android_kernel_samsung_univ.../net/tipc/port.h
Jon Paul Maloy 50100a5e39 tipc: use pseudo message to wake up sockets after link congestion
The current link implementation keeps a linked list of blocked ports/
sockets that is populated when there is link congestion. The purpose
of this is to let the link know which users to wake up when the
congestion abates.

This adds unnecessary complexity to the data structure and the code,
since it forces us to involve the link each time we want to delete
a socket. It also forces us to grab the spinlock port_lock within
the scope of node_lock. We want to get rid of this direct dependence,
as well as the deadlock hazard resulting from the usage of port_lock.

In this commit, we instead let the link keep list of a "wakeup" pseudo
messages for use in such situations. Those messages are sent to the
pending sockets via the ordinary message reception path, and wake up
the socket's owner when they are received.

This enables us to get rid of the 'waiting_ports' linked lists in struct
tipc_port that manifest this direct reference. As a consequence, we can
eliminate another BH entry into the socket, and hence the need to grab
port_lock. This is a further step in our effort to remove port_lock
altogether.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23 11:18:33 -07:00

187 lines
5.8 KiB
C

/*
* net/tipc/port.h: Include file for TIPC port code
*
* Copyright (c) 1994-2007, 2014, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, 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_PORT_H
#define _TIPC_PORT_H
#include "ref.h"
#include "net.h"
#include "msg.h"
#include "node_subscr.h"
#define TIPC_CONNACK_INTV 256
#define TIPC_FLOWCTRL_WIN (TIPC_CONNACK_INTV * 2)
#define TIPC_CONN_OVERLOAD_LIMIT ((TIPC_FLOWCTRL_WIN * 2 + 1) * \
SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
/**
* struct tipc_port - TIPC port structure
* @lock: pointer to spinlock for controlling access to port
* @connected: non-zero if port is currently connected to a peer port
* @conn_type: TIPC type used when connection was established
* @conn_instance: TIPC instance used when connection was established
* @published: non-zero if port has one or more associated names
* @max_pkt: maximum packet size "hint" used when building messages sent by port
* @ref: unique reference to port in TIPC object registry
* @phdr: preformatted message header used when sending messages
* @port_list: adjacent ports in TIPC's global list of ports
* @publications: list of publications for port
* @pub_count: total # of publications port has made during its lifetime
* @probing_state:
* @probing_interval:
* @timer_ref:
* @subscription: "node down" subscription used to terminate failed connections
*/
struct tipc_port {
spinlock_t *lock;
int connected;
u32 conn_type;
u32 conn_instance;
int published;
u32 max_pkt;
u32 ref;
struct tipc_msg phdr;
struct list_head port_list;
struct list_head publications;
u32 pub_count;
u32 probing_state;
u32 probing_interval;
struct timer_list timer;
struct tipc_node_subscr subscription;
};
extern spinlock_t tipc_port_list_lock;
struct tipc_port_list;
/*
* TIPC port manipulation routines
*/
u32 tipc_port_init(struct tipc_port *p_ptr,
const unsigned int importance);
void tipc_acknowledge(u32 port_ref, u32 ack);
void tipc_port_destroy(struct tipc_port *p_ptr);
int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *name_seq);
int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *name_seq);
int tipc_port_connect(u32 portref, struct tipc_portid const *port);
int tipc_port_disconnect(u32 portref);
int tipc_port_shutdown(u32 ref);
/*
* The following routines require that the port be locked on entry
*/
int __tipc_port_disconnect(struct tipc_port *tp_ptr);
int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
struct tipc_portid const *peer);
int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg);
struct sk_buff *tipc_port_get_ports(void);
void tipc_port_reinit(void);
/**
* tipc_port_lock - lock port instance referred to and return its pointer
*/
static inline struct tipc_port *tipc_port_lock(u32 ref)
{
return (struct tipc_port *)tipc_ref_lock(ref);
}
/**
* tipc_port_unlock - unlock a port instance
*
* Can use pointer instead of tipc_ref_unlock() since port is already locked.
*/
static inline void tipc_port_unlock(struct tipc_port *p_ptr)
{
spin_unlock_bh(p_ptr->lock);
}
static inline u32 tipc_port_peernode(struct tipc_port *p_ptr)
{
return msg_destnode(&p_ptr->phdr);
}
static inline u32 tipc_port_peerport(struct tipc_port *p_ptr)
{
return msg_destport(&p_ptr->phdr);
}
static inline bool tipc_port_unreliable(struct tipc_port *port)
{
return msg_src_droppable(&port->phdr) != 0;
}
static inline void tipc_port_set_unreliable(struct tipc_port *port,
bool unreliable)
{
msg_set_src_droppable(&port->phdr, unreliable ? 1 : 0);
}
static inline bool tipc_port_unreturnable(struct tipc_port *port)
{
return msg_dest_droppable(&port->phdr) != 0;
}
static inline void tipc_port_set_unreturnable(struct tipc_port *port,
bool unreturnable)
{
msg_set_dest_droppable(&port->phdr, unreturnable ? 1 : 0);
}
static inline int tipc_port_importance(struct tipc_port *port)
{
return msg_importance(&port->phdr);
}
static inline int tipc_port_set_importance(struct tipc_port *port, int imp)
{
if (imp > TIPC_CRITICAL_IMPORTANCE)
return -EINVAL;
msg_set_importance(&port->phdr, (u32)imp);
return 0;
}
#endif