alistair23-linux/net/tipc/bcast.h
Jon Maloy 908344cdda tipc: fix bug in multicast congestion handling
One aim of commit 50100a5e39 ("tipc:
use pseudo message to wake up sockets after link congestion") was
to handle link congestion abatement in a uniform way for both unicast
and multicast transmit. However, the latter doesn't work correctly,
and has been broken since the referenced commit was applied.

If a user now sends a burst of multicast messages that is big
enough to cause broadcast link congestion, it will be put to sleep,
and not be waked up when the congestion abates as it should be.

This has two reasons. First, the flag that is used, TIPC_WAKEUP_USERS,
is set correctly, but in the wrong field. Instead of setting it in the
'action_flags' field of the arrival node struct, it is by mistake set
in the dummy node struct that is owned by the broadcast link, where it
will never tested for. Second, we cannot use the same flag for waking
up unicast and multicast users, since the function tipc_node_unlock()
needs to pick the wakeup pseudo messages to deliver from different
queues. It must hence be able to distinguish between the two cases.

This commit solves this problem by adding a new flag
TIPC_WAKEUP_BCAST_USERS, and a new function tipc_bclink_wakeup_user().
The latter is to be called by tipc_node_unlock() when the named flag,
now set in the correct field, is encountered.

v2: using explicit 'unsigned int' declaration instead of 'uint', as
per comment from David Miller.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 14:50:15 -04:00

104 lines
3.7 KiB
C

/*
* net/tipc/bcast.h: Include file for TIPC broadcast code
*
* Copyright (c) 2003-2006, 2014, Ericsson AB
* Copyright (c) 2005, 2010-2011, 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_BCAST_H
#define _TIPC_BCAST_H
#define MAX_NODES 4096
#define WSIZE 32
#define TIPC_BCLINK_RESET 1
/**
* struct tipc_node_map - set of node identifiers
* @count: # of nodes in set
* @map: bitmap of node identifiers that are in the set
*/
struct tipc_node_map {
u32 count;
u32 map[MAX_NODES / WSIZE];
};
#define PLSIZE 32
/**
* struct tipc_port_list - set of node local destination ports
* @count: # of ports in set (only valid for first entry in list)
* @next: pointer to next entry in list
* @ports: array of port references
*/
struct tipc_port_list {
int count;
struct tipc_port_list *next;
u32 ports[PLSIZE];
};
struct tipc_node;
extern const char tipc_bclink_name[];
/**
* tipc_nmap_equal - test for equality of node maps
*/
static inline int tipc_nmap_equal(struct tipc_node_map *nm_a,
struct tipc_node_map *nm_b)
{
return !memcmp(nm_a, nm_b, sizeof(*nm_a));
}
void tipc_port_list_add(struct tipc_port_list *pl_ptr, u32 port);
void tipc_port_list_free(struct tipc_port_list *pl_ptr);
int tipc_bclink_init(void);
void tipc_bclink_stop(void);
void tipc_bclink_set_flags(unsigned int flags);
void tipc_bclink_add_node(u32 addr);
void tipc_bclink_remove_node(u32 addr);
struct tipc_node *tipc_bclink_retransmit_to(void);
void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked);
void tipc_bclink_rcv(struct sk_buff *buf);
u32 tipc_bclink_get_last_sent(void);
u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr);
void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent);
int tipc_bclink_stats(char *stats_buf, const u32 buf_size);
int tipc_bclink_reset_stats(void);
int tipc_bclink_set_queue_limits(u32 limit);
void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action);
uint tipc_bclink_get_mtu(void);
int tipc_bclink_xmit(struct sk_buff *buf);
void tipc_bclink_wakeup_users(void);
#endif