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authorTom Tucker <tom@opengridcomputing.com>2007-12-30 21:07:40 -0600
committerJ. Bruce Fields <bfields@citi.umich.edu>2008-02-01 16:42:09 -0500
commitf9f3cc4fae04c87c815a4b473fb577cf74ef27da (patch)
tree906550a4f9db0bf79adea43b3b9ac1fbc2b2c4e6
parent44a6995b32eb9b021ee71b279edb84728c9f5160 (diff)
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 <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
-rw-r--r--net/sunrpc/svcsock.c57
1 files changed, 29 insertions, 28 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 962dbf43a72..6e9dc8f9649 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",