SUNRPC: Fix memory barriers for req->rq_received

We need to ensure that all writes to the XDR buffers are done before
req->rq_received is visible to other processors.

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

1 files changed, 5 insertions, 0 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 9f775302d1df..6e71d6ace5a3 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1069,6 +1069,11 @@ call_decode(struct rpc_task *task)
                 return;
         }
 
+        /*
+         * Ensure that we see all writes made by xprt_complete_rqst()
+         * before it changed req->rq_received.
+         */
+        smp_rmb();
         req->rq_rcv_buf.len = req->rq_private_buf.len;
 
         /* Check that the softirq receive buffer is valid */