[CIFS] Add support for TCP_NODELAY

mount option sockopt=TCP_NODELAY helpful for faster networks
boosting performance.  Kernel bugzilla bug number 14032.

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 3bbcaa716b3c..2e9e09ca0e30 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -98,7 +98,7 @@ struct smb_vol {
         bool nostrictsync:1; /* do not force expensive SMBflush on every sync */
         unsigned int rsize;
         unsigned int wsize;
-        unsigned int sockopt;
+        bool sockopt_tcp_nodelay:1;
         unsigned short int port;
         char *prepath;
 };
@@ -1142,9 +1142,11 @@ cifs_parse_mount_options(char *options, const char *devname,
                                         simple_strtoul(value, &value, 0);
                         }
                 } else if (strnicmp(data, "sockopt", 5) == 0) {
-                        if (value && *value) {
-                                vol->sockopt =
-                                        simple_strtoul(value, &value, 0);
+                        if (!value || !*value) {
+                                cERROR(1, ("no socket option specified"));
+                                continue;
+                        } else if (strnicmp(value, "TCP_NODELAY", 11) == 0) {
+                                vol->sockopt_tcp_nodelay = 1;
                         }
                 } else if (strnicmp(data, "netbiosname", 4) == 0) {
                         if (!value || !*value || (*value == ' ')) {
@@ -1514,6 +1516,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
 
         tcp_ses->noblocksnd = volume_info->noblocksnd;
         tcp_ses->noautotune = volume_info->noautotune;
+        tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
         atomic_set(&tcp_ses->inFlight, 0);
         init_waitqueue_head(&tcp_ses->response_q);
         init_waitqueue_head(&tcp_ses->request_q);
@@ -1764,6 +1767,7 @@ static int
 ipv4_connect(struct TCP_Server_Info *server)
 {
         int rc = 0;
+        int val;
         bool connected = false;
         __be16 orig_port = 0;
         struct socket *socket = server->ssocket;
@@ -1845,6 +1849,14 @@ ipv4_connect(struct TCP_Server_Info *server)
                         socket->sk->sk_rcvbuf = 140 * 1024;
         }
 
+        if (server->tcp_nodelay) {
+                val = 1;
+                rc = kernel_setsockopt(socket, SOL_TCP, TCP_NODELAY,
+                                (char *)&val, sizeof(val));
+                if (rc)
+                        cFYI(1, ("set TCP_NODELAY socket option error %d", rc));
+        }
+
          cFYI(1, ("sndbuf %d rcvbuf %d rcvtimeo 0x%lx",
                  socket->sk->sk_sndbuf,
                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo));
@@ -1916,6 +1928,7 @@ static int
 ipv6_connect(struct TCP_Server_Info *server)
 {
         int rc = 0;
+        int val;
         bool connected = false;
         __be16 orig_port = 0;
         struct socket *socket = server->ssocket;
@@ -1987,6 +2000,15 @@ ipv6_connect(struct TCP_Server_Info *server)
          */
         socket->sk->sk_rcvtimeo = 7 * HZ;
         socket->sk->sk_sndtimeo = 5 * HZ;
+
+        if (server->tcp_nodelay) {
+                val = 1;
+                rc = kernel_setsockopt(socket, SOL_TCP, TCP_NODELAY,
+                                (char *)&val, sizeof(val));
+                if (rc)
+                        cFYI(1, ("set TCP_NODELAY socket option error %d", rc));
+        }
+
         server->ssocket = socket;
 
         return rc;