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>
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 @@
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 @@
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 @@
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 @@
} 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",