
||||
/* Record ports that became uncongested, ie
|
||||
* bits that changed from 0 to 1. */
|
||||
uncongested |= ~(*src) & *dst;
|
||||
*dst++ = *src++;
|
||||
}
|
||||
kunmap_atomic(addr, KM_SOFTIRQ0);
|
||||
|
||||
copied += to_copy;
|
||||
|
||||
map_off += to_copy;
|
||||
if (map_off == PAGE_SIZE) {
|
||||
map_off = 0;
|
||||
map_page++;
|
||||
}
|
||||
|
||||
frag_off += to_copy;
|
||||
if (frag_off == RDS_FRAG_SIZE) {
|
||||
frag = list_entry(frag->f_item.next,
|
||||
struct rds_page_frag, f_item);
|
||||
frag_off = 0;
|
||||
}
|
||||
}
|
||||
|
||||
/* the congestion map is in little endian order */
|
||||
uncongested = le64_to_cpu(uncongested);
|
||||
|
||||
rds_cong_map_updated(map, uncongested);
|
||||
}
|
||||
|
||||
/*
|
||||
* Rings are posted with all the allocations they'll need to queue the
|
||||
* incoming message to the receiving socket so this can't fail.
|
||||
* All fragments start with a header, so we can make sure we're not receiving
|
||||
* garbage, and we can tell a small 8 byte fragment from an ACK frame.
|
||||
*/
|
||||
struct rds_ib_ack_state {
|
||||
u64 ack_next;
|
||||
u64 ack_recv;
|
||||
unsigned int ack_required:1;
|
||||
unsigned int ack_next_valid:1;
|
||||
unsigned int ack_recv_valid:1;
|
||||
};
|
||||
|
||||
static void rds_ib_process_recv(struct rds_connection *conn,
|
||||
struct rds_ib_recv_work *recv, u32 byte_len,
|
||||
struct rds_ib_ack_state *state)
|
||||
{
|
||||
struct rds_ib_connection *ic = conn->c_transport_data;
|
||||
struct rds_ib_incoming *ibinc = ic->i_ibinc;
|
||||
struct rds_header *ihdr, *hdr;
|
||||
|
||||
/* XXX shut down the connection if port 0,0 are seen? */
|
||||
|
||||
rdsdebug("ic %p ibinc %p recv %p byte len %u\n", ic, ibinc, recv,
|
||||
byte_len);
|
||||
|
||||
if (byte_len < sizeof(struct rds_header)) {
|
||||
rds_ib_conn_error(conn, "incoming message "
|
||||
"from %pI4 didn't inclue a "
|
||||
"header, disconnecting and "
|
||||
"reconnecting\n",
|
||||
&conn->c_faddr);
|
||||
return;
|
||||
}
|
||||
byte_len -= sizeof(struct rds_header);
|
||||
|
||||
ihdr = &ic->i_recv_hdrs[recv - ic->i_recvs];
|
||||
|
||||
/* Validate the checksum. */
|
||||
if (!rds_message_verify_checksum(ihdr)) {
|
||||
rds_ib_conn_error(conn, "incoming message "
|
||||
"from %pI4 has corrupted header - "
|
||||
"forcing a reconnect\n",
|
||||
&conn->c_faddr);
|
||||
rds_stats_inc(s_recv_drop_bad_checksum);
|
||||
return;
|
||||
}
|
||||
|
||||
/* Process the ACK sequence which comes with every packet */
|
||||
state->ack_recv = be64_to_cpu(ihdr->h_ack);
|
||||
state->ack_recv_valid = 1;
|
||||
|
||||
/* Process the credits update if there was one */
|
||||
if (ihdr->h_credit)
|
||||
rds_ib_send_add_credits(conn, ihdr->h_credit);
|
||||
|
||||
if (ihdr->h_sport == 0 && ihdr->h_dport == 0 && byte_len == 0) {
|
||||
/* This is an ACK-only packet. The fact that it gets
|
||||
* special treatment here is that historically, ACKs
|
||||
* were rather special beasts.
|
||||
*/
|
||||
rds_ib_stats_inc(s_ib_ack_received);
|
||||
|
||||
/*
|
||||
* Usually the frags make their way on to incs and are then freed as
|
||||
* the inc is freed. We don't go that route, so we have to drop the
|
||||
* page ref ourselves. We can't just leave the page on the recv
|
||||
* because that confuses the dma mapping of pages and each recv's use
|
||||
* of a partial page. We can leave the frag, though, it will be
|
||||
* reused.
|
||||
*
|
||||
* FIXME: Fold this into the code path below.
|
||||
*/
|
||||
rds_ib_frag_drop_page(recv->r_frag);
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we don't already have an inc on the connection then this
|
||||
* fragment has a header and starts a message.. copy its header
|
||||
* into the inc and save the inc so we can hang upcoming fragments
|
||||
* off its list.
|
||||
*/
|
||||
if (ibinc == NULL) {
|
||||
ibinc = recv->r_ibinc;
|
||||
recv->r_ibinc = NULL;
|
||||
ic->i_ibinc = ibinc;
|
||||
|
||||
hdr = &ibinc->ii_inc.i_hdr;
|
||||
memcpy(hdr, ihdr, sizeof(*hdr));
|
||||
ic->i_recv_data_rem = be32_to_cpu(hdr->h_len);
|
||||
|
||||
rdsdebug("ic %p ibinc %p rem %u flag 0x%x\n", ic, ibinc,
|
||||
ic->i_recv_data_rem, hdr->h_flags);
|
||||
} else {
|
||||
hdr = &ibinc->ii_inc.i_hdr;
|
||||
/* We can't just use memcmp here; fragments of a
|
||||
* single message may carry different ACKs */
|
||||
if (hdr->h_sequence != ihdr->h_sequence
|
||||
|| hdr->h_len != ihdr->h_len
|
||||
|| hdr->h_sport != ihdr->h_sport
|
||||
|| hdr->h_dport != ihdr->h_dport) {
|
||||
rds_ib_conn_error(conn,
|
||||
"fragment header mismatch; forcing reconnect\n");
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
list_add_tail(&recv->r_frag->f_item, &ibinc->ii_frags);
|
||||
recv->r_frag = NULL;
|
||||
|
||||
if (ic->i_recv_data_rem > RDS_FRAG_SIZE)
|
||||
ic->i_recv_data_rem -= RDS_FRAG_SIZE;
|
||||
else {
|
||||
ic->i_recv_data_rem = 0;
|
||||
ic->i_ibinc = NULL;
|
||||
|
||||
if (ibinc->ii_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
|
||||
rds_ib_cong_recv(conn, ibinc);
|
||||
else {
|
||||
rds_recv_incoming(conn, conn->c_faddr, conn->c_laddr,
|
||||
&ibinc->ii_inc, GFP_ATOMIC,
|
||||
KM_SOFTIRQ0);
|
||||
state->ack_next = be64_to_cpu(hdr->h_sequence);
|
||||
state->ack_next_valid = 1;
|
||||
}
|
||||
|
||||
/* Evaluate the ACK_REQUIRED flag *after* we received
|
||||
* the complete frame, and after bumping the next_rx
|
||||
* sequence. */
|
||||
if (hdr->h_flags & RDS_FLAG_ACK_REQUIRED) {
|
||||
rds_stats_inc(s_recv_ack_required);
|
||||
state->ack_required = 1;
|
||||
}
|
||||
|
||||
rds_inc_put(&ibinc->ii_inc);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Plucking the oldest entry from the ring can be done concurrently with
|
||||
* the thread refilling the ring. Each ring operation is protected by
|
||||
* spinlocks and the transient state of refilling doesn't change the
|
||||
* recording of which entry is oldest.
|
||||
*
|
||||
* This relies on IB only calling one cq comp_handler for each cq so that
|
||||
* there will only be one caller of rds_recv_incoming() per RDS connection.
|
||||
*/
|
||||
void rds_ib_recv_cq_comp_handler(struct ib_cq *cq, void *context)
|
||||
{
|
||||
struct rds_connection *conn = context;
|
||||
struct rds_ib_connection *ic = conn->c_transport_data;
|
||||
struct ib_wc wc;
|
||||
struct rds_ib_ack_state state = { 0, };
|
||||
struct rds_ib_recv_work *recv;
|
||||
|
||||
rdsdebug("conn %p cq %p\n", conn, cq);
|
||||
|
||||
rds_ib_stats_inc(s_ib_rx_cq_call);
|
||||
|
||||
ib_req_notify_cq(cq, IB_CQ_SOLICITED);
|
||||
|
||||
while (ib_poll_cq(cq, 1, &wc) > 0) {
|
||||
rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
|
||||
(unsigned long long)wc.wr_id, wc.status, wc.byte_len,
|
||||
be32_to_cpu(wc.ex.imm_data));
|
||||
rds_ib_stats_inc(s_ib_rx_cq_event);
|
||||
|
||||
recv = &ic->i_recvs[rds_ib_ring_oldest(&ic->i_recv_ring)];
|
||||
|
||||
rds_ib_recv_unmap_page(ic, recv);
|
||||
|
||||
/*
|
||||
* Also process recvs in connecting state because it is possible
|
||||
* to get a recv completion _before_ the rdmacm ESTABLISHED
|
||||
* event is processed.
|
||||
*/
|
||||
if (rds_conn_up(conn) || rds_conn_connecting(conn)) {
|
||||
/* We expect errors as the qp is drained during shutdown */
|
||||
if (wc.status == IB_WC_SUCCESS) {
|
||||
rds_ib_process_recv(conn, recv, wc.byte_len, &state);
|
||||
} else {
|
||||
rds_ib_conn_error(conn, "recv completion on "
|
||||
"%pI4 had status %u, disconnecting and "
|
||||
"reconnecting\n", &conn->c_faddr,
|
||||
wc.status);
|
||||
}
|
||||
}
|
||||
|
||||
rds_ib_ring_free(&ic->i_recv_ring, 1);
|
||||
}
|
||||
|
||||
if (state.ack_next_valid)
|
||||
rds_ib_set_ack(ic, state.ack_next, state.ack_required);
|
||||
if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
|
||||
rds_send_drop_acked(conn, state.ack_recv, NULL);
|
||||
ic->i_ack_recv = state.ack_recv;
|
||||
}
|
||||
if (rds_conn_up(conn))
|
||||
rds_ib_attempt_ack(ic);
|
||||
|
||||
/* If we ever end up with a really empty receive ring, we're
|
||||
* in deep trouble, as the sender will definitely see RNR
|
||||
* timeouts. */
|
||||
if (rds_ib_ring_empty(&ic->i_recv_ring))
|
||||
rds_ib_stats_inc(s_ib_rx_ring_empty);
|
||||
|
||||
/*
|
||||
* If the ring is running low, then schedule the thread to refill.
|
||||
*/
|
||||
if (rds_ib_ring_low(&ic->i_recv_ring))
|
||||
queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
|
||||
}
|
||||
|
||||
int rds_ib_recv(struct rds_connection *conn)
|
||||
{
|
||||
struct rds_ib_connection *ic = conn->c_transport_data;
|
||||
int ret = 0;
|
||||
|
||||
rdsdebug("conn %p\n", conn);
|
||||
|
||||
/*
|
||||
* If we get a temporary posting failure in this context then
|
||||
* we're really low and we want the caller to back off for a bit.
|
||||
*/
|
||||
mutex_lock(&ic->i_recv_mutex);
|
||||
if (rds_ib_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 0))
|
||||
ret = -ENOMEM;
|
||||
else
|
||||
rds_ib_stats_inc(s_ib_rx_refill_from_thread);
|
||||
mutex_unlock(&ic->i_recv_mutex);
|
||||
|
||||
if (rds_conn_up(conn))
|
||||
rds_ib_attempt_ack(ic);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
int __init rds_ib_recv_init(void)
|
||||
{
|
||||
struct sysinfo si;
|
||||
int ret = -ENOMEM;
|
||||
|
||||
/* Default to 30% of all available RAM for recv memory */
|
||||
si_meminfo(&si);
|
||||
rds_ib_sysctl_max_recv_allocation = si.totalram / 3 * PAGE_SIZE / RDS_FRAG_SIZE;
|
||||
|
||||
rds_ib_incoming_slab = kmem_cache_create("rds_ib_incoming",
|
||||
sizeof(struct rds_ib_incoming),
|
||||
0, 0, NULL);
|
||||
if (rds_ib_incoming_slab == NULL)
|
||||
goto out;
|
||||
|
||||
rds_ib_frag_slab = kmem_cache_create("rds_ib_frag",
|
||||
sizeof(struct rds_page_frag),
|
||||
0, 0, NULL);
|
||||
if (rds_ib_frag_slab == NULL)
|
||||
kmem_cache_destroy(rds_ib_incoming_slab);
|
||||
else
|
||||
ret = 0;
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
void rds_ib_recv_exit(void)
|
||||
{
|
||||
kmem_cache_destroy(rds_ib_incoming_slab);
|
||||
kmem_cache_destroy(rds_ib_frag_slab);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user