mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 16:54:20 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
400 lines
10 KiB
C
400 lines
10 KiB
C
/* peer.c: Rx RPC peer management
|
|
*
|
|
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <rxrpc/rxrpc.h>
|
|
#include <rxrpc/transport.h>
|
|
#include <rxrpc/peer.h>
|
|
#include <rxrpc/connection.h>
|
|
#include <rxrpc/call.h>
|
|
#include <rxrpc/message.h>
|
|
#include <linux/udp.h>
|
|
#include <linux/ip.h>
|
|
#include <net/sock.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/div64.h>
|
|
#include "internal.h"
|
|
|
|
__RXACCT_DECL(atomic_t rxrpc_peer_count);
|
|
LIST_HEAD(rxrpc_peers);
|
|
DECLARE_RWSEM(rxrpc_peers_sem);
|
|
unsigned long rxrpc_peer_timeout = 12 * 60 * 60;
|
|
|
|
static void rxrpc_peer_do_timeout(struct rxrpc_peer *peer);
|
|
|
|
static void __rxrpc_peer_timeout(rxrpc_timer_t *timer)
|
|
{
|
|
struct rxrpc_peer *peer =
|
|
list_entry(timer, struct rxrpc_peer, timeout);
|
|
|
|
_debug("Rx PEER TIMEOUT [%p{u=%d}]", peer, atomic_read(&peer->usage));
|
|
|
|
rxrpc_peer_do_timeout(peer);
|
|
}
|
|
|
|
static const struct rxrpc_timer_ops rxrpc_peer_timer_ops = {
|
|
.timed_out = __rxrpc_peer_timeout,
|
|
};
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* create a peer record
|
|
*/
|
|
static int __rxrpc_create_peer(struct rxrpc_transport *trans, __be32 addr,
|
|
struct rxrpc_peer **_peer)
|
|
{
|
|
struct rxrpc_peer *peer;
|
|
|
|
_enter("%p,%08x", trans, ntohl(addr));
|
|
|
|
/* allocate and initialise a peer record */
|
|
peer = kmalloc(sizeof(struct rxrpc_peer), GFP_KERNEL);
|
|
if (!peer) {
|
|
_leave(" = -ENOMEM");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
memset(peer, 0, sizeof(struct rxrpc_peer));
|
|
atomic_set(&peer->usage, 1);
|
|
|
|
INIT_LIST_HEAD(&peer->link);
|
|
INIT_LIST_HEAD(&peer->proc_link);
|
|
INIT_LIST_HEAD(&peer->conn_idlist);
|
|
INIT_LIST_HEAD(&peer->conn_active);
|
|
INIT_LIST_HEAD(&peer->conn_graveyard);
|
|
spin_lock_init(&peer->conn_gylock);
|
|
init_waitqueue_head(&peer->conn_gy_waitq);
|
|
rwlock_init(&peer->conn_idlock);
|
|
rwlock_init(&peer->conn_lock);
|
|
atomic_set(&peer->conn_count, 0);
|
|
spin_lock_init(&peer->lock);
|
|
rxrpc_timer_init(&peer->timeout, &rxrpc_peer_timer_ops);
|
|
|
|
peer->addr.s_addr = addr;
|
|
|
|
peer->trans = trans;
|
|
peer->ops = trans->peer_ops;
|
|
|
|
__RXACCT(atomic_inc(&rxrpc_peer_count));
|
|
*_peer = peer;
|
|
_leave(" = 0 (%p)", peer);
|
|
|
|
return 0;
|
|
} /* end __rxrpc_create_peer() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* find a peer record on the specified transport
|
|
* - returns (if successful) with peer record usage incremented
|
|
* - resurrects it from the graveyard if found there
|
|
*/
|
|
int rxrpc_peer_lookup(struct rxrpc_transport *trans, __be32 addr,
|
|
struct rxrpc_peer **_peer)
|
|
{
|
|
struct rxrpc_peer *peer, *candidate = NULL;
|
|
struct list_head *_p;
|
|
int ret;
|
|
|
|
_enter("%p{%hu},%08x", trans, trans->port, ntohl(addr));
|
|
|
|
/* [common case] search the transport's active list first */
|
|
read_lock(&trans->peer_lock);
|
|
list_for_each(_p, &trans->peer_active) {
|
|
peer = list_entry(_p, struct rxrpc_peer, link);
|
|
if (peer->addr.s_addr == addr)
|
|
goto found_active;
|
|
}
|
|
read_unlock(&trans->peer_lock);
|
|
|
|
/* [uncommon case] not active - create a candidate for a new record */
|
|
ret = __rxrpc_create_peer(trans, addr, &candidate);
|
|
if (ret < 0) {
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* search the active list again, just in case it appeared whilst we
|
|
* were busy */
|
|
write_lock(&trans->peer_lock);
|
|
list_for_each(_p, &trans->peer_active) {
|
|
peer = list_entry(_p, struct rxrpc_peer, link);
|
|
if (peer->addr.s_addr == addr)
|
|
goto found_active_second_chance;
|
|
}
|
|
|
|
/* search the transport's graveyard list */
|
|
spin_lock(&trans->peer_gylock);
|
|
list_for_each(_p, &trans->peer_graveyard) {
|
|
peer = list_entry(_p, struct rxrpc_peer, link);
|
|
if (peer->addr.s_addr == addr)
|
|
goto found_in_graveyard;
|
|
}
|
|
spin_unlock(&trans->peer_gylock);
|
|
|
|
/* we can now add the new candidate to the list
|
|
* - tell the application layer that this peer has been added
|
|
*/
|
|
rxrpc_get_transport(trans);
|
|
peer = candidate;
|
|
candidate = NULL;
|
|
|
|
if (peer->ops && peer->ops->adding) {
|
|
ret = peer->ops->adding(peer);
|
|
if (ret < 0) {
|
|
write_unlock(&trans->peer_lock);
|
|
__RXACCT(atomic_dec(&rxrpc_peer_count));
|
|
kfree(peer);
|
|
rxrpc_put_transport(trans);
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
atomic_inc(&trans->peer_count);
|
|
|
|
make_active:
|
|
list_add_tail(&peer->link, &trans->peer_active);
|
|
|
|
success_uwfree:
|
|
write_unlock(&trans->peer_lock);
|
|
|
|
if (candidate) {
|
|
__RXACCT(atomic_dec(&rxrpc_peer_count));
|
|
kfree(candidate);
|
|
}
|
|
|
|
if (list_empty(&peer->proc_link)) {
|
|
down_write(&rxrpc_peers_sem);
|
|
list_add_tail(&peer->proc_link, &rxrpc_peers);
|
|
up_write(&rxrpc_peers_sem);
|
|
}
|
|
|
|
success:
|
|
*_peer = peer;
|
|
|
|
_leave(" = 0 (%p{u=%d cc=%d})",
|
|
peer,
|
|
atomic_read(&peer->usage),
|
|
atomic_read(&peer->conn_count));
|
|
return 0;
|
|
|
|
/* handle the peer being found in the active list straight off */
|
|
found_active:
|
|
rxrpc_get_peer(peer);
|
|
read_unlock(&trans->peer_lock);
|
|
goto success;
|
|
|
|
/* handle resurrecting a peer from the graveyard */
|
|
found_in_graveyard:
|
|
rxrpc_get_peer(peer);
|
|
rxrpc_get_transport(peer->trans);
|
|
rxrpc_krxtimod_del_timer(&peer->timeout);
|
|
list_del_init(&peer->link);
|
|
spin_unlock(&trans->peer_gylock);
|
|
goto make_active;
|
|
|
|
/* handle finding the peer on the second time through the active
|
|
* list */
|
|
found_active_second_chance:
|
|
rxrpc_get_peer(peer);
|
|
goto success_uwfree;
|
|
|
|
} /* end rxrpc_peer_lookup() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* finish with a peer record
|
|
* - it gets sent to the graveyard from where it can be resurrected or timed
|
|
* out
|
|
*/
|
|
void rxrpc_put_peer(struct rxrpc_peer *peer)
|
|
{
|
|
struct rxrpc_transport *trans = peer->trans;
|
|
|
|
_enter("%p{cc=%d a=%08x}",
|
|
peer,
|
|
atomic_read(&peer->conn_count),
|
|
ntohl(peer->addr.s_addr));
|
|
|
|
/* sanity check */
|
|
if (atomic_read(&peer->usage) <= 0)
|
|
BUG();
|
|
|
|
write_lock(&trans->peer_lock);
|
|
spin_lock(&trans->peer_gylock);
|
|
if (likely(!atomic_dec_and_test(&peer->usage))) {
|
|
spin_unlock(&trans->peer_gylock);
|
|
write_unlock(&trans->peer_lock);
|
|
_leave("");
|
|
return;
|
|
}
|
|
|
|
/* move to graveyard queue */
|
|
list_del(&peer->link);
|
|
write_unlock(&trans->peer_lock);
|
|
|
|
list_add_tail(&peer->link, &trans->peer_graveyard);
|
|
|
|
BUG_ON(!list_empty(&peer->conn_active));
|
|
|
|
rxrpc_krxtimod_add_timer(&peer->timeout, rxrpc_peer_timeout * HZ);
|
|
|
|
spin_unlock(&trans->peer_gylock);
|
|
|
|
rxrpc_put_transport(trans);
|
|
|
|
_leave(" [killed]");
|
|
} /* end rxrpc_put_peer() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* handle a peer timing out in the graveyard
|
|
* - called from krxtimod
|
|
*/
|
|
static void rxrpc_peer_do_timeout(struct rxrpc_peer *peer)
|
|
{
|
|
struct rxrpc_transport *trans = peer->trans;
|
|
|
|
_enter("%p{u=%d cc=%d a=%08x}",
|
|
peer,
|
|
atomic_read(&peer->usage),
|
|
atomic_read(&peer->conn_count),
|
|
ntohl(peer->addr.s_addr));
|
|
|
|
BUG_ON(atomic_read(&peer->usage) < 0);
|
|
|
|
/* remove from graveyard if still dead */
|
|
spin_lock(&trans->peer_gylock);
|
|
if (atomic_read(&peer->usage) == 0)
|
|
list_del_init(&peer->link);
|
|
else
|
|
peer = NULL;
|
|
spin_unlock(&trans->peer_gylock);
|
|
|
|
if (!peer) {
|
|
_leave("");
|
|
return; /* resurrected */
|
|
}
|
|
|
|
/* clear all connections on this peer */
|
|
rxrpc_conn_clearall(peer);
|
|
|
|
BUG_ON(!list_empty(&peer->conn_active));
|
|
BUG_ON(!list_empty(&peer->conn_graveyard));
|
|
|
|
/* inform the application layer */
|
|
if (peer->ops && peer->ops->discarding)
|
|
peer->ops->discarding(peer);
|
|
|
|
if (!list_empty(&peer->proc_link)) {
|
|
down_write(&rxrpc_peers_sem);
|
|
list_del(&peer->proc_link);
|
|
up_write(&rxrpc_peers_sem);
|
|
}
|
|
|
|
__RXACCT(atomic_dec(&rxrpc_peer_count));
|
|
kfree(peer);
|
|
|
|
/* if the graveyard is now empty, wake up anyone waiting for that */
|
|
if (atomic_dec_and_test(&trans->peer_count))
|
|
wake_up(&trans->peer_gy_waitq);
|
|
|
|
_leave(" [destroyed]");
|
|
} /* end rxrpc_peer_do_timeout() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* clear all peer records from a transport endpoint
|
|
*/
|
|
void rxrpc_peer_clearall(struct rxrpc_transport *trans)
|
|
{
|
|
DECLARE_WAITQUEUE(myself,current);
|
|
|
|
struct rxrpc_peer *peer;
|
|
int err;
|
|
|
|
_enter("%p",trans);
|
|
|
|
/* there shouldn't be any active peers remaining */
|
|
BUG_ON(!list_empty(&trans->peer_active));
|
|
|
|
/* manually timeout all peers in the graveyard */
|
|
spin_lock(&trans->peer_gylock);
|
|
while (!list_empty(&trans->peer_graveyard)) {
|
|
peer = list_entry(trans->peer_graveyard.next,
|
|
struct rxrpc_peer, link);
|
|
_debug("Clearing peer %p\n", peer);
|
|
err = rxrpc_krxtimod_del_timer(&peer->timeout);
|
|
spin_unlock(&trans->peer_gylock);
|
|
|
|
if (err == 0)
|
|
rxrpc_peer_do_timeout(peer);
|
|
|
|
spin_lock(&trans->peer_gylock);
|
|
}
|
|
spin_unlock(&trans->peer_gylock);
|
|
|
|
/* wait for the the peer graveyard to be completely cleared */
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
add_wait_queue(&trans->peer_gy_waitq, &myself);
|
|
|
|
while (atomic_read(&trans->peer_count) != 0) {
|
|
schedule();
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
remove_wait_queue(&trans->peer_gy_waitq, &myself);
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
_leave("");
|
|
} /* end rxrpc_peer_clearall() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* calculate and cache the Round-Trip-Time for a message and its response
|
|
*/
|
|
void rxrpc_peer_calculate_rtt(struct rxrpc_peer *peer,
|
|
struct rxrpc_message *msg,
|
|
struct rxrpc_message *resp)
|
|
{
|
|
unsigned long long rtt;
|
|
int loop;
|
|
|
|
_enter("%p,%p,%p", peer, msg, resp);
|
|
|
|
/* calculate the latest RTT */
|
|
rtt = resp->stamp.tv_sec - msg->stamp.tv_sec;
|
|
rtt *= 1000000UL;
|
|
rtt += resp->stamp.tv_usec - msg->stamp.tv_usec;
|
|
|
|
/* add to cache */
|
|
peer->rtt_cache[peer->rtt_point] = rtt;
|
|
peer->rtt_point++;
|
|
peer->rtt_point %= RXRPC_RTT_CACHE_SIZE;
|
|
|
|
if (peer->rtt_usage < RXRPC_RTT_CACHE_SIZE)
|
|
peer->rtt_usage++;
|
|
|
|
/* recalculate RTT */
|
|
rtt = 0;
|
|
for (loop = peer->rtt_usage - 1; loop >= 0; loop--)
|
|
rtt += peer->rtt_cache[loop];
|
|
|
|
do_div(rtt, peer->rtt_usage);
|
|
peer->rtt = rtt;
|
|
|
|
_leave(" RTT=%lu.%lums",
|
|
(long) (peer->rtt / 1000), (long) (peer->rtt % 1000));
|
|
|
|
} /* end rxrpc_peer_calculate_rtt() */
|