From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/rds/tcp_recv.c | 336 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 336 insertions(+) create mode 100644 net/rds/tcp_recv.c (limited to 'net/rds/tcp_recv.c') diff --git a/net/rds/tcp_recv.c b/net/rds/tcp_recv.c new file mode 100644 index 000000000..fbc5ef88b --- /dev/null +++ b/net/rds/tcp_recv.c @@ -0,0 +1,336 @@ +/* + * Copyright (c) 2006 Oracle. 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 + * OpenIB.org BSD 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. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include +#include +#include + +#include "rds.h" +#include "tcp.h" + +static struct kmem_cache *rds_tcp_incoming_slab; + +static void rds_tcp_inc_purge(struct rds_incoming *inc) +{ + struct rds_tcp_incoming *tinc; + tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); + rdsdebug("purging tinc %p inc %p\n", tinc, inc); + skb_queue_purge(&tinc->ti_skb_list); +} + +void rds_tcp_inc_free(struct rds_incoming *inc) +{ + struct rds_tcp_incoming *tinc; + tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); + rds_tcp_inc_purge(inc); + rdsdebug("freeing tinc %p inc %p\n", tinc, inc); + kmem_cache_free(rds_tcp_incoming_slab, tinc); +} + +/* + * this is pretty lame, but, whatever. + */ +int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to) +{ + struct rds_tcp_incoming *tinc; + struct sk_buff *skb; + int ret = 0; + + if (!iov_iter_count(to)) + goto out; + + tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); + + skb_queue_walk(&tinc->ti_skb_list, skb) { + unsigned long to_copy, skb_off; + for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) { + to_copy = iov_iter_count(to); + to_copy = min(to_copy, skb->len - skb_off); + + if (skb_copy_datagram_iter(skb, skb_off, to, to_copy)) + return -EFAULT; + + rds_stats_add(s_copy_to_user, to_copy); + ret += to_copy; + + if (!iov_iter_count(to)) + goto out; + } + } +out: + return ret; +} + +/* + * We have a series of skbs that have fragmented pieces of the congestion + * bitmap. They must add up to the exact size of the congestion bitmap. We + * use the skb helpers to copy those into the pages that make up the in-memory + * congestion bitmap for the remote address of this connection. We then tell + * the congestion core that the bitmap has been changed so that it can wake up + * sleepers. + * + * This is racing with sending paths which are using test_bit to see if the + * bitmap indicates that their recipient is congested. + */ + +static void rds_tcp_cong_recv(struct rds_connection *conn, + struct rds_tcp_incoming *tinc) +{ + struct sk_buff *skb; + unsigned int to_copy, skb_off; + unsigned int map_off; + unsigned int map_page; + struct rds_cong_map *map; + int ret; + + /* catch completely corrupt packets */ + if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES) + return; + + map_page = 0; + map_off = 0; + map = conn->c_fcong; + + skb_queue_walk(&tinc->ti_skb_list, skb) { + skb_off = 0; + while (skb_off < skb->len) { + to_copy = min_t(unsigned int, PAGE_SIZE - map_off, + skb->len - skb_off); + + BUG_ON(map_page >= RDS_CONG_MAP_PAGES); + + /* only returns 0 or -error */ + ret = skb_copy_bits(skb, skb_off, + (void *)map->m_page_addrs[map_page] + map_off, + to_copy); + BUG_ON(ret != 0); + + skb_off += to_copy; + map_off += to_copy; + if (map_off == PAGE_SIZE) { + map_off = 0; + map_page++; + } + } + } + + rds_cong_map_updated(map, ~(u64) 0); +} + +struct rds_tcp_desc_arg { + struct rds_connection *conn; + gfp_t gfp; +}; + +static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + struct rds_tcp_desc_arg *arg = desc->arg.data; + struct rds_connection *conn = arg->conn; + struct rds_tcp_connection *tc = conn->c_transport_data; + struct rds_tcp_incoming *tinc = tc->t_tinc; + struct sk_buff *clone; + size_t left = len, to_copy; + + rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset, + len); + + /* + * tcp_read_sock() interprets partial progress as an indication to stop + * processing. + */ + while (left) { + if (!tinc) { + tinc = kmem_cache_alloc(rds_tcp_incoming_slab, + arg->gfp); + if (!tinc) { + desc->error = -ENOMEM; + goto out; + } + tc->t_tinc = tinc; + rdsdebug("alloced tinc %p\n", tinc); + rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr); + /* + * XXX * we might be able to use the __ variants when + * we've already serialized at a higher level. + */ + skb_queue_head_init(&tinc->ti_skb_list); + } + + if (left && tc->t_tinc_hdr_rem) { + to_copy = min(tc->t_tinc_hdr_rem, left); + rdsdebug("copying %zu header from skb %p\n", to_copy, + skb); + skb_copy_bits(skb, offset, + (char *)&tinc->ti_inc.i_hdr + + sizeof(struct rds_header) - + tc->t_tinc_hdr_rem, + to_copy); + tc->t_tinc_hdr_rem -= to_copy; + left -= to_copy; + offset += to_copy; + + if (tc->t_tinc_hdr_rem == 0) { + /* could be 0 for a 0 len message */ + tc->t_tinc_data_rem = + be32_to_cpu(tinc->ti_inc.i_hdr.h_len); + } + } + + if (left && tc->t_tinc_data_rem) { + clone = skb_clone(skb, arg->gfp); + if (!clone) { + desc->error = -ENOMEM; + goto out; + } + + to_copy = min(tc->t_tinc_data_rem, left); + pskb_pull(clone, offset); + pskb_trim(clone, to_copy); + skb_queue_tail(&tinc->ti_skb_list, clone); + + rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " + "clone %p data %p len %d\n", + skb, skb->data, skb->len, offset, to_copy, + clone, clone->data, clone->len); + + tc->t_tinc_data_rem -= to_copy; + left -= to_copy; + offset += to_copy; + } + + if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) { + if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) + rds_tcp_cong_recv(conn, tinc); + else + rds_recv_incoming(conn, conn->c_faddr, + conn->c_laddr, &tinc->ti_inc, + arg->gfp); + + tc->t_tinc_hdr_rem = sizeof(struct rds_header); + tc->t_tinc_data_rem = 0; + tc->t_tinc = NULL; + rds_inc_put(&tinc->ti_inc); + tinc = NULL; + } + } +out: + rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n", + len, left, skb->len, + skb_queue_len(&tc->t_sock->sk->sk_receive_queue)); + return len - left; +} + +/* the caller has to hold the sock lock */ +static int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp) +{ + struct rds_tcp_connection *tc = conn->c_transport_data; + struct socket *sock = tc->t_sock; + read_descriptor_t desc; + struct rds_tcp_desc_arg arg; + + /* It's like glib in the kernel! */ + arg.conn = conn; + arg.gfp = gfp; + desc.arg.data = &arg; + desc.error = 0; + desc.count = 1; /* give more than one skb per call */ + + tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv); + rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp, + desc.error); + + return desc.error; +} + +/* + * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from + * data_ready. + * + * if we fail to allocate we're in trouble.. blindly wait some time before + * trying again to see if the VM can free up something for us. + */ +int rds_tcp_recv(struct rds_connection *conn) +{ + struct rds_tcp_connection *tc = conn->c_transport_data; + struct socket *sock = tc->t_sock; + int ret = 0; + + rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock); + + lock_sock(sock->sk); + ret = rds_tcp_read_sock(conn, GFP_KERNEL); + release_sock(sock->sk); + + return ret; +} + +void rds_tcp_data_ready(struct sock *sk) +{ + void (*ready)(struct sock *sk); + struct rds_connection *conn; + struct rds_tcp_connection *tc; + + rdsdebug("data ready sk %p\n", sk); + + read_lock(&sk->sk_callback_lock); + conn = sk->sk_user_data; + if (!conn) { /* check for teardown race */ + ready = sk->sk_data_ready; + goto out; + } + + tc = conn->c_transport_data; + ready = tc->t_orig_data_ready; + rds_tcp_stats_inc(s_tcp_data_ready_calls); + + if (rds_tcp_read_sock(conn, GFP_ATOMIC) == -ENOMEM) + queue_delayed_work(rds_wq, &conn->c_recv_w, 0); +out: + read_unlock(&sk->sk_callback_lock); + ready(sk); +} + +int rds_tcp_recv_init(void) +{ + rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", + sizeof(struct rds_tcp_incoming), + 0, 0, NULL); + if (!rds_tcp_incoming_slab) + return -ENOMEM; + return 0; +} + +void rds_tcp_recv_exit(void) +{ + kmem_cache_destroy(rds_tcp_incoming_slab); +} -- cgit v1.2.3-54-g00ecf