SUNRPC: Ensure client closes the socket when server initiates a close

 If the server decides to close the RPC socket, we currently don't actually
 respond until either another RPC call is scheduled, or until xprt_autoclose()
 gets called by the socket expiry timer (which may be up to 5 minutes
 later).

 This patch ensures that xprt_autoclose() is called much sooner if the
 server closes the socket.

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

2 files changed, 26 insertions, 19 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 069a6cbd49ea..8bc0d5acf0da 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -119,6 +119,17 @@ out_sleep:
         return 0;
 }
 
+static void xprt_clear_locked(struct rpc_xprt *xprt)
+{
+        xprt->snd_task = NULL;
+        if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) {
+                smp_mb__before_clear_bit();
+                clear_bit(XPRT_LOCKED, &xprt->state);
+                smp_mb__after_clear_bit();
+        } else
+                schedule_work(&xprt->task_cleanup);
+}
+
 /*
  * xprt_reserve_xprt_cong - serialize write access to transports
  * @task: task that is requesting access to the transport
@@ -145,9 +156,7 @@ int xprt_reserve_xprt_cong(struct rpc_task *task)
                 }
                 return 1;
         }
-        smp_mb__before_clear_bit();
-        clear_bit(XPRT_LOCKED, &xprt->state);
-        smp_mb__after_clear_bit();
+        xprt_clear_locked(xprt);
 out_sleep:
         dprintk("RPC: %4d failed to lock transport %p\n", task->tk_pid, xprt);
         task->tk_timeout = 0;
@@ -193,9 +202,7 @@ static void __xprt_lock_write_next(struct rpc_xprt *xprt)
         return;
 
 out_unlock:
-        smp_mb__before_clear_bit();
-        clear_bit(XPRT_LOCKED, &xprt->state);
-        smp_mb__after_clear_bit();
+        xprt_clear_locked(xprt);
 }
 
 static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
@@ -222,9 +229,7 @@ static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
                 return;
         }
 out_unlock:
-        smp_mb__before_clear_bit();
-        clear_bit(XPRT_LOCKED, &xprt->state);
-        smp_mb__after_clear_bit();
+        xprt_clear_locked(xprt);
 }
 
 /**
@@ -237,10 +242,7 @@ out_unlock:
 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 {
         if (xprt->snd_task == task) {
-                xprt->snd_task = NULL;
-                smp_mb__before_clear_bit();
-                clear_bit(XPRT_LOCKED, &xprt->state);
-                smp_mb__after_clear_bit();
+                xprt_clear_locked(xprt);
                 __xprt_lock_write_next(xprt);
         }
 }
@@ -256,10 +258,7 @@ void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
 {
         if (xprt->snd_task == task) {
-                xprt->snd_task = NULL;
-                smp_mb__before_clear_bit();
-                clear_bit(XPRT_LOCKED, &xprt->state);
-                smp_mb__after_clear_bit();
+                xprt_clear_locked(xprt);
                 __xprt_lock_write_next_cong(xprt);
         }
 }
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 3e8893001479..c458f8d1d6d1 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -425,7 +425,7 @@ static void xs_close(struct rpc_xprt *xprt)
         struct sock *sk = xprt->inet;
 
         if (!sk)
-                return;
+                goto clear_close_wait;
 
         dprintk("RPC:      xs_close xprt %p\n", xprt);
 
@@ -442,6 +442,10 @@ static void xs_close(struct rpc_xprt *xprt)
         sk->sk_no_check = 0;
 
         sock_release(sock);
+clear_close_wait:
+        smp_mb__before_clear_bit();
+        clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+        smp_mb__after_clear_bit();
 }
 
 /**
@@ -801,9 +805,13 @@ static void xs_tcp_state_change(struct sock *sk)
         case TCP_SYN_SENT:
         case TCP_SYN_RECV:
                 break;
+        case TCP_CLOSE_WAIT:
+                /* Try to schedule an autoclose RPC calls */
+                set_bit(XPRT_CLOSE_WAIT, &xprt->state);
+                if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
+                        schedule_work(&xprt->task_cleanup);
         default:
                 xprt_disconnect(xprt);
-                break;
         }
  out:
         read_unlock(&sk->sk_callback_lock);