forked from luck/tmp_suning_uos_patched
c637c10355
TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
62 lines
2.8 KiB
C
62 lines
2.8 KiB
C
/* net/tipc/socket.h: Include file for TIPC socket code
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*
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* Copyright (c) 2014, Ericsson AB
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the names of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* Alternatively, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2 as published by the Free
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* Software Foundation.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _TIPC_SOCK_H
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#define _TIPC_SOCK_H
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#include <net/sock.h>
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#include <net/genetlink.h>
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#define TIPC_CONNACK_INTV 256
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#define TIPC_FLOWCTRL_WIN (TIPC_CONNACK_INTV * 2)
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#define TIPC_CONN_OVERLOAD_LIMIT ((TIPC_FLOWCTRL_WIN * 2 + 1) * \
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SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
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int tipc_socket_init(void);
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void tipc_socket_stop(void);
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int tipc_sock_create_local(struct net *net, int type, struct socket **res);
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void tipc_sock_release_local(struct socket *sock);
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int tipc_sock_accept_local(struct socket *sock, struct socket **newsock,
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int flags);
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int tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq);
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struct sk_buff *tipc_sk_socks_show(struct net *net);
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void tipc_sk_mcast_rcv(struct net *net, struct sk_buff *buf);
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void tipc_sk_reinit(struct net *net);
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int tipc_sk_rht_init(struct net *net);
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void tipc_sk_rht_destroy(struct net *net);
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int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb);
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int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb);
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#endif
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