RPC: allow call_encode() to delay transmission of an RPC call.

 Currently, call_encode will cause the entire RPC call to abort if it returns
 an error. This is unnecessarily rigid, and gets in the way of attempts
 to allow the NFSv4 layer to order RPC calls that carry sequence ids.

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

3 files changed, 21 insertions, 11 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 99cad3ead81d..068e1fb0868b 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -211,6 +211,7 @@ int			xprt_reserve_xprt(struct rpc_task *task);
 int                     xprt_reserve_xprt_cong(struct rpc_task *task);
 int                     xprt_prepare_transmit(struct rpc_task *task);
 void                    xprt_transmit(struct rpc_task *task);
+void                    xprt_abort_transmit(struct rpc_task *task);
 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 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);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index a5f7029b1daa..534274056329 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -678,13 +678,11 @@ call_allocate(struct rpc_task *task)
 static void
 call_encode(struct rpc_task *task)
 {
-        struct rpc_clnt *clnt = task->tk_client;
         struct rpc_rqst *req = task->tk_rqstp;
         struct xdr_buf *sndbuf = &req->rq_snd_buf;
         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
         unsigned int    bufsiz;
         kxdrproc_t      encode;
-        int             status;
         u32             *p;
 
         dprintk("RPC: %4d call_encode (status %d)\n", 
@@ -712,12 +710,9 @@ call_encode(struct rpc_task *task)
                 rpc_exit(task, -EIO);
                 return;
         }
-        if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
-                                                 task->tk_msg.rpc_argp)) < 0) {
-                printk(KERN_WARNING "%s: can't encode arguments: %d\n",
-                                clnt->cl_protname, -status);
-                rpc_exit(task, status);
-        }
+        if (encode != NULL)
+                task->tk_status = rpcauth_wrap_req(task, encode, req, p,
+                                task->tk_msg.rpc_argp);
 }
 
 /*
@@ -865,10 +860,12 @@ call_transmit(struct rpc_task *task)
         if (task->tk_status != 0)
                 return;
         /* Encode here so that rpcsec_gss can use correct sequence number. */
-        if (!task->tk_rqstp->rq_bytes_sent)
+        if (task->tk_rqstp->rq_bytes_sent == 0) {
                 call_encode(task);
-        if (task->tk_status < 0)
-                return;
+                /* Did the encode result in an error condition? */
+                if (task->tk_status != 0)
+                        goto out_nosend;
+        }
         xprt_transmit(task);
         if (task->tk_status < 0)
                 return;
@@ -876,6 +873,10 @@ call_transmit(struct rpc_task *task)
                 task->tk_action = NULL;
                 rpc_wake_up_task(task);
         }
+        return;
+out_nosend:
+        /* release socket write lock before attempting to handle error */
+        xprt_abort_transmit(task);
 }
 
 /*
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 215be0d0ef6b..1ba55dc38b7a 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -709,6 +709,14 @@ out_unlock:
         return err;
 }
 
+void
+xprt_abort_transmit(struct rpc_task *task)
+{
+        struct rpc_xprt *xprt = task->tk_xprt;
+
+        xprt_release_write(xprt, task);
+}
+
 /**
  * xprt_transmit - send an RPC request on a transport
  * @task: controlling RPC task