From f9f3cc4fae04c87c815a4b473fb577cf74ef27da Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Sun, 30 Dec 2007 21:07:40 -0600 Subject: [PATCH] svc: Move connection limit checking to its own function Move the code that poaches connections when the connection limit is hit to a subroutine to make the accept logic path easier to follow. Since this is in the new connection path, it should not be a performance issue. Signed-off-by: Tom Tucker Acked-by: Neil Brown Reviewed-by: Chuck Lever Reviewed-by: Greg Banks Signed-off-by: J. Bruce Fields --- net/sunrpc/svcsock.c | 57 ++++++++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 28 deletions(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 962dbf4..6e9dc8f 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1105,17 +1105,30 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt) svc_sock_received(newsvsk); - /* make sure that we don't have too many active connections. - * If we have, something must be dropped. - * - * There's no point in trying to do random drop here for - * DoS prevention. The NFS clients does 1 reconnect in 15 - * seconds. An attacker can easily beat that. - * - * The only somewhat efficient mechanism would be if drop - * old connections from the same IP first. But right now - * we don't even record the client IP in svc_sock. - */ + if (serv->sv_stats) + serv->sv_stats->nettcpconn++; + + return &newsvsk->sk_xprt; + +failed: + sock_release(newsock); + return NULL; +} + +/* + * Make sure that we don't have too many active connections. If we + * have, something must be dropped. + * + * There's no point in trying to do random drop here for DoS + * prevention. The NFS clients does 1 reconnect in 15 seconds. An + * attacker can easily beat that. + * + * The only somewhat efficient mechanism would be if drop old + * connections from the same IP first. But right now we don't even + * record the client IP in svc_sock. + */ +static void svc_check_conn_limits(struct svc_serv *serv) +{ if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) { struct svc_sock *svsk = NULL; spin_lock_bh(&serv->sv_lock); @@ -1123,13 +1136,9 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt) if (net_ratelimit()) { /* Try to help the admin */ printk(KERN_NOTICE "%s: too many open TCP " - "sockets, consider increasing the " - "number of nfsd threads\n", - serv->sv_name); - printk(KERN_NOTICE - "%s: last TCP connect from %s\n", - serv->sv_name, __svc_print_addr(sin, - buf, sizeof(buf))); + "sockets, consider increasing the " + "number of nfsd threads\n", + serv->sv_name); } /* * Always select the oldest socket. It's not fair, @@ -1147,17 +1156,7 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt) svc_sock_enqueue(svsk); svc_sock_put(svsk); } - } - - if (serv->sv_stats) - serv->sv_stats->nettcpconn++; - - return &newsvsk->sk_xprt; - -failed: - sock_release(newsock); - return NULL; } /* @@ -1574,6 +1573,8 @@ svc_recv(struct svc_rqst *rqstp, long timeout) } else if (test_bit(SK_LISTENER, &svsk->sk_flags)) { struct svc_xprt *newxpt; newxpt = svsk->sk_xprt.xpt_ops->xpo_accept(&svsk->sk_xprt); + if (newxpt) + svc_check_conn_limits(svsk->sk_server); svc_sock_received(svsk); } else { dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n", -- 2.7.4