From 2bd698b60417a97f83dbeb69c4b487d823bf56bf Mon Sep 17 00:00:00 2001
From: Zach Brown <zab@versity.com>
Date: Tue, 6 Jun 2017 14:23:03 -0700
Subject: [PATCH] scoutfs: set NODELAY and REUSEADDR on net sockets

Add a helper that creates a socket and sets nodelay for all sockets and
set reuseaddr in listening sockets.

Signed-off-by: Zach Brown <zab@versity.com>
---
 kmod/src/net.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/kmod/src/net.c b/kmod/src/net.c
index d7b16b8a..f915e24a 100644
--- a/kmod/src/net.c
+++ b/kmod/src/net.c
@@ -1837,6 +1837,38 @@ static void scoutfs_net_accept_func(struct work_struct *work)
 	}
 }
 
+/*
+ * Create a new TCP socket and set all the options that are used for
+ * both connecting and listening sockets.
+ */
+static int create_sock_setopts(struct socket **sock_ret)
+{
+	struct socket *sock;
+	int optval;
+	int ret;
+
+	*sock_ret = NULL;
+
+	ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+	if (ret) {
+		trace_printk("sock create ret %d\n", ret);
+		return ret;
+	}
+
+	optval = 1;
+	ret = kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&optval,
+				sizeof(optval));
+	if (ret) {
+		trace_printk("nodelay ret %d\n", ret);
+		sock_release(sock);
+		return ret;
+	}
+
+	*sock_ret = sock;
+
+	return 0;
+}
+
 /*
  * The server work has acquired the listen lock.  We create a socket and
  * publish its bound address in the addr lock's lvb.
@@ -1855,6 +1887,7 @@ static void scoutfs_net_listen_func(struct work_struct *work)
 	struct sockaddr_in sin;
 	struct socket *sock;
 	int addrlen;
+	int optval;
 	int ret;
 
 	/* XXX option to set listening address */
@@ -1865,13 +1898,22 @@ static void scoutfs_net_listen_func(struct work_struct *work)
 	trace_printk("binding to %pIS:%u\n",
 		     &sin, be16_to_cpu(sin.sin_port));
 
-	ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+	ret = create_sock_setopts(&sock);
 	if (ret)
 		goto out;
 
 	trace_printk("listening sinf %p sock %p sk %p\n",
 		     sinf, sock, sock->sk);
 
+	optval = 1;
+	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&optval,
+				sizeof(optval));
+	if (ret) {
+		trace_printk("reuseaddr ret %d\n", ret);
+		sock_release(sock);
+		goto out;
+	}
+
 	sinf->sock = sock;
 	INIT_WORK(&sinf->accept_work, scoutfs_net_accept_func);
 
@@ -1914,7 +1956,7 @@ static void scoutfs_net_connect_func(struct work_struct *work)
 	int addrlen;
 	int ret;
 
-	ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+	ret = create_sock_setopts(&sock);
 	if (ret)
 		goto out;