SUNRPC: Use au_rslack when computing reply buffer size

au_rslack is significantly smaller than (au_cslack << 2). Using
that value results in smaller receive buffers. In some cases this
eliminates an extra segment in Reply chunks (RPC/RDMA).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 99bfeb17367cb268f1a6add30e532e721fd086bd..241e8423fd0c949bd575c9dab8d76bd36e350faf 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1690,7 +1690,7 @@ call_refreshresult(struct rpc_task *task)
 static void
 call_allocate(struct rpc_task *task)
 {
-       unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
+       const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
        struct rpc_rqst *req = task->tk_rqstp;
        struct rpc_xprt *xprt = req->rq_xprt;
        const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
@@ -1715,9 +1715,10 @@ call_allocate(struct rpc_task *task)
         * and reply headers, and convert both values
         * to byte sizes.
         */
-       req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
+       req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
+                          proc->p_arglen;
        req->rq_callsize <<= 2;
-       req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
+       req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + proc->p_replen;
        req->rq_rcvsize <<= 2;
 
        status = xprt->ops->buf_alloc(task);