kernel_optimize_test/net/tipc/name_distr.h
Hoang Huu Le cad2929dc4 tipc: update a binding service via broadcast
Currently, updating binding table (add service binding to
name table/withdraw a service binding) is being sent over replicast.
However, if we are scaling up clusters to > 100 nodes/containers this
method is less affection because of looping through nodes in a cluster one
by one.

It is worth to use broadcast to update a binding service. This way, the
binding table can be updated on all peer nodes in one shot.

Broadcast is used when all peer nodes, as indicated by a new capability
flag TIPC_NAMED_BCAST, support reception of this message type.

Four problems need to be considered when introducing this feature.
1) When establishing a link to a new peer node we still update this by a
unicast 'bulk' update. This may lead to race conditions, where a later
broadcast publication/withdrawal bypass the 'bulk', resulting in
disordered publications, or even that a withdrawal may arrive before the
corresponding publication. We solve this by adding an 'is_last_bulk' bit
in the last bulk messages so that it can be distinguished from all other
messages. Only when this message has arrived do we open up for reception
of broadcast publications/withdrawals.

2) When a first legacy node is added to the cluster all distribution
will switch over to use the legacy 'replicast' method, while the
opposite happens when the last legacy node leaves the cluster. This
entails another risk of message disordering that has to be handled. We
solve this by adding a sequence number to the broadcast/replicast
messages, so that disordering can be discovered and corrected. Note
however that we don't need to consider potential message loss or
duplication at this protocol level.

3) Bulk messages don't contain any sequence numbers, and will always
arrive in order. Hence we must exempt those from the sequence number
control and deliver them unconditionally. We solve this by adding a new
'is_bulk' bit in those messages so that they can be recognized.

4) Legacy messages, which don't contain any new bits or sequence
numbers, but neither can arrive out of order, also need to be exempt
from the initial synchronization and sequence number check, and
delivered unconditionally. Therefore, we add another 'is_not_legacy' bit
to all new messages so that those can be distinguished from legacy
messages and the latter delivered directly.

v1->v2:
 - fix warning issue reported by kbuild test robot <lkp@intel.com>
 - add santiy check to drop the publication message with a sequence
number that is lower than the agreed synch point

Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-17 08:53:34 -07:00

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3.3 KiB
C

/*
* net/tipc/name_distr.h: Include file for TIPC name distribution code
*
* Copyright (c) 2000-2006, Ericsson AB
* Copyright (c) 2005, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* 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.
*/
#ifndef _TIPC_NAME_DISTR_H
#define _TIPC_NAME_DISTR_H
#include "name_table.h"
#define ITEM_SIZE sizeof(struct distr_item)
/**
* struct distr_item - publication info distributed to other nodes
* @type: name sequence type
* @lower: name sequence lower bound
* @upper: name sequence upper bound
* @ref: publishing port reference
* @key: publication key
*
* ===> All fields are stored in network byte order. <===
*
* First 3 fields identify (name or) name sequence being published.
* Reference field uniquely identifies port that published name sequence.
* Key field uniquely identifies publication, in the event a port has
* multiple publications of the same name sequence.
*
* Note: There is no field that identifies the publishing node because it is
* the same for all items contained within a publication message.
*/
struct distr_item {
__be32 type;
__be32 lower;
__be32 upper;
__be32 port;
__be32 key;
};
void tipc_named_bcast(struct net *net, struct sk_buff *skb);
struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ);
struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ);
void tipc_named_node_up(struct net *net, u32 dnode, u16 capabilities);
void tipc_named_rcv(struct net *net, struct sk_buff_head *namedq,
u16 *rcv_nxt, bool *open);
void tipc_named_reinit(struct net *net);
void tipc_publ_notify(struct net *net, struct list_head *nsub_list,
u32 addr, u16 capabilities);
#endif