RPC: Fix the TCP resend semantics for NFSv4

Fix a regression due to the patch "NFS: disconnect before retrying NFSv4
requests over TCP"

The assumption made in xprt_transmit() that the condition
	"req->rq_bytes_sent == 0 and request is on the receive list"
should imply that we're dealing with a retransmission is false.
Firstly, it may simply happen that the socket send queue was full
at the time the request was initially sent through xprt_transmit().
Secondly, doing this for each request that was retransmitted implies
that we disconnect and reconnect for _every_ request that happened to
be retransmitted irrespective of whether or not a disconnection has
already occurred.

Fix is to move this logic into the call_status request timeout handler.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 4 insertions, 10 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 6d7221fe990a..396cdbe249d1 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1046,6 +1046,8 @@ call_status(struct rpc_task *task)
                 rpc_delay(task, 3*HZ);
         case -ETIMEDOUT:
                 task->tk_action = call_timeout;
+                if (task->tk_client->cl_discrtry)
+                        xprt_disconnect(task->tk_xprt);
                 break;
         case -ECONNREFUSED:
         case -ENOTCONN:
@@ -1169,6 +1171,8 @@ call_decode(struct rpc_task *task)
 out_retry:
         req->rq_received = req->rq_private_buf.len = 0;
         task->tk_status = 0;
+        if (task->tk_client->cl_discrtry)
+                xprt_disconnect(task->tk_xprt);
 }
 
 /*
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index ee6ffa01dfb1..456a14510308 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -735,16 +735,6 @@ void xprt_transmit(struct rpc_task *task)
                         xprt_reset_majortimeo(req);
                         /* Turn off autodisconnect */
                         del_singleshot_timer_sync(&xprt->timer);
-                } else {
-                        /* If all request bytes have been sent,
-                         * then we must be retransmitting this one */
-                        if (!req->rq_bytes_sent) {
-                                if (task->tk_client->cl_discrtry) {
-                                        xprt_disconnect(xprt);
-                                        task->tk_status = -ENOTCONN;
-                                        return;
-                                }
-                        }
                 }
         } else if (!req->rq_bytes_sent)
                 return;