[PATCH] RPC: rationalize set_buffer_size

 In fact, ->set_buffer_size should be completely functionless for non-UDP.

 Test-plan:
 Check socket buffer size on UDP sockets over time.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 19 insertions, 25 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 2543adf18551..99cad3ead81d 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -100,7 +100,7 @@ struct rpc_rqst {
 #define rq_slen                 rq_snd_buf.len
 
 struct rpc_xprt_ops {
-        void            (*set_buffer_size)(struct rpc_xprt *xprt);
+        void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
         int             (*reserve_xprt)(struct rpc_task *task);
         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
         void            (*connect)(struct rpc_task *task);
@@ -124,7 +124,7 @@ struct rpc_xprt {
         unsigned long           cong;           /* current congestion */
         unsigned long           cwnd;           /* congestion window */
 
-        unsigned int            rcvsize,        /* transport rcv buffer size */
+        size_t                  rcvsize,        /* transport rcv buffer size */
                                 sndsize;        /* transport send buffer size */
 
         size_t                  max_payload;    /* largest RPC payload size,
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 24b44e73f391..5a8f01d726e9 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -517,14 +517,8 @@ void
 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 {
         struct rpc_xprt *xprt = clnt->cl_xprt;
-
-        xprt->sndsize = 0;
-        if (sndsize)
-                xprt->sndsize = sndsize + RPC_SLACK_SPACE;
-        xprt->rcvsize = 0;
-        if (rcvsize)
-                xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
-        xprt->ops->set_buffer_size(xprt);
+        if (xprt->ops->set_buffer_size)
+                xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 }
 
 /*
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 06c2d95484e0..2e1529217e65 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -865,15 +865,7 @@ static void xs_tcp_write_space(struct sock *sk)
         read_unlock(&sk->sk_callback_lock);
 }
 
-/**
- * xs_udp_set_buffer_size - set send and receive limits
- * @xprt: generic transport
- *
- * Set socket send and receive limits based on the
- * sndsize and rcvsize fields in the generic transport
- * structure.
- */
-static void xs_udp_set_buffer_size(struct rpc_xprt *xprt)
+static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
 {
         struct sock *sk = xprt->inet;
 
@@ -889,14 +881,23 @@ static void xs_udp_set_buffer_size(struct rpc_xprt *xprt)
 }
 
 /**
- * xs_tcp_set_buffer_size - set send and receive limits
+ * xs_udp_set_buffer_size - set send and receive limits
  * @xprt: generic transport
+ * @sndsize: requested size of send buffer, in bytes
+ * @rcvsize: requested size of receive buffer, in bytes
  *
- * Nothing to do for TCP.
+ * Set socket send and receive buffer size limits.
  */
-static void xs_tcp_set_buffer_size(struct rpc_xprt *xprt)
+static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
 {
-        return;
+        xprt->sndsize = 0;
+        if (sndsize)
+                xprt->sndsize = sndsize + 1024;
+        xprt->rcvsize = 0;
+        if (rcvsize)
+                xprt->rcvsize = rcvsize + 1024;
+
+        xs_udp_do_set_buffer_size(xprt);
 }
 
 /**
@@ -989,7 +990,7 @@ static void xs_udp_connect_worker(void *args)
 
                 write_unlock_bh(&sk->sk_callback_lock);
         }
-        xs_udp_set_buffer_size(xprt);
+        xs_udp_do_set_buffer_size(xprt);
         status = 0;
 out:
         xprt_wake_pending_tasks(xprt, status);
@@ -1158,7 +1159,6 @@ static struct rpc_xprt_ops xs_udp_ops = {
 };
 
 static struct rpc_xprt_ops xs_tcp_ops = {
-        .set_buffer_size        = xs_tcp_set_buffer_size,
         .reserve_xprt           = xprt_reserve_xprt,
         .release_xprt           = xprt_release_xprt,
         .connect                = xs_connect,