/* * 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 <linux/kernel.h> #include <net/tcp.h> #include "rds.h" #include "tcp.h" static struct kmem_cache *rds_tcp_incoming_slab; 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 iovec *first_iov, size_t size) { struct rds_tcp_incoming *tinc; struct iovec *iov, tmp; struct sk_buff *skb; unsigned long to_copy, skb_off; int ret = 0; if (size == 0) goto out; tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); iov = first_iov; tmp = *iov; skb_queue_walk(&tinc->ti_skb_list, skb) { skb_off = 0; while (skb_off < skb->len) { while (tmp.iov_len == 0) { iov++; tmp = *iov; } to_copy = min(tmp.iov_len, size); to_copy = min(to_copy, skb->len - skb_off); rdsdebug("ret %d size %zu skb %p skb_off %lu " "skblen %d iov_base %p iov_len %zu cpy %lu\n", ret, size, skb, skb_off, skb->len, tmp.iov_base, tmp.iov_len, to_copy); /* modifies tmp as it copies */ if (skb_copy_datagram_iovec(skb, skb_off, &tmp, to_copy)) { ret = -EFAULT; goto out; } size -= to_copy; ret += to_copy; skb_off += to_copy; if (size == 0) 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; enum km_type km; }; 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 == NULL) { tinc = kmem_cache_alloc(rds_tcp_incoming_slab, arg->gfp); if (tinc == NULL) { 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 == NULL) { 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, arg->km); 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 */ int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp, enum km_type km) { 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; arg.km = km; 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, KM_USER0); release_sock(sock->sk); return ret; } void rds_tcp_data_ready(struct sock *sk, int bytes) { void (*ready)(struct sock *sk, int bytes); struct rds_connection *conn; struct rds_tcp_connection *tc; rdsdebug("data ready sk %p bytes %d\n", sk, bytes); read_lock(&sk->sk_callback_lock); conn = sk->sk_user_data; if (conn == NULL) { /* 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, KM_SOFTIRQ0) == -ENOMEM) queue_delayed_work(rds_wq, &conn->c_recv_w, 0); out: read_unlock(&sk->sk_callback_lock); ready(sk, bytes); } int __init 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 == NULL) return -ENOMEM; return 0; } void rds_tcp_recv_exit(void) { kmem_cache_destroy(rds_tcp_incoming_slab); }